Artículos de revistas sobre el tema "Genetique of population"

SUMMARYThe authors presented in this article a well documented review of the local cattle, sheep and goat populations in relation to the possibility of conservation planning. While the zebu and zebulike cattle populations are in the majority, it is possibly the Bos taurus populations that are of particular interest as they represent only about 1 % of the cattle population but are reputed to be trypanotolerant. Sheep and goats are kept in small family units (approximately 5 animals) mainly for slaughter purposes on special occasions (national and religious feasts) and for cash flow purposes. A short presentation of the prevailing local breed selection schemes and the introduction of non-indigenous genetic material, mainly for cross breeding purposes are also given.

RESUMELes ressources génétiques caprines (Capra hircus L.) d'Algérie n'ont pas fait l'objet d'une attention particulière comparativement au reste des populations de l'espèce du Bassin méditerranéen. En témoigne la méconnaissance de leur degré d'appartenance à l'une des trois catégories de la classification évolutive des animaux de ferme qui comprend espèce sauvage, population primaire - initialement population traditionnelle - et race standardisée. Des données relatives à la variabilité génétique de douze loci à effets visibles sont considérées pour caractériser les populations caprines des Monts Dahra et Aurès. Ces travaux se basent sur l'emploi de deux indices récemment introduits: l'indice de primarité loci en ségrégation (IPs) et l'indice de primarité allèles au locus Agouti (IPa). Les résultats obtenus plaident en faveur de l'appartenance de ces populations à la catégorie de population primaire.

AbstractThree species of the stygobitic isopod genus Stenasellus have been described from Italy: Stenasellus racovitzai, S. nuragicus, and S. assorgiai. Recent electrophoretic data suggest the presence of more than one species in the "racovitzai"-group. In order to clarify the degree of genetic variability and the evolutionary trends in the "racovitzai-group, we have analysed three natural populations currently known from Italy and Corsica, by the Random Amplified Polymorphic DNA (RAPD)" technique. RAPD has proven to be a rapid and valid method for the detection of intra and interspecific genetic polymorphism in Crustacea and to be suitable for the analysis of DNA of preserved samples. This technique was carried out to generate RAPD fingerprints from the populations of the five localities. The molecular data obtained by RAPD markers confirm previously obtained morphological and electrophoretic results. Trois especes du genre d'Isopodes stygobie Stenasellus ont ete decrite d'Italie: Stenasellus racovitzai, S. nuragicus et S. assorgiai. De recentes donnees electrophoretiques suggerent la presence de plus d'une espece dans le groupe "racovitzai. Afin de clarifier le degre de variabilite genetique et la tendance evolutionnaire dans ce groupe, nous avons analyse trois populations naturelles couramment connues d'Italie et de Corse par la technique "Random Amplified Polymorphic DNA (RAPD)". Cette technique s'est revelee une methode rapide et valable de detection du polymorphisme genetique intra- et interspecifique chez les Crustaces, et appropriee a l'analyse de DNA des echantillons conserves. Cette technique a ete effectuee pour produire les empreintes RAPD des populations des cinq localites. Les donnees moleculaires obtenues par les marqueurs RAPD confirment les resultats morphologiques et electrophoretiques precedemment obtenus.

Hearing loss is a major public health problem, with an incidence of about 1 in 1,000 newborns. The causes which determine the loss of hearing are multiple and can be of genetic or non-genetic causes. Among child hearing loss, 50% are caused by genetic causes. A significant importance is given to the GJB2 (connexin 26) gene which is responsible for more than half of causes of hearing loss determined by genetic factors. The authors expose an overview of the main significant genetic factors for the hearing loss at pediatric population.

SUMMARYAcanthocephaloides geneticus sp.nov. is described from Arnoglossus laterna (Bothidae) from the Mediterranean littoral (Sète-France). The new species most closely resembles Acanthocephaloides propinquus (Dujardin, 1845) Meyer, 1932, whose type host is Gobius niger (Gobiidae). A genetic comparison of the parasites collected from these two Teleostean fishes has confirmed the value of morphological differences which seemed too slight to raise the populations to species status.

RESUMELe Burkina Faso, avec plus de 11 millions de petits ruminants et près de 4 millions de bovins 2 (MAE, 1990) pour un territoire essentiellement sahélien de 274 00 km, est un pays exportateur de bétail. On estime la contribution des produits du bétail à 27% de la valeur de l'ensemble des produits agricoles. L'élevage occupe donc une place de choix dans les activités de la population. Avec le dernier recensement de 1989 (MAE, 1990), on connaît à peu prèsles effectifs du cheptel; cependant, on peut estimer que peu de travaux ont porté sur la description des races locales. Ces travaux sont surtout ceux de Doutressoulle (1947), Dumas et Raymond (1975), et Bourzat (1979).Les données présentées ici proviennent donc essentiellement des sources suscitées; pour certains aspects (taux de croissance) les chiffres proviennent de la cellule statistique du Ministère Délégué aux Ressources Animales (MDCRA, 1991) et de l'Etude prospective du sous-secteur élevage (MAE, 1991).

