Search This Blog

Thursday, October 5, 2023

Human–animal hybrid

From Wikipedia, the free encyclopedia
In this 19th-century piece by Edward Burne-Jones, the human woman Psyche receives affection from the hybrid deity Pan.

A human–animal hybrid and animal–human hybrid is an organism that incorporates elements from both humans and non-human animals. Technically, in a human–animal hybrid, each cell has both human and non-human genetic material. It is in contrast to an individual where some cells are human and some are derived from a different organism, called a human-animal chimera.

Examples of human–animal hybrids mainly include humanized mice that have been genetically modified by xenotransplantation of human genes. Humanized mice are commonly used as small animal models in biological and medical research for human therapeutics.

Human-animal hybrids are the subject of legal, moral, and technological debate in the context of recent advances in genetic engineering.

Human–animal hybrids have existed throughout social cultures for a long time (particularly in terms of mythology), being a part of storytelling across multiple continents, and have also been incorporated into comic books, films, video games, and other related mass media in recent decades.

Terminology

Defined by the magazine H+ as "genetic alterations that are blendings [sic] of animal and human forms", such hybrids may be referred by other names occasionally such as "para-humans". They may additionally may be called "humanized animals". Technically speaking, they are also related to "cybrids" (cytoplasmic hybrids), with "cybrid" cells featuring foreign human nuclei inside of them being a topic of interest. Possibly, a real-world human-animal hybrid may be an entity formed from either a human egg fertilized by a nonhuman sperm or a nonhuman egg fertilized by a human sperm.

Throughout past human evolution, there has been interbreeding between archaic and modern humans. For example, Neanderthal genes accounts for 1–4% of modern human genomes for people outside Sub-Saharan Africa. However, as archaic humans may not be classified as animals, such interbreeding is generally not classified as human–animal hybridization.

Examples

Artificially created human-animal hybrids include humanized mice that have been xenotransplanted with human gene products, so as to be utilized for gaining relevant insights in the in vivo context for understanding of human-specific physiology and pathologies. Humanized mice are commonly used as small animal models in biological and medical research for human therapeutics including infectious diseases and cancer. For example, genetically modified mice may be born with human leukocyte antigen genes in order to provide a more realistic environment when introducing human white blood cells into them in order to study immune system responses.

Moral discussions

President George W. Bush, pictured here in 2008 with then Interior Secretary Dirk Kempthorne to his side, has advocated for increased regulation of genetic engineering, including on research mixing animal and human elements.

Advances in genetic engineering have generally caused a large number of debates and discussions in the fields related to bioethics, including research relating to the creation of human-animal hybrids. Although the two topics are not strictly related, the debates involving the creation of human-animal hybrids have paralleled that of the debates around the stem-cell research controversy.

The question of what line exists between a "human" being and a "non-human" being has been a difficult one for many researchers to answer. While animals having one percent or less of their cells originally coming from humans may clearly appear to be in the same boat as other animals, no consensus exists on how to think about beings in a genetic middle ground that have something like an even mix. "I don't think anyone knows in terms of crude percentages how to differentiate between humans and nonhumans," U.S. patent office official John Doll has stated. Critics of increased government restrictions include scientists such as Dr. Douglas Kniss, head of the Laboratory of Perinatal Research at Ohio State University, who has remarked that formal laws aren't the best option since the "notion of animal-human hybrids is very complex." He's also argued that their creation is inherent "not the kind of thing we support" in his kind of research since scientists should "want to respect human life".

In contrast, notable socio-economic theorist Jeremy Rifkin has expressed opposition to research that creates beings crossing species boundaries, arguing that it interferes with the fundamental 'right to exist' possessed by each animal species. "One doesn't have to be religious or into animal rights to think this doesn't make sense," he has argued when expressing support for anti-chimera and anti-hybrid legislation. As well, William Cheshire, associate professor of neurology at the Mayo Clinic's Florida branch, has called the issue "unexplored biologic territory" and advocated for a "moral threshold of human neural development" to restrict the destroying a human embryo to obtain cell material and/or the creation of an organism that's partly human and partly animal." He has said, "We must be cautious not to violate the integrity of humanity or of animal life over which we have a stewardship responsibility".

Legality

While laws against the creation of hybrid beings have been proposed in U.S. states and in the U.S. Congress, several scientists have argued that legal barriers might go too far and prohibit medically beneficial studies into human modification.

In terms of scientific ethics, restrictions on the creation of human–animal hybrids have proved a controversial matter in multiple countries. While the state of Arizona banned the practice altogether in 2010, a proposal on the subject that sparked some interest in the United States Senate from 2011 to 2012 ended up going nowhere. Although the two concepts are not strictly related, discussions of experimentation into blended human and animal creatures has paralleled the discussions around embryonic stem-cell research (the 'stem cell controversy'). The creation of genetically modified organisms for a multitude of purposes has taken place in the modern world for decades, examples being specifically designed foodstuffs made to have features such as higher crop yields through better disease resistance.

President George W. Bush brought up the topic in his 2006 State of the Union Address, in which he called for the prohibition of "human cloning in all its forms", "creating or implanting embryos for experiments", "creating human-animal hybrids", and also "buying, selling, or patenting human embryos". He argued, "A hopeful society has institutions of science and medicine that do not cut ethical corners and that recognize the matchless value of every life." He also stated that humanity "should never be discarded, devalued or put up for sale."

A 2005 appropriations bill passed by the U.S. Congress and signed into law by President Bush contained specific wording forbidding any patents on humans or human embryos. In terms of outright bans on hybrid research in the first place, a measure came up in the 110th Congress entitled the Human-Animal Hybrid Prohibition Act of 2008. Congressman Chris Smith (R, NJ-4) introduced it on April 24, 2008. The text of the proposed act stated that "human dignity and the integrity of the human species are compromised" if such hybrids exist and set up the punishment of imprisonment for up to ten years as well as a fine of over one million dollars. Though attracting support from many co-sponsors such as then Representatives Mary Fallin, Duncan Hunter, Joseph R. Pitts, and Rick Renzi among others, the Act failed to get through Congress.

A related proposal had come up in the U.S. Senate the prior year, the Human-Animal Hybrid Prohibition Act of 2007, and it also had failed. That effort was proposed by then-Senator Sam Brownback (R, KS) on November 15, 2007. Featuring the same language as the later measure in the House, its bipartisan group of cosponsors included then Senators Tom Coburn, Jim DeMint, and Mary Landrieu.

A localized measure designed to ban the creation of hybrid entities came up in the state of Arizona in 2010. The proposal was signed into law by then Governor Jan Brewer. Its sponsor stated that it was needed to clarify important "ethical boundaries" in research.

In fiction

In Michelangelo's interpretation of the Fall of Man depicted inside of the Sistine Chapel, the Serpent of Paradise is depicted as a malevolent snake-human hybrid.

For thousands of years, these hybrids have been one of the most common themes in storytelling about animals throughout the world. The lack of a strong divide between humanity and animal nature in multiple traditional and ancient cultures has provided the underlying historical context for the popularity of tales where humans and animals have mingling relationships, such as in which one turns into the other or in which some mixed being goes through a journey. Interspecies friendships within the animal kingdom, as well as between humans and their pets, additionally provides an underlying root for the popularity of such beings.

