Form 943 2015: Fill & Download for Free

This question has been asked many times before.Here is the summary of my much longer answer posted elsewhere:In summary, the first attack was by the Muslims against the heartland and birthplace of Christianity, Jerusalem, in 638. The attacks against Christian territory and people continued for more than four hundred years, before the first crusade was launched. Furthermore, throughout the four hundred years between the fall of Jerusalem in 638 and the First Crusade in 1095, Christendom had been fighting perpetually -- and often desperately -- for its very survival. The First Crusade was not a "late" response to the fall of Jerusalem, but rather the first successful attempt to retake the city of Christ's passion that had never, for a single day, been forgotten by Christendom.For the full text of my previous answer giving the exact dates of the various campaigns see: Helena Schrader's answer to Who attacked first to start the Crusades? Christians or Muslims?EDIT: Due to Mr. Crawley’s comment (that I am “completely false”) I provide the detailed facts supporting my summary.Jerusalem fell to invading Muslim forces in 638 AD. It was conquered by force of arms, not by gentle persuasion and enlightened preaching (as some modern commentators suggest) after a year long siege. It would be 1099 AD or 461 years before it was returned to Christian hands. That over four hundred year gap between the Muslim conquest and the Christian liberation has led many to argue that 1) Christianity didn't really care all that much about Jerusalem, 2) after so much time it has become a Muslim city, and so 3) the First Crusade was not defensive or liberating but rather offensive and aggressive. It is, therefore, worthwhile to look at that "461 year gap" and see what happened between the Muslim conquest and the Christian re-conquest of Jerusalem.For the next three hundred years, Islam continued to expand -- by the sword. Indeed, within the next fifteen years alone Syria, Persia, Anatolia, Egypt and Libya fell. These losses crippled the economy of the Eastern Roman Empire, and in 655 the Byzantine navy was also effectively destroyed in a major engagement that left Constantinople incapable of providing support to the far-flung outposts of the Eastern Empire.The following year, however, the Shia-Sunni split led to the first civil war within the Dar al-Islam (the House of Islam) lasting from 656-661. At roughly the same time, Arab invaders encountered serious resistance from the Berbers in North Africa.By 678, however, the forces of Islam were again so powerful that they launched an assault on Constantinople itself. The Byzantines fought off the assault with the aid of their massive walls and the use of a new weapon which became known as "Greek fire" - a napalm-based substance that was delivered in pottery vessels that broke on impact resulting in fires that could not be extinguished by water. The attacking Arabs suffered such severe losses that they agreed to a thirty year truce in the wake of defeat. Constantinople was temporarily saved, but the Eastern Roman Empire was in no position to defend its remaining Mediterranean territories, much less undertake an offensive to regain what had been lost. In 698, the mighty (Christian) city of Carthage fell to the advancing Muslim forces and by 700 Islam was ready to turn its violent tactics of "conversion" on Western Europe.Attacks on Sicily and Sardinia are recorded as early as 704 and Corsica fell in 713. More important, of course, the invasion of the Iberian peninsula began in 711. By 720 the Muslims had forced the Christian defenders into the mountains of the northwest and, dismissing them as a no longer viable fighting force, crossed the Pyrenees to start subjecting the land of the Franks.In 732, outside of Tours, a Frankish army decisively defeated the invading Muslims in a desperate defensive battle. The Franks furthermore continued fighting the invaders, finally driving them back across the Pyrenees a generation later in 769. By 795 Charlemange had taken his forces over the Pyranees to assist the Spanish Christians in regaining their territories as well. The Reconquista had begun. In short, in the 8th century Western Christians joined Eastern Christians in opposing the brutal invasions conducted against them in the name of Islam.Meanwhile, Constantinople was still fighting for its very survival. In 717 a new Muslim force by land and sea appeared outside of Constantinople and a year-long siege ensued. After a desperate fight, the capital of the Eastern Roman Empire fought off