AbstractThe talitrid amphipod Talitrus saltator has a wide distribution along European Atlantic and Mediterranean sandy shores. Previous research had estimated genetic differences among populations with iso-enzyme electrophoresis, as well as differences in behavioural adaptation related to ecological features. In this study morphometric differences among four Mediterranean (Italian coasts) and three Atlantic (Portuguese and Welsh coasts) populations were estimated, which may give information on population dynamics and adaptability to environmental constraints. The localities chosen differed with regard to the following characteristics: sheltered/exposed shorelines, tidal/non-tidal shores, presence/absence of detritus, Atlantic/Mediterranean climate, high/low human frequentation. Samples of each population were collected in a standardized way and fresh individuals were weighed, their body lengths and eye diameters were measured, and the number of eggs in the female brood-pouches and the articles of each antenna were counted. The results were as follows: (i) an unbalanced sex ratio in each population studied, females being more abundant than males; (ii) significant differences between Mediterranean and Atlantic population groups as to weight and body length distributions, the Atlantic talitrids being larger than the Mediterranean ones; (iii) differences in eye colour, normally black in this species, but one Mediterranean and two Atlantic populations presented a certain proportion of blue-eyed individuals; (iv) right-left asymmetry of eye surface areas (right eye bigger than left one) in all populations, with one exception. The differences found among populations do not seem to follow a geographic cline, but could depend on ecological features of the localities. L'amphipode talitride Talitrus saltator a une large distribution le long des cotes sableuses de l'Atlantique europeen et de la Mediterranee. Des recherches anterieures ont evalue les differences genetiques parmi les populations par electrophorese iso-enzymatique, ainsi que les differences de comportement adaptatif en relation avec les facteurs de l'environnement. Dans cette etude, les differences morphometriques parmi quatre populations mediterraneennes (cotes italiennes) et trois populations atlantiques (cotes portugaises et galoises) ont ete evaluees, ce qui peut donner des informations sur les dynamiques de population et sur l'adaptabilite aux contraintes de l'environnement. Les localites choisies different en ce qui concerne les caracteristiques suivantes: lignes cotieres abritees/exposees, cotes a maree ou non, presence/absence de detritus, climat atlantique/mediterraneen, haute/basse frequentation humaine. Les echantillons de chaque population ont ete preleves suivant un meme standard et les individus frais ont ete peses, la longueur du corps et le diametre de l'oeil mesures, le nombre d'oeufs dans la poche incubatrice et les articles de chaque antenne comptes. Les resultats ont ete les suivants: (i) une sex ratio non equilibree dans toutes les populations etudiees, les femelles etant plus nombreuses que les males; (ii) des differences significatives entre les groupes de populations atlantiques et mediterraneens, quant a la distribution des poids et des longueurs du corps, les individus atlantiques etant plus grands que les mediterraneens; (iii) des differences dans la couleur de l'oeil, normalement noir chez cette espece, mais une population de l'Atlantique et deux de Mediterranee presentaient une certaine proportion d'individus a yeux bleus; (iv) une asymetrie droite-gauche de la surface de l'oeil (oeil droit plus gros que le gauche) dans toutes les populations, avec une exception. Les differences observees entre les populations ne semblent pas suivre un gradient geographique, mais pourraient dependre des caracteristiques ecologiques des localites.

RESUMECet article analyse dans quelle mesure les nouvelles perspectives offertes par les biotechnologies de la reproduction s'appliquent aux activités de conservation des ressources génétiques animales. Ces activités ont été regroupées autour de cinq thémes: Décrire, Détruire, Défendre, Stocker, Recréer. Ces techniques n'apportent aucun plus pour la description des caractéristiques d'une population ou d'une race. La principals menace qui pése sur une race d'animaux domestiques est de disparaitre par croisement avec une autre, et l'insémination artificielle représente de ce point de vue un danger certain. Inversement, l'insémination artificielle peut devenir un instrument de défense des races locales. II serait plus difficile de trouver une justification A l'utilisation de la plupart des autres biotechnologies (transfert d'embryons, sexage, clonage) pour la protection et la promotion des races locales. Pour la conservation des ressources génétiques, la cryoconservation des spermatozdides et des embryons, mais également les ovocytes, voire des morceaux de gonades et des cellules somatiques est un outil irremplagable. La demiére partie présente des calculs sur les possibilités de re-création de races, selon la nature du matériel stocks.

Depuis plusieurs decennies dans les pays saheliens, la production pastorale s’oriente de facon croissante vers le marche en vue de contribuer a la securite alimentaire tout en offrant aux eleveurs des moyens d’existence durable. Au Mali, des strategies de valorisation du lait local ont ete initiees, avec la mise en place d’un reseau de minilaiteries et de cooperatives de producteurs qui fournissent aux consommateurs, des produits de bonne qualite et en grande quantite. Les innovations sont inscrites dans un ensemble d’activites comprenant la modernisation des infrastructures et des procedes de transformation, l’observation des regles d’hygiene et l’acces aux soins veterinaires, l’accroissement de la productivite a travers l’amelioration genetique. Ces innovations ont des effets non seulement sur les performances economiques des systemes de production mais aussi sur les relations de pouvoir entre les acteurs de la filiere laitiere. Cet article vise a montrer que l’implantation des minilaiteries a contribue a ameliorer les revenus et la qualite de vie des populations aux alentours de Bamako, mais aussi, qu’elle a conduit a une restructuration des relations entre les acteurs. Certains d’entre eux, tels que les femmes ou les bergers, eprouvent plus de difficultes qu’avant a s’inserer dans la filiere. L’innovation apparait a la fois comme le moteur et le produit des transformations sociales.

Multisystem inflammatory syndrome: genetic and clinical characteristics in middle east pediatric patients Clinical, genetic and laboratory characteristics of Middle Eastern patients with Multisystem Inflammatory Syndrome in children (MIS-C) are not yet defined, this cohort study of 45 patients affected by MIS-C, mainly of Arab and of Asian origin, allows to define the genetic contribution to this disease. In the patients analyzed, a concentration of rare and probably pathogenic genetic variants of immune-related genes was found, and a possible association between genetic results, onset of MIS-C and resistance to treatment was also scored. Significant dysregulation of inflammatory markers was found in all patients analyzed, while mucocutaneous and gastrointestinal manifestations were found in 36 patients (80%), cardiac alterations in 22 (48.9%), neurological manifestations in 14 (31.1%). Genetic alterations in immune-related genes, including TLR3, TLR6, IL22RA2, IFNB1, and IFNA6, were identified in 19 patients (42.2%), with a significant difference with the control group (29 vs 3, P = <0.001). Patients with these variants tend to have an earlier onset of disease than controls (7 patients [36.8%] with genetic variants were 3 years younger at onset than 2 patients [7.7%] without genetic variants) and more resistance to treatment (8 patients [42.1%] with genetic variants who received 2 doses of intravenous immunoglobulins, compared to 3 patients [11.5%] with no evidence of genetic variants). The results of the study suggest that rare and probably deleterious genetic variants may play a role in MIS-C. This paves the way for further studies on larger and more diverse populations to fully characterize the contribution of genetics to this novel pathological entity.

The good result of this congress (the fifth of the series), in terms of quality of papers and number of participants, proves we were on the right track when in 1974 we founded the International Society for Twin Studies, and even more proves that the interest in gemellology is increasing.I wish to thank our many colleagues who contributed to the promotion, construction and success of this field of biomedical research, and particularly Gordon Allen, Ian MacGillivray, Walter Nance, Paolo Parisi, and of course Aldur Eriksson.For my part, I would like to emphasize that going from the title “Study of Twins” given to my book in 1951 to the word gemellology placed in the title of our quarterly Acta Geneticae Medicae et Gemellologiae in 1952, I wanted to affirm: first, that the study of twins is a branch of modern genetics; second, that the study of twins represents a “logos,” that is, a subject composed of acquired concepts, of constant phenomena and specific methods of research on twins in normality, in pathology and in population. With this word, now also adopted by Professor Nance in his Presidential Address, “Introduction to Gemellology,” twin research has become an identified field of science.In order that the Amsterdam Congress may be as fruitful as the previous ones, I believe it useful to look out of the window of the future with you to see some roads which could be new frontiers of gemellology.