In various mythologies throughout history, many particularly famous hybrids have existed, including as a part of Egyptian and Indian spirituality. The entities have also been characters in fictional media more recently in history such as in H. G. Wells' work The Island of Doctor Moreau, adapted into the popular 1932 film Island of Lost Souls. In legendary terms, the hybrids have played varying roles from that of trickster and/or villain to serving as divine heroes in very different contexts, depending on the given culture.

For example, Pan is a deity in Greek mythology that rules over and symbolizes the untamed wild, being worshiped by hunters, fishermen, and shepherds in particular. The mischievous yet cheerful character is a Satyr who has the hindquarters, legs, and horns of a goat while otherwise being essentially human in appearance, with stories of his encounters with different gods, humans, and others being retold for centuries on after the days of early Greece by groups such as the Delphian Society. Specifically, the human-animal hybrid has appeared in acclaimed works of art by figures such as Francis Bacon. Additional famous mythological hybrids include the Egyptian god of death, named Anubis, and the fox-like Japanese beings that are called Kitsune.

Legendary historical and mythological human-animal hybrids

The pig-like hybrid being Zhu Bajie, pictured in this piece of fan art, plays a major role in the famous Ming dynasty era religious novel Journey to the West.

Beings displaying a mixture of human and animal traits while also having a similarly blended appearance have played a vast and varied role in multiple traditions around the world. Artist and scholar Pietro Gaietto has written that "representations of human-animal hybrids always have their origins in religion". In "successive traditions they may change in meaning but they still remain within spiritual culture", Gaietto has argued, when looking back in an evolution-minded point of view. The beings show up in both Greek and Roman mythology, with various elements of ancient Egyptian society ebbing and flowing into those cultures in particular. Prominent examples in ancient Egyptian religion, featuring some of the earliest such hybrid beings, include the canine-like god of death known as Anubis and the lion-like Sphinx. Other instances of these types of characters include figures within both Chinese and Japanese mythology. The observation of interspecies friendships within the animal kingdom, as well as the bonds existing between humans and their pets, have been a source of the appeal in such stories.

A prominent hybrid figure that's internationally known is the mythological Greek figure of Pan. A deity that rules over and symbolizes the untamed wild, he helps express the inherent beauty of the natural world as the Greeks saw things. He specifically received reverence by ancient hunters, fishermen, shepherds, and other groups with a close connection to nature. Pan is a Satyr who possesses the hindquarters, legs, and horns of a goat while otherwise being essentially human in appearance; stories of his encounters with different gods, humans, and others have been a part of popular culture in several different cultures for many years. The human-animal hybrid has appeared in acclaimed works of art by figures such as Francis Bacon, also being mentioned in poetic pieces such as in John Fletcher's writings.

In Chinese mythology, the figure of Chu Pa-chieh undergoes a personal journey in which he gives up wickedness for virtue. After causing a disturbance in heaven from his licentious actions, he is exiled to Earth. By mistake, he enters the womb of a sow and ends up being born as a half-man/half-pig entity. With the head and ears of a pig coupled with a human body, his already animal-like sense of selfishness from his past life remains. Killing and eating his mother as well as devouring his brothers, he makes his way to a mountain hideout, spending his days preying on unwary travelers unlucky enough to cross his path. However, the exhortations of the kind goddess Kuan Yin, journeying in China, persuade him to seek a nobler path, and his life's journey and the side of goodness proceeds on such that he even is ordained a priest by the goddess herself. Remarking on the character's role in the religious novel Journey to the West, where the being first appears, professor Victor H. Mair has commented that "[p]ig-human hybrids represent descent and the grotesque, a capitulation to the basest appetites" rather than "self-improvement".

This image depicts a set of Tanuki statues on the side of a Japanese road.

Several hybrid entities have long played a major role in Japanese media and in traditional beliefs within the country. For example, a warrior god known as Amida received worship as a part of Japanese mythology for many years; he possessed a generally humanoid appearance while having a canine-like head. However, the god's devotional popularity fell in about the middle of the 19th century. A Tanuki resembles a raccoon dog, but its shape-shifting talents allow it to turn into humans for the purposes of trickery, such as impersonating Buddhist monks. The fox-like creatures known as Kitsune also possess similar powers, and stories abound of them tricking human men into marriage by turning into seductive women.

Other examples include characters in ancient Anatolia and Mesopotamia. The latter region has had the tradition of a malevolent human-animal hybrid deity in Pazuzu, the demon featuring a humanoid shape yet having grotesque features such as sharp talons. The character picked up revived attention when an interpretation of it appeared in William Peter Blatty's 1971 novel The Exorcist and the Academy Award winning 1973 film adaption of the same name, with the demon possessing the body of an innocent young girl. The movie, regarded as one of the greatest horror films of all time, has a prologue in which co-protagonist Father Merrin (Max von Sydow) visits an archaeological dig in Iraq and ominously discovers an old statue of the monstrous being.

Theriocephaly studies

Ganesha, who has an elephant's head, is one of the most revered entities in the Hindu pantheon.

"Theriocephaly" (from Greek θηρίον therion 'beast' and κεφαλή kefalí 'head') is the anthropomorphic condition or quality of having the head of an animal with a body either mostly or entirely looking human – the term being commonly used to refer the depiction of deities or otherwise specially able individuals. An entity with such qualities is said to be "theriomorphous". Many of the gods and goddesses worshipped by the ancient Egyptians, for example, were commonly depicted as being theriocephalic. This phenomenon partly represented an intermediate step in a longer process of anthropomorphization of former animal deities. Fe. the goddess Hathor in her earliest form was depicted as a cow and in her latest manifestation as a woman with cows ears and sometimes a hairstyle resembling cows horns. But the form of depiction sometimes depended also on the aspects of a deity an artist wanted to accentuate (fe. Ba the aspect of personality of a human soul was depicted as a bird with a humans head). This can also be seen in the different hieroglyphes that could be used to write the name of a single deity. Other notable examples include:

  • Horus features the head of a falcon.
  • Anubis has a jackal's head.
  • Set, often depicted with the head of an unknown creature, gets associated with a being referred to as the "Set animal" by Egyptologists.
  • Khonsu, (god of the moon disc) depicted as a man with a falcons head and or as a human child, both with a moon disc on top of the head.

Examples from other geographic areas include:

More modern fictional hybrids

Many prominent pieces of children's literature over the past two centuries have featured humanized animal characters, often as protagonists in the stores. In the opinion of popular educator Lucy Sprague Mitchell, the appeal of such mythical and fantastic beings comes from how children desire "direct" language "told in terms of images— visual, auditory, tactile, muscle images". Another author has remarked that an "animal costume" provides "a way to emphasize or even exaggerate a particular characteristic".

