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Sunday, October 13, 2019

Warp drive

From Wikipedia, the free encyclopedia

Wormhole travel as envisioned by Les Bossinas for NASA
Wormhole travel as envisioned by Les Bossinas for NASA
 
A warp drive is a theoretical superluminal spacecraft propulsion system in many science fiction works, most notably Star Trek and I, Robot by Isaac Asimov. A spacecraft equipped with a warp drive may travel at speeds greater than that of light by many orders of magnitude. In contrast to some other fictitious FTL technologies such as a jump drive, the warp drive does not permit instantaneous travel between two points, but rather involves a measurable passage of time which is pertinent to the concept. In contrast to hyperdrive, spacecraft at warp velocity would continue to interact with objects in "normal space." The general concept of "warp drive" was introduced by John W. Campbell in his 1931 novel Islands of Space.

Einstein's theory of special relativity states that energy and mass are interchangeable, and speed of light travel is impossible for material objects that weigh more than photons. The problem of a material object exceeding light speed is that an infinite amount of kinetic energy would be required to travel at exactly the speed of light. This can theoretically be solved by warping space to move an object instead of increasing the kinetic energy of the object to do so. Such a solution to the faster than light travel problem leads to two directly opposite approaches to light-speed travel in science fiction: in the first, spaceships themselves are brought to light speed and beyond; in the second, not-yet-local space itself is made to come to the ship while the ship moves at sub-light speeds.

Star Trek

Original warp scale – The Original Series, The Animated Series, Enterprise, and Discovery

Warp effect as depicted in Star Trek: The Original Series
 
Warp effect as depicted in Star Trek: The Next Generation
 
Warp drive is one of the fundamental features of the Star Trek franchise; in the first pilot episode of Star Trek: The Original Series, "The Cage", it is referred to as a "hyperdrive", with Captain Pike stating the speed to reach planet Talos IV as "time warp, factor 7". When beginning to explain travel times to the illusion survivors (before being interrupted by the sight of Vina), crewmember Jose stated that "the time barrier's been broken", allowing a group of interstellar travelers to return to Earth far sooner than would have otherwise been possible. Later in the pilot, when Spock is faced with the only action of escaping, he announces to the crew they have no choice but to leave, stating "Our time warp factor ..." before the ship's systems start failing. In the second pilot for The Original Series, "Where No Man Has Gone Before", time was dropped from the speed setting with Kirk ordering speeds in the simple "ahead warp factor one" that became so familiar from then on.

The warp drive velocity in Star Trek is generally expressed in "warp factor" units, which—according to Star Trek Star Fleet Technical Manual—corresponds to the magnitude of the warp field. Achieving warp factor 1 is equal to breaking the light barrier, while the actual velocity corresponding to higher factors is determined using an ambiguous formula. According to the Star Trek episode writer's guide for The Original Series, warp factors are converted to multiples of the speed of light by multiplication with the cubic function of the warp factor itself. Accordingly, "warp 1" is equivalent to the speed of light, "warp 2" is eight times the speed of light, "warp 3" is 27 times the speed of light, etc. Several episodes of The Original Series placed the Enterprise in peril by having it travel at high warp factors. However, the velocity (in present dimensional units) of any given warp factor is rarely the subject of explicit expression, and travel times for specific interstellar distances are not consistent through the various series. In the Star Trek: The Next Generation Technical Manual it was written that the real warp speed depends on external factors such as particle density or electromagnetic fields and only roughly corresponds with the calculated speed of current warp factor. The reference work Star Trek Maps established the theory of subspace (or warp) highways. In certain regions, a spaceship can fly at a multiple of the speed that corresponds to the current warp factor.

In The Original Series, warp factor 6 was established as the common speed of the USS Enterprise NCC-1701. In some cases, the starship traveled at warp 7 or above, but with risk of damaging the ship or the engines. Warp 9 in The Original Series was the "never exceed" speed for the hulls and engines of Constitution-class starships, equivalent to the aircraft VNE V-speed. Warp 6 was the VNO "Normal Operation" maximum safe cruising speed for that vessel class. Only five stories in the original Star Trek series involved the Enterprise traveling beyond warp 9. In any instance, it was a result of the influence of alien beings or foreign technology. The warp 14.1 incident in That Which Survives was the result of runaway engines which brought the hull within seconds of structural failure before power was disengaged.

Later on, a prequel series titled Star Trek: Enterprise describes the warp engine technology as a "Gravimetric Field Displacement Manifold" (Commander Tucker's tour, "Cold Front"), and describes the device as being powered by a matter/anti-matter reaction which powers the two separate nacelles (one on each side of the ship) to create a displacement field. Enterprise, set in 2151 and onwards, follows the voyages of the first human ship capable of traveling at warp factor 5.2, which under the old warp table formula (the cube of the warp factor times the speed of light), is about 140 times the speed of light (i.e., 5.2 cubed). In the series pilot episode "Broken Bow", Capt. Archer equates warp 4.5 to "Neptune and back [from Earth] in six minutes" (which would correspond to a distance of 547 light-minutes or 66 au, consistent with Neptune's being a minimum of 29 au distant from Earth).

