RESUMO
The discovery early in this century of the exceptional longevity of the Sardinian population has given new impetus to demographic studies of this phenomenon during the classical period. In the 1970s, it was hypothesised that the average mortality rate in Roman Sardinia was lower than in metropolitan Rome itself, postulating an ancient precedent for the remarkable longevity observable nowadays in the island's population. In the present study, the available evidence was examined in order to test this hypothesis. Literary, juridical, epigraphic, papyrological, anthropological and archaeological sources regarding the population of the Roman Empire, including Sardinia, were retrieved by accessing Science Direct, PubMed, Scopus and Google Scholar databases, as well as regional libraries, regardless of time limitation, and were independently reviewed by the authors. For Roman Sardinia, only funerary epitaphs were retrieved, in contrast with the numerous sources available for the whole Roman Empire. Inscriptions revealing the existence of three alleged nonagenarians, two centenarians, two ultracentenarians and one supercentenarian were found, corresponding to 2% in a total of 381 inscriptions. The majority were located in a highly Romanised rural area of central-western Sardinia. However, the ages reported in the epitaphs may be inaccurate because of the influence of confounders such as age rounding, approximations and/or amplifications, and are unrelated to the total number of inhabitants. In conclusion, the funerary evidence, the only available data from Roman Sardinia, is too weak to estimate the life expectancy of the local ancient population and cannot offer valuable arguments to support the hypothesis that exceptional longevity has been a Sardinian trait since Roman times.
Assuntos
Expectativa de Vida , Longevidade/fisiologia , Mundo Romano/história , Idoso de 80 Anos ou mais , Bases de Dados Factuais , História Antiga , Humanos , Itália/epidemiologiaAssuntos
Gota/história , Anamnese , Grécia , História do Século XX , História Antiga , Humanos , Mundo Romano/históriaRESUMO
In 1911, the Danish physician Hans Christian Gram (1853-1938) sustained to have found signs of hyperthyroidism in a marble head of a Roman woman that he observed in the Ny Carlsberg Glyptotek in Copenhagen. It could be one of the first examples of a clinical diagnosis of an endocrine disease in an ancient statue.
Assuntos
Endocrinologia/história , Hipertireoidismo/diagnóstico , Medicina nas Artes/história , Escultura/história , Dinamarca , Endocrinologistas/história , Feminino , Cabeça/patologia , História do Século XIX , História Antiga , Humanos , Hipertireoidismo/história , Mundo Romano/história , Cidade de RomaRESUMO
The arrival of the Longobards in Northern Italy in 568 CE marked a period of renewed political stability in the Peninsula after the collapse of the Western Roman Empire. The trajectory of the spread of Longobards in Italy across the Alps and into the South is known from many literary sources. However, their mobility and residence patterns at a population level remain to be fully understood. Here we present a multi-isotopic analysis (87Sr/86Sr and 18O/16O) of 39 humans and 14 animals buried at the Longobard necropolis of Povegliano Veronese (VR, Italy; 6th-8th century CE), to address mode and tempo of the spread of this population in the Peninsula. The geographical location of Povegliano Veronese plays a key role: the site lies along the Via Postumia, which was one of the main ancient Roman roads of Northern Italy, representing an important route in post-classical Italy. The integration of isotopic data with the archaeological evidence allowed us to determine the presence of individuals from at least three different regions of origin, building a diachronic map of the dynamics of mobility of this group in northern Italy.