The anthropomorphic characters in the seminal works by English writer Beatrix Potter in particular live an ambiguous situation, having human dress yet displaying many instinctive animal traits. Writing on the popularity of Peter Rabbit, a later author commented that in "balancing humanized domesticity against wild rabbit foraging, Potter subverted parental authority and its built in hypocrisy" in Potter's child-centered books. Writer Lisa Fraustino has cited on the subject R.M. Lockley's tongue-in-cheek observation: "Rabbits are so human. Or is it the other way around— humans are so rabbit?"

Writer H. G. Wells created his famous work The Island of Doctor Moreau, featuring a mixture of horror and science fiction elements, to promote the anti-vivisection cause as a part of his long-time advocacy for animal rights. Wells' story describes a man stuck on an island ruled over by the titular Dr. Moreau, a morally depraved scientist who has created several human-animal hybrids referred to as 'Beast Folk' through vivisection and even by combining parts of other animals for some of the 'Beast Folk'. The story has been adapted into film several times, with varying success. The most acclaimed version is the 1932 black-and-white treatment called Island of Lost Souls. Wells himself wrote that "this story was the response of an imaginative mind to the reminder that humanity is but animal rough-hewn to a reasonable shape and in perpetual internal conflict between instinct and injunction," with the scandals surrounding Oscar Wilde being the impetus for the English writer's treatment of themes such as ethics and psychology. Challenging the Victorian era viewpoints of its time, the 1896 work presents a complex situation in which enhancing animals into hybrids involves both terrifying violence and pain as well as appears essentially futile, given the power of raw instinct. A pessimistic view towards the ability of human civilization to live by law-abiding, moral standards for long thus follows.

The 1986 horror film The Fly features a deformed and monstrous human-animal hybrid, played by actor Jeff Goldblum. His character, scientist Seth Brundle, undergoes a teleportation experiment that goes awry and fuses him at a fundamental genetic level with a common fly caught besides him. Brundle experiences drastic mutations as a result that horrify him. Movie critic Gerardo Valero has written that the famous horror work, "released at the dawn of the AIDS epidemic", "was seen by many as a metaphor for the disease" while also playing on bodily fears about dismemberment and coming apart that human beings inherently share.

The science fiction film Splice, released 2009, shows scientists mixing together human and animal DNA in the hopes of advancing medical research at the pharmaceutical company that they work at. Calamitous results occur when the hybrid named Dren is born.

The H. P. Lovecraft–inspired movie Dagon, released in 2001, additionally features grotesque hybrid beings. In terms of comic books, examples of fictional human-animal hybrids include the characters in Charles Burns' Black Hole series. In those comics, a set of teenagers in a 1970s era town become afflicted by a bizarre disease; the sexually transmitted affliction mutates them into monstrous forms.

Multiple video games have featured human-animal hybrids as enemies for the protagonist(s) to defeat, including powerful boss characters. For instance, the 2014 survival horror release The Evil Within includes grotesque hybrid beings, looking like the undead, attacking main character Detective Sebastian Castellanos. With partners Joseph Oda and Julie Kidman, the protagonist attempts investigate a multiple homicide at a mental hospital yet discovers a mysterious figure who turns the world around them into a living nightmare, Castellanos having to find the truth about the criminal psychopath.

Heroic character examples of human-animal anthropomorphic characters include the two protagonists of the 2002 movie The Cat Returns (Japanese title: 猫の恩返し), with the animated film featuring a young girl (named "Haru") being transformed against her will into a feline-human hybrid and fighting a villainous king of the cats with the help of a dashing male cat companion (known as the "Baron") at her side.

With general U.S. popular culture and its various subcultures, the furry fandom consists of individuals interested in a variety of artistic materials, this often featuring "furry art... [that] depicts a human-animal hybrid in everyday life". Specific people involved in creative media will frequently come up with a "fursona" depicting a version or versions of themselves as a hybrid creature. This practice functions as an outlet based on "on personal ideas of self-expression" (self-realization).

Examples include Splice, a 2009 movie about experimental genetic research, and The Evil Within, a survival horror video game released in 2014 in which the protagonist fights grotesque hybrid creatures among other enemies.

Hallucination (artificial intelligence)

From Wikipedia, the free encyclopedia
https://en.wikipedia.org/wiki/Hallucination_(artificial_intelligence)

ChatGPT attempting to summarize a non-existent New York Times article based on just the URL.

In the field of artificial intelligence (AI), a hallucination or artificial hallucination (also called confabulation or delusion) is a confident response by an AI that does not seem to be justified by its training data. For example, a hallucinating chatbot might, when asked to generate a financial report for a company, falsely state that the company's revenue was $13.6 billion (or some other number apparently "plucked from thin air").

Such phenomena are termed "hallucinations", in loose analogy with the phenomenon of hallucination in human psychology. However, one key difference is that human hallucination is usually associated with false percepts, but an AI hallucination is associated with the category of unjustified responses or beliefs. Some researchers believe the specific term "AI hallucination" unreasonably anthropomorphizes computers.

AI hallucination gained prominence around 2022 alongside the rollout of certain large language models (LLMs) such as ChatGPT. Users complained that such bots often seemed to pointlessly embed plausible-sounding random falsehoods within their generated content. By 2023, analysts considered frequent hallucination to be a major problem in LLM technology.

Analysis

Various researchers cited by Wired have classified adversarial hallucinations as a high-dimensional statistical phenomenon, or have attributed hallucinations to insufficient training data. Some researchers believe that some "incorrect" AI responses classified by humans as "hallucinations" in the case of object detection may in fact be justified by the training data, or even that an AI may be giving the "correct" answer that the human reviewers are failing to see. For example, an adversarial image that looks, to a human, like an ordinary image of a dog, may in fact be seen by the AI to contain tiny patterns that (in authentic images) would only appear when viewing a cat. The AI is detecting real-world visual patterns that humans are insensitive to. However, these findings have been challenged by other researchers. For example, it was objected that the models can be biased towards superficial statistics, leading adversarial training to not be robust in real-world scenarios.

In natural language processing

In natural language processing, a hallucination is often defined as "generated content that is nonsensical or unfaithful to the provided source content". Depending on whether the output contradicts the prompt or not they could be divided to closed-domain and open-domain respectively.

Hallucination was shown to be a statistically inevitable byproduct of any imperfect generative model that is trained to maximize training likelihood, such as GPT-3, and requires active learning (such as Reinforcement learning from human feedback) to be avoided. Errors in encoding and decoding between text and representations can cause hallucinations. AI training to produce diverse responses can also lead to hallucination. Hallucinations can also occur when the AI is trained on a dataset wherein labeled summaries, despite being factually accurate, are not directly grounded in the labeled data purportedly being "summarized". Larger datasets can create a problem of parametric knowledge (knowledge that is hard-wired in learned system parameters), creating hallucinations if the system is overconfident in its hardwired knowledge. In systems such as GPT-3, an AI generates each next word based on a sequence of previous words (including the words it has itself previously generated during the same conversation), causing a cascade of possible hallucination as the response grows longer. By 2022, papers such as the New York Times expressed concern that, as adoption of bots based on large language models continued to grow, unwarranted user confidence in bot output could lead to problems.