the besiegers, but it remained mired in a struggle for survival. There could be no thought of freeing something as distant as Jerusalem when Anatolia was constantly raided and plundered. It was not until 740 that the Byzantine victory at Acroinon provided the Eastern Roman Empire with a degree of security in the Anatolian heartland.The Byzantine victory at Acroinon notably coincided with a general decline in the power and strength of the Umayyad dynasty, which was also beset with problems on its eastern frontiers. This allowed the Eastern Roman Empire to at last start a "reconquista" of its own. In 746, Constantinople regained control of Syria and Armenia, but already by 781 the Byzantines were again on the defensive. For the next half century, the Byzantine Empire was locked in yet another bitter struggle in Anatolia.Meanwhile Arab rule of the conquered Christian territories from Syria to Spain was characterized by brutality, oppression and humiliation for their majority Christian subjects. (See The Myth of the Andalusian Paradise.) The small Arab elite ruled initially over populations that were overwhelmingly Christian. Due to the burdensome taxes, humiliations and oppression, however, more and more people chose to abandon their faith for the sake of economic gain. Yet conversion is a far slower process than invasion and occupation. To this day, even after 1,400 years of Muslim rule, there are significant Christian minorities in Syria, Lebanon, and Egypt. Historians estimate that after four hundred years of occupation the inhabitants of formerly Christian territories were still roughly half Christian.The plight of the oppressed Christians population (whether majority or large minority) remained, therefore a motivation for the recovery of lost territory and by the mid-9th century, the Eastern Roman Empire had recovered sufficient strength to launch a sustained "reconquista." In 853 Constantinople sent a fleet to attack Damietta in the Nile Delta. Thereafter, despite some setbacks, the Byzantines continued to regain lost territory right through the middle of the next century. In 943 they liberated Mesopotamia with its overwhelmingly Christian Armenian population. In 961 they recovered Crete and in 965 Cyprus. In 969 Antioch was at last freed from Muslim rule and Aleppo offered tribute to Constantinople to avoid a similar fate.The recovery of Jerusalem now seemed possible, and Constantinople was determined to regain this most sacred of all Christian cities. A series of campaigns were launched that systematically recovered the coast of the Levant including Beirut, Sidon, Tiberias and Nazareth. Acre and even Caesarea were returned to the Eastern Empire, but Jerusalem remained just out of reach. As the tenth century came to a close, the Byzantines lost momentum and their attempt to regain their lost territories faltered.What followed was the worst phase yet for subject Christians in Palestine. The new and powerful Shia Fatamid Caliphate pushed back their Sunni rivals and took control of Palestine, including Jerusalem. The Caliph al-Hakim, who ruled from 996-1021, persecuted Christians and Jews and destroyed what was left of the Church of the Holy Sepulcher.In the West, however, the setbacks had started sooner. In 827 the Muslim conquest of Sicily commenced and although it would take until 902 to complete it would eventually be successful. Meanwhile, in 837 a Muslim army had landed on the Italian mainland, ironically at the request of the Duke of Naples who wanted help in his squabbles with his local enemies. Throughout the rest of the century, the various Italian cities remained divided among themselves and all too ready to accept Muslim assistance, which in turn opened the doorway to Muslim mercenaries sacking, pillaging and pirating from bases in Italy. In 846 Rome itself was attacked by a Muslim raiding force and the basilica of St. Peter was looted but not destroyed.When three years later a larger Muslim fleet set out to attack Rome again, however, it was met by a combined Christian fleet that defeated it. What followed, however, was not peace but rather a long struggle for control of the Italian mainland. Indeed, the Muslims succeeded in establishing a base for raiding on the coast of Provence at La Garde-Freinet in about 888. While neither the raids from Italy or the base in Provence were comparable to the great Muslim conquests of the 7th century, they posed a menace to travel and trade and kept Western Christendom on the defense.This did not end until 915 when an alliance of Roman and Byzantine forces drove the last Muslim strongholds