Abstract Merle patterning in dogs, caused by the insertion of a short interspersed element (SINE) in the genetic structure of SILV gene, is characterized by patches of diluted pigment intermingled with normal melanin. Sequencing analyses of SINE element localized in the canine SILV gene discovered a variability of the poly (A)-tail length which is responsible for the different expression of merle pattern. The SINE element with the length of poly(A)-tail between 91 - 101 nucleotides is responsible for the merle phenotype with all characters of merle pattern. On the contrary the dogs which have SINE element with the shorter length of poly(A) tail between 54-65 nucleotides are referred as cryptic merles without expresion of Merle pattern. The aim of this study was to improve molecular genetics method for the detection of cryptic allele for merle patterning in dogs. A total of 40 dogs of four breeds - Border collie, Shetland sheepdog, Australian Shepherd dog, and Chihuahua were used in this study. Canine genomic DNA was isolated from samples of whole blood and buccal cells by commercial column kit. Detection of merle (M), cryptic merle (Mc) and non-merle (m) alleles was done using M13-tailed primer protocol and two different allele-sizing methods for the verification of the electrophoresis result. In the analyzed population of dogs were detected 20 dogs with non-merle genotype mm, 17 dogs with merle genotype Mm, 2 dogs with double merle genotype MM and one dog with merle phenotype but with the presence of cryptic merle allele Mc with the consequential genotype MMc.

Актуальность: Ограниченный репродуктивный потенциал у человека и прогрессирующее ухудшение репродуктивного здоровья населения стали причиной развития вспомогательных репродуктивных технологий в последние десятилетия. С целью повышения вероятности имплантации бластоцисты, снижения частоты спонтанных абортов у семейных пар, которые имеют проблемы репродукции, в клиническую практику был введен преимплантационный генетический скрининг (ПГС). Культивирование эмбрионов человека in vitro в циклах экстракорпорального оплодотворении (ЭКО), а также возможность получения генетического материала при проведении ПГС позволяют оценить частоту и спектр хромосомных нарушений в бластоцистах человека. Цель: Анализ частоты и спектра числовых хромосомных аномалий в бластоцистах, полученных в рамках циклов ЭКО-ПГС. Материалы и методы. Проведен ретроспективный анализ молекулярных кариотипов 113 бластоцист, полученных в рамках циклов ЭКО-ПГС от 47 женщин. Полногеномная амплификация (ПГА) ДНК из клеток трофэктодермы проводилась с использованием набора реактивов PicoPlex (Rubicon Genomics, США). Анализ образцов ДНК, полученных после ПГА, был проведен методом микроматричной сравнительной геномной гибридизации (aCGH) с использованием микрочипа GenetiSure Pre-Screen, 8×60K (Agilent Technologies, США). Результаты: Эффективность ПГА составила 97,3% (110/113). Сбалансированный кариотип был установлен в 31% (34/110) бластоцист. Частота бластоцист с хромосомным дисбалансом в группе женщин моложе 35 лет оказалась значимо ниже (46,9 %) по сравнению с частотой бластоцист с хромосомным дисбалансом в группе женщин старше 35 лет (81,0 %) (р < 0,001). Хромосомные аномалии были представлены анеуплоидиями (74 %), в 26 % - структурными нарушениями хромосом. Распределение анеуплоидий имело следующую структуру: трисомии аутосом составили 41 %, моносомии аутосом - 48 %, анеуплоидии половых хромосом - 7%, тетрасомии аутосом - 3 %, нуллисомии аутосом - 1 %. Наиболее часто отмечались анеуплоидии хромосом 5, 15, 16, 17, 19, 21 и 22. Выводы: Анализ хромосомных аберраций в бластоцистах продемонстрировал высокую частоту хромосомного дисбаланса (69%) и широкий спектр как числовых, так и структурных нарушений хромосом. ПГС методом aCGH позволяет отобрать бластоцисты со сбалансированным набором хромосом. По результатам переносов бластоцист в циклах ЭКО-ПГС клиническая беременность наступила в 32% случаев. Introduction: Limited reproductive potential in humans and the progressive decline of the reproductive health of the population have led to the development of assisted reproductive technologies in recent decades. In order to improve pregnancy rates in couples with reproduction problems, preimplantation genetic screening was introduced into clinical practice. Cultivation of human embryos in vitro in in vitro fertilization cycles (IVF), as well as the possibility of obtaining genetic material during preimplantation genetic screening and diagnosis (PGS / PGD), allow us to estimate the frequency and spectrum of chromosomal abnormalities in human blastocysts. Aim: Analysis of the rate and spectrum of aneuploidies in human blastocysts obtained in the IVF-PGD cycles. Material and methods: A retrospective analysis of the molecular karyotypes of 113 blastocysts obtained in the cycles of assisted reproductive technology IVF-PGD from 47 women was carried out. The whole genomic amplification of DNA from trophectoderm cells was performed using the PicoPlex reagent kit (Rubicon Genomics, USA). Analysis of DNA samples obtained after whole genome amplification was carried out by array comparative genomic hybridization (aCGH) using a GenetiSure Pre-Screen microchip, 8×60K (Agilent Technologies, USA). Results: The efficiency of whole genome amplification was 97.3% (110/113). A balanced karyotype was established in 31% (34/110) blastocysts. The rate of a blastocyst with chromosomal imbalance in the group of women under 35 years old was lower (46.9%) compared to the rate of blastocyst with chromosomal imbalance in the group of women over 35 years old (81.0%) (p < 0.001). 74% of the identified chromosomal abnormalities were aneuploidy, 26% - structural chromosomal abberations. The distribution of aneuploidies had the following structure: autosomal trisomies (41%), autosomal monosomies (48%), aneuploidies of sex chromosomes (7%), autosomal tetrasomies (3%), autosomal nullisomies (1%). Aneuploidies of chromosomes 5, 15, 16, 17, 19, 21 and 22 were noted with the greatest frequency. Conclusions: Analysis of chromosomal aberrations in human embryos at the blastocyst stage showed a high frequency of chromosomal imbalance (69%) and a wide range of both numerical and structural abnormalities of chromosomes. PGS with aCGH allows the selection of blastocysts with a balanced karyotype. According to the results of blastocyst transfers in IVF-PGD cycles, clinical pregnancy occurred in 32 % of cases.

