132-593: The disappearance of Genette Tate is a missing person case in which a 13-year-old girl disappeared while delivering newspapers in Aylesbeare , Devon , England, on 19 August 1978. Despite extensive searches, Tate's body has not been found and the cause of her disappearance remains unknown. The case is one of Britain's longest missing person inquiries and has been described as a murder investigation by Devon and Cornwall Police . Tate's disappearance remains one of Britain's best known missing person cases. Genette Louise Tate
264-620: A funeral resulting when a person goes missing may be extremely painful with long-lasting effects on family and friends. A number of organizations seek to connect, share best practices, and disseminate information and images of missing children to improve the effectiveness of missing children investigations, including the International Commission on Missing Persons , the International Centre for Missing & Exploited Children (ICMEC), as well as national organizations, including
396-587: A Juvenile Facilities Study. The estimated number of 800,000 missing children reports has been widely circulated in the popular press. The United States' National Crime Information Center (NCIC) of the Federal Bureau of Investigation , mandated by the National Child Search Assistance Act , maintains its own "Missing Person File" to which local police report people for whom they are searching. The NCIC "Missing Person File" does have
528-445: A buffer to recruit or titrate ions or antibiotics. Extracellular DNA acts as a functional extracellular matrix component in the biofilms of several bacterial species. It may act as a recognition factor to regulate the attachment and dispersal of specific cell types in the biofilm; it may contribute to biofilm formation; and it may contribute to the biofilm's physical strength and resistance to biological stress. Cell-free fetal DNA
660-576: A catastrophe ... [or] are missing under circumstances indicating their disappearance may not have been voluntary". In 2013, the NCIC entered 445,214 "EMJ" reports (440,625 in the EMJ category under the age of 18; but 462,567 under the age of 18 in all categories, and 494,372 under the age of 21 in all categories), and NCIC's total reports numbered 627,911. Of the children under age 18, a total of 4,883 reports were classified as "missing under circumstances indicating that
792-426: A category that is entitled "Juvenile" or "EMJ" (for: Enter Missing Person – Juvenile), but that category does not reflect the total number of all juveniles reported missing to the NCIC, for whom local police are searching. The NCIC also uses its own classification criteria; it does not use the above NISMART definitions of what constitutes a missing child. The NCIC data is limited to individuals who have been reported to
924-459: A cell makes up its genome ; the human genome has approximately 3 billion base pairs of DNA arranged into 46 chromosomes. The information carried by DNA is held in the sequence of pieces of DNA called genes . Transmission of genetic information in genes is achieved via complementary base pairing. For example, in transcription, when a cell uses the information in a gene, the DNA sequence is copied into
1056-450: A chain by covalent bonds (known as the phosphodiester linkage ) between the sugar of one nucleotide and the phosphate of the next, resulting in an alternating sugar-phosphate backbone . The nitrogenous bases of the two separate polynucleotide strands are bound together, according to base pairing rules (A with T and C with G), with hydrogen bonds to make double-stranded DNA. The complementary nitrogenous bases are divided into two groups,
1188-445: A complementary RNA sequence through the attraction between the DNA and the correct RNA nucleotides. Usually, this RNA copy is then used to make a matching protein sequence in a process called translation , which depends on the same interaction between RNA nucleotides. In an alternative fashion, a cell may copy its genetic information in a process called DNA replication . The details of these functions are covered in other articles; here
1320-492: A double helix can thus be pulled apart like a zipper, either by a mechanical force or high temperature . As a result of this base pair complementarity, all the information in the double-stranded sequence of a DNA helix is duplicated on each strand, which is vital in DNA replication. This reversible and specific interaction between complementary base pairs is critical for all the functions of DNA in organisms. Most DNA molecules are actually two polymer strands, bound together in
1452-536: A file to the Crown Prosecution Service in which they sought a new decision on whether to prosecute him. The file was submitted in April 2016, and the Crown Prosecution Service said that due to Black's death, there would be no posthumous decision to charge him with Tate's murder. In August 2018, on the eve of the 40th anniversary of his daughter's disappearance, John Tate made a further plea for information about
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#17330863142001584-566: A filing system related to the case, which is stored at the Devon and Cornwall Police headquarters in Exeter. Robert Black , a serial killer convicted in 1994 for similar crimes involving the abduction and murder of young girls, was questioned by Devon and Cornwall Police in connection with the Tate case. During the course of his job as a long distance delivery van driver in the 1970s, Black had made deliveries in
1716-428: A full set of the mitochondrial genes. Each human mitochondrion contains, on average, approximately 5 such mtDNA molecules. Each human cell contains approximately 100 mitochondria, giving a total number of mtDNA molecules per human cell of approximately 500. However, the amount of mitochondria per cell also varies by cell type, and an egg cell can contain 100,000 mitochondria, corresponding to up to 1,500,000 copies of
1848-480: A general exception, as these require a specialized agency such as a coast guard . In many countries, such as the United States, voluntary search and rescue teams can be called out to assist the police in the search. Rescue agencies such as fire departments , mountain rescue and cave rescue may also participate in cases that require their specialized resources. Police forces such as Lancashire Constabulary stress
1980-439: A helical fashion by noncovalent bonds; this double-stranded (dsDNA) structure is maintained largely by the intrastrand base stacking interactions, which are strongest for G,C stacks. The two strands can come apart—a process known as melting—to form two single-stranded DNA (ssDNA) molecules. Melting occurs at high temperatures, low salt and high pH (low pH also melts DNA, but since DNA is unstable due to acid depurination, low pH
2112-571: A higher number is also possible but this would be against the natural principle of least effort . The phosphate groups of DNA give it similar acidic properties to phosphoric acid and it can be considered as a strong acid . It will be fully ionized at a normal cellular pH, releasing protons which leave behind negative charges on the phosphate groups. These negative charges protect DNA from breakdown by hydrolysis by repelling nucleophiles which could hydrolyze it. Pure DNA extracted from cells forms white, stringy clumps. The expression of genes
