• In humans, a major roadblock in achieving successful SCNT leading to embryonic stem cells has been the fact that human SCNT embryos fail to progress beyond the eight-cell stage. (news-medical.net)
  • They derived several human embryonic stem cell lines from these cloned embryos whose DNA was an exact match to the adult cell that donated the DNA. (news-medical.net)
  • Such human fully integrated and complete SEMs recapitulate the organization of nearly all known lineages and compartments of post-implantation human embryos, including the epiblast, the hypoblast, the extra-embryonic mesoderm and the trophoblast layer surrounding the latter compartments. (nature.com)
  • Although it is possible to culture structures derived from human blastocysts ex vivo, these cultures do not recapitulate the events and structural organization of the in vivo embryos 6 ( Supplementary Information ). (nature.com)
  • Researchers there are working on technology that induces human skin cells to change into the kind of stem cells that have been created by embryos. (cbc.ca)
  • Some argue that the possibility of mimicking stem cells without acquiring them from embryos, side-steps that moral dilemma. (cbc.ca)
  • Embryonic stem cells come from embryos, embryonic germ cells from testes, and adult stem cells can come from bone marrow. (cbc.ca)
  • This new method of generating stem cells does not require embryos as starting points and could be used to generate cells from many adult tissues, such as a patient's own skin cells,' said principal author Andras Nagy, senior investigator at Mount Sinai's Samuel Lunenfeld Research Institute. (cbc.ca)
  • Dr Hwang, 52, gained worldwide fame after producing the world's first cloned human embryos and stem cells tailored to be used on individuals. (bbc.co.uk)
  • Human cloning science offers the possibility that stem cells harvested from cloned embryos could be used to treat diseases like Parkinson's, diabetes and heart disease. (bbc.co.uk)
  • However, opponents argue that creating and experimenting with human embryos is unethical. (bbc.co.uk)
  • There are no international laws governing the use of cells and embryos, but scientists said a tough regulatory climate - like that in force in the UK - could prevent such abuses or misunderstandings. (bbc.co.uk)
  • Most human embryos reproduced by most human cloning techniques would actually be genetically unique -- i.e., having never existed before. (lifeissues.net)
  • Some prohibit only cloning for reproductive purposes and allow the creation of cloned human embryos for research, whereas others prohibit the creation of cloned embryos for any purpose. (who.int)
  • The artificial cloning of organisms, sometimes known as reproductive cloning, is often accomplished via somatic-cell nuclear transfer (SCNT), a cloning method in which a viable embryo is created from a somatic cell and an egg cell. (wikipedia.org)
  • Human cloning ought to be banned, both reproductive cloning and so-called therapeutic cloning-or as Stanford University recently referred to it, "human nuclear transplantation. (probe.org)
  • A second argument for cloning starts with the idea of reproductive rights. (bartleby.com)
  • When the cloning process is used in this way, to produce a living duplicate of an existing animal, it is commonly called reproductive cloning. (eurostemcell.org)
  • In most countries, it is illegal to attempt reproductive cloning in humans. (eurostemcell.org)
  • Many of these accurate definitions can also be used in bills and treaties concerning related issues, e.g., human embryonic stem cell research, human genetic engineering, abortion, the use of abortifacients, conscience clauses, IVF and other artificial reproductive technology research and regulation, etc. (lifeissues.net)
  • Note that each and every individual "loophole" discussed below that permits human cloning by default (and most bills have literally dozens of such loopholes) thus permits it for both "therapeutic" and for "reproductive" human cloning. (lifeissues.net)
  • Elaboration of an international convention against reproductive cloning of human beings has been under consideration in the United Nations since December 2001 when the subject was included in the agenda of the fifty- sixth session as a supplementary agenda item at the request of France and Germany. (who.int)
  • By transferring adult cell DNA into an embryonic stem cell, it is possible to create a line of immortal embryonic cells that are able to develop into any type of adult cell, genetically identical to the donor. (news-medical.net)
  • The adult cell nuclei were transferred into metaphase-II stage human oocytes, producing a karyotypically normal diploid embryonic stem cell line from each of the adult male donor cells. (news-medical.net)
  • To date, no human embryonic stem cell lines have been derived using therapeutic cloning, so both these possibilities remain very much in the future. (eurostemcell.org)