off the Italian mainland. For a time, however, the Muslims continued to raid the Italian coastal cities. In 934/35 Genoa was sacked, its male population massacred and the women and children carried off into slavery. Pisa beat off attacks in 1004, 1011, and 1012. Four years later, Salerno came under siege and was only rescued by a band of Normans -- notably on an armed pilgrimage to Jerusalem.It was only now, at the start of the 11th century, that the tide began to turn in favor of the Christians in the West. The Italian city states were gaining sufficient wealth to finance stronger defenses. In 1034, the Pisans launched an attack on Muslim North Africa. A generation later the Pisans again raided Muslim territory, this time Palermo in 1062 and 1063. Finally, in 1087, a combined force raised from Pisa, Genoa, Rome and Amalfi struck at the main base for many Muslim pirate attacks on Italian ships and cities: Mahdia in what is now Tunisia. The expedition was so successful that it enabled the victors to free prisoners, obtain huge reparations payments, and gain trading privileges. Most important, after the raid on Mahdia, Muslim attacks on Italy ceased almost entirely.But just as the Western Christians were gaining strength again, the Eastern Roman Empire underwent a new crisis. The Seljuk Turks had converted to Islam and with the passion of the newly converted and the skills of nomadic warriors they set about establishing their domination over Syria and then turned on Armenia, Cilicia, and the Levant, driving the Byzantines out, before striking at Anatolia. The Byzantine Emperor Romanus IV Diogenes assembled his forces and rushed to the defense of this vital heartland -- only to be decisively defeated on August 26, 1071 at the Battle of Manzikert. Shortly afterwards the embattled Byzantines started sending appeals for help to the apparently now stronger West. That aid would, a quarter century later, materialize in the form of what we have come to call the First Crusade.Furthermore, since Mr. Crawley — who despite repeated requests refused (or cannot) name a single source except wikipedia — insists I know nothing and have it all wrong, I provide below a list of selected (not comprehensive) sources on which I have built my opinion.PRIMARY SOURCESChronicle of the Third Crusade: A Translation of the Itinerarium Peregrinorum et Gesta Regis Ricardi. Crusade Texts in Translation. Translated by Helen Nicholson, Ashgate Publishing Ltd., 1997.---. The Conquest of Jerusalem and the Third Crusade: Crusade Texts in Translation. Translated by Peter W. Edbury, Ashgate Publishing Ltd., 1998.Baha al-Din ibn Shaddad. The Rare and Excellent History of Saladin. Translated by D.S. Richards, Ashgate Publishing Ltd. 2002.Gabrieli, Francesco. Arab Historians of the Crusades. University of California Press, 1969.Letters from the East: Crusaders, Pilgrims and Settlers in the 12th and 13th Centuries: Crusade Texts in Translation. Translated by Malcolm Barber and Keith Bate. Ashgate Publishing, 2013.Novare, Philip de. The Wars of Frederick II Against the Ibelins in Syria and Cyprus. Translated by John La Monte, Morningside Heights Columbia University Press, 1936.Pilgrimage to Jerusalem and the Holy Land, 1187 - 1291. Crusades Texts in Translation. Translated by Denys Pringle. Ashgate, 2012.Tyre, William Archbishop of. A History of Deeds Done Beyond the Sea. Morningside Heights Columbia University Press, 1943.SECONDARY SOURCES (Especially recommended sources are marked with a *)Allen, S.J. and Emilie Amt. The Crusades: A Reader. University of Toronto Press, 2014.Andrea, Alfred J & Andrew Holt, editors. Seven Myths of the Crusades. Hackett Publishing Co. , 2015.Barber, Malcolm. The Crusader States. Yale University Press, 2012.*---. The New Knighthood: A History of the Order of the Temple, Cambridge University Press, 1994.*Barber, Richard. The Knight and Chivalry. Boydell Press, 1970Bartlett, W. B.. Downfall of the Crusader Kingdom. The History Press Ltd, 2010.Brand, Charles M.. Byzantium Confronts the West. ACLS Humanities E-Book, 2012.*Boas, Andrian J.. Crusader Archaeology: The Material Culture of the Latin East. Routledge, 1999.* ---. Domestic Settings: Sources on Domestic Architecture and Day-to-Day Activities in the Crusader States. Brill, 2010.Conder, Claude Reignier. The Latin Kingdom of Jerusalem 1099 to 1291 AD. Committee of the Palestine Exploration Fund, 1897.*Edbury, Peter W. John of Ibelin and the Kingdom of Jerusalem. The Boydell Press, 1997.*---. The Kingdom of Cyprus and the Crusades, 1191 – 1374. Cambridge University Press, 1991.