Assuntos
Restos Mortais/química , Osso e Ossos/química , Migração Humana/história , Mundo Romano/história , Dente/química , Animais , Arqueologia/métodos , Restos Mortais/anatomia & histologia , Sepultamento/história , Bovinos , Feminino , Cabras , História Antiga , Cavalos , Humanos , Itália , Masculino , Isótopos de Oxigênio/análise , Carneiro Doméstico , Isótopos de Estrôncio/análise , SuínosRESUMO
The assassination of Julius Caesar in 44 BCE triggered a power struggle that ultimately ended the Roman Republic and, eventually, the Ptolemaic Kingdom, leading to the rise of the Roman Empire. Climate proxies and written documents indicate that this struggle occurred during a period of unusually inclement weather, famine, and disease in the Mediterranean region; historians have previously speculated that a large volcanic eruption of unknown origin was the most likely cause. Here we show using well-dated volcanic fallout records in six Arctic ice cores that one of the largest volcanic eruptions of the past 2,500 y occurred in early 43 BCE, with distinct geochemistry of tephra deposited during the event identifying the Okmok volcano in Alaska as the source. Climate proxy records show that 43 and 42 BCE were among the coldest years of recent millennia in the Northern Hemisphere at the start of one of the coldest decades. Earth system modeling suggests that radiative forcing from this massive, high-latitude eruption led to pronounced changes in hydroclimate, including seasonal temperatures in specific Mediterranean regions as much as 7 °C below normal during the 2 y period following the eruption and unusually wet conditions. While it is difficult to establish direct causal linkages to thinly documented historical events, the wet and very cold conditions from this massive eruption on the opposite side of Earth probably resulted in crop failures, famine, and disease, exacerbating social unrest and contributing to political realignments throughout the Mediterranean region at this critical juncture of Western civilization.
Assuntos
Mudança Climática/história , Clima Frio/efeitos adversos , Desastres/história , Mundo Romano/história , Erupções Vulcânicas/efeitos adversos , Alaska , Clima , Produtos Agrícolas/história , Fome Epidêmica/história , História Antiga , Camada de Gelo , Região do Mediterrâneo , Política , Erupções Vulcânicas/históriaRESUMO
Understanding the population of Central Italy during the 1st millennium BCE is a crucial topic in the biological history of the Mediterranean basin. This period saw the emergence of the Etruscan and Roman cultures which had a significant impact on the bio-cultural history of the region. In this study, we analyse a prehistoric population from Caracupa (Iron Age, Latium, Central Italy). The results suggest an overall good level of health for the population. Despite this, some musculoskeletal changes related to biomechanical stressors were observed, probably as the result of strenuous physical activity. The results of a Simple Matching analysis of intragroup distance distributions suggest potential model of kinship structures and lineages. This may be due to the relative geographic isolation of the Caracupa population. Furthermore, in order to investigate the wider population of Central Italy during the 1st millennium BCE, we have constructed a population pattern using genetic and phenotypic skeletal and dental traits. The comparison between Central Italy and more isolated populations indicated a divergence between the Western and Eastern sides of Central Italy. However, we do not exclude a probable common genetic substratum for all Central Italian populations during the 1st millennium BCE.
Assuntos
Mundo Romano/história , Adolescente , Adulto , Antropologia , Estatura/fisiologia , Osso e Ossos/anatomia & histologia , Osso e Ossos/patologia , Criança , Feminino , História Antiga , Humanos , Itália/etnologia , Masculino , Pessoa de Meia-Idade , Saúde da População/história , Adulto JovemRESUMO
The decline of the Roman rule caused significant political instability and led to the emergence of various 'Barbarian' powers. While the names of the involved groups appeared in written sources, it is largely unknown how these changes affected the daily lives of the people during the 5th century AD. Did late Roman traditions persist, did new customs emerge, and did both amalgamate into new cultural expressions? A prime area to investigate these population and settlement historical changes is the Carpathian Basin (Hungary). Particularly, we studied archaeological and anthropological evidence, as well as radiogenic and stable isotope ratios of strontium, carbon, and nitrogen of human remains from 96 graves at the cemetery of Mözs-Icsei dulo. Integrated data analysis suggests that most members of the founder generation at the site exhibited burial practises of late Antique traditions, even though they were heterogeneous regarding their places of origin and dietary habits. Furthermore, the isotope data disclosed a nonlocal group of people with similar dietary habits. According to the archaeological evidence, they joined the community a few decades after the founder generation and followed mainly foreign traditions with artificial skull modification as their most prominent characteristic. Moreover, individuals with modified skulls and late Antique grave attributes attest to deliberate cultural amalgamation, whereas burials of largely different isotope ratios underline the recipient habitus of the community. The integration of archaeological and bioarchaeological information at the individual level discloses the complex coalescence of people and traditions during the 5th century.