The classification and colonization of reindeer and caribou (Rangifer tarandus) was assessed from analysis of both proteins, nuclear DNA and mitochondrial DNA. I demonstrate that the current subspecies designations are not compatible with the differentiation at these markers, suggesting that the morphological differences among extant subspecies did not evolve in separate glacial refugia. Thus, morphological differences among extant subspecies probably evolved as adaptive responses to post-glacial environmental changes. An exception to this is the North American woodland caribou, where all three marker systems support a subspecies-specific refugium as the ancestral origin of these animals. Three major mtDNA haplogroups reported, represent three separate origins of the species during the last glaciation. The most influential origin has contributed to the gene pool of all extant subspecies, suggesting the existence of a large and continuous glacial population ranging across extensive areas of tundra in Eurasia and Beringia. The North American tundra forms (R.t. granti and groenlandicus) and the arctic forms (R.t platyrhynchus, R.t pearyi and R.t eogroenlandicus) almost exclusively comprise haplotypes of such an origin. Another small and isolated refugium seems to have arisen in western Eurasia in close connection to the extensive ice sheet that covered Fennoscandia. The two Eurasian subspecies R.t. tarandus and R.t. fennicus appear to have a diphyletic origin as both the putatively small and isolated Eurasian refugium and the large Beringia refugium have contributed to their gene pools. A third distinct and geographically well-defined refugial area was probably located south to the extensive North American continental ice sheet from where the ancestors of the present North American woodland caribou (R.t. caribou) likely originated.Abstract in Norwegian / Sammendrag: Systematisk inndeling og kolonisering av rein (Rangifer tarandus) ble bestemt ved å analysere for variasjon i genetiske markører som proteiner, kjerneDNA og mitokondrieDNA. Dagens oppdeling av rein i underarter viser liten overensstemmelse med variasjonsmønsteret i de undersøkte markørene, noe som viser at de morfologiske forskjellene som karakteriserer dagens underarter ikke har utviklet seg i atskilte refugier i løpet av siste istid. Unntak fra dette er nordamerikansk skogsrein (woodland caribou-R.t. caribou) hvor alle tre markørsystemene indikerer at denne har utviklet seg i et refugium forskjellig fra andre underarter. De tre registrerte hovedhaplogruppene i mitokondrie-DNA representerer tre atskilte opprinnelser av rein i løpet av siste istid. Den mest innflytelsesrike av disse bidro vesentlig til genbanken til alle dagens underarter av rein, noe som tyder på at det under siste istid eksisterte en stor reinpopulasjon med kontinuerlig utbredelse gjennom store deler av tundraen i Eurasia og Beringia. De nordamerikanske tundrareintypene (R.t. granti og R.t. groenlandicus), samt de arktiske typene (R.t. platyrhunchus, R.t. pearyi og R.t. eogroenlandicus) består nærmest utelukkende av haplotyper med denne opprinnelse. Et annet lite og isolert refugium syntes å ha oppstått i Vest-Europa i nærheten av den omfattende isbreen som dekket Fennoskandia. De to europeiske underarter, R.t. tarandus og R.t. fennicus, syntes å ha en todelt opprinnelse med genetisk påvirkning fra både det antatt lille og isolerte refugiet i Eurasia samt fra det store Beringia refugiet. Et tredje geografisk distinkt refugium var antagelig lokalisert sør for den omfattende isbreen i Nord Amerika hvorfra forfedrene til dagens nordamerikanske skogsrein (R.t. caribou) har sin mest sannsynlige opprinnelse.

Reindeer and caribou was probably the key species for the human immigration and colonization in the Arctic and sub-Arctic by the retreat of the ice in the last glacial period. The close connection between human and reindeer has contributed to great interest and variation in reindeer taxonomy and origin. Through the history several both species, subspecies and types of reindeer and caribou have been described. The early taxonomy of the species is marked by comparisons of individual specimen using traits as body size, skin colour or antler formations - characteristics known to be highly variable and subjected to environmental and nutritional level. During the mid 1900s the taxonomy was more based on variation of morphological traits among populations by analysing a large series of specimens representative of the various geographic populations and a consensus of classification of several subspecies, all belonging to the same species, evolved. During late 1900 the development of modern molecular techniques procured tools for revealing genetic structure of populations reflecting different origin and isolation rather than environmental influences. The genetic structure revealed a major genetic dichotomy between American woodland caribou on the one hand and all other types of reindeer and caribou on the other which gave evidence that the ancestors of present woodland caribou had survived and evolved in ice free refugium south to the glacier in North America and the ancestors of all other types of reindeer and caribou had evolved separated from these in refugium in Eurasia and Beringia. The ancestors of present reindeer in Scandinavia appear furthermore to have evolved from different populations separated during the last glaciation period and the colonization and origin of present wild and domestic reindeer will be discussed in this perspective.Taksonomi og opprinnelse til reinAbstract in Norwegian / Sammendrag: Rein og caribou har hatt stor betydning for det moderne menneskets utvikling og kolonisering av nordlige Eurasia og Amerika etter siste istid. Den nære sammenhengen mellom mennesker og rein har bidratt til stor interesse og variasjon i oppfatningen av reinens taksonomi og opprinnelse. Et utall av både arter, underarter og raser av rein er beskrevet opp gjennom historien. Tidlig taksonomi av rein bar preg av å være basert på enkeltobservasjoner og på morfologiske karakterer som kroppsstørrelse, pelsfarge og størrelse og form på gevir, karakterer som i stor grad påvirkes av miljø og næringsforhold. Først på midten av 1900 tallet ble taksonomien i større grad basert på ulike morfologiske trekk som viste variasjon mellom bestander av rein, og en fikk bl.a. en forståelse av at alle underarter og former av rein og caribou tilhørte samme art. Med utviklingen av den moderne molekylærbiologien på slutten av 1900-tallet fikk en tilgang til verktøy som avdekket genetiske strukturer som reflekterer ulik opprinnelse og utvikling mer enn miljømessig påvirkning. Den genetiske strukturen som ble avdekket, viste liten overensstemmelse med oppdelingen i underarter som var basert på morfologiske trekk. Molekylærgenetiske struktur viser et hovedskille mellom amerikansk woodland caribou på den ene siden og all annen rein og caribou på den andre siden, noe som reflekterer at forfedrene til woodland caribou levde og utviklet seg i isfrie områder sør for iskanten i Nord-Amerika, mens forfedrene til andre typer rein levde atskilt fra disse i isfrie områder i Eurasia og Beringia. Forfedrene til dagens rein i Fennoskandia syntes også å ha utviklet seg fra atskilte bestander av rein som kan føres tilbake til slutten av siste istid. Innvandring og opprinnelse til dagens vill- og tamrein i Fennoskandia vil bli belyst i dette perspektiv.