2244-667: A long-standing puzzle known as the " C-value enigma ". However, some DNA sequences that do not code protein may still encode functional non-coding RNA molecules, which are involved in the regulation of gene expression . Some noncoding DNA sequences play structural roles in chromosomes. Telomeres and centromeres typically contain few genes but are important for the function and stability of chromosomes. An abundant form of noncoding DNA in humans are pseudogenes , which are copies of genes that have been disabled by mutation. These sequences are usually just molecular fossils , although they can occasionally serve as raw genetic material for
2376-446: A maroon Triumph or similar vehicle upon Within Road at around the time of the disappearance, and police issued a photofit picture of a man they wanted to question in relation to the incident. This man was described as being a "very handsome" individual in his early 20s with a pale complexion, short dark hair, who had been wearing a light-coloured shirt. Despite the police investigation and
2508-409: A narrower, deeper major groove. The A form occurs under non-physiological conditions in partly dehydrated samples of DNA, while in the cell it may be produced in hybrid pairings of DNA and RNA strands, and in enzyme-DNA complexes. Segments of DNA where the bases have been chemically modified by methylation may undergo a larger change in conformation and adopt the Z form . Here, the strands turn about
2640-452: A non-custodial parent). A child staying too long with a non-custodial parent can be enough to qualify as an abduction. During the year 1999 in the United States, there were an estimated 800,000 reported missing children cases. Of these, 203,900 children were reported as the victims of family abductions and 58,200 of non-family abductions. However, only 115 were the result of "stereotypical" kidnaps (by someone unknown or of slight acquaintance to
2772-555: A non-profit organization called Black and Missing but not Forgotten, which provides assistance in spreading awareness about a missing person. It has also been speculated by Kristen Gilchrist that, in Canadian news media, Aboriginal women receive three and a half times less coverage than white women. Their articles were found to be shorter and less detailed—with an average word count for white women of 713 compared to 518 for Aboriginal women—and less likely to be front-page news. Depictions of
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#17330863142002904-442: A radius of 10 Å (1.0 nm). According to another study, when measured in a different solution, the DNA chain measured 22–26 Å (2.2–2.6 nm) wide, and one nucleotide unit measured 3.3 Å (0.33 nm) long. The buoyant density of most DNA is 1.7g/cm . DNA does not usually exist as a single strand, but instead as a pair of strands that are held tightly together. These two long strands coil around each other, in
3036-654: A report in 2011 on recommendations to the government to keep child runaways safe. DNA Deoxyribonucleic acid ( / d iː ˈ ɒ k s ɪ ˌ r aɪ b oʊ nj uː ˌ k l iː ɪ k , - ˌ k l eɪ -/ ; DNA ) is a polymer composed of two polynucleotide chains that coil around each other to form a double helix . The polymer carries genetic instructions for the development, functioning, growth and reproduction of all known organisms and many viruses . DNA and ribonucleic acid (RNA) are nucleic acids . Alongside proteins , lipids and complex carbohydrates ( polysaccharides ), nucleic acids are one of
3168-431: A search of the surrounding countryside involving thousands of volunteers, Tate's disappearance remains unexplained. In 2002, DNA belonging to Tate was found on one of her jumpers kept by her mother, which would allow her body to be identified if discovered. On the 25th anniversary of the case in 2003, Genette's parents both stated their belief that she is no longer alive. Police have amassed more than 20,000 index cards in
3300-416: A second protein when read in the opposite direction along the other strand. In bacteria , this overlap may be involved in the regulation of gene transcription, while in viruses, overlapping genes increase the amount of information that can be encoded within the small viral genome. DNA can be twisted like a rope in a process called DNA supercoiling . With DNA in its "relaxed" state, a strand usually circles
3432-445: A simple TTAGGG sequence. These guanine-rich sequences may stabilize chromosome ends by forming structures of stacked sets of four-base units, rather than the usual base pairs found in other DNA molecules. Here, four guanine bases, known as a guanine tetrad , form a flat plate. These flat four-base units then stack on top of each other to form a stable G-quadruplex structure. These structures are stabilized by hydrogen bonding between
3564-622: A week, 95 percent within a month, 97 percent within six months and 98 percent within a year. In 2019, the KAP published a search in only 13 cases, the result of which was: eight alive, three dead, two still missing. The legal status of missing persons in Austria is regulated by the Declaration of Death Act ( Todeserklärungsgesetz ). Over 305,000 people were reported missing in Australia from 2008 to 2015, which
3696-464: Is a dramatic absence of harmonized and systematic data collection, analysis and dissemination at all levels without which countries lack important evidence that informs national policies and responses. Missing Children Europe, the European federation for missing children, aims to meet this need. The CRM system is expected to have a clear impact on the way hotlines are able to work together and collect data on
3828-435: Is a person who has disappeared and whose status as alive or dead cannot be confirmed as their location and condition are unknown. A person may go missing through a voluntary disappearance, or else due to an accident , crime , or death in a location where they cannot be found (such as at sea), or many other reasons. In most parts of the world, a missing person will usually be found quickly. Criminal abductions are some of
3960-546: Is a risk that the finds or their location may not be found a second time, they must be picked up and delivered to the nearest police station. In the United Kingdom, The Huffington Post reported in 2012, over 140,000 children go missing each year, as calculated by the Child Exploitation and Online Protection Centre (CEOP) of the United Kingdom's National Crime Agency . Statistical information on missing persons in
4092-447: Is called intercalation . Most intercalators are aromatic and planar molecules; examples include ethidium bromide , acridines , daunomycin , and doxorubicin . For an intercalator to fit between base pairs, the bases must separate, distorting the DNA strands by unwinding of the double helix. This inhibits both transcription and DNA replication, causing toxicity and mutations. As a result, DNA intercalators may be carcinogens , and in
Disappearance of Genette Tate - Misplaced Pages Continue
4224-435: Is called a polynucleotide . The backbone of the DNA strand is made from alternating phosphate and sugar groups. The sugar in DNA is 2-deoxyribose , which is a pentose (five- carbon ) sugar. The sugars are joined by phosphate groups that form phosphodiester bonds between the third and fifth carbon atoms of adjacent sugar rings. These are known as the 3′-end (three prime end), and 5′-end (five prime end) carbons,
4356-434: Is dependent on ionic strength and the concentration of DNA. As a result, it is both the percentage of GC base pairs and the overall length of a DNA double helix that determines the strength of the association between the two strands of DNA. Long DNA helices with a high GC -content have more strongly interacting strands, while short helices with high AT content have more weakly interacting strands. In biology, parts of