In August 2022, Meta warned during its release of BlenderBot 3 that the system was prone to "hallucinations", which Meta defined as "confident statements that are not true". On 15 November 2022, Meta unveiled a demo of Galactica, designed to "store, combine and reason about scientific knowledge". Content generated by Galactica came with the warning "Outputs may be unreliable! Language Models are prone to hallucinate text." In one case, when asked to draft a paper on creating avatars, Galactica cited a fictitious paper from a real author who works in the relevant area. Meta withdrew Galactica on 17 November due to offensiveness and inaccuracy.

There are several reasons for natural language models to hallucinate data. For example:

  • Hallucination from data: There are divergences in the source content (which would often happen with large training data sets).
  • Hallucination from training: Hallucination still occurs when there is little divergence in the data set. In that case, it derives from the way the model is trained. A lot of reasons can contribute to this type of hallucination, such as:
    • An erroneous decoding from the transformer
    • A bias from the historical sequences that the model previously generated
    • A bias generated from the way the model encodes its knowledge in its parameters

ChatGPT

OpenAI's ChatGPT, released in beta-version to the public on November 30, 2022, is based on the foundation model GPT-3.5 (a revision of GPT-3). Professor Ethan Mollick of Wharton has called ChatGPT an "omniscient, eager-to-please intern who sometimes lies to you". Data scientist Teresa Kubacka has recounted deliberately making up the phrase "cycloidal inverted electromagnon" and testing ChatGPT by asking it about the (nonexistent) phenomenon. ChatGPT invented a plausible-sounding answer backed with plausible-looking citations that compelled her to double-check whether she had accidentally typed in the name of a real phenomenon. Other scholars such as Oren Etzioni have joined Kubacka in assessing that such software can often give you "a very impressive-sounding answer that's just dead wrong".

When CNBC asked ChatGPT for the lyrics to "Ballad of Dwight Fry", ChatGPT supplied invented lyrics rather than the actual lyrics. Asked questions about New Brunswick, ChatGPT got many answers right but incorrectly classified Samantha Bee as a "person from New Brunswick". Asked about astrophysical magnetic fields, ChatGPT incorrectly volunteered that "(strong) magnetic fields of black holes are generated by the extremely strong gravitational forces in their vicinity". (In reality, as a consequence of the no-hair theorem, a black hole without an accretion disk is believed to have no magnetic field.) Fast Company asked ChatGPT to generate a news article on Tesla's last financial quarter; ChatGPT created a coherent article, but made up the financial numbers contained within.

Other examples involve baiting ChatGPT with a false premise to see if it embellishes upon the premise. When asked about "Harold Coward's idea of dynamic canonicity", ChatGPT fabricated that Coward wrote a book titled Dynamic Canonicity: A Model for Biblical and Theological Interpretation, arguing that religious principles are actually in a constant state of change. When pressed, ChatGPT continued to insist that the book was real. Asked for proof that dinosaurs built a civilization, ChatGPT claimed there were fossil remains of dinosaur tools and stated "Some species of dinosaurs even developed primitive forms of art, such as engravings on stones". When prompted that "Scientists have recently discovered churros, the delicious fried-dough pastries... (are) ideal tools for home surgery", ChatGPT claimed that a "study published in the journal Science" found that the dough is pliable enough to form into surgical instruments that can get into hard-to-reach places, and that the flavor has a calming effect on patients.

By 2023, analysts considered frequent hallucination to be a major problem in LLM technology, with a Google executive identifying hallucination reduction as a "fundamental" task for ChatGPT competitor Google Bard. A 2023 demo for Microsoft's GPT-based Bing AI appeared to contain several hallucinations that went uncaught by the presenter.

In May 2023, it was discovered Stephen Schwartz submitted six fake case precedents generated by ChatGPT in his brief to the Southern District of New York on Mata v. Avianca, a personal injury case against the airline Avianca. Schwartz said that he had never previously used ChatGPT, that he did not recognize the possibility that ChatGPT's output could have been fabricated, and that ChatGPT continued to assert the authenticity of the precedents after their nonexistence was discovered. In response, Brantley Starr of the Northern District of Texas banned the submission of AI-generated case filings that have not been reviewed by a human, noting that:

[Generative artificial intelligence] platforms in their current states are prone to hallucinations and bias. On hallucinations, they make stuff up—even quotes and citations. Another issue is reliability or bias. While attorneys swear an oath to set aside their personal prejudices, biases, and beliefs to faithfully uphold the law and represent their clients, generative artificial intelligence is the product of programming devised by humans who did not have to swear such an oath. As such, these systems hold no allegiance to any client, the rule of law, or the laws and Constitution of the United States (or, as addressed above, the truth). Unbound by any sense of duty, honor, or justice, such programs act according to computer code rather than conviction, based on programming rather than principle.

On June 23 P. Kevin Castel tossed the Mata case and issued a $5,000 fine to Schwartz and another lawyer for bad faith conduct, who continued to stand by the fictitious precedents despite his previous claims. He characterized numerous errors and inconsistencies in the opinion summaries, describing one of the cited opinions as "gibberish" and "[bordering] on nonsensical".

In June 2023, Mark Walters, a gun rights activist and radio personality, sued OpenAI in a Georgia state court after ChatGPT mischaracterized a legal complaint in a manner alleged to be defamatory against Walters. The complaint in question was brought in May 2023 by the Second Amendment Foundation against Washington attorney general Robert W. Ferguson for allegedly violating their freedom of speech, whereas the ChatGPT-generated summary bore no resemblance and claimed that Walters was accused of embezzlement and fraud while holding a Second Amendment Foundation office post that he never held in real life. According to AI legal expert Eugene Volokh, OpenAI may be shielded against this claim by Section 230, unless the court finds that OpenAI "materially contributed" to the publication of defamatory content.

Terminologies

In Salon, statistician Gary N. Smith argues that LLMs "do not understand what words mean" and consequently that the term "hallucination" unreasonably anthropomorphizes the machine. Journalist Benj Edwards, in Ars Technica, writes that the term "hallucination" is controversial, but that some form of metaphor remains necessary; Edwards suggests "confabulation" as an analogy for processes that involve "creative gap-filling".

A list of use of the term "hallucination", definitions or characterizations in the context of LLMs include:

  • "a tendency to invent facts in moments of uncertainty" (OpenAI, May 2023)
  • "a model's logical mistakes" (OpenAI, May 2023)
  • fabricating information entirely, but behaving as if spouting facts (CNBC, May 2023)
  • "making up information" (The Verge, February 2023)

In other artificial intelligence

The concept of "hallucination" is applied more broadly than just natural language processing. A confident response from any AI that seems unjustified by the training data can be labeled a hallucination. Wired noted in 2018 that, despite no recorded attacks "in the wild" (that is, outside of proof-of-concept attacks by researchers), there was "little dispute" that consumer gadgets, and systems such as automated driving, were susceptible to adversarial attacks that could cause AI to hallucinate. Examples included a stop sign rendered invisible to computer vision; an audio clip engineered to sound innocuous to humans, but that software transcribed as "evil dot com"; and an image of two men on skis, that Google Cloud Vision identified as 91% likely to be "a dog".