Modified warp scale – The Next Generation, Deep Space Nine and Voyager

Michael Okuda's new warp scale
 
For Star Trek: The Next Generation and the subsequent series, Star Trek artist Michael Okuda drew up a new warp scale and devised a formula based on the original one but with an important difference: In the half-open interval from 9 to 10, the exponent w increases toward infinity. Thus, in the Okuda scale, warp velocities approach warp 10 asymptotically. According to the Star Trek: The Next Generation Technical Manual there is no exact formula for this interval because the quoted velocities are based on a hand-drawn curve; what can be said is that at velocities greater than warp 9, the form of the warp function changes because of an increase in the exponent of the warp factor w. Due to the resultant increase in the derivative, even minor changes in the warp factor eventually correspond to a greater than exponential change in velocity. Warp Factor 10 was set as an unattainable maximum (according to the new scale, reaching or exceeding warp 10 required an infinite amount of energy). This is described in Star Trek Technical Manuals as "Eugene's limit", in homage to creator/producer Gene Roddenberry

In Star Trek: The Next Generation Technical Manual it was established that the normal operating speed of the Enterprise-D (Galaxy-class) was warp 6 (new scale), the maximum rated cruise was warp 9.2 and the maximum design speed of warp factor 9.6. In two episodes, the Enterprise-D could travel at warp 9.8 at "extreme risk", while fleeing from an enemy. According to the Star Trek: Deep Space Nine Technical Manual the Galaxy-class starships and some other starfleet vessels like Nebula-class or Excelsior-class were refitted during the Dominion War with newer technology including modifications which increased their maximum speed to warp 9.9. 

According to the reference book USS Enterprise Owners' Workshop Manual the Enterprise-E can reach a maximum velocity of warp 9.95. The Star Trek: Starship Spotter reference book states that the Intrepid-class starship Voyager has a maximum sustainable cruising speed of warp 9.975, while the Prometheus-class can reach a maximum of warp 9.99, with maximum cruising speed of warp 9.9.
As stated in the collection Star Trek Fact Files, no ship, including highly developed ships like the Borg cube, may exceed warp factor 9.99 with her normal warp drive. To achieve higher speeds, the use of transwarp technology is required.

Warp velocities

In the book Star Trek Encyclopedia, some warp velocities are given directly. For comparison, the following table shows these values and also the calculated speeds of the original warp scale, the calculated speeds of a simplified Okuda scale and some canonical reference values for warp speeds from onscreen sources. 

Warp
factor
Warp scale from Encyclopedia
directly given values
(Michael Okuda)
Cubic warp scale
v = w3c
(Franz Joseph)
Revised warp scale
v = w10/3c
(Michael Okuda)
Onscreen Reference (Canon)
(Multiple of speed of light)
1
2 10× 10× In the Star Trek: Enterprise episode "Dead Stop", it is said that Enterprise would take about a decade (10 years) to travel 130 light years at warp 2. Thus warp 2 corresponds to about 13 times the speed of light.
3 39× 27× 39× In the Star Trek: The Next Generation episode "The Most Toys" the crew of Enterprise-D discovers that the android Data may have been stolen while on board another ship, Jovis. At this point the Jovis, which has a maximum warp factor of 3, has had a 23-hour head start, which the Enterprise-D figures puts her anywhere within a 0.102 light year radius of her last known position. (By conversion, this implies that warp 3 is equivalent to about 39c.)
4 102× 64× 102× In the Star Trek: Voyager episode "Resolutions", it is said that a Voyager shuttle would need about 700 years of flight time for a 70,000 light-year journey back to Earth. It follows that warp 4, the stated maximum speed of the shuttle, is about 100 times the speed of light. In the movie Star Trek: Beyond it is stated that the USS Franklin (NX-326) was the first Earth ship who was capable of warp 4. Montgomery Scott (Simon Pegg): "This is the USS Franklin, sir, can you believe it? First Earth ship capable of warp 4." It is unclear when the Franklin was first launched but it is speculated to be between 2145 and 2151.
4.5 150× 91× 150× In the Star Trek: Enterprise pilot "Broken Bow", Commander Tucker states "warp 4.5 next Thursday", to which Captain Archer responds "Neptune and back in six minutes". The distance from Earth to Neptune varies all the time as both planets orbit the sun, however the average distance between the two is around 30.63 au (4.58 billion km) and 29.76 au (4.45 billion km) average 4.52 billion km. Therefore, a round trip of 9.04 billion km in six minutes would imply that warp 4.5 is about 84 times the speed of light.
5 213× 125× 213× In the Star Trek: Enterprise episode "The Expanse", Captain Archer says the flight to the Delphic Expanse is equivalent to a three-month trip. Upon arrival of the Enterprise, the distance to Earth is given as 50 light years. Thus, warp 5, the maximum speed of the Enterprise, corresponds to about 200 times the speed of light.
6 392× 216× 392×
7 656× 343× 656× In the Star Trek: Enterprise episode "", the Enterprise will fly through an 11.6 light year long subspace corridor for a meeting with Degra. However, the Enterprise is thrown 127 years into the past. As the older Enterprise encounters their younger counterpart (to warn them), Captain Lorian suggests modifying the warp drive so that the younger Enterprise can briefly reach warp Factor 6.9 and cover this distance in about two days without using the corridor. Thus, warp 6.9 corresponds to about 2117 times the speed of light. In the Star Trek: Discovery episode "New Eden" (S2:E2), Commander Michael Burnham says a signal "is in the Beta Quadrant, 51,450 light years away," to which Captain Christopher Pike replies, "at top speed that would take us 150 years to get that far," indicating the maximum speed of the Discovery is 343 times the speed of light (51,450 light years / 150 years). That corresponds to warp 7 of the original warp scale.
8 1024× 512× 1024×
9 1516× 729× 1516× In the episode Bloodlines from the series Star Trek: The Next Generation, Riker claims that the Enterprise would need around 20 minutes for a 300 billion kilometer flight at warp 9. Thus warp 9 corresponds to a speed of 900 billion kilometers per hour (= 250 million kilometers per second) or about 830 times the speed of light.
9.9 3053× 970× 2083× In the episode The 37s from the Star Trek: Voyager series warp 9.9 is directly mentioned in a dialog with four billion miles per second (6.5 billion km per second), which is about 21,468 times faster than the speed of light.
9.95 5000× 985× 2119×
9.975 6667× 993× 2137× In the Voyager episode "Maneuvers", it is mentioned that the speed of the Voyager is approximately two billion kilometers per second, which is 6667 times the speed of light. According to Gene Roddenberry's first concept script Star Trek is ..., the original Enterprise had a maximum speed of 0.73 light years per hour, which is about 6395 times the speed of light. This corresponds roughly with warp 9.975 of the Okuda scale and the established maximum warp of the starship USS Voyager.
9.99 7912× 997× 2147× According to the episode Threshold from Star Trek: Voyager, warp 9.99 is the beginning of transwarp and the end of normal warp speeds.
9.9999 199,516× ~1000× ~2154×
10 Infinite
velocity
1000× 2154× In the episode "Threshold", Tom Paris breaks the warp 10 threshold, but travel beyond the threshold is later discovered to be unacceptably hazardous to biological life. In the episode "Where No One Has Gone Before" the Enterprise-D was shown to exceed warp 10, traveling 2.7 million light years from their home galaxy in a matter of minutes (though the ship's extreme velocity was due to the influence of an alien being and could not be achieved by starship engines).
11 Beyond
scale
1331× 2960× In episode The Changeling the Enterprise briefly reached warp factor 11, as a result of Nomad's "correction of inefficiencies" in the antimatter control system. In the episode By Any Other Name the Kelvans modified the Enterprise's engines for greater sustained speed of warp factor 11 to travel from the Milky Way Galaxy to the Andromeda Galaxy.
12 1728× 3956×
13 2197× 5166× In the alternative future depicted in "All Good Things ...", the series finale of The Next Generation, the "future" Enterprise-D travels at warp 13, perhaps as a result of another reconfiguration of the warp scale.
14 2744× 6613× At one point in "That Which Survives" the Enterprise traveled at a warp factor of 14.1.
15 3375× 8323×
18.56 6395× According to Gene Roddenberry's first concept script Star Trek is ..., the original Enterprise had a maximum speed of 0.73 light years per hour, which is about 6395 times the speed of light. This corresponds with warp factor 18.56 of the cubic scale.