4488-454: Is estimated to be one person reported missing every 18 minutes. Around 38,159 missing person reports are made on average every year in Australia. Royal Canadian Mounted Police missing child statistics for a ten-year period show a total of 60,582 missing children in 2007. The file named Fichier des personnes recherchées (FPR) is a data collection of the French national police. It is also under
4620-507: Is facing a crisis of missing children. Every single month, we have approximately 150 reports of children who go missing. That is a crisis because we are only 2.7 million people." She said her organization would work with the International Centre for Missing & Exploited Children (ICMEC) to recommend a model law to the Parliament of Jamaica . It has been estimated that 100,000 Japanese people disappear annually. The term jouhatsu refers to
4752-647: Is increasingly recognized as a concern for national and international policy makers especially in cross border abduction cases, organized child trafficking and child pornography as well as the transient nature of unaccompanied minors seeking asylum. According to the UNHCR, over 15,000 unaccompanied and separated children claimed asylum in the European Union , Norway and Switzerland in 2009. The precarious situation of these children makes them particularly vulnerable to human rights abuses, rendering their protection critical, given
4884-411: Is influenced by how the DNA is packaged in chromosomes, in a structure called chromatin . Base modifications can be involved in packaging, with regions that have low or no gene expression usually containing high levels of methylation of cytosine bases. DNA packaging and its influence on gene expression can also occur by covalent modifications of the histone protein core around which DNA is wrapped in
5016-432: Is introduced by enzymes called topoisomerases . These enzymes are also needed to relieve the twisting stresses introduced into DNA strands during processes such as transcription and DNA replication . DNA exists in many possible conformations that include A-DNA , B-DNA , and Z-DNA forms, although only B-DNA and Z-DNA have been directly observed in functional organisms. The conformation that DNA adopts depends on
5148-458: Is no clear-cut distinction between countries of origin and destination in Europe. Trafficking in children has been perceived mainly in connection with sexual exploitation, but the reality is much more complex. Children in Europe are also trafficked for exploitation through labor, domestic servitude, begging, criminal activities and other exploitative purposes. In the report, UNICEF also warns that there
5280-422: Is nothing special about the four natural nucleobases that evolved on Earth. On the other hand, DNA is tightly related to RNA which does not only act as a transcript of DNA but also performs as molecular machines many tasks in cells. For this purpose it has to fold into a structure. It has been shown that to allow to create all possible structures at least four bases are required for the corresponding RNA , while
5412-432: Is one of four types of nucleobases (or bases ). It is the sequence of these four nucleobases along the backbone that encodes genetic information. RNA strands are created using DNA strands as a template in a process called transcription , where DNA bases are exchanged for their corresponding bases except in the case of thymine (T), for which RNA substitutes uracil (U). Under the genetic code , these RNA strands specify
Disappearance of Genette Tate - Misplaced Pages Continue
5544-514: Is rarely used). The stability of the dsDNA form depends not only on the GC -content (% G,C basepairs) but also on sequence (since stacking is sequence specific) and also length (longer molecules are more stable). The stability can be measured in various ways; a common way is the melting temperature (also called T m value), which is the temperature at which 50% of the double-strand molecules are converted to single-strand molecules; melting temperature
5676-428: Is recreated by an enzyme called DNA polymerase . This enzyme makes the complementary strand by finding the correct base through complementary base pairing and bonding it onto the original strand. As DNA polymerases can only extend a DNA strand in a 5′ to 3′ direction, different mechanisms are used to copy the antiparallel strands of the double helix. In this way, the base on the old strand dictates which base appears on
5808-469: Is still missing to this day. Within the U.S., there are several organizations that bring awareness and equality to missing people of color, such as the Black and Missing Foundation , a non - profit organization founded in 2008. The Black and Missing Foundation 's goal is to provide resources to families of missing people of color and educate minority groups on personal safety. Additionally, Deidra Robey leads
5940-424: Is that a person must be absent for at least 24 hours before being legally classed as missing, but this is rarely the case. Law enforcement agencies often stress that the case should be reported as early as possible. In fact, it is extremely crucial to report a missing person as soon as possible. This is in order to take immediate action in the vital first 48 hours after a person is declared missing. In these 48 hours,
6072-546: Is the European hotline for missing children active in all 27 countries of the EU as well as Albania , Serbia , Switzerland , Ukraine and the United Kingdom . The hotline was an initiative pushed for by Missing Children Europe, the European federation for missing and sexually exploited children. The Council of Europe estimates that about one in five children in Europe are victims of some form of sexual violence. In 70% to 85% of cases,
6204-516: Is the largest human chromosome with approximately 220 million base pairs , and would be 85 mm long if straightened. In eukaryotes , in addition to nuclear DNA , there is also mitochondrial DNA (mtDNA) which encodes certain proteins used by the mitochondria. The mtDNA is usually relatively small in comparison to the nuclear DNA. For example, the human mitochondrial DNA forms closed circular molecules, each of which contains 16,569 DNA base pairs, with each such molecule normally containing
6336-486: Is to allow the cell to replicate chromosome ends using the enzyme telomerase , as the enzymes that normally replicate DNA cannot copy the extreme 3′ ends of chromosomes. These specialized chromosome caps also help protect the DNA ends, and stop the DNA repair systems in the cell from treating them as damage to be corrected. In human cells , telomeres are usually lengths of single-stranded DNA containing several thousand repeats of
6468-657: The DNA sequence . Mutagens include oxidizing agents , alkylating agents and also high-energy electromagnetic radiation such as ultraviolet light and X-rays . The type of DNA damage produced depends on the type of mutagen. For example, UV light can damage DNA by producing thymine dimers , which are cross-links between pyrimidine bases. On the other hand, oxidants such as free radicals or hydrogen peroxide produce multiple forms of damage, including base modifications, particularly of guanosine, and double-strand breaks. A typical human cell contains about 150,000 bases that have suffered oxidative damage. Of these oxidative lesions,