Mitigation methods

The hallucination phenomenon is still not completely understood. Therefore, there is still ongoing research to try to mitigate its apparition. Particularly, it was shown that language models not only hallucinate but also amplify hallucinations, even for those which were designed to alleviate this issue. Researchers have proposed a variety of mitigation measures, including getting different chatbots to debate one another until they reach consensus on an answer. Another approach proposes to actively validate the correctness corresponding to the low-confidence generation of the model using web search results. Nvidia Guardrails, launched in 2023, can be configured to block LLM responses that don't pass fact-checking from a second LLM.

Ozone depletion and climate change

Ozone depletion and climate change, or Ozone hole global warming in more popular terms, are environmental challenges whose connections have been explored and which have been compared and contrasted, for example in terms of global regulation, in various studies and books.

There is widespread scientific interest in better regulation of climate change, ozone depletion and air pollution, as in general the human relationship with the biosphere is deemed of major historiographical and political significance. Already by 1994 the legal debates about respective regulation regimes on climate change, ozone depletion and air pollution were being dubbed "monumental" and a combined synopsis provided.

There are some parallels between atmospheric chemistry and anthropogenic emissions in the discussions which have taken place and the regulatory attempts which have been made. Most important is that the gases causing both problems have long lifetimes after emission to the atmosphere, thus causing problems that are difficult to reverse. However, the Vienna Convention for the Protection of the Ozone Layer and the Montreal Protocol that amended it are seen as success stories, while the Kyoto Protocol on anthropogenic climate change has largely failed. Currently, efforts are being undertaken to assess the reasons and to use synergies, for example with regard to data reporting and policy design and further exchanging of information. While the general public tends to see global warming as a subset of ozone depletion, in fact ozone and chemicals such as chlorofluorocarbons (CFCs) and other halocarbons, which are held responsible for ozone depletion, are important greenhouse gases. Furthermore, natural levels of ozone in both the stratosphere and troposphere have a warming effect.

There are various ways in which ozone depletion and climate change are interconnected, but ozone depletion is not a primary cause of climate change.

The Earth's atmospheric ozone has two effects on the Earth's temperature balance. Firstly, it absorbs solar ultraviolet radiation, leading to the heating of the stratosphere. Secondly, it also traps heat in the troposphere by absorbing infrared radiation emitted by the Earth's surface. Consequently, the impact of changes in ozone concentrations on climate depends on the altitude at which these changes occur. Human-produced chlorine- and bromine-containing gases, which cause major ozone losses in the lower stratosphere, have a cooling effect on the Earth's surface. In contrast, ozone increases in the troposphere caused by surface-pollution gases, contribute to the "greenhouse" effect and have a warming effect on the Earth's surface.

Policy approach

Sir Robert (Bob) Watson played an important role in both cases

There are both links and major differences between ozone depletion and global warming and the way the two challenges have been handled. While in the case of atmospheric ozone depletion, in a situation of high uncertainty and against strong resistance, climate change regulation attempts at the international level such as the Kyoto Protocol have failed to reduce global emissions. The Vienna Convention for the Protection of the Ozone Layer and the Montreal Protocol were both originally signed by only some member states of the United Nations (43 nations in the case of the Montreal Protocol in 1986) while Kyoto attempted to create a worldwide agreement from scratch. Expert consensus concerning CFCs in the form of the Scientific Assessment of Ozone Depletion was reached long after the first regulatory steps were taken, and as of 29 December 2012, all countries in the United Nations plus the Cook Islands, the Holy See, Niue and the supranational European Union had ratified the original Montreal Protocol. These countries have also ratified the London, Copenhagen, and Montreal amendments to the Protocol. As of 15 April 2014, the Beijing amendments had not been ratified by two state parties.

After the Vienna Convention, the halocarbon industry shifted its position and started supporting a protocol to limit CFC production. US manufacturer DuPont acted more quickly than their European counterparts. The EU shifted its position as well after Germany, which has a substantial chemical industry, gave up its defence of the CFC industry and started supporting more regulation. Government and industry in France and the UK had tried to defend their CFC-producing industries even after the Montreal Protocol had been signed.

The Vienna Convention was installed before a scientific consensus on the ozone hole was established. On the contrary, until the 1980s the EU, NASA, NAS, UNEP, WMO and the British government had issued scientific reports with divergent conclusions. Sir Robert (Bob) Watson, Director of the Science Division at NASA, played a crucial role in the process of reaching a unified assessment.

Policy and consensus

Layers of the atmosphere (not to scale). The Earth's ozone layer is mainly found in the lower portion of the stratosphere from approximately 20 to 30 kilometres (12 to 19 mi) above Earth.

Aant Elzinga wrote in 1996 about the consensus, that the Intergovernmental Panel on Climate Change has tried in the prior two reports a global consensus approach to climate action. Stephen Schneider and Paul N. Edwards, noted in 1997, that after the IPCC Second Assessment Report, the lobby group Global Climate Coalition and a few self-proclaimed “contrarian” scientists tried to discredit the conclusions of the report. They pointed out that the goal of the IPCC is to fairly represent the complete range of credible scientific opinion and if possible a consensus view.

In 2007, Reiner Grundmann compared climate actions in Europe and the United States, he interpreted the inaction besides existing consensus, and noted, Political agenda that drove US climate change policy. The high visibility of skeptical scientists in the media resonates with this, and wrote that Germany started ambitious goals, reduced emissions, because ‘balanced reporting’ led to a bias in climate change coverage in advantage of skeptical arguments in the U.S., but not so much in Germany. Additionally, Grundmann pointed out that after warnings from scientists in 1986 the German Parliament commissioned the Enquetekommission ‘Vorsorge zum Schutz der Erdatmosphäre’ (Precaution for the Protection of the Earth's Atmosphere), to assess the situation, consisting of scientists, politicians and representatives of interest groups. Three years later the report made an impact with the assessment of the state of the art in climate research, an assessment of the threat of climate change itself as well as suggestions for clear emissions reduction targets, even though he argues there was no consensus, and attributed the success of the report to strong precautionary action, and that no scientific outsiders or climate change deniers were involved.

A linear model of policy-making, based on a position that "the more knowledge we have, the better the political response will be", was not applied in the ozone case. On the contrary, the CFC regulation process focused more on managing ignorance and uncertainties as a basis of political decision making, as the relationships between science, public (lack of) understanding and policy were better taken into account. In the meantime, such a player in the IPCC process as Michael Oppenheimer conceded some limitations of the IPCC consensus approach and asked for concurring, smaller assessments of special problems instead of repetitions of the large-scale approach every six years. It has become more important to provide a broader exploration of uncertainties. Others also see mixed blessings in the drive for consensus within the IPCC process and have asked for dissenting or minority positions to be included or for statements about uncertainties to be improved.

Public opinion

The two atmospheric problems have achieved significantly different levels of understanding by the public, including both the basic science and policy issues. People have limited scientific knowledge about global warming and tend to confuse it with or see it as a subset of the ozone hole. Not only on the policy level, ozone regulation fared much better than climate change in public opinion. Americans voluntarily switched away from aerosol sprays before the legislation was enforced, while climate change has failed in achieving a broader scientific comprehension and in raising comparable concern.