Transwarp

Transwarp generally refers to speeds and technologies that are beyond conventional warp drives. The warp drive has a natural physical or economical limit beyond which higher speeds are no longer possible. The reference work Star Trek Fact Files indicates this limit at warp factor 9.99. This is the highest conventional warp speed mentioned for a spaceship (Borg cube). Also in the episode Threshold (Star Trek Voyager) the warp factor 9.99 is suggested as the limit. This is the last warp factor mentioned before the leap takes place in the transwarp state. 

In the book Star Trek: The Next Generation Technical Manual the authors describes the idea of transwarp:
Finally, we had to create a back door for various powerful aliens like Q who got the knack of hurling the ship through the room for millions of light years during a commercial break.
The transwarp concept itself is not tied to any particular technology or speed limit. 

The first mention of a transwarp drive took place in the movie Star Trek III: The Search for Spock. There, the Starfleet developed a new spaceship type, the USS Excelsior (NX-2000), which should have a superior engine. The Excelsior captain plans to break the speed record of the USS Enterprise (warp 14.1 cubic scale). The principle of this drive is not explained. Later, in Star Trek VI: The Undiscovered Country, the USS Excelsior had a normal warp drive. In Star Trek Fact Files it is stated that the experiment was a failure and the spaceship was converted to a normal warp drive. 

The entire episode Threshold from Star Trek Voyager is about a transwarp experiment by the USS Voyager crew. To get home faster, a shuttle is modified with novel dilithium crystals. The crew is trying to break the transwarp threshold. This threshold is between warp 9.99 and warp 10, and transwarp itself represented the infinite speed. The shuttle allegedly found itself at all points in the universe at the same time during the flight. However, the pilot suffers genetic mutations after the flight, so it is not repeated. Due to the shuttle's limited memory, only a small portion of the sensor data was recorded. The entire experiment is described in the reference work Star Trek Fact Files.

Some episodes later, fictionalized a few months later, the crew of USS Voyager encounters a species called the Voth. This species has spaceships with transwarp drive. However, this drive does not work on the basis of transwarp conduits, as the transwarp drive of the Borg, but is a further development of the conventional warp drive.

The mention of a second transwarp technology took place in the episode Descent of the series Star Trek: The Next Generation. A group of renegade Borg used transwarp conduits. These are wormhole-like tunnels through subspace. It was said in the dialogue that the flight through these tunnels was 20 times faster than the flight with maximum warp speed of the Enterprise. The flight itself was described as follows: "falling into a fast-moving river and getting swept away by the current." In the episode Endgame it is explained that the origin of these corridors was in six transwarp hubs spread across the galaxy. There were two ways to use these conduits outside these hubs. In The Next Generation, the Enterprise was able to open such a channel with a precisely modulated tachyon impulse, traveling 65 light-years. However, when the USS Voyager tried the same thing in Day of Honor, the attempt failed and almost destroyed the ship. The second possibility is the use of the transwarp coil. In episode Dark Frontier the crew of Voyager steals such a coil from the Borg and is able to shorten their journey home by 15 years, before the coil burns out.