6600-545: The East Devon village of Aylesbeare , 8 miles (13 km) east of Exeter . After her parents' separation, Genette maintained regular contact with her mother. Tate disappeared while delivering newspapers shortly after 3:30 p.m. ( BST ) on Saturday 19 August 1978. At approximately 3:28 p.m., two schoolfriends saw Tate walking along Withen Lane, pushing her bicycle. Tate had delivered fourteen newspapers by this point, and conversed briefly with her friends as they ascended
6732-711: The National Center for Missing & Exploited Children in the US, Missing People in the UK, Child Focus in Belgium, and The Smile of the Child in Greece. People disappear for many reasons. Some individuals choose to disappear, for others disappearance is inadvertent (e.g. getting lost) or it is imposed on them (abduction/imprisonment). Reasons for disappearance may include: A common misconception
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#17330863142006864-406: The amino-acid sequences of proteins is determined by the rules of translation , known collectively as the genetic code . The genetic code consists of three-letter 'words' called codons formed from a sequence of three nucleotides (e.g. ACT, CAG, TTT). In transcription, the codons of a gene are copied into messenger RNA by RNA polymerase . This RNA copy is then decoded by a ribosome that reads
6996-469: The cell nucleus as nuclear DNA , and some in the mitochondria as mitochondrial DNA or in chloroplasts as chloroplast DNA . In contrast, prokaryotes ( bacteria and archaea ) store their DNA only in the cytoplasm , in circular chromosomes . Within eukaryotic chromosomes, chromatin proteins, such as histones , compact and organize DNA. These compacting structures guide the interactions between DNA and other proteins, helping control which parts of
7128-515: The 116 000 European missing children hotline network, one in six are assumed to rough sleep on the run, one in eight resort to stealing to survive and one in four children are at serious risk of some form of abuse. The number of rough sleeping children across Europe is on the rise. These runaways fall into vulnerable situations of sexual abuse , alcohol abuse and drug abuse leading to depression. Runaways are 9 times likelier to have suicidal tendencies than other children. The Children's Society published
7260-419: The 3′ and 5′ carbons along the sugar-phosphate backbone confers directionality (sometimes called polarity) to each DNA strand. In a nucleic acid double helix , the direction of the nucleotides in one strand is opposite to their direction in the other strand: the strands are antiparallel . The asymmetric ends of DNA strands are said to have a directionality of five prime end (5′ ), and three prime end (3′), with
7392-588: The 5′ end having a terminal phosphate group and the 3′ end a terminal hydroxyl group. One major difference between DNA and RNA is the sugar, with the 2-deoxyribose in DNA being replaced by the related pentose sugar ribose in RNA. The DNA double helix is stabilized primarily by two forces: hydrogen bonds between nucleotides and base-stacking interactions among aromatic nucleobases. The four bases found in DNA are adenine ( A ), cytosine ( C ), guanine ( G ) and thymine ( T ). These four bases are attached to
7524-458: The Aboriginals were also described by Gilchrist as more "detached" in tone. Some of the most widely covered missing person cases have been kidnappings of children by strangers; however these instances are rare. In most parts of the world, criminal abductions make up only a small percentage of missing person cases and, in turn, most of these abductions are by someone who knows the child (such as
7656-435: The DNA are transcribed. DNA is a long polymer made from repeating units called nucleotides . The structure of DNA is dynamic along its length, being capable of coiling into tight loops and other shapes. In all species it is composed of two helical chains, bound to each other by hydrogen bonds . Both chains are coiled around the same axis, and have the same pitch of 34 ångströms (3.4 nm ). The pair of chains have
7788-453: The DNA double helix that need to separate easily, such as the TATAAT Pribnow box in some promoters , tend to have a high AT content, making the strands easier to pull apart. In the laboratory, the strength of this interaction can be measured by finding the melting temperature T m necessary to break half of the hydrogen bonds. When all the base pairs in a DNA double helix melt,
7920-554: The EKIS as missing was between 400 and 500 at all times mentioned in 2015 to 2017. In 2017, 10,000 missing person reports were filed in Austria. As of May 1, 2018, 1,267 people had been reported missing, including 746 children and young people. Only 505 came from EU countries. In January 2019, 1037 people were recorded as missing in the EKIS, in January 2020 884 people. Between 2016 and 2019, 85 percent of missing persons cases were resolved within
8052-560: The Exeter area. In 1996, an eyewitness claimed to have seen a vehicle of the model Black is known to have driven in 1978 at Exeter Airport on the day of Genette's disappearance. The police inquiries were unable to establish that Black had been in Aylesbeare on the day of the disappearance. The Crown Prosecution Service decided in August 2008 that insufficient evidence existed to charge Black with Tate's murder. After Black's conviction in 2011 for
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#17330863142008184-502: The NCIC as missing, and are being searched for, by local police. In addition, the EMJ category does not contain all reports of juveniles who have been reported missing to the NCIC. While the EMJ category holds records of some of the juveniles reported missing, the totals for the EMJ category excludes those juveniles recorded missing but who "have a proven physical or mental disability ... are missing under circumstances indicating that they may be in physical danger ... are missing after
8316-401: The RNA sequence by base-pairing the messenger RNA to transfer RNA , which carries amino acids. Since there are 4 bases in 3-letter combinations, there are 64 possible codons (4 combinations). These encode the twenty standard amino acids , giving most amino acids more than one possible codon. There are also three 'stop' or 'nonsense' codons signifying the end of the coding region; these are
8448-488: The TAG, TAA, and TGA codons, (UAG, UAA, and UGA on the mRNA). Cell division is essential for an organism to grow, but, when a cell divides, it must replicate the DNA in its genome so that the two daughter cells have the same genetic information as their parent. The double-stranded structure of DNA provides a simple mechanism for DNA replication . Here, the two strands are separated and then each strand's complementary DNA sequence
8580-423: The U.S. Office of Juvenile Justice and Delinquency Prevention from 2002 comprehensively described missing children cases for year 1999. The study considered a child missing when the child's whereabouts were unknown to the primary caretaker, with the result that the caretaker was alarmed for at least 1 hour and tried to locate the child. The estimated number of "caretaker missing children (reported and not reported)"
8712-453: The UK. According to the CIA out of the 800,000 people trafficked annually across national borders in the world, up to 50% are minors. The United Nations is operating a Commission on Missing Persons that serves as an international coordination center and provides also statistical material regarding missing persons worldwide. The International Red Cross and Red Crescent Movement strives to clarify