Assuntos
Arqueologia , Mundo Romano/história , Mudança Social/história , Adolescente , Restos Mortais/anatomia & histologia , Restos Mortais/fisiologia , Cemitérios , Criança , Pré-Escolar , Comportamento Alimentar , Feminino , História Antiga , Humanos , Hungria , Lactente , Recém-Nascido , Masculino , Crânio/anatomia & histologia , Crânio/fisiologia , Adulto JovemRESUMO
Despite the recent flurry of interest in various aspects of ancient urbanism, we still know little about how much traffic flowed in and out of ancient cities, in part because of problems with using commodities as proxies for trade. This article investigates another approach, which is to estimate these flows from the built environment, concentrating on transport infrastructure such as city gates. To do this, I begin by discussing a new model for how we would expect this kind of infrastructure to expand with population, before investigating the relationship between the populations of sites and the total numbers and widths of city gates, focusing on the Greek and Roman world. The results suggest that there is indeed a systematic relationship between the estimated populations of cities and transport infrastructure, which is entirely consistent with broader theoretical and empirical expectations. This gives us a new way of exploring the connectivity and integration of ancient cities, contributing to a growing body of general theory about how settlements operate across space and time.
Assuntos
Meios de Transporte/história , Urbanização/história , Cidades/história , Mundo Grego/história , História Antiga , Humanos , Modelos Teóricos , Mundo Romano/história , Cidade de RomaRESUMO
In past centuries, epidemics, the scourge of humankind, caused pain, anger, uncertainty of the future, social as well as economic disorder and a significant impact on their victims, involving also their spiritual sphere. The latter effect led to undoubted effects on participation in the religious and social life of communities. The custom of preparing artistic votive expressions has been lost in the mists of time and evidence of ex voto gifts, offered by believers to pagan gods, has been found in prehistoric archaeological sites. Furthermore, several finds from the Ancient Greek and Roman worlds may be observed in our museums. These remains are generally ceramic and metal artifacts, reproducing limbs and other body parts which had been healed. These elements, according to the belief of those making the offerings, had benefited from the miraculous intervention of a thaumaturgical deity. With the advent of Christianity, some pre-existing religious practices were endorsed by the new religion. Believers continued to demonstrate their gratitude in different ways either to miracle-working saints or to the Virgin Mary, because they thought that, thanks to an act of faith, their own health or that of a family member would benefit from the direct intervention of the divine entities to whom they had prayed. In the Ancient Greek world, it was believed that the god Asclepius could directly influence human events, as testified by the popularity of shrines and temples to the god, especially at Epidaurus. In the Christian world as well, particular places have been detected, often solitary and secluded in the countryside or in the mountains, where, according to tradition, direct contact was established between the faithful and Saints or the Virgin Mary Herself. Manifestations occurred by means of miracles and apparitions, thereby creating a direct link between the supernatural world and believers. Religious communities, in these extraordinary places, responded to the call through the building of shrines and promotion of the cult. Over time, the faithful reached these places of mystery, performing pilgrimages with the aim of strengthening their religious faith, but also with the purpose of seeking intercession and grace. In this case, the request for clemency assumed spiritual characteristics and also became a profession of faith. Accordingly, the shrines in the Christian world are places where supernatural events may occur. In these environments the believer resorted to faith, when medicine showed its limits in a tangible way. For the above reasons, while epidemics were occurring, the requests for clemency were numerous and such petitions were both individual and collective. In particular, by means of votive offerings (ex voto) the believers, both individually and collectively, gave the evidence of the received grace to the thaumaturgical Saint. Through the votive act, a perpetual link between the believer and the Saints or Holy Virgin was forged and a strong request for communion was transmitted. The aim of the present study is to describe the role played by votive tablets (ex voto) in the last 500-600 years, as visible evidence of human suffering. From this perspective, these votive expressions may assume the role of markers because, in accordance with the expressions of popular faith, they allow us to follow the most important outbreaks that have caused distress to Christian communities.
Assuntos
Cura pela Fé/história , Medicina nas Artes/história , Pinturas/história , Peste/história , Religião e Medicina , Cristianismo/história , Mundo Grego/história , História do Século XV , História do Século XVI , História do Século XVII , História do Século XVIII , História Antiga , História Medieval , Humanos , Mundo Romano/história , SimbolismoRESUMO
Since ancient times, the Calabrian territories were affected continuously and in different dominations: first Magna Greece civilisation and after the Roman domination. The latter influenced strongly some areas of the Calabrian territory, where we witnessed a gradual replacement of small farmer properties with plants of the first Roman villas. An example of Roman thermal plant was in the city of Curinga (CZ), where in 1966 were found the remains of a thermal building dating to late-Roman period, probably a part of a much more complex structure identifiable as a large Roman villa. In this context are exposed the results of a first scientific aim to study the thermal complex of Curinga, with the development of a specific diagnosis protocol and its next application to the artefact itself, to get a general but exhaustive survey of its conditions, its conservation and degradation state, essential for the execution of future maintenance projects.