Quantum slipstream

Another form of transwarp used in Star Trek is called Quantum Slipstream

Similar to the Borg transwarp conduits, the slipstream is a narrowly focused, directed field that is initiated by manipulating the fabric of the space-time continuum using the starship's navigational deflector array. This creates a subspace tunnel, which is projected ahead of the vessel. Once a ship has entered this tunnel, the forces inside propel it at incredible speed. To maintain the slipstream, a ship has to constantly modify the quantum field with its deflector dish. The speed of the drive is inversely proportional to the time and distance. When the crew enters the Dauntless in the episode Hope and Fear for the first time and accidentally activates the propulsion system, the spaceship flies a flight of 15 light-years over a period of about 10 seconds. That is equivalent to approximately 50 million times the speed of light. After realizing that they would have to leave Voyager forever to get home with the Dauntless, the crew tries to match the drive of the USS Voyager to the parameters of the Dauntless. The modified Voyager is able to cover a distance of 300 light years with the slipstream modification before the system becomes unstable. The way back to Earth is stated in a fake message, created by Arturis, with seven months aboard the Dauntless. For this period, the stocks are filled. At a residual distance of 60,000 light years at this time, this would correspond to a speed of about 100,000 times the speed of light or 1/500th of the time of a short slipstream jump.

However, in the episode "Timeless", the technology proved to be dangerously unstable, resulting in the loss of all hands of the Voyager in an alternate timeline. Due to a phase variance, the slipstream tunnel, produced by a replica slipstream drive of the Voyager, collapsed during the flight and the ship crashed on a planet near the border on the edge of the Delta Quadrant. Harry Kim and Chakotay survived, because they used the Delta Flyer, which flew ahead of the Voyager, and reached the Earth safely. They used, some years after this event, a temporal communication device to change the timeline and rescue the ship and the crew.

Folding space

In addition to the possibility to let a spaceship glide through space in a warp field, there is also space folding in Star Trek. Spatial folding means that two points of space-time are directly connected and an instantaneous change takes place. The space between is simply folded into a higher-dimensional hyperspace or subspace.

In the episode That Which Survives of The Original Series, the Enterprise encountered the remains of people called Kalandans. These are able to instantaneously teleport spaceships as well as people over long distances.

In the episode Contagion of the series Star Trek: The Next Generation, the Enterprise-D discovered the former homeworld of the Iconians. These people were able to instantaneously teleport people over long distances with the help of Iconian Gateways. To ensure the gateway did not fall into the wrong hands, Captain Picard destroyed it.

A year later, in The High Ground, terrorists on the planet Rutia IV used a space folding teleporter called an inverter. However, this caused progressive physical harm to people during transport; multiple use almost always ended in death.

The USS Voyager came in touch with this technology several times on their way home. In the episode Prime Factors the crew tried to buy a Spatial Trajector from the Sikarians. This wraps an object in a kind of subspace bubble, and teleports it to another location using spatial folding. The range was 40,000 light-years. However, the technology was not compatible with the warp core and almost destroyed Voyager when it was used.

Three years later, in the episode Vis à Vis, Voyager discovered a stranded spaceship with a coaxial warp drive. This also used spatial folding for locomotion. But the system was very unstable and if there is a fault in the drive it could cause a tear in the space-time continuum. A replica of the drive was only tested in a shuttle and never used for the Voyager

Last but not least, spatial folding appeared as a Geodesic Fold in the episode Inside Man. A geodesic fold occurs when a Verteron beam is fired at the atmosphere of a giant star at two different locations. This connects both points in space and creates a short lived passage. However, this was not usable because of deadly radiation that occurred during flight. A Ferengi ship's faked message from the Alpha Quadrant made the crew believe there was a safe passage. However, the Ferengi only wanted to get the Borg technology aboard Voyager and would have let the crew die. At the last moment, travel through the passage was aborted.

Fictional history

The episode "Metamorphosis", from The Original Series, establishes a backstory for the invention of warp drive on Earth, in which Zefram Cochrane discovered the "space warp". Cochrane is repeatedly referred to afterwards, but the exact details of the first warp trials were not shown until the second Star Trek: The Next Generation movie, Star Trek: First Contact. The movie depicts Cochrane as having first operated a warp drive on Earth in 2063. This successful first trial led directly to first contact with the Vulcans.

It was also established that many other civilizations had warp drive before humans; First Contact co-writer Ronald D. Moore suggested Cochrane's drive was in some way superior to forms which existed beforehand, and was gradually adopted by the galaxy at large.

Slingshot effect

The "slingshot effect" is first depicted in "Tomorrow Is Yesterday" (1967) as a method of time travel. The procedure involves traveling at a high warp velocity in the proximity to a star, on a precisely calculated "slingshot" path; if successful, it causes a ship to enter a time warp, leading to the past or future. The same technique is used in the episode "Assignment: Earth" (1968) for historic research. The term "time warp" was first used in "The Naked Time" (1966) when a previously untried cold-start intermix of matter and antimatter threw the Enterprise back three days in time. The term was later used in Star Trek IV in describing the slingshot effect. The technique was mentioned as a viable method of time travel in The Next Generation episode "Time Squared" (1989).

This "slingshot" effect has been explored in theoretical physics: it is hypothetically possible to slingshot oneself "around" the event horizon of a black hole. As a result of the black hole's extreme gravitation, time would pass at a slower rate near the event horizon, relative to the outside universe; the traveler would experience the passage of only several minutes or hours, while hundreds of years would pass in 'normal' space.