The metaphors used in the CFC discussion (ozone shield, ozone hole) resonated better with non-scientists and their concerns. The ozone case was communicated to lay persons "with easy-to-understand bridging metaphors derived from the popular culture" and related to "immediate risks with everyday relevance", while the public opinion on climate change sees no imminent danger. The ozone hole was much more seen as a "hot issue" and imminent risk compared to global climate change, as lay people feared a depletion of the ozone layer (ozone shield) risked increasing severe consequences such as skin cancer, cataracts, damage to plants, and reduction of plankton populations in the ocean's photic zone. This was not the case with global warming.

Personal risk assessment and knowledge

Sheldon Ungar, a Canadian sociologist, assumes that while the quantity of specialized knowledge is exploding, in contrast scientific ignorance among lay people is the norm and even increasing. Public opinion failed to tie climate change to concrete events which could be used as a threshold or beacon to signify immediate danger. Scientific predictions of a temperature rise of 2 °C (4 °F) to 3 °C (5 °F) over several decades do not resonate with people, for example in North America, who experience similar swings during a single day. As scientists define global warming as a problem of the future, a liability in the "attention economy", pessimistic outlooks in general and the attribution of extreme weather to climate change have often been discredited or ridiculed in the public arena (compare the Gore effect). Even when James Hansen tried to use the 1988–89 North American drought as a call to action, scientists kept stating, in line with the IPCC findings, that even extreme weather is not climate. While the greenhouse effect, per se, is essential for life on earth, the case was quite different with the ozone hole and other metaphors about ozone depletion. The scientific assessment of the ozone problem also had large uncertainties; both the ozone content of the upper atmosphere and its depletion are complicated to measure and the link between ozone depletion and rates of enhanced skin cancer is rather weak. But the metaphors used in the discussion (ozone shield, ozone hole) resonated better with lay people and their concerns.

The idea of rays penetrating a damaged “shield” meshes nicely with abiding and resonant cultural motifs, including “Hollywood affinities.” These range from the shields on the Starship Enterprise to Star Wars ... It is these pre-scientific bridging metaphors built around the penetration of a deteriorating shield that render the ozone problem relatively simple. That the ozone threat can be linked with Darth Vader means that it is encompassed in common sense understandings that are deeply ingrained and widely shared.

— Sheldon Ungar

The CFC regulation attempts at the end of the 1980s profited from those easy to grasp metaphors and the personal risk assumptions taken from them. The fate of celebrities like President Ronald Reagan, who had skin cancer removal from his nose in 1985 and 1987, was also of high importance. In case of the public opinion on climate change, no imminent danger is perceived.

Cost-benefit assessments and industry policy

Cass Sunstein and others have compared the differing approach of the United States to the Montreal Protocol, which it accepted, and the Kyoto Protocol, which it rejected. Sunstein assumes that the cost-benefit assessments of climate change action for the US were instrumental in the US' withdrawal from participation in Kyoto. Daniel Magraw, also a lawyer, considers governmental motivations besides relative costs and benefits as being of higher importance. Peter Orszag and Terry Dinan took an insurance perspective and assume that an assessment which predicted dire consequences of climate change would be more of a motivation for the US to change its stance on global warming and adopting regulation measurements.

The US chemical company DuPont had already lost some of their zeal in defending their products after a strategic manufacturing patent for Freon was set to expire in 1979. A citizen boycott of spray cans gained importance in parallel. Not by chance, the United States banned the use of CFCs in aerosol cans in 1978.

Government and industry in France and the UK tried to defend their CFC-producing industries even after the Montreal Protocol had been signed. The European Community rejected proposals to ban CFCs in aerosol sprays for a long time. The EU shifted its position after Germany, which also has a large chemical industry, gave up its defence of the CFC industry and started supporting moves towards regulation. After regulation was more and more enforced, DuPont acted faster than their European counterparts as they may have feared court action related to increased skin cancer, especially as the EPA had published a study in 1986 claiming that an additional 40 million cases and 800,000 cancer deaths were to be expected in the US in the next 88 years. The identification and marketing of a 100% ozone-safe hydrocarbon refrigerant called "Greenfreeze" by the NGO Greenpeace in the early 1990s had a rapid significant impact in major markets of Europe and Asia. The climate change protocols were less successful. In the case of Kyoto, then secretary of the environment Angela Merkel, prevented a possible failure by suggesting to use 1990 as starting date for emission reduction. In so far the demise of the Eastern European heavy industry allowed for a high commitment, but actual emissions kept on growing on a global scale.

Science background

Radiative forcing from various greenhouse gases and other sources.

There are various links between the two fields of human-atmospheric interaction. Policy experts have advocated for a closer linking of ozone protection and climate protection efforts.

Drew Shindell has used climate models to assess both climate change and ozone depletion. In his view, while research up to now has been more about the impact of CFC emissions on stratospheric ozone, the future will be more about the interaction between climate change and ozone feedback. Ozone is a greenhouse gas itself. Many ozone-depleting substances are also greenhouse gases, some agents of radiative forcing are thousands of times more powerful than carbon dioxide over the short and medium term. The increases in concentrations of these chemicals have produced 0.34 ± 0.03 W/m2 of radiative forcing, corresponding to about 14% of the total radiative forcing from increases in the concentrations of well-mixed greenhouse gases. Already the natural ozone variability in the stratosphere seems to be closely correlated with the 11-year solar cycle of irradiance changes and has, via a dynamic coupling between the stratosphere and troposphere, a significant impact on climate. Ozone acts like a shield in the stratosphere, and protects life from extremely harmful ultraviolet radiation that comes from the sun. In the absence of stratospheric ozone, life forms would simply not exist.

Sources of Stratospheric Chlorine

As with carbon dioxide and methane, there are some natural sources of tropospheric chlorine, such as sea spray. Chlorine from ocean spray is soluble and thus is washed by rainfall before it reaches the stratosphere. It is stratospheric chlorine that affects ozone depletion. Only methyl chloride, which is one of the halocarbons, has a mainly natural source, and it is responsible for about 20% of the chlorine in the stratosphere; the remaining 80% comes from man-made sources. Chlorofluorocarbons, in contrast, are insoluble and long-lived, allowing them to reach the stratosphere. In the lower atmosphere, there is much more chlorine from CFCs and related haloalkanes than there is in hydrogen chloride from salt spray, and in the stratosphere halocarbons are dominant.

The same CO
2
radiative forcing that produces global warming is expected to cool the stratosphere. This cooling, in turn, is expected to produce a relative increase in ozone (O
3
) depletion in the polar area and in the frequency of ozone holes. Conversely, ozone depletion represents a radiative forcing of the climate system of about −0.15 ± 0.10 watts per square metre (W/m2).

Solar water disinfection

From Wikipedia, the free encyclopedia
Solar water disinfection (SODIS) application in Indonesia using clear polyethylene terephthalate (PET) plastic beverage bottles

Solar water disinfection, in short SODIS, is a type of portable water purification that uses solar energy to make biologically-contaminated (e.g. bacteria, viruses, protozoa and worms) water safe to drink. Water contaminated with non-biological agents such as toxic chemicals or heavy metals require additional steps to make the water safe to drink.