---. The Lusignan Kingdom of Cyprus and Its Muslim Neighors. Bank of Cyprus Foundation, 1993.--- and John Gordon Rowe. William of Tyre: Historian of the Latin East. Cambridge University Press, 1988.Edge, David and John Miles Paddock. Arms and Armour of the Medieval Knight. Saturn Books, 1996.Edington, Susan B. and Helen Nicholson, editors. Deeds Done Beyond the Sea: Essays on William of Tyre, Cyprus and the Military Orders Presented to Peter Edbury. Routledge, 2014.Ellenblum, Ronnie. Frankish Rural Settlement in the Latin Kingdom of Jerusalem. Cambridge University Press, 1998.Folda, Jaroslave. Crusader Art: The Art of the Crusaders in the Holy Land, 1099-1291. Ashgate Publishing, 2008.*France, John. Hattin. Oxford University Press, 2015.Ehrenkreutz, Andrew S.. Saladin. State University of New York Press, 1972.Galatariotou, Catia. The Making of a Saint: The Life, Times and Sanctification of Neophytos the Recluse. Cambridge University Press, 1991.Gillingham, John. Richard I. Yale University Press, 1999.Hamilton, Bernard. The Leper King and His Heirs: Baldwin IV and the Crusader Kingdom of Jerusalem. Cambridge University Press, 2000.---. “Women in the Crusader States: The Queens of Jerusalem 1100 – 90.” Medieval Women, edited by Derek Baker, Basil Blackwell, 1978.Hazard, Harry W., editor. A History of the Crusades, Vol. IV: The Art and Architecture of the Crusader States. Univ. of Wisconsin Press, 1977.Herzog, Annie. Die Frau auf den Fuerstenthronen der Kreuzfahrerstaaten. Emil Ebering, 1919.Hill, George. A History of Cyprus, Vol. 2: The Frankish Period. Cambridge University Press, 1948.Hopkins, Andrea. Knights: The Complete Story of the Age of Chivalry: From Historical Fact to Tales of Romance and Poetry. Collins and Brown Ltd, 1990.Jacoby, David, editor. Medieval Trade in the Eastern Mediterranean and Beyond. Routledge, 2018.---. Studies on the Crusader States and on Venetian Expansion. Routledge, 2018.Jotischky, Andrew. Crusading and the Crusader States. Pearson Longman, 2004.La Monte, John L.. Feudal Monarchy in the Latin Kingdom of Jerusalem, 1100 to 1291. Medieval Academy of America, 1932.*MacEvitt, Christopher. The Crusades and the Christian World of the East: Rough Tolerance. University of Pennsylvania Press, 2008.Marshall, Christopher. Warfare in the Latin East 1192 - 1291. Cambridge University Press, 1992.Mayer, Hans Eberhard, Kings and Lords in the Latin Kingdom of Jerusalem. Ashgate Publishing Ltd., 1994.---. Probleme des lateinischen Koenigreichs Jerusalem. Variorum Reprints, 1983.Milger, Peter. Die Kreuzzuege: Krieg im Namen Gottes. Bertelsmann, 1988.*Miller, David,.Richard the Lionheart: The Mighty Crusader. Phoenix, 2013.Miller, Timothy S. and John W. Nesbitt. Walking Corpses: Leprosy in Byzantium and the Medieval West. Cornell University Press, 2014.*Mitchell, Piers D.. Medicine in the Crusades: Warfare, Wounds and the Medieval Surgeon. Cambridge University Press, 2004.#Morgan, M.R.. The Chronicle of Ernoul and the Continuations of William of Tyre. Oxford Historical Monographs, Oxford University Press, 1973.Morton, Nicholas. The Teutonic Knights in the Holy Land, 1190-1291. Boydell, 2009Mount, Toni. Medieval Medicine. Amberley, 2015.Nicholson, The Knights Templar: A New History. Sutton Publishing, 2001.Nicolle, David. Hattin 1187: Saladin’s Greatest Victory. Osprey Military Campaign Series, 1993.Perry, Guy. John of Brienne: King of Jerusalem, Emperor of Constantinople, c. 1175-1237. Cambridge University Press, 2013.Pringle, Denys. Secular Buildings in the Crusader Kingdom of Jerusalem: An Archaeological Gazetteer. Cambridge University Press, 1997.Robinson, John J., Dungeon. Fire and Sword: The Knights Templar in the Crusades. Michael O’Mara Books, 1991.Roehricht, Reinhold. Die Geschichte des Koenigreichs Jerusalem (1100-1291). Cambridge University Press, 2004.Riley-Smith, Jonathan. The Crusades: A History. Bloomsbury Academic, 2014.--. The Feudal Nobility and the Kingdom of Jerusalem, 1174-1277. Macmillan, 1973.--. Hospitallers: The History of the Order of St. John. Hambledon Press, 1999.*Riley-Smith, Jonathan, editor. The Atlas of the Crusades. Facts on File, 1991.Runciman, Sir Steven. The Families of Outremer: The Feudal Nobility of the Crusader Kingdom of Jerusalem, 1099-1291, The Athlone Press, 1960.*Stark, Rodney. God’s Battalions: The Case for the Crusades. HarperCollins, 2010.Tyerman, Christopher. How to Plan a Crusade: Reason and Religious War in the Middle Ages. Allen Lane, 2015.Zacour, Norman P. and Harry W. Hazard, A History of the Crusades Volume Five: The Impact of the Crusades on the Near East. Wisconsin University Press, 1985.