I will review the drastic change seen in herd composition and slaughtering strategy the last decades inthe reindeer husbandry of Fennoscandia (i. e. Finland, Norway and Sweden). Herd composition was traditionally a function of the multipurpose herd, where reproduction of draught power played a major role. Hence, the slaughter scheme was based on adult males, in particular castrates. The herd represented the owner's capital and was viewed as the best insurance for staying in business. Indeed, a big and well composed herd announced social status as well as authority. Historically this has resulted in rises and falls in reindeer numbers. Control of the herd was being emphasized through age and sex composition and selection of behavioural traits and easily recognisable animals which favour handling. A high proportion of adults alleviated control of the herd as it eased the herding and reduced the mortality risk as they were able to withstand the highly stochastic environment. The introduction of the snowmobiles in the 1960s revolutionized the herding and transportation and hence reduced the importance of the male segment of the herd and amplified the ongoing transformation of the modern society into a market based economy. Now, the challenge was to efficiently convert the limited primary plant production into animal product, mainly meat. This is primarily achieved by balancing the animal numbers in accordance to the forage resources. However, also herd composition and slaughtering strategy are essential for maximizing the meat output per area unit. A highest possible proportion of reproductive females combined with a slaughtering scheme based on calves was tested and partly implemented in Soviet-Union already in the 1930s and introduced in the 1960s in Finland. Also in parts of Norway and Sweden this scheme was modified and tested. However, the formal work of refining and testing this new strategy based on modern population theory blended with traditional knowledge, started in Riast/Hylling reindeer herding district in southern Norway in the early 1970s and was completed around 1985. The work was followed up in Ruvhten Sitje (earlier called Tännäs Sameby), the neighbouring herding community of Riast/Hylling on the Swedish side of the border. In its stringent form the modern herd should comprise the highest proportion possible of reproductive females. The stocking rate should be adjusted to allow females to reproduce early; preferably at an age of 1.5 year, and they should be able to raise calves successfully every year. The male segment should be large enough to serve the females successfully during rut. Using 1.5 years old males as breeding bulls means that they can be slaughtered after rut. The culling should primarily aim at calves and removal of females reaching reproductive senescence, normally at around 12 years of age. Only the best female calves are selected as replacement of the senescence females slaughtered and the best male calves are selected as breeding bulls for the next year's rut. Calculations suggest that this new herd composition and slaughtering strategy could increase the meat production per area unit by around 50% compared to a traditional herd composition and off take scheme. However, such a strategy necessitates a strict control of environmental factors, including forage resources, as well as predators and human disturbance. Breeding programme based on selection on autumn calf weight has been proven successful. This work has been carried out in Ruvhten Sitje. The challenge is to establish appropriate breeding objectives in an ever changing environment. Selection for only calf weight may lead to improvement of capacity of growth only, which necessitates improvement of the environment in order to realize the genetic potential. Emphasize on maternal ability may lead to increase efficiency. To secure the genetic improvement in an open nucleus breeding scheme, with partly different breeding goals and different dedication to the breeding work is challenging. As the female part of the herd has been in focus in this research I will evaluate the importance of the male segment for offspring performance and herd productivity based on a 10 years study in the experimental research herd in Kaamanen, Finland. The results confirm basically the findings from Riast/Hylling and Ruvhten Sitje; 10% of 1.5years old males in good shape are sufficient to secure normal pregnancy rate, a synchronous rut and early parturition and hence a decent production output. I will review the "state of the art" and the biological challenges and limitations in applying such a "modern" production strategy. Today herd composition and slaughtering strategies vary and are modifications of the modern strategy developed adjusted according to natural condition, social settings and the production objectives. However, in many areas the variable grazing pressure makes the implementation of the model difficult. New products call for new adaptations. This is seen locally where products related to eco-tourism and so called ecological services (for example keeping up the semi-natural grazing induced vegetation types and serving as prey for the predators). This will call for new compositions of the herd and new slaughtering strategies. Accordingly herd composition has to be put in a historical context.Flokkstruktur og slaktestrategi i reindrifta - et historisk perspektivAbstract in Norwegian / Sammendrag: I denne oversiktsartikkelen vil jeg gjennomgå bakgrunnen for den drastiske omleggingen av flokkstruktur og slaktestrategi som har funnet sted i reindrifta i Fennoskandia de siste tiårene. Tradisjonelt var flokkstrukturen sterkt påvirket av behovet for trekkdyr, og slakteuttaket var i stor grad basert på voksne bukker, spesielt kastrater. Akkumulasjon av dyr var ansett som den beste forsikringen for fortsatt drift og ga status og makt. Dette førte til relativt store svingninger i tamreintallet. Et høyt innslag av voksne dyr sikret kontroll over flokken da de var lettere å gjete og bedre i stand til å takle harde vintre. Det materielle grunnlaget for omleggingen av flokkstruktur og slaktestrategi var innføringen av mekanisert trekkraft; særlig snøskuteren på 1960-tallet, kombinert med en markedsøkonomi basert på kjøttproduksjon. Det biologiske utgangspunktet er en begrenset beiteressurs som må utnyttes optimalt. Dette gjøres primært gjennom å tilpasse beitebelegget til ressursgrunnlaget. Men også flokksammensetningen og en tilpasset slaktestrategi er avgjørende for hvor mange kilo kjøtt en kan høste på et gitt areal. Innen reindrifta var en høy simleandel kombinert med slakt av kalver allerede utprøvd i Sovjetunionen på 1930-tallet og vant innpass i finsk reindrift på 1960-tallet. En slik omlegging ble modifisert og utprøvd også i enkelte områder i Norge og Sverige, og diskusjonen gikk høyt om dens berettigelse. Arbeidet med å utvikle og etterprøve denne nye strategien basert på moderne produksjonsteori og tradisjonellkunnskap startet for fullt i Riast/Hylling reinbeitedistrikt i Sør-Norge i begynnelsen av 1970-tallet og ble avsluttet rundt 1985. Dette arbeidet ble videreført i Ruvhten Sitje (tidligere Tännäs Sameby). I sin rendyrkede form innebærer den nye flokkstrukturen en høyest mulig andel simler i vinterflokken. Disse reproduserer og fostrer årlig opp kalver slik at flest mulig er i live og i godt hold første høst. Antall bukker holdes på et minimum, men høyt nok til å sikre full bedekking. Slaktestrategien tilpasses denne flokkstrukturen ved at de fleste kalvene slaktes; bare de beste settes på til livdyr eller parringsbukker. Dette betyr at simlene utrangeres når aldringen begynner å påvirke reproduksjonen negativt, normalt ved 12 års alder. Bruk av 1,5-årige parringsbukker innebærer at disse kan slaktes etter brunst. Som et resultat blir vinterflokken bestående av produktive simler pluss påsettet av simlekalver til livdyr og bukkekalver til bedekking av simlene neste høst. Beregninger viser at en ved å optimalisere flokksammensetningen etter slike kriterier kan øke slakteuttaket per arealenhet med rundt 50% sammenlignet med en tradisjonell struktur og uttak. Dette krever imidlertid kontroll med miljøet gjennom en god beitebalanse og med andre miljøfaktorer som rovvilt og menneskelig forstyrrelse. Utvalg av framtidige mordyr og avlsbukker, basert på simlekalvenes og bukkekalvenes høstvekt har vist seg å gi en avlsmessig framgang. Dette arbeidet har vært utført i Ruvhten Sitje. Utfordringen i avlsarbeidet er valg av utvalgskriterier i et variabelt miljø. Ensidig vekt på kalvetilvekst kan innebære ensidig avl for kapasitet, noe som krever styrking av miljøet for å kunne realisere det genetiske potensialet. Vektlegging av morsegenskaper kanimidlertid øke dyrenes effektivitet. Å sikre den genetiske framgangen i et åpent system (liten kontroll over hanndyrsegmentet) med uensartede avlsmål og ulik grad av bevisst avlsarbeid blant reineierne er også en utfordring. Siden simlesegmentet har vært i fokus i dette arbeidet, vil jeg vurdere bukkesegmentets betydning for produksjonsresultatet basert på forskning utført i forsøksflokken i Kaamanen de siste ti årene. Funnene herfra samsvarer i all hovedsak med Rørosmodellens anbefalinger om at rundt 10% 1,5-årige bukker i godt hold sikrer full bedekking, en tilfredsstillende synkronisering av brunsten og en tidlig kalving og dermed et godt produksjonsresultat. Særlig en tidlig kalving og konsentrert kalving er avgjørende. Jeg vil gå gjennom disse nye strategiene og de biologiske utfordringer og begrensinger som ligger i dem. Flokkstrukturen og slaktestrategien i reindrifta i dag kjennetegnes av stor diversitet og modifiseringer av Rørosmodellen ut fra naturgitte og sosiale forhold og ulike produksjonsmål. Det er imidlertid klart at misstilpasninger i beitebruken mange steder gjør det vanskelig å gjennomføre modellen. Produksjonsspektret er imidlertid stadig i endring og må tilpasses lokalt. Andre produkter knyttet til turisme og såkalte økologiske tjenester, for eksempel opprettholdelse av det åpne, kulturpåvirkede beitelandskapet i fjellet og mat til rovdyr som storsamfunnet vil ta vare på, vil betinge nye flokkstrukturer og slaktestrategier.