Warp core

A primary component of the warp drive method of propulsion in the Star Trek universe is the "gravimetric field displacement manifold", more commonly referred to as a warp core. It is a fictional reactor that taps the energy released in a matter-antimatter annihilation to provide the energy necessary to power a starship's warp drive, allowing faster-than-light travel. Starship warp cores generally also serve as powerplants for other primary ship systems.

When matter and antimatter come into contact, they annihilate—both matter and antimatter are converted directly and entirely into enormous quantities of energy, in the form of subnuclear particles and electromagnetic radiation (specifically, mesons and gamma rays). In the Star Trek universe, fictional "dilithium crystals" are used to regulate this reaction. These crystals are described as being non-reactive to anti-matter when bombarded with high levels of radiation. 

Usually, the reactants are deuterium, which is an isotope of hydrogen, and antideuterium (its antimatter counterpart). In The Original Series and in-universe chronologically subsequent series, the warp core reaction chamber is often referred to as the "dilithium intermix chamber" or the "matter/antimatter reaction chamber", depending upon the ship's intermix type. The reaction chamber is surrounded by powerful magnetic fields to contain the anti-matter. If the containment fields ever fail, the subsequent interaction of the antimatter fuel with the container walls would result in a catastrophic release of energy, with the resultant explosion capable of utterly destroying the ship. Such "warp core breaches" are used as plot devices in many Star Trek episodes. An intentional warp core breach can also be deliberately created, as one of the methods by which a starship can be made to self-destruct.

The mechanism that provides a starship's propulsive force is the "warp nacelle", a cylindrical pod (or pods) offset from the hull. Nacelles generate the actual "warp bubble" outside the ship; destruction of a nacelle will cripple the ship and possibly cause a warp core breach.

Warp requirements for 10m OD sphere

Real-world theories and science

In 1994, physicist Miguel Alcubierre formulated a theoretical solution, called the Alcubierre drive, for faster-than-light travel which models the warp drive concept. Calculations found that such a model would require prohibitive amounts of negative energy or mass.

In 2012, NASA researcher Harold White hypothesized that by changing the shape of the warp drive, much less negative mass and energy could be used, though the energy required ranges from the mass of Voyager 1 to the mass of the observable universe, or many orders of magnitude greater than anything currently possible by modern technology. NASA engineers have begun preliminary research into such technology.

In 2018, the U.S. Defense Intelligence Agency made public a 2010 report that surveyed multiple different approaches to faster-than-light travel. Caltech professor Sean Carroll, who reviewed the report, explained that, while the theories were legitimate, they did not represent "something that's going to connect with engineering anytime soon, probably anytime ever."

Prevention of mental disorders

From Wikipedia, the free encyclopedia
Prevention of mental disorders are measures that try to decrease the chances of a mental disorder occurring. A 2004 WHO report stated that "prevention of these disorders is obviously one of the most effective ways to reduce the [disease] burden." The 2011 European Psychiatric Association (EPA) guidance on prevention of mental disorders states "There is considerable evidence that various psychiatric conditions can be prevented through the implementation of effective evidence-based interventions." A 2011 UK Department of Health report on the economic case for mental health promotion and mental illness prevention found that "many interventions are outstandingly good value for money, low in cost and often become self-financing over time, saving public expenditure". In 2016, the National Institute of Mental Health re-affirmed prevention as a research priority area.

Methods

Parenting

Parenting may affect the child's mental health, and evidence suggests that helping parents to be more effective with their children can address mental health needs.

Assessing parenting capability has been raised in child protection and other contexts. Delaying of potential very young pregnancies could lead to better mental health causal risk factors such as improved parenting skills and more stable homes, and various approaches have been used to encourage such behaviour change. Some countries run conditional cash transfer welfare programs where payment is conditional on behaviour of the recipients. Compulsory contraception has been used to prevent future mental illness.

Pre-emptive CBT

Use of cognitive behavioral therapy (CBT) with people at risk has significantly reduced the number of episodes of generalized anxiety disorder and other anxiety symptoms, and also given significant improvements in explanatory style, hopelessness, and dysfunctional attitudes. In 2014 the UK National Institute for Health and Care Excellence (NICE) recommended preventive CBT for people at risk of psychosis. As of 2018, some health providers now advocate pre-emptive use of CBT to prevent worsening of mental illnesses.

Mental silence meditation

Sahaja meditators scored above control groups for emotional well-being and mental health measures on SF-36 ratings, leading to proposed use for mental illness prevention, although this result could be due to meditators having other characteristics leading to good mental health, such as higher general self care.

Internet- and mobile-based interventions

A review found that a number of studies have shown that internet- and mobile-based interventions can be effective in preventing mental disorders.

Specific diseases

Depression

For depressive disorders, when people participated in interventions, some studies show the number of new cases is reduced by 22% to 38%. These interventions included CBT. Such interventions also save costs. Depression prevention continues to be called for.

Anxiety

  • use of cognitive behavioral therapy (CBT) with people at risk has significantly reduced the number of episodes of generalized anxiety disorder and other anxiety symptoms, and also given significant improvements in explanatory style, hopelessness, and dysfunctional attitudes. Other interventions (parental inhibition reduction, behaviourism, parental modelling, problem-solving and communication skills) have also produced significant benefits. People with subthreshold panic disorder were found to benefit from use of CBT.
  • for older people, a stepped-care intervention (watchful waiting, CBT and medication if appropriate) achieved a 50% lower incidence rate of depression and anxiety disorders in a patient group aged 75 or older.
  • for younger people, it has been found that teaching CBT in schools reduced anxiety in children, and a review found that most universal, selective and indicated prevention programs are effective in reducing symptoms of anxiety in children and adolescents.
  • for university students mindfulness has been shown to reduce subsequent anxiety.