  • This has led to a lot of interest in SCNT, which is best known as the method used to pioneer whole animal cloning technology, such as Dolly the sheep. (news-medical.net)
  • In 1996, Dolly the sheep achieved notoriety for being the first mammal cloned from a somatic cell. (wikipedia.org)
  • Cloning, or somatic cell nuclear transfer (SCNT), is the technique used to produce Dolly the sheep, the first animal to be produced as a genetic copy of another adult. (eurostemcell.org)
  • To produce Dolly, the cloned blastocyst was transferred into the womb of a recipient ewe, where it developed and when born quickly became the world's most famous lamb. (eurostemcell.org)
  • Indeed, if passed, Hatch/Feinstein/Kerry would explicitly legalize doing in humans the very cloning procedure -- somatic cell nuclear transfer (SCNT) -- that was used to make Dolly the sheep . (lifeissues.net)
  • Comment: Indeed, if passed, "total cloning bans" H.R. 534, H.R. 234, H.R. 916, and S. 245 would not ban anything either - not even the SCNT cloning technique that was used to make Dolly the sheep. (lifeissues.net)
  • Although many species produce clonal offspring in this fashion, Dolly, the lamb born in 1996 at a research institute in Scotland, was the first asexually produced mammalian clone. (who.int)
  • Somatic-cell nuclear transfer, the technique by which Dolly was created, was first used 40 years ago in research with tadpoles and frogs. (who.int)
  • The most famous clone was a Scottish sheep named Dolly. (medlineplus.gov)
  • One cloning technology that has been developed for mammalian and human cells is somatic cell nuclear transfer (SCNT). (news-medical.net)
  • Somatic cell nuclear transfer (SCNT) is a type of cloning that has to be done in a lab. (bartleby.com)
  • In SCNT they take the nucleolus out of an egg cell, replace it with the nucleolus of a somatic cell (body cell with two complete sets of chromosomes), and make the egg cell divide into a blastocyst ("What Is Cloning? (bartleby.com)
  • The nucleus of an adult somatic cell (such as a skin cell) is removed and transferred to an enucleated egg, which is then stimulated with electric current or chemicals to activate cell division. (who.int)
  • if it implants and the pregnancy goes to term, the resulting individual will carry the same nuclear genetic material as the donor of the adult somatic cell. (who.int)
  • Scientists were initially interested in somatic-cell nuclear transfer as a means of determining whether genes remain functional even after most of them have been switched off as the cells in a developing organism assume their specialized functions as blood cells, muscle cells, and so forth. (who.int)
  • SCNT is a method of cloning mammalian cells that can be used to create personalized embryonic stem cells from an adult animal or human. (news-medical.net)
  • But SCNT can also be used to clone human cells for transplant or other therapies. (news-medical.net)
  • In 2013, scientists reported a successful SCNT procedure by modifying the protocol for specific human oocyte biology. (news-medical.net)
  • This was the first successful reprogramming of human somatic cells into embryonic stem cells using a cloning technique, SCNT. (news-medical.net)
  • Another successful attempt at human SCNT was made using cells from two adult males. (news-medical.net)
  • The use of embryonic stem cells, which can be produced through SCNT, in some stem cell research has attracted controversy. (wikipedia.org)
  • The therapeutic potential of cloned human cells has been demonstrated by another study using human oocytes to reprogram adult cells of a type 1 diabetic. (news-medical.net)
  • Although attempts have not yet been made to create a therapeutic transplant from embryonic stem cells, the methods have been developed to allow the creation of functional, mature cells using human cell cloning technology. (news-medical.net)
  • In therapeutic cloning, the blastocyst is not transferred to a womb. (eurostemcell.org)
  • Another long-term hope for therapeutic cloning is that it could be used to generate cells that are genetically identical to a patient. (eurostemcell.org)
  • Therapeutic cloning, which creates embryonic stem cells . (medlineplus.gov)
  • After many divisions in culture, this single cell forms a blastocyst (an early stage embryo with about 100 cells) with almost identical DNA to the original donor who provided the adult cell - a genetic clone. (eurostemcell.org)
  • Instead, embryonic stem cells are isolated from the cloned blastocyst. (eurostemcell.org)
  • Eve was delivered by Caesarian section from her twin sister (the woman who donated the nuclear genetic material from which she was cloned also served as the surrogate mother). (probe.org)