8844-489: The US is provided by annual National Crime Information Center (NCIC) "Missing Person and Unidentified Person Statistics", annual AMBER Alert Reports (minors only) and a comprehensive 2002 NISMART –2 study (covering children missing in year 1999). AMBER Alerts are reserved for confirmed abductions, where the child is at risk of serious injury or death. In 2018, 161 such alerts were issued, concerning 203 children. Of those 161 cases, 23 were found to be hoaxes or unfounded (minor
8976-422: The abuser is somebody the child knows and trusts. Child sexual violence can take many forms: sexual abuse within the family circle, child pornography and prostitution, corruption, solicitation via Internet and sexual assault by peers. In some of the cases, with no other available option, children flee their homes and care institutions, in search of a better and safer life. Of the 50–60% of child runaways reported by
9108-442: The axis of the double helix once every 10.4 base pairs, but if the DNA is twisted the strands become more tightly or more loosely wound. If the DNA is twisted in the direction of the helix, this is positive supercoiling, and the bases are held more tightly together. If they are twisted in the opposite direction, this is negative supercoiling, and the bases come apart more easily. In nature, most DNA has slight negative supercoiling that
9240-407: The canonical bases plus uracil. Twin helical strands form the DNA backbone. Another double helix may be found tracing the spaces, or grooves, between the strands. These voids are adjacent to the base pairs and may provide a binding site . As the strands are not symmetrically located with respect to each other, the grooves are unequally sized. The major groove is 22 ångströms (2.2 nm) wide, while
9372-467: The case of thalidomide, a teratogen . Others such as benzo[ a ]pyrene diol epoxide and aflatoxin form DNA adducts that induce errors in replication. Nevertheless, due to their ability to inhibit DNA transcription and replication, other similar toxins are also used in chemotherapy to inhibit rapidly growing cancer cells. DNA usually occurs as linear chromosomes in eukaryotes , and circular chromosomes in prokaryotes . The set of chromosomes in
9504-438: The case, saying, "I am not even 100% sure Black did it. I need proof that Black killed her." He said that his rapidly declining health meant that he could no longer make his annual trip from Manchester to Aylesbeare, and that his final wish was to give his daughter a dignified Christian burial and to be buried alongside her. He died in April 2020, aged 77, with the case still unsolved. Missing person A missing person
9636-581: The cell (see below) , but the major and minor grooves are always named to reflect the differences in width that would be seen if the DNA was twisted back into the ordinary B form . In a DNA double helix, each type of nucleobase on one strand bonds with just one type of nucleobase on the other strand. This is called complementary base pairing . Purines form hydrogen bonds to pyrimidines, with adenine bonding only to thymine in two hydrogen bonds, and cytosine bonding only to guanine in three hydrogen bonds. This arrangement of two nucleotides binding together across
9768-447: The child, taking them a long distance with intent to murder or to hold them permanently or for ransom). The Wall Street Journal reported in 2012 that: "It is estimated that some 8 million children go missing around the world each year." The BBC News reported that of the children who go missing worldwide, "while usually the child is found quickly the ordeal can sometimes last months, even years." The issue of child disappearances
9900-619: The chromatin structure or else by remodeling carried out by chromatin remodeling complexes (see Chromatin remodeling ). There is, further, crosstalk between DNA methylation and histone modification, so they can coordinately affect chromatin and gene expression. For one example, cytosine methylation produces 5-methylcytosine , which is important for X-inactivation of chromosomes. The average level of methylation varies between organisms—the worm Caenorhabditis elegans lacks cytosine methylation, while vertebrates have higher levels, with up to 1% of their DNA containing 5-methylcytosine. Despite
10032-476: The conditions found in cells, it is not a well-defined conformation but a family of related DNA conformations that occur at the high hydration levels present in cells. Their corresponding X-ray diffraction and scattering patterns are characteristic of molecular paracrystals with a significant degree of disorder. Compared to B-DNA, the A-DNA form is a wider right-handed spiral, with a shallow, wide minor groove and
10164-466: The costs if the situation was not caused by gross negligence, if there is a risk of death and if there is a reasonable chance of survival. A relatively large number of people are lost in Switzerland due to accidents in alpine sports. In the event of melting glaciers, the police have issued instructions on how to deal with the bodies: photograph the finds, mark them, write down the coordinates and, if there
10296-405: The creation of new genes through the process of gene duplication and divergence . A gene is a sequence of DNA that contains genetic information and can influence the phenotype of an organism. Within a gene, the sequence of bases along a DNA strand defines a messenger RNA sequence, which then defines one or more protein sequences. The relationship between the nucleotide sequences of genes and
10428-399: The customers on her newspaper round was still in her purse on the bicycle. The possibility of a hit-and-run traffic accident was also ruled out, as no tyre marks were found on the road and her bicycle was undamaged. Kidnapping was initially considered a possibility, although both Devon and Cornwall Police and Tate's family gradually discounted this possibility. Eyewitnesses reported seeing
10560-449: The cytoplasm called the nucleoid . The genetic information in a genome is held within genes, and the complete set of this information in an organism is called its genotype . A gene is a unit of heredity and is a region of DNA that influences a particular characteristic in an organism. Genes contain an open reading frame that can be transcribed, and regulatory sequences such as promoters and enhancers , which control transcription of
10692-724: The disappearance may not have been voluntary, i.e., abduction or kidnapping" (9,572 under age 21), and an additional 9,617 as "missing under circumstances indicating that his/her physical safety may be in danger" (15,163 under age 21). The total missing person records entered into NCIC were 661,593 in 2012, 678,860 in 2011 (550,424 of whom were under 21), 692,944 in 2010 (531,928 of whom were under 18, and 565,692 of whom were under 21), and 719,558 in 2009. A total of 630,990 records were cleared or canceled during 2013. At end-of-year 2013, NCIC had 84,136 still-active missing person records, with 33,849 (40.2%) being of juveniles under 18, and 9,706 (11.5%) being of juveniles between 18 and 20. 116 000
10824-405: The double helix (from six-carbon ring to six-carbon ring) is called a Watson-Crick base pair. DNA with high GC-content is more stable than DNA with low GC -content. A Hoogsteen base pair (hydrogen bonding the 6-carbon ring to the 5-carbon ring) is a rare variation of base-pairing. As hydrogen bonds are not covalent , they can be broken and rejoined relatively easily. The two strands of DNA in