Psychosis

In those at high risk there is tentative evidence that psychosis incidence may be reduced with the use of CBT or other types of therapy. In 2014 the UK National Institute for Health and Care Excellence (NICE) recommended preventive CBT for people at risk of psychosis.

There is also tentative evidence that treatment may help those with early symptoms. Antipsychotic medications are not recommended for preventing psychosis.

For schizophrenia, one study of preventative CBT showed a positive effect and another showed neutral effect.

Targeted vs universal

There has been an historical trend among public health professionals to consider targeted programmes. However identification of high risk groups can increase stigma, in turn meaning that the targeted people do not engage. Thus policy recommends universal programs, with resources within such programs weighted towards high risk groups.

Universal prevention (aimed at a population that has no increased risk for developing a mental disorder, such as school programs or mass media campaigns) need very high numbers of people to show effect (sometimes known as the "power" problem). Approaches to overcome this are (1) focus on high-incidence groups (e.g. by targeting groups with high risk factors), (2) use multiple interventions to achieve greater, and thus more statistically valid, effects, (3) use cumulative meta-analyses of many trials, and (4) run very large trials.

History

History of mental illness prevention strategies

  • In 2018 the University of Birmingham Mental Health Policy Commission focused on prevention, including the challenges of funding given the shortness of political cycles versus the longer paybacks of prevention.
  • In 2018 11 European researchers published a review of mental illness prevention stating that "Increasing evidence suggests that preventive interventions in psychiatry that are feasible, safe, and cost-effective could translate into a broader focus on prevention in our field." and that "Gaps between knowledge, policy, and practice need to be bridged."
  • In 2018 Massachusetts announced a mental health strategy including many prevention elements. The executive summary began "Behavioral health promotion and upstream prevention works."
  • In 2017 the Australian Government funded a new Centre for Research Excellence in Prevention of Anxiety and Depression.
  • The US Substance Abuse and Mental Health Services Administration (SAMHSA) advocates a 5-step prevention framework.
  • In 2016:
    • the UK NHS Mental Health Taskforce included 'preventing mental health' in its 3 Priorities, focusing on children and young ages, and the importance of employment.
    • the UK NGO Mental Health Foundation published a review of prevention approaches.
    • the UK NGO Mind produced public mental health recommendations for more prevention.
  • In 2015:
    • the Hunter Institute of mental health in Australia published its "Prevention First" strategic framework for prevention.
    • the UK NGO Mental Health Foundation published a review of prevention research, paving the way for prevention strategies.
    • the official journal of the World Psychiatric Association included a survey of public mental health which concluded "the evidence base for public mental health interventions is convincing, and the time is now ripe to move from knowledge to action".
  • In 2014 the UK Chief Medical Officer, Professor Dame Sally Davies, chose mental health for her major annual report, and included prevention of mental illness heavily in this.
  • In 2013 the Faculty of Public Health, the UK professional body for public health professionals, produced its "Better Mental Health for All" resource, which aims at "the promotion of mental wellbeing and the primary prevention of mental illness".
  • In 2012, Mind, the UK mental health NGO, included "Staying well; Support people likely to develop mental health problems, to stay well." as its first goal for 2012–16.
  • The 2011 mental health strategy of Manitoba (Canada) included intents to (i) reduce risk factors associated with mental ill-health and (ii) increase mental health promotion for both adults and children.
  • The 2011 US National Prevention Strategy included mental and emotional well-being, with recommendations including (i) better parenting and (ii) early intervention.
  • Australia's mental health plan for 2009–14 included "Prevention and Early Intervention" as priority 2.
  • The 2008 EU "Pact for Mental Health" made recommendations for youth and education including (i) promotion of parenting skills, (ii) integration of socio-emotional learning into education curricular and extracurricular activities, and (iii) early intervention throughout the educational system.
  • The 2006 Canadian "Out of the Shadows at last" included a section on prevention.

History of mental illness prevention programmes

Historically prevention has been a very small part of the spend of mental health systems. For instance the 2009 UK Department of Health analysis of prevention expenditure did not include any apparent spend on mental health. The situation is the same in research.

However more recently some prevention programmes have been proposed or implemented. Prevention programmes can include public health policies to raise general health, creating supportive environments, strengthening communities, developing personal skills, and reorienting services.
  • In 2017 the UK PHE and LSE produced research showing short payback periods for a number of prevention interventions.
  • In 2017 the Scotland Mental Health Strategy included prevention, including a focus on improving parenting skills.
  • In 2016, the UK Education Policy Institute advocated prevention through increased mental health literacy, better parenting and improving children's resilience and digital world skills.
  • In 2013 the UK NGO Mental Health Foundation and partners began to use Video Interaction Guidance (VIG) in an early years intervention to reduce later life mental illness.
  • In 2013 in Australia the National Health and Medical Research Council supported a set of parenting strategies to prevent teenagers becoming anxious or depressed.
  • In 2012 the UK Schizophrenia Commission recommended "a preventative strategy for psychosis including promoting protective factors for mental wellbeing and reducing risks such as cannabis use in early adolescence."
  • In 2010 the European Union DataPrev database was launched. It states "A healthy start is crucial for mental health and wellbeing throughout life, with parenting being the single most important factor," and recommends a range of interventions.
  • In 2009 the US National Academies publication on preventing mental, emotional, and behavioral disorders among young people focused on recent research and program experience and stated that "A number of promotion and prevention programs are now available that should be considered for broad implementation." A 2011 review of this by the authors said "A scientific base of evidence shows that we can prevent many mental, emotional, and behavioral disorders before they begin" and made recommendations including
    • supporting the mental health and parenting skills of parents,
    • encouraging the developmental competencies of children and
    • using preventive strategies particularly for children at risk (such as children of parents with mental illness, or with family stresses such as divorce or job loss).
In India the 1982 National Mental health Programme included prevention, but implementation has been slow, particularly of prevention elements.