  • Embryo-like models with spatially organized morphogenesis and structure of all defining embryonic and extra-embryonic tissues of the post-implantation human conceptus (that is, the embryonic disc, the bilaminar disc, the yolk sac, the chorionic sac and the surrounding trophoblast layer) remain lacking 1 , 2 . (nature.com)
  • Mouse naive embryonic stem cells have recently been shown to give rise to embryonic and extra-embryonic stem cells capable of self-assembling into post-gastrulation structured stem-cell-based embryo models with spatially organized morphogenesis (called SEMs) 3 . (nature.com)
  • Implantation of the human embryo leads to a number of changes in organization that are essential for gastrulation and future development 1 . (nature.com)
  • and (3) evidence of developmental dynamism relating to ability to progress, in a structurally organized manner, through morphologically characterized developmental milestones of the early post-implantation human embryo following initial aggregate formation 3 . (nature.com)
  • Opponents argue that any embryo has the potential to develop into a mature human. (cbc.ca)
  • Thus to use the phrase "of an existing or previously existing human being" to refer to the product of human cloning would not be a scientifically accurate description of the cloned or genetically engineered human embryo -- thus creating yet another loophole in the bill or treaty. (lifeissues.net)
  • To clone a human CTR (hCTR), a BIN-67 cDNA library was screened using a cDNA probe from a porcine renal CTR (pCTR) that we recently cloned. (jci.org)
  • Transfection of this cDNA into COS cells resulted in expression of receptors with high affinity for salmon CT (Kd = approximately 0.44 nM) and for human CT (Kd = approximately 5.4 nM). (jci.org)
  • The cloned cDNA encodes a putative peptide of 490 amino acids with seven potential transmembrane domains. (jci.org)
  • Thus, the clone would be genetically identical to the nucleus donor only if the egg came from the same donor or from her maternal line. (who.int)
  • Beyond this scientific interest, the commercial concern in animal cloning focuses on replicating large numbers of genetically identical animals, especially those derived from a progenitor that has been modified genetically. (who.int)
  • The ability to study human post-implantation development remains limited owing to ethical and technical challenges associated with intrauterine development after implantation 1 . (nature.com)
  • In bioethics, there are a variety of ethical positions regarding the practice and possibilities of cloning. (wikipedia.org)
  • The Ethical Debate Concerning Cloning In the year that has elapsed since the announcement of Dolly's birth, there has been much discussion of the ethical implications of cloning humans. (bartleby.com)
  • Several authors have attempted to outline some of the ethical objections to cloning while at the same time minimizing the role religion plays in this debate. (bartleby.com)
  • However, a number of other features are needed, and a variety of specialised cloning vectors (small piece of DNA into which a foreign DNA fragment can be inserted) exist that allow protein production, affinity tagging, single-stranded RNA or DNA production and a host of other molecular biology tools. (wikipedia.org)
  • But previous approaches required the use of viruses to deliver the four genes needed to activate the cell and accomplish that task. (cbc.ca)
  • If artificial cloning and natural cloning both lead to the same result, which is the formation of a clone, that is, an organism with identical or nearly identical genes to another organism, then the plight of This creation is very different between the two creatures. (wikipedia.org)
  • Cloning is commonly used to amplify DNA fragments containing whole genes, but it can also be used to amplify any DNA sequence such as promoters, non-coding sequences and randomly fragmented DNA. (wikipedia.org)
  • The fact that the DNA of a fully differentiated (adult) cell could be stimulated to revert to a condition comparable to that of a newly fertilized egg and to repeat the process of embryonic development demonstrates that all the genes in differentiated cells retain their functional capacity, although only a few are active. (who.int)
  • Researchers have determined that several steps in the protocol were critical for human cellular reprogramming. (news-medical.net)
  • However, researchers at the Harvard Stem Cell Institute say reprogrammed cells won't eliminate the need or value of studying embryonic stem cells. (cbc.ca)
  • Two other independent researchers, Severino Antinori (an Italian working in an undisclosed Muslim country) and Panos Zavos (from Lexington, Kentucky) have also been hinting at human cloning success and suggesting that a birth will be announced soon. (probe.org)
