Therapeutic hypothermia in term infants after perinatal encephalopathy: The last 5 years in Switzerland

Background: Therapeutic hypothermia (TH) following perinatal asphyxial encephalopathy in term infants improves mortality and neurodevelopmental outcome. In Europe, most neonatal units perform active cooling whereas in Switzerland passive cooling is predominantly used. Aims: (i) To determine how many infants were cooled within the last 5 years in Switzerland, (ii) to assess the cooling methods, (iii) to evaluate the variation of temperature of different cooling methods, and (iv) to evaluate the use of neuromonitoring. Study design: Retrospective cohort study. Patients: Notes of all cooled term infants between March 2005 and December 2010 in 9 perinatal and two paediatric intensive care centres were retrospectively reviewed. Active cooling was compared to passive cooling alone and to passive cooling in combination with gel packs. Results: 150 infants were cooled. Twenty-seven (18.2%) were cooled actively, 34 (23%) passively and 87 (58.8%) passively in combination with gel packs. Variation of temperature was significantly different between the three methods. Passive cooling had a significant higher variation of temperature (SD of 0.89) than both passive cooling in combination with gel packs (SD of 0.79) and active cooling (SD of 0.76). aEEG before TH was obtained in 35.8% of the infants and 86.5% had full EEG. One cUS was performed in 95.3% and MRI in 62.2% of the infants. Conclusion: Target temperature can be achieved with all three cooling methods. Passive cooling has the highest variation of temperature. Neuromonitoring should be improved in Swiss neonatal and paediatric intensive care units. Our results stress the importance of national registries.

Controversies of fetal cardiac intervention

Remarkable advances in ultrasound imaging technology have made it possible to diagnose fetal cardiovascular lesions as early as 12-14 weeks of gestation and to assess their physiological relevance by echocardiography. Moreover, invasive techniques have been developed and refined to relieve significant congenital heart disease (CHD), such as critical aortic and pulmonary stenoses in the pediatric population including neonates. Recognition of the fact that certain CHDs can evolve in utero, and early intervention may improve the outcome by altering the natural history of such conditions has led to the evolution of a new fetal therapy, i.e. fetal cardiac intervention. Two entities, pulmonary valvar atresia and intact ventricular septum (PA/IVS) and hypoplastic left heart syndrome (HLHS), are associated with significant morbidity and mortality even with postnatal surgical therapy. These cases are believed to occur due to restricted blood flow, leading to impaired growth and function of the right or left ventricle. Therefore, several centers started the approach of antenatal intervention with the primary goal of improving the blood flow through the stenotic/atretic valve orifices to allow growth of cardiac structures. Even though centers with a reasonable number of cases seem to have improved the technique and the immediate outcome of fetal interventions, the field is challenged by ethical issues as the intervention puts both the mother and the fetus at risk. Moreover, the perceived benefits of prenatal treatment have to be weighed against steadily improving postnatal surgical and hybrid procedures, which have been shown to reduce morbidity and mortality for these complex heart defects. This review is an attempt to provide a balanced opinion and an update on fetal cardiac intervention.

The Pneumococcal Polysaccharide Capsule and Pneumolysin Differentially Affect CXCL8 and IL-6 Release from Cells of the Upper and Lower Respiratory Tract

The polysaccharide capsule and pneumolysin toxin are major virulence factors of the human bacterial pathogen Streptococcus pneumoniae. Colonization of the nasopharynx is asymptomatic but invasion of the lungs can result in invasive pneumonia. Here we show that the capsule suppresses the release of the pro-inflammatory cytokines CXCL8 (IL-8) and IL-6 from the human pharyngeal epithelial cell line Detroit 562. Release of both cytokines was much less from human bronchial epithelial cells (iHBEC) but levels were also affected by capsule. Pneumolysin stimulates CXCL8 release from both cell lines. Suppression of CXCL8 homologue (CXCL2/MIP-2) release by the capsule was also observed in vivo during intranasal colonization of mice but was only discernable in the absence of pneumolysin. When pneumococci were administered intranasally to mice in a model of long term, stable nasopharyngeal carriage, encapsulated S. pneumoniae remained in the nasopharynx whereas the nonencapsulated pneumococci disseminated into the lungs. Pneumococcal capsule plays a role not only in protection from phagocytosis but also in modulation of the pro-inflammatory immune response in the respiratory tract.