Here are some ways to imagine a billion dollars...1. Compared to annual wagesThis is a chart with the top 10 nations with the highest average annual wage in the world:Source: Where are workers earning the most?$1,000,000,000 is 16-21 thousand times each of these. If they remained stable, someone would make a billion dollars if they spent nothing and worked for 16-21 thousand years.Country | Highest average wage | SalariesLuxembourg | $61,511 | 16,257USA | $57,139 | 17,501Switzerland | $57,082 | 17,519Ireland | $53,286 | 18,767Norway | $51,718 | 19,336Australia | $51,148 | 19,551Netherlands | $51,003 | 19,607Denmark | $49,589 | 20,166Canada | $48,164 | 20,762Belgium | $48,093 | 20,7932. Buying the most expensive carsThese are the top 3 most expensive cars in the world. You could buy approximately:222 x Lamborghini Veneno worth $4.5 MillionOR208 x Koenigsegg CCXR Trevita worth$4.8 MillionOR125 x Maybach Exelero worth $8 Million3. Buying private islandsYou could buy about 10 of the most expensive private islands such asPumpkin Key in Florida, US: $110,000,000ORIsla del Venado in Mazatlan, Mexico: $100,000,000ORRangyai Island in Thailand, Asia: $160,000,0004. Buying tech companiesYou could have boughtInstagram in 2012Relying solely on word of mouth to spread the word, the app reached more than 100 million users by April 2012. In that same month, Facebook purchased Instagram, along with its 13 employees, for $1 billion in cash and stocks.ORSpotify in 2011In 2011, Spotify raised $100 million from Russian investment firm DST Global and venture-capital firm Kleiner Perkins Caufield & Byers. At that time, the company was valued at a cool $1 billion.OR2/3 of YouTube in 2006In November 2006, Google bought YouTube for $1.65 billion, and the site now operates as Google’s subsidiary.5. Buying football teamsYou could buy eitherLiverpool - Team value: $982 mil.ORJuventus - Team value: $837 mil.ORAC Milan - Team value: $775 mil.(and have some spare cash left)6. Buying materialsYou could buy15.4kg of 1-carat diamondsCost: A colorless, 1-carat can cost more than $65,000 per gram, or $13,000 per caratOR250kg of plutoniumCost: Roughly $4,000 per gramOR333.3kg of crystal LSDCost: The crystal form of LSD costs about $3,000 per gran6. Comparing to other billionairesYou could be worth as much asThe American businesswoman and founder of Spanx Sara BlakelyORThe American Fashion Designer Tory BurchORThe Indian businessman Sidhart BurmanOR YOU COULD SIMPLY BUY QUORA!!Net Worth: $600-$943 MillionLinks:Top Ten Most Expensive Cars In The World 2015-2016Islands For SaleReal Madrid Tops Ranking Of The World's Most Valuable Soccer Teams10 Tech Companies That Are Worth A Billion Dollars19 Of The Most Expensive Substances In The WorldThe Forbes World's Billionaires list is the definitive list of the world's wealthiest people, profiling and ranking billionaires from 70 countries by their estimated net worth.Quora Net Worth - ISFeedFacebook billionaires dominate '40 richest under 40' listThanks for the A2A.

