Question: Ole and Lena are central characters in jokes by which specific portion of  Americans, in the broad sense?

Context articles: Horse breed
Rational addiction
Retinylidene protein
Yandang Mountains
Advanced maternal age
History of creationism
List of musicology topics
Seat (legal entity)
Ole and Lena
Scandinavian Americans

A horse breed is a selectively bred population of domesticated horses, often with pedigrees recorded in a breed registry.
 However, the term is sometimes used in a very broad sense to define landrace animals, or naturally selected horses of a common phenotype located within a limited geographic region.
 Depending on definition, hundreds of "breeds" exist today, developed for many different uses.
 Horse breeds are loosely divided into three categories based on general temperament: spirited "hot bloods" with speed and endurance; "cold bloods," such as draft horses and some ponies, suitable for slow, heavy work; and "warmbloods," developed from crosses between hot bloods and cold bloods, often focusing on creating breeds for specific riding purposes, particularly in Europe.
Rational addiction is the hypothesis that addictions can be usefully modeled as specific kinds of rational, forward-looking, optimal consumption plans.
 The canonical theory comes from work done by Kevin M. Murphy and Gary S. Becker.
 A theory of addictions in the broad sense—for example, to heroin, tobacco, religion, or food—the article tried to reconcile addictions with the standard rational choice framework of modern economics.
Retinylidene protein, is a family of proteins that use retinal as a chromophore for light reception.
 It is the molecular basis for a variety of light-sensing systems from phototaxis in flagellates to eyesight in animals. Retinylidene proteins include all forms of opsin and rhodopsin (in the broad sense).
 While rhodopsin in the narrow sense refers to a dim-light visual pigment found in vertebrates, usually on rod cells, "rhodopsin" in the broad sense (as used here) refers any molecule consisting of an opsin and a retinal chromophore in the ground state.
 When activated by light, the chromophore is isomerized, at which point the molecule as a whole is no longer rhodopsin, but a related molecule such as metarhodopsin.
 However, it remains a retinylidene protein.
 The chromophore then separates from the opsin, at which point the bare opsin is a retinylidene protein.
 Thus, the molecule remains a retinylidene protein throughout the phototransduction cycle.
Yandang Mountains or Yandangshan (Chinese:  雁蕩山 ,  雁荡山 ,  "Yàndàng Shān",  "Wild Goose Pond Mountain(s)") refers, in the broad sense, to a coastal mountain range in southeastern Zhejiang province in eastern China, covering much of the prefecture-level city of Wenzhou (from Pingyang County in the south to Yueqing County in the northeast) and extending to the county-level city of Wenling in Taizhou prefecture.
 The mountain range is divided in two by the Oujiang River, the two parts being the North Yandang and South Yandang.
 More narrowly, Yandangshan is also used more narrowly to refer to Mount Yandang , a specific part of the North Yandang around an ancient caldera near a small town of the same name (雁荡镇 , "Yàndàng Zhèn").
 The highest peaks of North Yandang are located here, and this is also the main tourist spot.
 In this article, name "Yandang Mountains" is used to refer the mountain range and "Mt. Yandang" to refer to the caldera.
Advanced maternal age, in a broad sense, is the instance of a woman being of an older age at a stage of reproduction, although there are various definitions of specific age and stage of reproduction.
The history of creationism relates to the history of thought based on the premise that the natural universe had a beginning, and came into being supernaturally.
 The term "creationism" in its broad sense covers a wide range of views and interpretations, and was not in common use before the late 19th century.
 Throughout recorded history, many people have viewed the universe as a created entity.
 Many ancient historical accounts from around the world refer to or imply a creation of the earth and universe.
 Although specific historical understandings of creationism have used varying degrees of empirical, spiritual and/or philosophical investigations, they are all based on the view that the universe was created.
 The Genesis creation narrative has provided a basic framework for Jewish and Christian epistemological understandings of how the universe came into being - through the divine intervention of the god, Yahweh.
 Historically, literal interpretations of this narrative were more dominant than allegorical ones.
This is a list of musicology topics.
 Musicology is the scholarly study of music.
 A person who studies music is a musicologist.
 The word is used in narrow, intermediate and broad senses.
 In the narrow sense, musicology is confined to the music history of Western culture.
 In the intermediate sense, it includes all relevant cultures and a range of musical forms, styles, genres and traditions, but tends to be confined to the humanities - a combination of historical musicology, ethnomusicology, and the humanities of systematic musicology (philosophy, theoretical sociology, aesthetics).
 In the broad sense, it includes all musically relevant disciplines (both humanities and sciences) and all manifestations of music in all cultures, so it also includes all of systematic musicology (including psychology, biology, and computing).
In legal English, the seat of a corporation or organisation, as a legal entity, is the location of its headquarters.
<ref name="T1012/03"> Decision T 1012/03 of December 1, 2006 of the Boards of Appeal of the European Patent Office, Reasons 27.
</ref> According to international and national procedural law, "specific legal actions with legal effect for and against the legal entity can be performed at the seat of this entity."
 However, "the term 'seat' is sometimes also used in a broad sense without a specific legal meaning.
 In this case [it] only defines where an entity is located and does not mean that this location is a legal seat where specific juridical acts can be performed."
Ole and Lena (also Sven and Ole) are central characters in jokes by Scandinavian Americans, particularly in the Upper Midwest region of the U.S., particularly in Minnesota, Wisconsin, Iowa, South Dakota and North Dakota where Scandinavian immigrant traditions are common.
Scandinavian Americans or Nordic Americans are Americans of Scandinavian (in the broad sense), or part-Scandinavian ancestry, defined in this article to include Danish Americans (estimate: 1,453,897), Faroese Americans (no estimates), Finnish Americans (estimate: 677,272), Greenlandic Americans (estimate: 352), Icelandic Americans (estimate: 51,234), Norwegian Americans (estimate: 4,602,337), Sami Americans (estimate: 30,000), Swedish Americans (estimate: 4,293,208).
 Also included are persons who reported 'Northern European' ancestry (estimate: 230,027) or 'Scandinavian' ancestry (estimate: 582,549).
 According to 2010 census data, there are approximately 11,890,524 people of Scandinavian ancestry in the United States.