Assuntos
Temperatura Alta , Plantas , Mundo Romano/história , Arqueologia/história , Grécia , História Antiga , ItáliaRESUMO
The study of Roman childhood has been the focus of research primarily using documentary and archaeological evidence, while relatively few non-adult skeletal assemblages have been analyzed. This paper presents the study of 93 non-adult individuals from four cemeteries in the Roman (1st-3rd c. CE) civitas capital of Aventicum (Avenches), Switzerland. The results of the analysis offer a new bioarchaeological perspective on mortality and disease patterns during childhood in Roman Switzerland, adding to the discussion regarding living conditions in the urban centers at the periphery of the Roman Empire. This study also highlights the importance of studying perinates in archaeological populations, since the current research inform us about the experiences of mothers and their offspring in Aventicum. The mortality and disease patterns of the perinates, representing 71% of the total non-adult sample (66/93), suggest that pregnancy and the time around birth were extremely challenging at Aventicum. It is argued that environmental constraints, e.g. the risk of infectious diseases such as malaria and natural phenomena such as recurring floods resulting in resources scarcity, could have considerably affected the mother-fetus pair in this urban settlement.
Assuntos
Doenças Ósseas/história , Mundo Romano/história , Adolescente , Criança , Pré-Escolar , Feminino , Feto , História Antiga , Humanos , Lactente , Recém-Nascido , Masculino , Gravidez , SuíçaRESUMO
Lead pollution in Arctic ice reflects midlatitude emissions from ancient lead-silver mining and smelting. The few reported measurements have been extrapolated to infer the performance of ancient economies, including comparisons of economic productivity and growth during the Roman Republican and Imperial periods. These studies were based on sparse sampling and inaccurate dating, limiting understanding of trends and specific linkages. Here we show, using a precisely dated record of estimated lead emissions between 1100 BCE and 800 CE derived from subannually resolved measurements in Greenland ice and detailed atmospheric transport modeling, that annual European lead emissions closely varied with historical events, including imperial expansion, wars, and major plagues. Emissions rose coeval with Phoenician expansion, accelerated during expanded Carthaginian and Roman mining primarily in the Iberian Peninsula, and reached a maximum under the Roman Empire. Emissions fluctuated synchronously with wars and political instability particularly during the Roman Republic, and plunged coincident with two major plagues in the second and third centuries, remaining low for >500 years. Bullion in silver coinage declined in parallel, reflecting the importance of lead-silver mining in ancient economies. Our results indicate sustained economic growth during the first two centuries of the Roman Empire, terminated by the second-century Antonine plague.
Assuntos
Poluentes Ambientais , Gelo/análise , Chumbo , Mundo Romano/história , Conflitos Armados/história , Surtos de Doenças/história , Poluentes Ambientais/análise , Poluentes Ambientais/história , Indústrias Extrativas e de Processamento/história , Groenlândia , História Antiga , Humanos , Chumbo/análise , Chumbo/história , Prata/históriaRESUMO
New archaeological excavations at Alken Enge, Jutland, Denmark, have revealed a comprehensive assemblage of disarticulated human remains within a 75-ha wetland area. A minimum of 82 individuals have been uncovered. Based on the distribution, the total population is estimated to be greater than 380 individuals, exclusively male and predominantly adult. The chronological radiocarbon evidence of the human bones indicates that they belong to a single, large event in the early first century AD. The bones show a high frequency of unhealed trauma from sharp-edged weapons, which, together with finds of military equipment, suggests that the find is of martial character. Taphonomic traces indicate that the bones were exposed to animal gnawing for a period of between 6 mo and 1 y before being deposited in the lake. Furthermore, the find situations, including collections of bones, ossa coxae threaded onto a stick, and cuts and scraping marks, provide evidence of the systematic treatment of the human corpses after the time of exposure. The finds are interpreted as the remains of an organized and possibly ritually embedded clearing of a battlefield, including the physical manipulation of the partly skeletonized bones of the deceased fighters and subsequent deposition in the lake. The date places the finds in the context of the Germanic region at the peak of the Roman expansion northward and provides the earliest direct archaeological evidence of large-scale conflict among the Germanic populations and a demonstration of hitherto unrecognized postbattle practices.