Could epigenetic changes in parents predispose children to allergies? Recent studies suggest it's possible. Suggest not prove. Best studied example is for increased risk of asthma in children and grandchildren of smokers, especially mothers and grandmothers who smoked when pregnant. While smoking is a different trigger from childhood allergies, the common thread is whether or not such different triggers induce epigenetic changes that are stably transmitted to the germ cells/gametes (egg and sperm). Chicken-and-egg question w.r.t. epigenetic changes associated with allergies: Do such changes drive the pathology or are they responses to it? This is as yet unresolved.In this answer, let's briefly examineWhat are epigenetic changes and how they differ from genetic changes.Data that suggest heritable epigenetic changes could predispose to allergies.What's the connection between heritable epigenetic changes and allergies?How heritable epigenetic changes influence children's chances of allergies.What are epigenetic changes and how they differ from genetic changesEpigenetic means not in the classical Mendelian definition of DNA sequence changes but rather reversible but stable, heritable alterations in their genetic architecture (1), in this case during the period parents had allergies.The most relevant epigenetic changesInclude DNA methylation, hydroxyl methylation, chromatin remodeling, expression of non-coding RNAs.In DNA methylation, methyl (CH3) groups bind to cytosine residues adjacent to guanine residues (called CpG sites). This results in 5-methylcytosine and leads to gene silencing.While many CpG sites in the genome are already methylated, there are CpG islands, i.e., clusters of CpG-rich sites, in many gene promoters, and in locus control and initial exon regions.Triggers that drive epigenetic changes relevant to allergies include nutrition, smoking, stress or more accurately distress. As Marshall defines, 'Stress is a term often used to connote an adverse situation. Yet our use of the term stress derives from an engineering term that is used to reflect the impact of a situation (often called a stressor) on host homeostasis. It is best thought of as a psychophysiological process that is a product of both the appraisal of a given situation (either acutely or chronically over time) and the ability to cope with that situation. If the situation threatens harm, loss, or danger and/or the host-coping ability is deemed inadequate, the stress is termed distress. Most common uses of the term stress actually mean distress' (2).The most relevant inheritable epigenetic changes are those in germ cells/gametes, i.e., sperms and eggs.Data that suggest heritable epigenetic changes could predispose to allergiesMany epidemiological studies (3, 4, 5, 6, 7) show that mothers who smoked when pregnant had children predisposed to low birth weight, sudden unexplained death in infancy, asthma, low lung function and increased respiratory symptoms in infancy.Caveat of these studies is that children born to mothers who smoke are exposed to smoke after birth as well. Separating effects of prenatal and postnatal smoking exposure is impossible.Mothers' second-hand smoke exposure also increased children's asthma risk in at least one study (8).Rat asthma models suggest epigenetic changes can be transmitted not only to children but also to grandchildren (9).Grandchildren of grandmothers who smoked when pregnant had increased risk of asthma even when the mother herself didn't smoke when pregnant (10).Prospective study of 100000 women and their children.Questionnaires included information on grandmothers' smoking habits.In effect, mothers' attributes stood as proxies for grandmothers.Recall bias is a weakness of study.Effect of grandmother smoking when pregnant was as strong as mother alone smoking when pregnant.What's the connection between heritable epigenetic changes and allergies?Tobacco smoking is associated with changes in DNA methylation at several sites across the genome (11).DNA derived from cord blood of infants whose mothers smoked when pregnant also showed differential methylation of similar CpG sites (12).In one study, the ALOX12 (arachidonate 12-lipoxygenase) gene was hypomethylated in children with persistent early childhood wheezing (13). Hypomethylation means relatively unfettered gene expression, in this case of the ALOX12 gene.Hypomethylation was present in DNA collected at birth and at 4 years of age.Hypomethylation correlated with maternal exposure to a persistent organic pollutant, dichlorodiphenyldichloroethylene (DDE), a metabolite of the pesticide DDT.Maternal exposure was assessed by measuring pollutant levels in serum in early pregnancy.ALOX12 encodes the 12-LOX enzyme involved in arachidonic acid metabolism. It leads to inflammatory molecules that may be involved in chronic airway inflammation and remodeling seen in asthma.How heritable epigenetic changes influence children's chances of