  • This incredibly high 50% success rate for human cloning leaves most researchers believing that either this isn't really a clone or they simply aren't revealing all the other failures. (probe.org)
  • A cloning pioneer regarded as a hero in his South Korean homeland has resigned and apologised for using human eggs from his own researchers. (bbc.co.uk)
  • The stem cells could be studied in the laboratory to help researchers understand what goes wrong in diseases like these. (eurostemcell.org)
  • Researchers hope to use these cells to grow healthy tissue to replace injured or diseased tissues in the human body. (medlineplus.gov)
  • Note: Please read The Little Lamb That Made a Monkey of Us All for the author's comments on the news of a successful lamb cloning (March 7, 1997). (probe.org)
  • General Assembly the following year,3 and the World Medical Association's Resolution on Cloning, endorsed in 1997, have confronted the issue but lack binding legal force. (who.int)
  • Cloning of human cells is a technology that holds the potential to cure many diseases and provide a source of exactly matched transplant tissues and organs. (news-medical.net)
  • Much of this process relies on the morphogenesis of the extra-embryonic tissues and the effect this has on the organization of embryonic cells. (nature.com)
  • This gene encodes a cell surface membrane protein of the immunoglobulin superfamily. (origene.com)
  • Scientists have been all abuzz in the last few years over stem cells - cellular magicians that promise to dazzle and amaze. (cbc.ca)
  • Scientists say embryonic stem cells are the most useful type because they have the potential to become any type of cell within the body. (cbc.ca)
  • Scientists are fascinated by the ability of stem cells to become any type of cell. (cbc.ca)
  • Scientists produced embryonic stem cells from the DNA of one person combined with a human donor egg. (technologyreview.com)
  • Embryonic stem cells are immortal, and have the potential to develop into any type of adult cell, even after months growing in culture dishes. (news-medical.net)
  • The mitochondrial DNA of the stem cells, however, matched the donor egg's mitochondrial DNA. (news-medical.net)
  • Dermal fibroblasts were taken from a 35-year old male and a 75-year-old male and used to create embryonic stem cells. (news-medical.net)
  • Here we extend those findings to humans using only genetically unmodified human naive embryonic stem cells (cultured in human enhanced naive stem cell medium conditions) 4 . (nature.com)
  • The first clinical trials involving a patient receiving human embryonic stem cells began in October 2010 at the Shepard Center, a spinal cord injury hospital in Atlanta. (cbc.ca)
  • But there has been intense debate over the use of stem cells. (cbc.ca)
  • What are stem cells? (cbc.ca)
  • Stem cells can be thought of as blank slates or cells that have yet to become specialized. (cbc.ca)
  • Stem cells come in three forms: embryonic stem cells, embryonic germ cells and adult stem cells. (cbc.ca)
  • Embryonic stem cells are pluripotent - they have the ability to become virtually any type of cell within the body. (cbc.ca)
  • Adult stem cells are more limited. (cbc.ca)
  • In a study published in the online journal Nature on March 1, 2009, Canadian researches described a new method for generating stem cells from adult human tissue. (cbc.ca)
  • The ability to transform skin cells into stem cells isn't new. (cbc.ca)
  • What could stem cells be used for? (cbc.ca)
  • Learn about the different kinds and functions of stem cells, and about the medical possibilities and controversies surrounding stem cell research. (bioedonline.org)
  • Dr Hwang's breakthrough was seen as particularly important as the stem cells he created were a perfect match for the patient, which could mean treatments without the risk of the body rejecting them. (bbc.co.uk)
  • These stem cells are genetically matched to the donor organism, holding promise for studying genetic disease. (eurostemcell.org)
  • For example, stem cells could be generated using the nuclear transfer process described above, with the donor adult cell coming from a patient with diabetes or Alzheimer's. (eurostemcell.org)
  • Those were spindle removal, donor cell fusion, and cytoplast activation. (news-medical.net)
  • The resulting cells were pluripotent and could be differentiated into insulin-producing beta cells to restore the function of the pancreas in the donor. (news-medical.net)
  • However, an animal created through this technique would not be a precise genetic copy of the source of its nuclear DNA because each clone derives a small amount of its DNA from the mitochondria of the egg (which lie outside the nucleus) rather than from the donor of cell nucleus. (who.int)
  • Moreover, treatment with imiquimod downregulated MHC class I molecules on tumor cells possibly resulting in a reduced binding affinity for inhibitory receptor NKG2A expressed on γδ T cells. (aacrjournals.org)