Assuntos
Conflitos Armados/história , Osso e Ossos/patologia , Sepultamento/história , Comportamento Ritualístico , Adulto , Arqueologia , Cadáver , Dinamarca , Feminino , História Antiga , Humanos , Masculino , Pessoa de Meia-Idade , Datação Radiométrica , Mundo Romano/história , Adulto JovemRESUMO
OBJECTIVES: We obtained the oxygen and strontium isotope composition of teeth from Roman period (1st to 4th century CE) inhabitants buried in the Vagnari cemetery (Southern Italy), and present the first strontium isotope variation map of the Italian peninsula using previously published data sets and new strontium data. We test the hypothesis that the Vagnari population was predominantly composed of local individuals, instead of migrants originating from abroad. MATERIALS AND METHODS: We analyzed the oxygen (18 O/16 O) and strontium (87 Sr/86 Sr) isotope composition of 43 teeth. We also report the 87 Sr/86 Sr composition of an additional 13 molars, 87 Sr/86 Sr values from fauna (n = 10), and soil (n = 5) samples local to the area around Vagnari. The 87 Sr/86 Sr variation map of Italy uses 87 Sr/86 Sr values obtained from previously published data sources from across Italy (n = 199). RESULTS: Converted tooth carbonate (δ18 ODW ) and 87 Sr/86 Sr data indicate that the majority of individuals buried at Vagnari were local to the region. ArcGIS bounded Inverse Distance Weighting (IDW) interpolation of the pan-Italian 87 Sr/86 Sr data set approximates the expected 87 Sr/86 Sr range of Italy's geological substratum, producing the first strontium map of the Italian peninsula. DISCUSSION: Results suggest that only 7% of individuals buried at Vagnari were born elsewhere and migrated to Vagnari, while the remaining individuals were either local to Vagnari (58%), or from the southern Italian peninsula (34%). Our results are consistent with the suggestion that Roman Imperial lower-class populations in southern Italy sustained their numbers through local reproduction measures, and not through large-scale immigration from outside the Italian peninsula.
Assuntos
Isótopos de Oxigênio/análise , Mundo Romano/história , Isótopos de Estrôncio/análise , Dente/química , Migrantes/história , Adolescente , Adulto , Antropologia Física , Cemitérios/história , Feminino , História Antiga , Humanos , Itália , Masculino , Pessoa de Meia-Idade , Solo/química , Adulto JovemRESUMO
Sinkholes are a well-known geologic hazard but their past occurrence, useful for subsidence risk prediction, is difficult to define, especially for ancient historic times. Consequently, our knowledge about Holocene carbonate landscapes is often limited. A multidisciplinary study of Trieste Karst (Italy), close to early Roman military fortifications, led to the identification of possible ancient road tracks, cut by at least one sinkhole. Electrical Resistivity Tomography through the sinkhole has suggested the presence of a cave below its bottom, possibly responsible of the sinkhole formation, while Ground Penetrating Radar has detected no tectonic disturbances underneath the tracks. Additionally, archaeological surveys led to the discovery of over 200 Roman shoe hobnails within or close to the investigated route. According to these data, the tracks are interpreted as the remains of a main Roman road, whose itinerary has been reconstructed for more than 4 km together with other elements of ancient landscape. Our results provide the first known evidence of a Roman main road swallowed by sinkholes and suggest that Holocene karst landscapes could be much different from what previously believed. In fact, sinkholes visible nowadays in the investigated region could have been flat areas filled by sediments up to the Roman time.
Assuntos
Arqueologia , Mundo Romano/história , História Antiga , ItáliaRESUMO
The archaeological excavations carried out in 1999 in the Collatina necropolis of the Roman Imperial Age (1st-3rd centuries AD) (Rome, Italy) discovered the skeletal remains of two adult males with evidence of paranasal lesions. Both individuals showed postmortem damage in the frontal bone, through which it was possible to macroscopically detect an oblong new bone formation. In both specimens, radiological examination of the defects' morphology showed new pediculated-based bone formations. Radiology also confirmed the presence of benign osseous masses arising from the right frontal sinus and interpreted as osteomata. Their dimensions did not exceed 10â¯mm, so that mechanical complications and compression of the adjacent structures could be ruled out. The osteomata of paranasal sinuses are rarely reported in paleopathology, since they can be discovered only incidental to bone breakage or radiography. Hence, the evaluation of their occurrence in past populations represents an important challenge. The two cases presented here show direct and rare evidence of frontal sinus osteomata dating back to the Roman Imperial Age.