Solar water disinfection is usually accomplished using some mix of electricity generated by photovoltaics panels (solar PV), heat (solar thermal), and solar ultraviolet light collection.

Solar disinfection using the effects of electricity generated by photovoltaics typically uses an electric current to deliver electrolytic processes which disinfect water, for example by generating oxidative free radicals which kill pathogens by damaging their chemical structure. A second approach uses stored solar electricity from a battery, and operates at night or at low light levels to power an ultraviolet lamp to perform secondary solar ultraviolet water disinfection.

Solar thermal water disinfection uses heat from the sun to heat water to 70–100 °C for a short period of time. A number of approaches exist. Solar heat collectors can have lenses in front of them, or use reflectors. They may also use varying levels of insulation or glazing. In addition, some solar thermal water disinfection processes are batch-based, while others (through-flow solar thermal disinfection) operate almost continuously while the sun shines. Water heated to temperatures below 100 °C is generally referred to as pasteurized water.

The ultraviolet part of sunlight can also kill pathogens in water. The SODIS method uses a combination of UV light and increased temperature (solar thermal) for disinfecting water using only sunlight and repurposed PET plastic bottles. SODIS is a free and effective method for decentralized water treatment, usually applied at the household level and is recommended by the World Health Organization as a viable method for household water treatment and safe storage. SODIS is already applied in numerous developing countries. Educational pamphlets on the method are available in many languages,[3] each equivalent to the English-language version.

Process for household application

SODIS instructions for using solar water disinfection

Guides for the household use of SODIS describe the process.

Colourless, transparent PET water or soda bottles of 2 litre or smaller size with few surface scratches are selected for use. Glass bottles are also suitable. Any labels are removed and the bottles are washed before the first use. Water from possibly-contaminated sources is filled into the bottles, using the clearest water possible. Where the turbidity is higher than 30 NTU it is necessary to filter or precipitate out particulates prior to exposure to the sunlight. Filters are locally made from cloth stretched over inverted bottles with the bottoms cut off. In order to improve oxygen saturation, the guides recommend that bottles be filled three-quarters, shaken for 20 seconds (with the cap on), then filled completely, recapped, and checked for clarity.

Aluminum reflects ultraviolet well

The filled bottles are then exposed to the fullest sunlight possible. Bottles will heat faster and hotter if they are placed on a sloped Sun-facing reflective metal surface. A corrugated metal roof (as compared to thatched roof) or a slightly curved sheet of aluminum foil increases the light inside the bottle. Overhanging structures or plants that shade the bottles must be avoided, as they reduce both illumination and heating. After sufficient time, the treated water can be consumed directly from the bottle or poured into clean drinking cups. The risk of re-contamination is minimized if the water is stored in the bottles. Refilling and storage in other containers increases the risk of contamination.

Suggested treatment schedule
Weather conditions Minimum treatment duration
Sunny (less than 50% cloud cover) 6 hours
Cloudy (50–100% cloudy, little to no rain) 2 days
Continuous rainfall Unsatisfactory performance;
use rainwater harvesting

The most favorable regions for application of the SODIS method are located between latitude 15°N and 35°N, and also 15°S and 35°S. These regions have high levels of solar radiation, with limited cloud cover and rainfall, and with over 90% of sunlight reaching the earth's surface as direct radiation. The second most favorable region lies between latitudes 15°N and 15°S. these regions have high levels of scattered radiation, with about 2500 hours of sunshine annually, due to high humidity and frequent cloud cover.

Local education in the use of SODIS is important to avoid confusion between PET and other bottle materials. Applying SODIS without proper assessment (or with false assessment) of existing hygienic practices & diarrhea incidence may not address other routes of infection. Community trainers must themselves be trained first.

Applications

SODIS is an effective method for treating water where fuel or cookers are unavailable or prohibitively expensive. Even where fuel is available, SODIS is a more economical and environmentally friendly option. The application of SODIS is limited if enough bottles are not available, or if the water is highly turbid. In fact, if the water is highly turbid, SODIS cannot be used alone; additional filtering is then necessary.

A basic field test to determine if the water is too turbid for the SODIS method to work properly is the newspaper test. For the newspaper test the user has to place the filled bottle upright on top of a newspaper headline and look down through the bottle opening. If the letters of the headline are readable, the water can be used for the SODIS method. If the letters are not readable then the turbidity of the water likely exceeds 30 NTU, and the water must be pretreated.

In theory, the method could be used in disaster relief or refugee camps. However, supplying bottles may be more difficult than providing equivalent disinfecting tablets containing chlorine, bromine, or iodine. In addition, in some circumstances, it may be difficult to guarantee that the water will be left in the sun for the necessary time.

Other methods for household water treatment and safe storage exist (e.g., chlorination) different filtration procedures or flocculation/disinfection. The selection of the adequate method should be based on the criteria of effectiveness, the co-occurrence of other types of pollution (turbidity, chemical pollutants), treatment costs, labor input and convenience, and the user's preference.

When the water is highly turbid, SODIS cannot be used alone; additional filtering or flocculation is then necessary to clarify the water prior to SODIS treatment. Recent work has shown that common table salt (NaCl) is an effective flocculation agent for decreasing turbidity for the SODIS method in some types of soil. This method could be used to increase the geographic areas for which the SODIS method could be used as regions with highly turbid water could be treated for low costs.

SODIS may alternatively be implemented using plastic bags. SODIS bags have been found to yield as much as 74% higher treatment efficiencies than SODIS bottles, which may be because the bags are able to reach elevated temperatures that cause accelerated treatment. SODIS bags with a water layer of approximately 1 cm to 6 cm reach higher temperatures more easily than SODIS bottles, and treat Vibrio cholerae more effectively. It is assumed this is because of the improved surface area to volume ratio in SODIS bags. In remote regions plastic bottles are not locally available and need to be shipped in from urban centers which may be expensive and inefficient since bottles cannot be packed very tightly. Bags can be packed more densely than bottles, and can be shipped at lower cost, representing an economically preferable alternative to SODIS bottles in remote communities. The disadvantages of using bags are that they can give the water a plastic smell, they are more difficult to handle when filled with water, and they typically require that the water be transferred to a second container for drinking.

Another important benefit in using the SODIS bottles as opposed to the bags or other methods requiring the water to be transferred to a smaller container for consumption is that the bottles are a point-of-use household water treatment method. Point-of-use means that the water is treated in the same easy to handle container it will be served from, thus decreasing the risk of secondary water contamination.

Cautions

The PET recycling mark shows that a bottle is made from polyethylene terephthalate, making it suitable for solar water disinfection

If the water bottles are not left in the sun for the proper length of time, the water may not be safe to drink and could cause illness. If the sunlight is less strong, due to overcast weather or a less sunny climate, a longer exposure time in the sun is necessary.