<strong><span style="font-family: TimesNewRomanPS-BoldMT;"><font face="TimesNewRomanPS-BoldMT"><p align="left"> </p></font></span><p align="left"><span style="font-size: x-small; font-family: TimesNewRomanPS-BoldMT;"><span style="font-size: x-small; font-family: TimesNewRomanPS-BoldMT;">SAMMENDRAG</span></span></p></strong><span style="font-size: x-small; font-family: TimesNewRomanPSMT;"><span style="font-size: x-small; font-family: TimesNewRomanPSMT;"><p align="left">Med utgangspunkt i data fra et populasjonsbasert utvalg av 7 992 norske tvillinger ble sammenhengen</p><p align="left">mellom gjentatte ørebetennelser og forhold under svangerskapet studert. Som parametre på intrauterine</p><p align="left">vekstforhold ble informasjon om fødselsvekt og gestasjonsalder fra Medisinsk Fødselsregister benyttet.</p><p align="left">Informasjon om rapporterte øreinfeksjoner ble basert på spørreskjemaer som ble besvart av tvillingene i</p><p align="left">alderen 18–25 år. Først studerte vi individuelle effekter av fødselsvekt og gestasjonsalder på forekomsten av</p><p align="left">otitis media (OM). Rapportert fødselsvekt hos individer med OM var signifikant lavere enn hos kontrollene,</p><p align="left">med en gjennomsnittsforskjell på 86 gram. Hos de som rapporterte OM var gjennomsnittlig gestasjonsalder</p><p align="left">3 dager kortere enn i kontrollmaterialet. Deretter beregnet vi effekten av fødselsvekt ved bruk av co-twin</p><p align="left">kontroll metoden. Blant monozygote (MZ) tvillingpar gjenspeiler fødselsvektforskjeller innenfor tvillingparet</p><p align="left">intra-uterine miljøforskjeller. Blant dizygote (DZ) par kan vektforskjellen være både genetiske og</p><p align="left">miljøbetinget. Ved sammenligning av fødselsvektforskjeller innenfor tvillingparene er tvillingen som ikke</p><p align="left">har gjentatte øreinfeksjoner en matchet kontroll blant OM diskordante par. Resultatene antyder at lav</p><p align="left">fødselsvekt er en risikofaktor for otitis media. Gjennomsnittlig vektforskjell blant par diskordante for OM</p><p align="left">var 48 gram, og den av tvillingen som ikke rapporterte OM hadde signifikant høyere fødselsvekt.</p><font face="TimesNewRomanPSMT" size="2"><font face="TimesNewRomanPSMT" size="2"><p align="left">Kværner KJ, Tambs K, Harris J, Magnus P.</p></font></font></span><font face="TimesNewRomanPSMT" size="2"><p align="left"> </p></font></span><p align="left"><strong><span style="font-size: x-small; font-family: TimesNewRomanPS-BoldMT;"><span style="font-size: x-small; font-family: TimesNewRomanPS-BoldMT;">Do pregnancy-related factors influence the development of<strong><font face="TimesNewRomanPS-BoldMT" size="2"><font face="TimesNewRomanPS-BoldMT" size="2"><p align="left">otitis media?</p></font></font></strong></span><strong><font face="TimesNewRomanPS-BoldMT" size="2"><p align="left"> </p></font></strong></span></strong><em><span style="font-size: x-small; font-family: TimesNewRomanPS-ItalicMT;"><span style="font-size: x-small; font-family: TimesNewRomanPS-ItalicMT;">Nor J Epidemiol </span></span></em><span style="font-size: x-small; font-family: TimesNewRomanPSMT;"><span style="font-size: x-small; font-family: TimesNewRomanPSMT;">1997; </span></span><strong><span style="font-size: x-small; font-family: TimesNewRomanPS-BoldMT;"><span style="font-size: x-small; font-family: TimesNewRomanPS-BoldMT;">7 </span></span></strong><span style="font-size: x-small; font-family: TimesNewRomanPSMT;"><span style="font-size: x-small; font-family: TimesNewRomanPSMT;">(1): 55-58.</span></span></p><p align="left"> </p><strong><span style="font-family: TimesNewRomanPS-BoldMT;"><font face="TimesNewRomanPS-BoldMT"><p align="left"> </p></font></span><p align="left"><span style="font-size: x-small; font-family: TimesNewRomanPS-BoldMT;"><span style="font-size: x-small; font-family: TimesNewRomanPS-BoldMT;">ENGLISH SUMMARY</span></span></p></strong><span style="font-size: x-small; font-family: TimesNewRomanPSMT;"><span style="font-size: x-small; font-family: TimesNewRomanPSMT;"><p align="left">The association between intrauterine growth, as measured by weight and gestational age, and the occurrence</p><p align="left">of recurrent ear infections was studied using data from a population based sample of 7992 Norwegian twins.</p><p align="left">Perinatal measures were collected from the Medical Birth Registry, and reports of recurrent ear infections</p><p align="left">were based on questionnaires completed when the twins were aged 18-25. First, the individual effects of</p><p align="left">birth weight and gestational age on the occurrence of otitis media (OM) were estimated. Birth weight among</p><p align="left">individuals who reported OM was significantly lower than for controls, with a mean weight difference of 86</p><p align="left">grams. The average difference in gestational age was 3 days shorter among individuals with a positive</p><p align="left">history of OM. Next, the effect of birth weight was estimated using a co-twin control application. Among</p><p align="left">MZ twins within pair differences in birth weight reflect environmental differences experienced in utero.</p><p align="left">Among DZ pairs birth weight differences may be due to genetic and environmental differences. Among OM</p><p align="left">discordant pairs, the co-twin without a history of OM is a matched control for comparisons of intra-pair</p><p align="left">differences in birth weight. When within pair birth weight differences were compared, the co-twin without a</p><p align="left">history of OM was used as the matched control. Results indicated that lower birth weight may be a risk</p><p align="left">factor for OM. The average birth weight difference among OM discordant pairs was 48 grams, with the</p><p>control twin weighing significantly more than the twin with a history of OM.</p></span></span>