Assuntos
Seio Frontal , Osteoma/história , Paleopatologia , Neoplasias dos Seios Paranasais/história , Mundo Romano/história , Adulto , Determinação da Idade pelos Dentes , Restos Mortais/diagnóstico por imagem , Restos Mortais/patologia , Tomografia Computadorizada de Feixe Cônico , Diagnóstico Diferencial , Seio Frontal/diagnóstico por imagem , Seio Frontal/patologia , História Antiga , Humanos , Masculino , Osteoma/diagnóstico por imagem , Osteoma/patologia , Neoplasias dos Seios Paranasais/diagnóstico por imagem , Neoplasias dos Seios Paranasais/patologia , Cidade de Roma , Determinação do Sexo pelo EsqueletoRESUMO
The aim of this research was to determine the species of intestinal parasite present in a Roman Imperial period population in Asia Minor, and to use this information to improve our understanding of health in the eastern Mediterranean region in Roman times. We analyzed five samples from the latrines of the Roman bath complex at Sagalassos, Turkey. Fecal biomarker analysis using 5ß-stanols has indicated the feces were of human origin. The eggs of roundworm (Ascaris) were identified in all five samples using microscopy, and the cysts of the protozoan Giardia duodenalis (which causes dysentery) were identified multiple times in one sample using ELISA. The positive G. duodenalis result at Sagalassos is particularly important as it represents the earliest reliable evidence for this parasite in the Old World (i.e. outside the Americas). As both these species of parasite are spread through the contamination of food and water by fecal material, their presence implies that Roman sanitation technologies such as latrines and public baths did not break the cycle of reinfection in this population. We then discuss the evidence for roundworm in the writings of the Roman physician Galen, who came from Pergamon, another town in western Asia Minor.
Assuntos
Balneologia/história , Enteropatias Parasitárias/história , Enteropatias Parasitárias/parasitologia , Paleopatologia/métodos , Parasitos/isolamento & purificação , Parasitologia/métodos , Mundo Romano/história , Banheiros/história , Animais , Ascaríase/história , Ascaríase/parasitologia , Ascaris/isolamento & purificação , Fezes/parasitologia , Giardia lamblia/isolamento & purificação , Giardíase/história , Giardíase/parasitologia , História Antiga , Humanos , Enteropatias Parasitárias/patologia , Parasitos/classificação , TurquiaRESUMO
The Vadinienses were a Cantabrian people who lived between the first and fourth centuries in the north of the Iberian Peninsula, northeast of the present province of León and the corresponding part of the current territory of Asturias. In this paper we study the possible causes of illness and death of the Vadinienses represented in their gravestones. The analysis of Vadinienses epitaphs shows that two-thirds of the deaths occurred in people between the ages of 20-30, a finding that is not interpreted as representative of the usual age of death at that time. The most likely causes of death are infections and violent deaths in sports competitions or work accidents. Analyzing females independently, almost half of the deceased were under the age of 20, being the main possibilities the deaths related to pregnancy and childbirth at very early ages.
Los vadinienses fueron un pueblo cántabro que habitó entre los siglos I y IV en el norte de la península ibérica -noreste de la actual provincia de León y la parte correspondiente de la actual Asturias-. En este trabajo se estudian las posibles causas de enfermedad y muerte de la población vadiniense representada en sus lápidas funerarias. Dos terceras partes de los vadinienses, según los datos de sus epitafios, murieron entre los 20-30 años, hallazgo que no se interpreta como representativo de la edad de muerte habitual en la época. Se consideran como las causas de muerte más probables las infecciones y las muertes violentas en competiciones deportivas o en accidentes laborales. Cuando se analiza de modo independiente al sexo femenino, casi la mitad de las fallecidas lo hicieron antes de los 20 años de edad, valorando como principales posibilidades las muertes relacionadas con embarazos y partos en edades muy precoces.