The following issues should also be considered:

Bottle material
Some glass or PVC materials may prevent ultraviolet light from reaching the water. Commercially available bottles made of PET are recommended. The handling is much more convenient in the case of PET bottles. Polycarbonate (resin identification code 7) blocks all UVA and UVB rays, and therefore should not be used. Bottles that are clear are to be preferred over bottles that have been colored, for example green lemon/lime soda pop bottles.
Aging of plastic bottles
SODIS efficiency depends on the physical condition of the plastic bottles, with scratches and other signs of wear reducing the efficiency of SODIS. Heavily scratched or old, blind bottles should be replaced.
Shape of containers
The intensity of the UV radiation decreases rapidly with increasing water depth. At a water depth of 10 cm (4 inches) and moderate turbidity of 26 NTU, UV-A radiation is reduced to 50%. PET soft drink bottles are often easily available and thus most practical for the SODIS application.
Oxygen
Sunlight produces highly reactive forms of oxygen (oxygen free radicals and hydrogen peroxides) in the water. These reactive molecules contribute in the destruction process of the microorganisms. Under normal conditions (rivers, creeks, wells, ponds, tap) water contains sufficient oxygen (more than 3 mg/L of oxygen) and does not have to be aerated before the application of SODIS.
Leaching of bottle material
There has been some concern over the question of whether plastic drinking containers can release chemicals or toxic components into water, a process possibly accelerated by heat. The Swiss Federal Laboratories for Materials Testing and Research have examined the diffusion of adipates and phthalates (DEHA and DEHP) from new and reused PET-bottles in the water during solar exposure. The levels of concentrations found in the water after a solar exposure of 17 hours in 60 °C (140 °F) water were far below WHO guidelines for drinking water and in the same magnitude as the concentrations of phthalate and adipate generally found in high-quality tap water. Concerns about the general use of PET-bottles were also expressed after a report published by researchers from the University of Heidelberg on the release of antimony from PET-bottles for soft drinks and mineral water stored over several months in supermarkets. However, the antimony concentrations found in the bottles are orders of magnitude below WHO and national guidelines for antimony concentrations in drinking water. Furthermore, SODIS water is not stored over such extended periods in the bottles.
Regrowth of bacteria
Once removed from sunlight, remaining bacteria may again reproduce in the dark. A 2010 study showed that adding just 10 parts per million of hydrogen peroxide is effective in preventing the regrowth of wild Salmonella.
Toxic chemicals
Solar water disinfection does not remove toxic chemicals that may be present in the water, such as factory waste.

Health impact, diarrhea reduction

According to the World Health Organization, more than two million people per year die of preventable water-borne diseases, and one billion people lack access to a source of improved drinking water.

It has been shown that the SODIS method (and other methods of household water treatment) can very effectively remove pathogenic contamination from the water. However, infectious diseases are also transmitted through other pathways, i.e. due to a general lack of sanitation and hygiene. Studies on the reduction of diarrhea among SODIS users show reduction values of 30–80%.

Research

The effectiveness of the SODIS was first discovered by Aftim Acra, of the American University of Beirut in the early 1980s. Follow-up was conducted by the research groups of Martin Wegelin at the Swiss Federal Institute of Aquatic Science and Technology (EAWAG) and Kevin McGuigan at the Royal College of Surgeons in Ireland. Clinical control trials were pioneered by Ronan Conroy of the RCSI team in collaboration with Michael Elmore-Meegan.ICROSS

A joint research project on SODIS was implemented by the following institutions:

The project embarked on a multi-country study including study areas in Zimbabwe, South Africa and Kenya.

Other developments include the development of a continuous flow disinfection unit and solar disinfection with titanium dioxide film over glass cylinders, which prevents the bacterial regrowth of coliforms after SODIS.

Research has shown that a number of low-cost additives are capable of accelerating SODIS and that additives might make SODIS more rapid and effective in both sunny and cloudy weather, developments that could help make the technology more effective and acceptable to users. A 2008 study showed that powdered seeds of five natural legumes (peas, beans and lentils)—Vigna unguiculata (cowpea), Phaseolus mungo (black lentil), Glycine max (soybean), Pisum sativum (green pea), and Arachis hypogaea (peanut)—when evaluated as natural flocculants for the removal of turbidity, were as effective as commercial alum and even superior for clarification in that the optimum dosage was low (1 g/L), flocculation was rapid (7–25 minutes, depending on the seed used) and the water hardness and pH was essentially unaltered. Later studies have used chestnuts, oak acorns, and Moringa oleifera (drumstick tree) for the same purpose.

Other research has examined the use of doped semiconductors to increase the production of oxygen radicals under solar UV-A. Recently, researchers at the National Centre for Sensor Research and the Biomedical Diagnostics Institute at Dublin City University have developed an inexpensive printable UV dosimeter for SODIS applications that can be read using a mobile phone. The camera of the phone is used to acquire an image of the sensor and custom software running on the phone analyses the sensor colour to provide a quantitative measurement of UV dose.

In isolated regions the effect of wood smoke increases lung disease, due to the constant need for building fires to boil water and cook. Research groups have found that boiling of water is neglected due to the difficulty of gathering wood, which is scarce in many areas. When presented with basic household water treatment options residents in isolated regions in Africa have shown a preference for the SODIS method over boiling or other basic water treatment methods.

A very simple solar water purifier for rural households has been developed which uses 4 layers of saree cloth and solar tubular collectors to remove all coliforms.

In July 2020 researchers report the development of a reusable aluminium surface for efficient solar-based water sanitation to below the WHO and EPA standards for drinkable water.

Promotion

The Swiss Federal Institute of Aquatic Science and Technology (EAWAG), through the Department of Water and Sanitation in Developing Countries (Sandec), coordinates SODIS promotion projects in 33 countries including Bhutan, Bolivia, Burkina Faso, Cambodia, Cameroon, DR Congo, Ecuador, El Salvador, Ethiopia, Ghana, Guatemala, Guinea, Honduras, India, Indonesia, Kenya, Laos, Malawi, Mozambique, Nepal, Nicaragua, Pakistan, Perú, Philippines, Senegal, Sierra Leone, Sri Lanka, Togo, Uganda, Uzbekistan, Vietnam, Zambia, and Zimbabwe.

SODIS projects are funded by, among others, the SOLAQUA Foundation, several Lions Clubs, Rotary Clubs, Migros, and the Michel Comte Water Foundation.

SODIS has also been applied in several communities in Brazil, one of them being Prainha do Canto Verde, Beberibe west of Fortaleza. Villagers there using the SODIS method have been quite successful, since the temperature during the day can go beyond 40 °C (104 °F) and there is a limited amount of shade.

One of the most important things to consider for public health workers reaching out to communities in need of suitable, cost efficient, and sustainable water treatment methods is teaching the importance of water quality in the context of health promotion and disease prevention while educating about the methods themselves. Although skepticism has posed a challenge in some communities to adopt SODIS and other household water treatment methods for daily use, disseminating knowledge on the important health benefits associated with these methods will likely increase adoption rates.

Hydrogen-like atom

From Wikipedia, the free encyclopedia https://en.wikipedia.org/wiki/Hydrogen-like_atom ...