  • Another example of artificial cloning is molecular cloning, a technique in molecular biology in which a single living cell is used to clone a large population of cells that contain identical DNA molecules. (wikipedia.org)
  • Molecular cloning refers to the process of making multiple molecules. (wikipedia.org)
  • The term applies not only to entire organisms but also to copies of molecules (such as DNA) and cells. (who.int)
  • Natural cloning occurs through a variety of natural mechanisms, from single-celled organisms to complex multicellular organisms. (wikipedia.org)
  • A type of cloning that occurs naturally is when identical twins are born ("What Is Cloning? (bartleby.com)
  • Most natural cloning occurs in those species that produce their descendants asexually, that is, without combining the male and female genetic material. (who.int)
  • Cloning new organs and stem cell research . (globalchange.com)
  • They are in an early stage of development and have the ability to become any type of cell to form skin, bones, organs or other body parts. (cbc.ca)
  • Retrieved on December 04, 2023 from https://www.news-medical.net/life-sciences/Cloning-Human-Cells.aspx. (news-medical.net)
  • Although the simple use of the word 'clone' may have negative connotations, many people have resigned themselves to the idea of cloning cows that produce more milk or using a cloned mouse for use in controlled experimentation. (bartleby.com)
  • It's given name is the "Human Cloning Ban and Stem Cell Research Protection Act of 2003," the stated purpose of which, supposedly, is to "prohibit human cloning and to protect important areas of medical research, including stem cell research. (lifeissues.net)
  • Occasionally, the term cloning is misleadingly used to refer to the identification of the chromosomal location of a gene associated with a particular phenotype of interest, such as in positional cloning. (wikipedia.org)
  • Cloning describes the processes used to create an exact genetic replica of another cell, tissue or organism. (medlineplus.gov)
  • Cloning is the process of producing individual organisms with identical genomes, either by natural or artificial means. (wikipedia.org)
  • In the field of biotechnology, cloning is the process of creating cloned organisms of cells and of DNA fragments. (wikipedia.org)
  • In this procedure, the nucleus of an egg cell is removed and replaced by the nucleus of a cell from another adult. (eurostemcell.org)
  • A third view says that cloning will provide for the possibility of improvement by giving birth to children who are free of birth defects, because when any two people create a child through sex there is the possibility for genetic defects. (bartleby.com)
  • The structural differences may account for observed differences in binding affinity between the porcine renal and human ovarian CTRs. (jci.org)
  • Loss of cell division cycle‑associated 5 promotes cell apoptosis by activating DNA damage response in clear cell renal cell carcinoma. (nih.gov)
  • Diabetic nephropathy (DN) is a leading selectin), and soluble thrombomodulin--are cause of chronic renal failure and is a grow- providing further evidence of the relation- ing concern given the increasing incidence ship between endothelial cell activation and of type 2 diabetes. (who.int)
  • found evidence and they did not require insulin therapy of endothelial cell injury in renal failure for glucose control. (who.int)
  • depictions commonly involve themes related to identity, the recreation of historical figures or extinct species, or cloning for exploitation (i.e. cloning soldiers for warfare). (wikipedia.org)
  • Silencing oncogene cell division cycle associated 5 induces apoptosis and G1 phase arrest of non-small cell lung cancer cells via p53-p21 signaling pathway. (nih.gov)
  • The cloning method is based on the fact that cytoplasmic factors in mature, metaphase II oocytes are able to reset the identity of a transplanted adult cell nucleus to an embryonic state. (news-medical.net)
  • After being inserted into the egg, the adult cell nucleus is reprogrammed by the host cell. (eurostemcell.org)
  • Coined by Herbert J. Webber, the term clone derives from the Ancient Greek word κλών (klōn), twig, which is the process whereby a new plant is created from a twig. (wikipedia.org)
  • Using TCR alpha and beta repertoire sequencing for T-cell subsets, as well as single-cell RNAseq and TCRseq, we track the concentrations and phenotypes of individual T-cell clones in response to primary and secondary yellow fever immunization - the model for acute infection in humans - showing their large diversity. (elifesciences.org)
  • T-cells have 2 subsets of betic patients with and without nephropathy. (who.int)
  • These cells have been sought after as potential therapies for diseases ranging from heart disease to Parkinson's to cancer. (news-medical.net)