allergiesIn order for parental epigenetic changes to be heritable, theyShould be in germ cells.Should escape the inevitable germ cell reprogramming during development (14, 15; see figure below from 15).This reprogramming removes epigenetic signatures acquired during life.Occurs in both germline (egg and sperm) and zygote.Thus, chances of epigenetic inheritance are quite low except in 'imprinted loci resistant to postzygotic reprogramming' (16).miRNAs or microRNAs are noncoding RNAs that fold back on themselves forming hair-pin structures (17).Binding to protein-coding mRNAs (messenger RNAs), they regulate post-transcriptional gene expression, mainly through repression.Human sperm contain >100 miRNAs (18).miRNAs have been shown to be a vehicle for heritable epigenetic changes.Comparison of smokers versus non-smokersIn one study, 28 known human miRNAs were significantly differentially expressed between sperm of smokers and non-smokers (19).10 of these 28 MiRNAs are known to be involved in pathways essential for healthy sperm and normal embryo development.In addition these altered miRNAs target as many as 25 other epigenetic pathways such as a variety of DNA and histone modification pathways.This suggests a potential mechanism by which miRNA expression altered by environmental exposure in one generation could be agents of phenotypic change in future generations.BibliographyDeans, Carrie, and Keith A. Maggert. "What Do You Mean,“Epigenetic”?." Genetics 199.4 (2015): 887-896. Page on researchgate.netMarshall, Gailen D. "Neuroendocrine mechanisms of immune dysregulation: applications to allergy and asthma." Annals of Allergy, Asthma & Immunology 93.2 (2004): S11-S17.Stick, Stephen M., et al. "Effects of maternal smoking during pregnancy and a family history of asthma on respiratory function in newborn infants." The Lancet 348.9034 (1996): 1060-1064. Page on rainestudy.org.auDezateux, C., et al. "Impaired airway function and wheezing in infancy: the influence of maternal smoking and a genetic predisposition to asthma." American journal of respiratory and critical care medicine 159.2 (1999): 403-410. Page on atsjournals.orgNeuman, Åsa, et al. "Maternal smoking in pregnancy and asthma in preschool children: a pooled analysis of eight birth cohorts." American journal of respiratory and critical care medicine 186.10 (2012): 1037-1043. Page on atsjournals.orgHollams, Elysia M., et al. "Persistent effects of maternal smoking during pregnancy on lung function and asthma in adolescents." American journal of respiratory and critical care medicine 189.4 (2014): 401-407. Page on atsjournals.orgWerhmeister, F. C., et al. "Intrauterine exposure to smoking and wheezing in adolescence: the 1993 Pelotas Birth Cohort." Journal of developmental origins of health and disease 6.03 (2015): 217-224. Page on researchgate.netSimons, Elinor, et al. "Maternal second-hand smoke exposure in pregnancy is associated with childhood asthma development." The Journal of Allergy and Clinical Immunology: In Practice 2.2 (2014): 201-207.Rehan, Virender K., et al. "Perinatal nicotine-induced transgenerational asthma." American Journal of Physiology-Lung Cellular and Molecular Physiology 305.7 (2013): L501-L507. Page on physiology.orgMagnus, Maria C., et al. "Grandmother's smoking when pregnant with the mother and asthma in the grandchild: the Norwegian Mother and Child Cohort Study." Thorax 70.3 (2015): 237-243. Page on bmj.comBreitling, Lutz P., et al. "Tobacco-smoking-related differential DNA methylation: 27K discovery and replication." The American Journal of Human Genetics 88.4 (2011): 450-457. Page on els-cdn.comJoubert, Bonnie R. "450K Epigenome-Wide Scan Identifies Differential DNA Methylation in Newborns Related to Maternal Smoking During Pregnancy (vol 120, pg 1425, 2012)." ENVIRONMENTAL HEALTH PERSPECTIVES 120.12 (2012): A455-A455. Page on nih.govMorales, Eva, et al. "DNA hypomethylation at ALOX12 is associated with persistent wheezing in childhood." American journal of respiratory and critical care medicine 185.9 (2012): 937-943. Page on atsjournals.orgHeard, Edith, and Robert A. Martienssen. "Transgenerational epigenetic inheritance: myths and mechanisms." Cell 157.1 (2014): 95-109. Page on els-cdn.comSharma, Abhay. "Transgenerational epigenetic inheritance requires a much deeper analysis." Trends in molecular medicine 21.5 (2015): 269-270.Henderson, A. John. "The sins of the mothers: does grandmaternal smoking influence the risk of asthma in children?." Thorax 70.3 (2015): 207-208.Maccani, Matthew Alan, and Valerie S. Knopik. "Cigarette smoke exposure-associated alterations to non-coding RNA." Frontiers in genetics 3 (2012): 53.Krauss-Etschmann, Susanne, et al. "Clinical Epigenetics." (2015). Page on biomedcentral.comMarczylo, Emma L., et al. "Smoking induces differential miRNA expression in human spermatozoa: a potential transgenerational epigenetic concern?." Epigenetics 7.5 (2012): 432-439. Page on tandfonline.com