It is already known that home visiting programs for pregnant women and parents of young children can produce replicable effects on children's general health and development in a variety of community settings. Similarly positive benefits from social and emotional education are well proven. Research has shown that risk assessment and behavioral interventions in pediatric clinics reduced abuse and neglect outcomes for young children. Early childhood home visitation also reduced abuse and neglect, but results were inconsistent.

Issues in implementation

Prevention programs can face issues in (i) ownership, because health systems are typically targeted at current suffering, and (ii) funding, because program benefits come on longer timescales than the normal political and management cycle. Assembling collaborations of interested bodies appears to be an effective model for achieving sustained commitment and funding.

Saturday, October 12, 2019

Mumps

From Wikipedia, the free encyclopedia

Mumps
Other namesEpidemic parotitis
Mumps PHIL 130 lores.jpg
Child with mumps
SpecialtyInfectious disease
SymptomsFever, muscle pain, headache, feeling generally unwell, painful swelling of the parotid gland
ComplicationsMeningitis, pancreatitis, deafness, infertility (males)
Usual onset~17 days after exposure
Duration7–10 days
CausesMumps rubulavirus
Diagnostic methodViral culture, antibodies in the blood
PreventionMumps vaccine
TreatmentSupportive
MedicationPain medication, intravenous immunoglobulin
Prognosis1 in 10,000 die
FrequencyMore common in the developing world

Mumps is a viral disease caused by the mumps virus. Initial signs and symptoms often include fever, muscle pain, headache, poor appetite, and feeling generally unwell. This is then usually followed by painful swelling of one or both parotid salivary glands. Symptoms typically occur 16 to 18 days after exposure and resolve after 7 to 10 days. Symptoms are often more severe in adults than in children. About a third of people have mild or no symptoms. Complications may include meningitis (15%), pancreatitis (4%), inflammation of the heart, permanent deafness, and testicular inflammation, which uncommonly results in infertility. Women may develop ovarian swelling, but this does not increase the risk of infertility.

Mumps is highly contagious and spreads rapidly among people living in close quarters. The virus is transmitted by respiratory droplets or direct contact with an infected person. Only humans get and spread the disease. People are infectious from about 7 days before onset of parotid inflammation to about 8 days after. Once an infection has run its course, a person is typically immune for life. Reinfection is possible, but the ensuing infection tends to be mild. Diagnosis is usually suspected due to parotid swelling and can be confirmed by isolating the virus on a swab of the parotid duct. Testing for IgM antibodies in the blood is simple and may be useful; however, it can be falsely negative in those who have been immunized.

Mumps is preventable by two doses of the mumps vaccine. Most of the developed world includes it in their immunization programs, often in combination with measles, rubella, and varicella vaccine. Countries that have low immunization rates may see an increase in cases among older age groups and thus worse outcomes. No specific treatment is known. Efforts involve controlling symptoms with pain medication such as paracetamol (acetaminophen). Intravenous immunoglobulin may be useful in certain complications. Hospitalization may be required if meningitis or pancreatitis develops. About one in 10,000 people who are infected die.

Without immunization, about 0.1 to 1.0% of the population is affected per year. Widespread vaccination has resulted in a more than 90% decline in rates of disease. Mumps is more common in the developing world, where vaccination is less common. Outbreaks, however, may still occur in a vaccinated population. Before the introduction of a vaccine, mumps was a common childhood disease worldwide. Larger outbreaks of disease typically occurred every 2 to 5 years. Children between the ages of 5 and 9 were most commonly affected. Among immunized populations, those in their early 20s often are affected. Around the equator, it often occurs all year round, while in the more northerly and southerly regions of the world, it is more common in the winter and spring. Painful swelling of the parotid glands and testicles was described by Hippocrates in the fifth century BCE.

Signs and symptoms

Mumps is usually preceded by a set of prodromal symptoms, including low-grade fever, headache, and feeling generally unwell. This is followed by progressive swelling of one or both parotid glands. Parotid gland swelling usually lasts about a week. Other symptoms of mumps can include dry mouth, sore face and/or ears, and difficulty speaking.

Complications

  • Painful testicular inflammation develops in 15–40% of men who have completed puberty and contract the mumps virus. This testicular inflammation is generally one-sided (both testicles are swollen in 15–30% of mumps orchitis cases) and typically occurs about 10 days after the parotid gland becomes inflamed. Testicular swelling has been documented as late as 6 weeks after parotid-gland swelling. Decreased fertility is an uncommon consequence of testicular inflammation from mumps and infertility is rare.
  • Studies have reached differing conclusions regarding whether infection with the mumps virus during pregnancy leads to an increased rate of spontaneous abortion.
  • Before vaccination, about 10% of cases of aseptic meningitis were due to mumps. The symptoms generally resolve within 10 days. Infection of the brain itself (encephalitis) occurs in between 0.02 and 0.3% of cases.
  • Ovarian inflammation occurs in about 5% percent of adolescent and adult females.
  • Acute pancreatic inflammation occurs in about 4% percent of cases, manifesting as abdominal pain and vomiting.
  • Brain inflammation is very rare, and fatal in about 1% of the cases when it occurs.
  • Profound (91 dB or more) but rare sensorineural hearing loss can occur, which can be uni- or bilateral. Acute unilateral deafness occurs in about 0.005% of cases.