<strong><span style="font-family: TimesNewRomanPS-BoldMT;"><span style="font-family: TimesNewRomanPS-BoldMT;"><p align="left"> </p></span></span><span style="font-size: x-small; font-family: TimesNewRomanPS-BoldMT;"><span style="font-size: x-small; font-family: TimesNewRomanPS-BoldMT;">SAMMENDRAG</span></span></strong><span style="font-size: x-small; font-family: TimesNewRomanPSMT;"><span style="font-size: x-small; font-family: TimesNewRomanPSMT;"><p align="left">Vi vet foreløpig lite om utbredelsen av osteoporose i Norge – dvs. bentetthet (BMD) minst 2,5 standardavvik</p><p align="left">under gjennomsnittet for unge kvinner. Vi vet heller ikke om det har vært noen økning de siste 10-årene.</p><p align="left">Denne artikkelen gir en oversikten over emnet osteoporose – med vekt på risikofaktorer og forebyggende</p><span style="font-size: x-small; font-family: TimesNewRomanPSMT;"><span style="font-size: x-small; font-family: TimesNewRomanPSMT;"><p align="left">tiltak, og drøfter WHOs definisjon av osteoporose. I henhold til denne er osteoporose</p></span></span></span><span style="font-size: x-small; font-family: TimesNewRomanPSMT;"><p align="left"> </p></span></span><p align="left"><em><span style="font-size: x-small; font-family: TimesNewRomanPS-ItalicMT;"><span style="font-size: x-small; font-family: TimesNewRomanPS-ItalicMT;">både </span></span></em><span style="font-size: x-small; font-family: TimesNewRomanPSMT;"><span style="font-size: x-small; font-family: TimesNewRomanPSMT;">en risikofaktor for<span style="font-size: x-small; font-family: TimesNewRomanPSMT;"><span style="font-size: x-small; font-family: TimesNewRomanPSMT;"><p align="left">brudd –</p></span></span></span><span style="font-size: x-small; font-family: TimesNewRomanPSMT;"><p align="left"> </p></span></span></p><p align="left"><em><span style="font-size: x-small; font-family: TimesNewRomanPS-ItalicMT;"><span style="font-size: x-small; font-family: TimesNewRomanPS-ItalicMT;">og </span></span></em><span style="font-size: x-small; font-family: TimesNewRomanPSMT;"><span style="font-size: x-small; font-family: TimesNewRomanPSMT;">en betegnelse på en tilstand som forutsetter minst ett brudd (etablert osteoporose). Definisjonen<p align="left">innebærer at diagnosen osteoporose avhenger av det normalmaterialet man sammenliker med, og medfører at</p><p align="left">en meget stor andel av norske kvinner over 70 år vil få diagnosen osteoporose. En slik medikalisering vil</p><p align="left">kunne føre til hyppige legekontroller, angst og lavere fysisk aktivitet av redsel for å falle. Osteoporose er</p><p align="left">asymptomatisk før man har fått brudd, og har ingen automatiske behandlingsmessige konsekvenser. Man kan</p><span style="font-size: x-small; font-family: TimesNewRomanPSMT;"><span style="font-size: x-small; font-family: TimesNewRomanPSMT;"><p align="left">likevel frykte at WHOs definisjon vil tvinge frem krav om medikamentell</p></span></span></span><span style="font-size: x-small; font-family: TimesNewRomanPSMT;"><p align="left"> </p></span></span></p><p align="left"><em><span style="font-size: x-small; font-family: TimesNewRomanPS-ItalicMT;"><span style="font-size: x-small; font-family: TimesNewRomanPS-ItalicMT;">forebyggende </span></span></em><span style="font-size: x-small; font-family: TimesNewRomanPSMT;"><span style="font-size: x-small; font-family: TimesNewRomanPSMT;">behandling. Dette er<p align="left">problematisk fordi det er stor overlapping i bentetthet mellom de som får brudd og de som ikke får. Måling av</p><p align="left">BMD er imidlertid den beste metoden vi i dag har for å forutsi brudd – og er like god som blodtrykksmåling er</p><p align="left">til å forutsi slag. For å vurdere individuell risiko, bør imidlertid flere risikofaktorer for brudd kombineres. De</p><p align="left">viktigste risikofaktorene for lav bentetthet er: lav kroppsvekt/lav relativ vekt, vektreduksjon, lavt inntak av</p><p align="left">kalsium/D-vitamin, røyking, tidlig menopause, inaktivitet, høyt alkoholkonsum og genetiske faktorer. Tiltak</p><p align="left">med fokus på noen av disse har vist positiv effekt på BMD.</p><span style="font-size: x-small; font-family: TimesNewRomanPSMT;"><span style="font-size: x-small; font-family: TimesNewRomanPSMT;"><p align="left">Søgaard AJ.