10956-442: The edges of the bases and chelation of a metal ion in the centre of each four-base unit. Other structures can also be formed, with the central set of four bases coming from either a single strand folded around the bases, or several different parallel strands, each contributing one base to the central structure. In addition to these stacked structures, telomeres also form large loop structures called telomere loops, or T-loops. Here,
11088-481: The end of an otherwise complementary double-strand of DNA. However, branched DNA can occur if a third strand of DNA is introduced and contains adjoining regions able to hybridize with the frayed regions of the pre-existing double-strand. Although the simplest example of branched DNA involves only three strands of DNA, complexes involving additional strands and multiple branches are also possible. Branched DNA can be used in nanotechnology to construct geometric shapes, see
11220-399: The fate and whereabouts of missing persons when loss of contact is due to armed conflict or other situations of violence; natural or man-made disaster; migration and in other situations of humanitarian need. It is also supporting the families of missing persons to rebuild their social lives and find emotional well-being. Austria has a competence center for missing persons. The police records
11352-418: The focus is on the interactions between DNA and other molecules that mediate the function of the genome. Genomic DNA is tightly and orderly packed in the process called DNA condensation , to fit the small available volumes of the cell. In eukaryotes, DNA is located in the cell nucleus , with small amounts in mitochondria and chloroplasts . In prokaryotes, the DNA is held within an irregularly shaped body in
11484-461: The four major types of macromolecules that are essential for all known forms of life . The two DNA strands are known as polynucleotides as they are composed of simpler monomeric units called nucleotides . Each nucleotide is composed of one of four nitrogen-containing nucleobases ( cytosine [C], guanine [G], adenine [A] or thymine [T]), a sugar called deoxyribose , and a phosphate group . The nucleotides are joined to one another in
11616-448: The functions of these RNAs are not entirely clear. One proposal is that antisense RNAs are involved in regulating gene expression through RNA-RNA base pairing. A few DNA sequences in prokaryotes and eukaryotes, and more in plasmids and viruses , blur the distinction between sense and antisense strands by having overlapping genes . In these cases, some DNA sequences do double duty, encoding one protein when read along one strand, and
11748-448: The helical axis in a left-handed spiral, the opposite of the more common B form. These unusual structures can be recognized by specific Z-DNA binding proteins and may be involved in the regulation of transcription. For many years, exobiologists have proposed the existence of a shadow biosphere , a postulated microbial biosphere of Earth that uses radically different biochemical and molecular processes than currently known life. One of
11880-646: The high risks to which they are exposed. Most of these children are boys aged 14 years and over, with diverse ethnic, cultural, religious and social backgrounds mainly originating from Afghanistan, Somalia, Angola, the Democratic Republic of Congo, Eritrea and Iraq. Among exploiters taking advantage of the children, are sometimes their own relatives who gain benefit in the form of social or family allowances. According to research done by Frontex, some types of threats faced by unaccompanied migrant minors include sexual exploitation in terms of pornography, prostitution and
12012-448: The hydration level, DNA sequence, the amount and direction of supercoiling, chemical modifications of the bases, the type and concentration of metal ions , and the presence of polyamines in solution. The first published reports of A-DNA X-ray diffraction patterns —and also B-DNA—used analyses based on Patterson functions that provided only a limited amount of structural information for oriented fibers of DNA. An alternative analysis
12144-427: The hydrolytic activities of cellular water, etc., also occur frequently. Although most of these damages are repaired, in any cell some DNA damage may remain despite the action of repair processes. These remaining DNA damages accumulate with age in mammalian postmitotic tissues. This accumulation appears to be an important underlying cause of aging. Many mutagens fit into the space between two adjacent base pairs, this
12276-412: The importance of 5-methylcytosine, it can deaminate to leave a thymine base, so methylated cytosines are particularly prone to mutations . Other base modifications include adenine methylation in bacteria, the presence of 5-hydroxymethylcytosine in the brain , and the glycosylation of uracil to produce the "J-base" in kinetoplastids . DNA can be damaged by many sorts of mutagens , which change
12408-557: The internet; economic exploitation including forced donation of organs; criminal exploitation including drug smuggling and child trafficking including forced marriage and begging. Criminal networks are heavily involved with human trafficking to the EU and this includes also exploitation of minors as manpower in the sex trade and other criminal activities. According to a 2007 UNICEF report on Child Trafficking in Europe, 2 million children are being trafficked in Europe every year. Child trafficking occurs in virtually all countries in Europe. There
12540-759: The jurisdiction of the Ministry of the Interior and the Ministry of Defence. On May 26, 2002, a monument to missing persons was unveiled in County Kilkenny , Ireland by President Mary McAleese . It was the first monument of its kind in the world. The founder of Jamaica's Hear the Children's Cry, child-rights advocate Betty Ann Blaine, asked the government to introduce missing-children legislation in Jamaica. She said in May 2015: "Jamaica
12672-399: The lane. At the top of the hill, Tate mounted her bicycle and rode ahead as her friends paused to read an article in the newspaper they had been given. She would not typically have performed this newspaper round, and had agreed to do the job for one week as the paper boy who normally did the round was on holiday. Tate was wearing a white cotton T-shirt with her name embroidered in red letters on
12804-431: The left shoulder, light brown trousers, and white plimsolls . Seven minutes later, the two girls discovered Tate's bicycle lying in the middle of the road. Several newspapers she had been scheduled to deliver were scattered across the tarmac. Approximately 25 minutes after the discovery, Tate's parents returned to Barton Farm Cottage from a shopping trip to Exeter. The girls had Tate's bicycle with them, and asked if she
12936-439: The matter. The complaint can be filed one year after an event that can be linked to a danger to life or five years after the last sign of life of the interested person. If the person found by the authorities is of age, they can only inform other people with her consent. Police search and emergency room costs are usually charged in part or in full to the applicants. Helicopter searches are particularly expensive. The insurance covers
13068-467: The media, supported the conclusion that a person's race and socioeconomic status impacted media coverage. He gave the kidnappings of Elizabeth Smart and Alexis Patterson as an example—when Smart, a young affluent Caucasian girl from Utah, went missing, the media coverage was worldwide. After several months of searching, she was found alive. In comparison, when Patterson, a young black girl from Wisconsin, went missing, she received only local news coverage and