Cause

The mumps virus is an enveloped, single-stranded, linear negative-sense RNA virus of the genus Rubulavirus and family Paramyxovirus. The genome consists of 15,384 bases encoding nine proteins. Proteins involved in viral replication are the nucleoprotein, phosphoprotein, and polymerase protein while the genomic RNA forms the ribonucleocapsid. Humans are the only natural host for the virus. 

Mumps is spread from person to person through contact with respiratory secretions, such as saliva from an infected person. When an infected person coughs or sneezes, the droplets aerosolize and can enter the eyes, nose, or mouth of another person. Mumps can also be spread by sharing eating utensils or cups. The virus can also survive on surfaces and then be spread after contact in a similar manner. A person infected with mumps is contagious from around 7 days before the onset of symptoms until about 8 days after symptoms start. The incubation period (time until symptoms begin) can be from 12–25 days, but is typically 16–18 days. About 20-40% of persons infected with the mumps virus do not show symptoms, so being infected and spreading the virus without knowing it is possible.

Diagnosis

During an outbreak, a diagnosis can be made by determining recent exposure and parotitis. However, when the disease incidence is low, other infectious causes of parotitis should be considered, such as HIV, coxsackievirus, and influenza. Some viruses such as enteroviruses may cause aseptic meningitis that is very clinically similar to mumps.

A physical examination confirms the presence of the swollen glands. Usually, the disease is diagnosed on clinical grounds, and no confirmatory laboratory testing is needed. If uncertainty exists about the diagnosis, a test of saliva or blood may be carried out; a newer diagnostic confirmation, using real-time nested polymerase chain reaction technology, has also been developed. As with any inflammation of the salivary glands, the serum level of the enzyme amylase is often elevated.

Prevention

The most common preventive measure against mumps is a vaccination with a mumps vaccine, invented by American microbiologist Maurice Hilleman at Merck. The vaccine may be given separately or as part of the MMR vaccine or MMRV vaccine. The World Health Organization (WHO) recommends the use of mumps vaccines in all countries with well-functioning childhood vaccination programmes. In the United Kingdom, they are routinely given to children at age 13 months with a booster at 3–5 years (preschool). The American Academy of Pediatrics recommends the routine administration of MMR vaccine at ages 12–15 months and at 4–6 years. In some locations, the vaccine is given again between 4 and 6 years of age, or between 11 and 12 years of age if not previously given. The efficacy of the vaccine depends on its strain, but is usually around 80%. The Jeryl Lynn strain is most commonly used in developed countries, but has been shown to have reduced efficacy in epidemic situations. The Leningrad-Zagreb strain commonly used in developing countries appears to have superior efficacy in epidemic situations.

Because of the outbreaks within college and university settings, many governments have established vaccination programs to prevent large-scale outbreaks. In Canada, provincial governments and the Public Health Agency of Canada have all participated in awareness campaigns to encourage students ranging from grade one to college and university to get vaccinated.

The WHO, the American Academy of Pediatrics, the Advisory Committee on Immunization Practices of the Centers for Disease Control and Prevention, the American Academy of Family Physicians, the British Medical Association, and the Royal Pharmaceutical Society of Great Britain recommend routine vaccination of children against mumps. General mumps vaccination with MMR began in the United Kingdom in 1988.

Before the introduction of the mumps vaccine, the mumps virus was the leading cause of viral meningoencephalitis in the United States. However, encephalitis occurs rarely (less than two per 100,000). In one of the largest studies in the literature, the most common symptoms of mumps meningoencephalitis were found to be fever (97%), vomiting (94%), and headache (88.8%). The mumps vaccine was introduced into the United States in December 1967: since its introduction, a steady decrease in the incidence of mumps has occurred, with 151,209 cases of mumps reported in 1968. From 2001 to 2008, the case average was only 265 per year, excluding an outbreak of less than 6000 cases in 2006 attributed largely to university contagion in young adults.

Management

The treatment of mumps is supportive. Symptoms may be relieved by the application of intermittent ice or heat to the affected neck/testicular area and by acetaminophen for pain relief. Warm saltwater gargles, soft foods, and extra fluids may also help relieve symptoms. Acetylsalicylic acid (aspirin) is not used to treat children due to the risk of Reye syndrome.

No effective postexposure recommendation is made to prevent secondary transmission, nor is the postexposure use of vaccine or immunoglobulin effective.

Mumps is considered most contagious in the 5 days after the onset of symptoms, and isolation is recommended during this period. In someone who has been admitted to the hospital, standard and droplet precautions are needed. People who work in healthcare cannot work for 5 days.

Epidemiology

In the United States, typically between a few hundred and few thousand cases occur in a year.

History

Mumps has been known to humans since antiquity. It was mentioned by Hippocrates in his Of the Epidemics written in 400 BC, wherein he described the painful swelling of the parotid glands and testicles. The disease was first described scientifically as late as 1790 by a British physician Robert Hamilton (1721–1793) in the Transactions of the Royal Society of Edinburgh. The disease was one of the most medically significant diseases among the armies involved in the fighting both World War I and World War II. A number of attempts to prove that mumps is contagious failed. Its contagiousness was finally proved in 1934 by Claude D. Johnson and Ernest William Goodpasture (1886–1960), who demonstrated that mumps was transmitted by a filterable virus.

Lie point symmetry

From Wikipedia, the free encyclopedia https://en.wikipedia.org/wiki/Lie_point_symmetry     ...