</p></span></span></span><span style="font-size: x-small; font-family: TimesNewRomanPSMT;"><p align="left"> </p></span></span></p><p align="left"><strong><span style="font-size: x-small; font-family: TimesNewRomanPS-BoldMT;"><span style="font-size: x-small; font-family: TimesNewRomanPS-BoldMT;">Osteoporosis – risk factor or disease? Definition, distribution, aetiology, diagnosis and<strong><span style="font-size: x-small; font-family: TimesNewRomanPS-BoldMT;"><span style="font-size: x-small; font-family: TimesNewRomanPS-BoldMT;"></span></span></strong></span><strong><span style="font-size: x-small; font-family: TimesNewRomanPS-BoldMT;"><p align="left"> </p><p align="left"> </p><p align="left"><span style="font-size: x-small; font-family: TimesNewRomanPSMT;"></span><strong><span style="font-size: x-small; font-family: TimesNewRomanPS-BoldMT;"><span style="font-size: x-small; font-family: TimesNewRomanPS-BoldMT;">ENGLISH SUMMARY</span></span></strong><span style="font-size: x-small; font-family: TimesNewRomanPSMT;"><span style="font-size: x-small; font-family: TimesNewRomanPSMT;"><p align="left">At present we do not know the distribution of osteoporosis in the Norwegian population – i.e. bone mineral</p><p align="left">density (BMD) below 2.5 standard deviations of the mean of young females. Nor do we know whether or not</p><p align="left">there has been any increase in the prevalence of osteoporosis the last decades. This paper reviews research</p><p align="left">about osteoporosis – focusing on risk factors and preventive measures, and discusses the WHO definition of</p><span style="font-size: x-small; font-family: TimesNewRomanPSMT;"><span style="font-size: x-small; font-family: TimesNewRomanPSMT;"><p align="left">osteoporosis. Osteoporosis is, in accordance to this definition,</p></span></span></span><span style="font-size: x-small; font-family: TimesNewRomanPSMT;"><p align="left"> </p></span></span><p align="left"><em><span style="font-size: x-small; font-family: TimesNewRomanPS-ItalicMT;"><span style="font-size: x-small; font-family: TimesNewRomanPS-ItalicMT;">both </span></span></em><span style="font-size: x-small; font-family: TimesNewRomanPSMT;"><span style="font-size: x-small; font-family: TimesNewRomanPSMT;">a risk factor for fracture </span></span><em><span style="font-size: x-small; font-family: TimesNewRomanPS-ItalicMT;"><span style="font-size: x-small; font-family: TimesNewRomanPS-ItalicMT;">and </span></span></em><span style="font-size: x-small; font-family: TimesNewRomanPSMT;"><span style="font-size: x-small; font-family: TimesNewRomanPSMT;">the notion of a<p align="left">condition which presuppose a fracture (established osteoporosis). The definition implies that the diagnosis of</p><p align="left">osteoporosis depend upon the material of reference we compare with, and entail that a large majority of</p><p align="left">women above 70 years of age will have osteoporosis. This medicalization may lead to more frequent visits to</p><p align="left">physicians for control, more anxiety and less frequent physical activity because of fear of falling. Osteoporosis</p><p align="left">does not cause pain or loss of function before a fracture has occurred, and the diagnosis is not meant to initiate</p><p align="left">therapy. Nevertheless we worry that the diagnosis may have its own momentum in that direction, and enforce</p><p align="left">demands for more medicine for the purpose of prevention. This is problematic because there is a large overlap</p><p align="left">in BMD between those who will have a future fracture – and those who will not. However, measuring BMD is</p><p align="left">the best single method to predict future fracture, and is just as good as a measure of blood pressure is to predict</p><p align="left">stroke. To assess individual risk, one should, however, use more than one fracture risk factor. The most</p><p align="left">important risk factors for low BMD are: low weight/low body mass index, weight reduction, low intake of</p><p align="left">calcium/vitamin-D, smoking, early menopause, inactivity, high alcohol consumption and genetic factors.</p><p>Interventions focusing on some of these factors have been effective in increasing/not reducing BMD.</p></span></span></p></p></span></strong></span></strong><em><span style="font-size: x-small; font-family: TimesNewRomanPS-ItalicMT;"><span style="font-size: x-small; font-family: TimesNewRomanPS-ItalicMT;">Nor J Epidemiol </span></span></em><span style="font-size: x-small; font-family: TimesNewRomanPSMT;"><span style="font-size: x-small; font-family: TimesNewRomanPSMT;">1999; </span></span><strong><span style="font-size: x-small; font-family: TimesNewRomanPS-BoldMT;"><span style="font-size: x-small; font-family: TimesNewRomanPS-BoldMT;">9 </span></span></strong><span style="font-size: x-small; font-family: TimesNewRomanPSMT;"><span style="font-size: x-small; font-family: TimesNewRomanPSMT;">(2): 165-172</span></span></p><p align="left">prevention.</p>