13200-441: The minor groove is 12 Å (1.2 nm) in width. Due to the larger width of the major groove, the edges of the bases are more accessible in the major groove than in the minor groove. As a result, proteins such as transcription factors that can bind to specific sequences in double-stranded DNA usually make contact with the sides of the bases exposed in the major groove. This situation varies in unusual conformations of DNA within
13332-725: The missing person's data, which is stored in the Austrian Search System (EKIS) and (automatically) in the Schengen Information System (SIS). In 2016, a total of 8,887 cases were processed and stored in the EKIS. Of these, 6,322 cases involved EU citizens, except for 44 resolved, and 2,565 non-EU citizens, except for 264 resolved. As of October 1, 2017, a total of 1,300 people were reported missing in Austria: 349 were women, 198 of whom were minors; 951 were male, of whom 597 were minors. The number of EU citizens who were stored in
13464-516: The mitochondrial genome (constituting up to 90% of the DNA of the cell). A DNA sequence is called a "sense" sequence if it is the same as that of a messenger RNA copy that is translated into protein. The sequence on the opposite strand is called the "antisense" sequence. Both sense and antisense sequences can exist on different parts of the same strand of DNA (i.e. both strands can contain both sense and antisense sequences). In both prokaryotes and eukaryotes, antisense RNA sequences are produced, but
13596-477: The most dangerous are double-strand breaks, as these are difficult to repair and can produce point mutations , insertions , deletions from the DNA sequence, and chromosomal translocations . These mutations can cause cancer . Because of inherent limits in the DNA repair mechanisms, if humans lived long enough, they would all eventually develop cancer. DNA damages that are naturally occurring , due to normal cellular processes that produce reactive oxygen species,
13728-403: The most widely reported missing person cases. By contrast, some missing person cases remain unresolved for many years. Laws related to these cases are often complex since, in many jurisdictions, relatives and third parties may not deal with a person's assets until their death is considered proven by law and a formal death certificate issued. The situation, uncertainties, and lack of closure or
13860-526: The murder of Jennifer Cardy in 1981, a spokesman for the Police Service of Northern Ireland commented on the "striking similarities" between the murder of Cardy and the disappearance of Tate. Devon and Cornwall Police reviewed the case in June 2014 in the hope of finding sufficient real evidence to prosecute Black. At the time of his death in January 2016, Devon and Cornwall Police were five weeks from submitting
13992-456: The need to try to find the person quickly, to assess how vulnerable the person is, and to search places that the person may have links to. Various charities exist to assist the investigations into unsolved cases. These include the National Center for Missing & Exploited Children in the US, Missing People in the UK, Child Focus in Belgium, and The Smile of the Child in Greece. Some missing person cases are given wide media coverage, with
14124-464: The new strand, and the cell ends up with a perfect copy of its DNA. Naked extracellular DNA (eDNA), most of it released by cell death, is nearly ubiquitous in the environment. Its concentration in soil may be as high as 2 μg/L, and its concentration in natural aquatic environments may be as high at 88 μg/L. Various possible functions have been proposed for eDNA: it may be involved in horizontal gene transfer ; it may provide nutrients; and it may act as
14256-445: The news media has provided white individuals, particularly affluent women, more comprehensive news coverage than people of color . The authors have noted that while a correlation has been established, they have no clear causation . They suggest that the socioeconomic status or attractiveness of a child may also influence their chances of appearing in the news media. American journalist Howard Kurtz , best known for his analysis of
14388-454: The open reading frame. In many species , only a small fraction of the total sequence of the genome encodes protein. For example, only about 1.5% of the human genome consists of protein-coding exons , with over 50% of human DNA consisting of non-coding repetitive sequences . The reasons for the presence of so much noncoding DNA in eukaryotic genomes and the extraordinary differences in genome size , or C-value , among species, represent
14520-460: The people in Japan who purposely vanish from their established lives without a trace. In the 1970s and 1980s, almost all South American countries were ruled for a long time by right-wing military dictatorships. Most of them violently suppressed the opposition, usually with the secret kidnapping of unwanted people by unnamed members of the security forces. While the families reported the disappearances,
14652-428: The place of thymine in RNA and differs from thymine by lacking a methyl group on its ring. In addition to RNA and DNA, many artificial nucleic acid analogues have been created to study the properties of nucleic acids, or for use in biotechnology. Modified bases occur in DNA. The first of these recognized was 5-methylcytosine , which was found in the genome of Mycobacterium tuberculosis in 1925. The reason for
14784-440: The police will be able to interview any eyewitness and get any suspect descriptions while it is still fresh in their minds. In most common law jurisdictions, a missing person can be declared dead in absentia (or "legally dead") after seven years. This time frame may be reduced in certain cases. In most countries, the police are the default agency for leading an investigation into a missing person case. Disappearances at sea are
14916-530: The presence of these noncanonical bases in bacterial viruses ( bacteriophages ) is to avoid the restriction enzymes present in bacteria. This enzyme system acts at least in part as a molecular immune system protecting bacteria from infection by viruses. Modifications of the bases cytosine and adenine, the more common and modified DNA bases, play vital roles in the epigenetic control of gene expression in plants and animals. A number of noncanonical bases are known to occur in DNA. Most of these are modifications of
15048-412: The prime symbol being used to distinguish these carbon atoms from those of the base to which the deoxyribose forms a glycosidic bond . Therefore, any DNA strand normally has one end at which there is a phosphate group attached to the 5′ carbon of a ribose (the 5′ phosphoryl) and another end at which there is a free hydroxyl group attached to the 3′ carbon of a ribose (the 3′ hydroxyl). The orientation of
15180-404: The problem of missing children. The British Asylum Screening Unit estimated that 60% of the unaccompanied minors accommodated in social care centres in the UK go missing and are not found again. In the UK these open centres, from where minors are able to call their traffickers, act as 'human markets' for the facilitators and traffickers who generally collect their prey within 24 hours of arrival in
15312-466: The proposals was the existence of lifeforms that use arsenic instead of phosphorus in DNA . A report in 2010 of the possibility in the bacterium GFAJ-1 was announced, though the research was disputed, and evidence suggests the bacterium actively prevents the incorporation of arsenic into the DNA backbone and other biomolecules. At the ends of the linear chromosomes are specialized regions of DNA called telomeres . The main function of these regions