  • Since then, there has been a flurry of announcements about developments in stem cell research and hints of promising treatments for diseases such as Alzheimer's, Parkinson's and cancer. (cbc.ca)
  • The term "clone", from the Greek word for twig, denotes a group of identical entities. (who.int)
  • In sexual reproduction, clones are created when a fertilized egg splits to produce identical (monozygous) twins with identical genomes. (who.int)
  • Why Is Cloning So Difficult and How Did They Do It? (probe.org)
  • The research conducted by his team requires large numbers of human eggs, which are difficult to obtain. (bbc.co.uk)
  • T-cells play a crucial role in the immune response to pathogens by mediating antibody formation and clearance of infected cells, and by defining an overall response strategy. (elifesciences.org)
  • In May 2007, Ontario and California announced a $30-million stem cell research deal aimed at finding new therapies for those diseases. (cbc.ca)
  • These studies suggest that this gene product may also be important in T cell function and contribute to the prevention of autoimmune diseases. (origene.com)
  • The present report gives an overview of the terms and methods used in cloning and summarizes the debates in the General Assembly. (who.int)
  • The interaction of CD54 and the corresponding ligand CD11a/CD18 expressed on γδ T cells is responsible for triggering effector function in γδ T cells. (aacrjournals.org)
  • While I have to agree with the author's concerns (we'll call him Kettle) about the use of waffling and fake science in the supposed cloning "bans" proposed by the Pots, if truth be told, there's enough concern to go around for both the Pots and the Kettles. (lifeissues.net)
  • A human ovarian small cell carcinoma line (BIN-67) expresses abundant calcitonin (CT) receptors (CTR) (143,000 per cell) that are coupled, to adenylate cyclase. (jci.org)
  • The diverse repertoire of T-cell receptors (TCR) plays a key role in the adaptive immune response to infections. (elifesciences.org)
  • In December 1999, the editors of Science, the journal devoted to scientific and medical matters, called stem cell research the 'Breakthrough of the Year. (cbc.ca)
  • He is the co-author of the book The Natural Limits to Biological Change , served as general editor of Creation, Evolution and Modern Science , co-author of Basic Questions on Genetics, Stem Cell Research and Cloning (The BioBasics Series) , and has published numerous journal articles. (probe.org)
  • Ontario and California together account for about 70 per cent of the stem cell research currently conducted in North America. (cbc.ca)
  • Some of that money would be aimed at turning the state into the second-largest stem cell research region in the United States. (cbc.ca)
  • Not only that, but poor Eve, who I believe is a full human being with a soul, will be a research subject all her life, however long that is. (probe.org)
  • The professor said he was resigning from all public posts, including his chairmanship of the World Stem Cell Hub, which is designed to produce stem cell lines for disease research worldwide. (bbc.co.uk)
  • What is cloning, and what does it have to do with stem cell research? (eurostemcell.org)
  • This form of cloning is unrelated to stem cell research. (eurostemcell.org)
  • The "pros" and "cons" of human cloning research have already been dealt with at length in the literature, so they will not be reviewed here. (lifeissues.net)
  • Rather, after having published analyses of dozens of state, national, federal and international legislative attempts to ban human cloning research, I simply wish to offer seriously considered suggestions for the use of scientifically accurate language and definitions to be used in such endeavors in order to prevent loopholes which would result in much human cloning not being really banned. (lifeissues.net)
  • Homo sapiens programmed cell death 1 (PDCD1), mRNA. (origene.com)
  • Unlike some movies, cloning in real life doesn't produce a full grown exact replica of someone. (bartleby.com)
  • Th2 cells produce cy- patients which might reduce the morbidity tokine interleukins IL-4 and IL-10, which and mortality due to infection. (who.int)
  • The autoimmune nature of diabetes and inflammatory cytokine IL-10 (as markers the major contribution of lymphocyte T- of inflammatory changes) and the soluble cells are well established. (who.int)
  • In eukaryotes, DNA polymerase δ (Pol δ) bound to the proliferating cell nuclear antigen (PCNA) replicates the lagging strand and cooperates with flap endonuclease 1 (FEN1) to process the Okazaki fragments for their ligation. (nature.com)
  • Cloning is a natural form of reproduction that has allowed life forms to spread for hundreds of millions of years. (wikipedia.org)