15444-486: The search. All ponds in the Aylesbeare area were searched by underwater search units , and search dogs assisted police in their search of surrounding terrain. Devon and Cornwall Police discounted the possibility of Tate running away from home, as at the time of her disappearance she had no personal possessions with her beyond the clothing she was wearing. She had also left behind in her bedroom money she had been saving for an upcoming family holiday. The money collected from
15576-478: The searchers turning to the public for assistance. The persons' photographs may be displayed on bulletin boards, milk cartons, postcards, websites and social media to publicize their description. A racial disparity between the American news media response when a white individual goes missing and when a black individual goes missing has been observed. According to Seong-Jae Min & John C. Feaster, throughout history
15708-432: The section on uses in technology below. Several artificial nucleobases have been synthesized, and successfully incorporated in the eight-base DNA analogue named Hachimoji DNA . Dubbed S, B, P, and Z, these artificial bases are capable of bonding with each other in a predictable way (S–B and P–Z), maintain the double helix structure of DNA, and be transcribed to RNA. Their existence could be seen as an indication that there
15840-431: The sequence of amino acids within proteins in a process called translation . Within eukaryotic cells, DNA is organized into long structures called chromosomes . Before typical cell division , these chromosomes are duplicated in the process of DNA replication, providing a complete set of chromosomes for each daughter cell. Eukaryotic organisms ( animals , plants , fungi and protists ) store most of their DNA inside
15972-473: The shape of a double helix . The nucleotide contains both a segment of the backbone of the molecule (which holds the chain together) and a nucleobase (which interacts with the other DNA strand in the helix). A nucleobase linked to a sugar is called a nucleoside , and a base linked to a sugar and to one or more phosphate groups is called a nucleotide . A biopolymer comprising multiple linked nucleotides (as in DNA)
16104-552: The single-ringed pyrimidines and the double-ringed purines . In DNA, the pyrimidines are thymine and cytosine; the purines are adenine and guanine. Both strands of double-stranded DNA store the same biological information . This information is replicated when the two strands separate. A large part of DNA (more than 98% for humans) is non-coding , meaning that these sections do not serve as patterns for protein sequences . The two strands of DNA run in opposite directions to each other and are thus antiparallel . Attached to each sugar
16236-498: The single-stranded DNA curls around in a long circle stabilized by telomere-binding proteins. At the very end of the T-loop, the single-stranded telomere DNA is held onto a region of double-stranded DNA by the telomere strand disrupting the double-helical DNA and base pairing to one of the two strands. This triple-stranded structure is called a displacement loop or D-loop . In DNA, fraying occurs when non-complementary regions exist at
16368-518: The strands separate and exist in solution as two entirely independent molecules. These single-stranded DNA molecules have no single common shape, but some conformations are more stable than others. In humans, the total female diploid nuclear genome per cell extends for 6.37 Gigabase pairs (Gbp), is 208.23 cm long and weighs 6.51 picograms (pg). Male values are 6.27 Gbp, 205.00 cm, 6.41 pg. Each DNA polymer can contain hundreds of millions of nucleotides, such as in chromosome 1 . Chromosome 1
16500-469: The sugar-phosphate to form the complete nucleotide, as shown for adenosine monophosphate . Adenine pairs with thymine and guanine pairs with cytosine, forming A-T and G-C base pairs . The nucleobases are classified into two types: the purines , A and G , which are fused five- and six-membered heterocyclic compounds , and the pyrimidines , the six-membered rings C and T . A fifth pyrimidine nucleobase, uracil ( U ), usually takes
16632-435: The vast majority of which were runaways from institutions. Furthermore, only an estimated 115 of 33,000 non-familial abductions were stereotypical kidnappings, involving a stranger or slight acquaintance, who holds the child for ransom, abducts with intent to kill or keep permanently. Data in the study was derived from a Law Enforcement Study, National Household Surveys of both Adult Caretakers and Youth (telephone interviews) and
16764-741: The victims were unjustly imprisoned, tortured and finally killed. In Argentina, they were loaded onto a plane and thrown into the sea. During the Argentina's military dictatorship (1976–1983) , almost 30,000 people disappeared in this way, permanently and without leaving any trace. According to a report by the Russian news agency TASS released in 2018, between 70,000 and 100,000 people go missing in Russia every year. About 25% of missing persons cases remain unsolved. The cantonal police are responsible for reports of disappearances, which do not have specialized sections on
16896-480: Was around 1.3 million, with about 800 thousand missing children estimated to have been reported. The 1,300,000 number is further broken down into approximately 33,000 non-familial abductions, 117,000 familial abductions, 629,000 runaway/thrownaway cases, 198,000 lost/injured, and 375,000 "benign explanations". By the time the study data were collected, 99.8% of 1.3 million caretaker missing children had been returned home alive or located. Only 0.2% percent or 2,500 had not,
17028-502: Was at home. When Tate's father said that his daughter was not at home, he and her mother, assisted by several friends and neighbours, began a search around Within Road for Tate. At 5 p.m., John Tate reported his daughter missing to Devon and Cornwall Police . Within hours of Tate's disappearance, police mounted an extensive search. Seventy uniformed policemen and fifty detectives from Devon and Cornwall Police, assisted by mounted officers from Avon and Somerset Police , were assigned to
17160-524: Was born in Taunton , Somerset , on 5 May 1965. She was the only child born to John and Sheila Tate. At the time of Genette's birth, the Tate family lived in the Taunton suburb of Wedlands. They relocated briefly to Cornwall before moving to Devon . Genette's parents separated when she was young, and her father remarried. She lived with her father, stepmother Violet, and stepsister Tania at Barton Farm Cottage in
17292-471: Was not missing), 92 were familial abductions, 38 were non-familial abductions and remaining 8 were runaways, lost, injured or unclassified. As of early 2019, 11 children were still missing and 7 were found deceased, with remaining children having been recovered. Notably, even though all states have operational AMBER program, 16 did not issue any alerts in 2018. National Incidence Studies of Missing, Abducted, Runaway, and Thrownaway Children (NISMART–2) study by
17424-517: Was proposed by Wilkins et al. in 1953 for the in vivo B-DNA X-ray diffraction-scattering patterns of highly hydrated DNA fibers in terms of squares of Bessel functions . In the same journal, James Watson and Francis Crick presented their molecular modeling analysis of the DNA X-ray diffraction patterns to suggest that the structure was a double helix. Although the B-DNA form is most common under
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