Delay of cortical thinning in very preterm born children

BACKGROUND: Cortical gray matter thinning occurs during childhood due to pruning of inefficient synaptic connections and an increase in myelination. Preterms show alterations in brain structure, with prolonged maturation of the frontal lobes, smaller cortical volumes and reduced white matter volume. These findings give rise to the question if there is a differential influence of age on cortical thinning in preterms compared to controls. AIMS: To investigate the relationship between age and cortical thinning in school-aged preterms compared to controls. STUDY DESIGN AND OUTCOME MEASURES: The automated surface reconstruction software FreeSurfer was applied to obtain measurements of cortical thickness based on T1-weighted MRI images. SUBJECTS: Forty-one preterms (<32weeks gestational age and/or <1500g birth weight) and 30 controls were included in the study (7-12years). RESULTS: In preterms, age correlated negatively with cortical thickness in right frontal, parietal and inferior temporal regions. Furthermore, young preterms showed a thicker cortex compared to old preterms in bilateral frontal, parietal and temporal regions. In controls, age was not associated with cortical thickness. CONCLUSION: In preterms, cortical thinning still seems to occur between the age of 7 and 12years, mainly in frontal and parietal areas whereas in controls, a substantial part of cortical thinning appears to be completed before they reach the age of 7years. These data indicate slower cortical thinning in preterms than in controls.

The impact of a register on the management of neonatal cooling in Switzerland.

BACKGROUND Therapeutic hypothermia following hypoxic ischaemic encephalopathy in term infants was introduced into Switzerland in 2005. Initial documentation of perinatal and resuscitation details was poor and neuromonitoring insufficient. In 2011, a National Asphyxia and Cooling Register was introduced. AIMS To compare management of cooled infants before and after introduction of the register concerning documentation, neuromonitoring, cooling methods and evaluation of temperature variability between cooling methods. STUDY DESIGN Data of cooled infants before the register was in place (first time period: 2005-2010) and afterwards (second time period: 2011-2012) was collected with a case report form. RESULTS 150 infants were cooled during the first time period and 97 during the second time period. Most infants were cooled passively or passively with gel packs during both time periods (82% in 2005-2010 vs 70% in 2011-2012), however more infants were cooled actively during the second time period (18% versus 30%). Overall there was a significant reduction in temperature variability (p < 0.001) comparing the two time periods. A significantly higher proportion of temperature measurements within target temperature range (72% versus 77%, p < 0.001), fewer temperature measurements above (24% versus 7%, p < 0.001) and more temperatures below target range (4% versus 16%, p < 0.001) were recorded during the second time period. Neuromonitoring improved after introduction of the cooling register. CONCLUSION Management of infants with HIE improved since introducing the register. Temperature variability was reduced, more temperature measurements in the target range and fewer temperature measurements above target range were observed. Neuromonitoring has improved, however imaging should be performed more often.

Dinámica vegetal desde el tardiglaciar en la cuenca del Duero: interacciones con clima, fuego e impacto humano

La cuenca del Duero constituye un vasto territorio ibérico cuyo paisaje se encuentra actualmente muy alterado por la mano del hombre y es prácticamente imposible localizar alguna manifestación de su cubierta vegetal natural. Aunque la historia de la vegetación en los sectores central y oriental es relativamente bien conocida, en su mitad occidental los registros paleoecológicos estudiados hasta la fecha son prácticamente inexistentes. Esto hace que se desconozca la respuesta de la vegetación a las diferentes oscilaciones climáticas que se han producido desde el Último Máximo Glaciar, cuál fue el impacto de las diferentes culturas sobre el medio, cuándo se produjo una alteración profunda de la vegetación natural y cuál ha sido la historia de los incendios. Este último aspecto, el papel e importancia de los incendios, reviste un especial interés en la península Ibérica dada su situación geográfica y climática dentro de la cuenca Mediterránea, donde el fuego es un factor ecológico de primer nivel. Las distintas técnicas paleoecológicas son las más adecuadas para abordar todas estas preguntas. De este modo, los avatares de la vegetación a través del tiempo se han reconstruido mediante el análisis polínico y de macrofósiles, el impacto humano se ha trazado utilizando indicadores polínicos ligados a actividades antrópicas y esporas de hongos coprófilos, estudiándose los incendios a partir del registro de partículas microscópicas de carbón. La alta resolución temporal y taxonómica alcanzada en estos análisis, así como la amplia superficie abarcada con los yacimientos estudiados, hacen que la información obtenida sea altamente detallada y complete el conocimiento que se tiene sobre la cuenca del Duero. El Tardiglaciar se registra por primera vez en la Meseta Norte Ibérica en la secuencia de Ayoó de Vidriales, donde una vegetación esteparia prácticamente desarbolada domina durante los periodos fríos. Durante el interestadial Bølling/Allerød la expansión forestal (pinos, abedules) fue muy leve y tardía y fue interrumpida bruscamente por el Dryas Reciente. Al final del Dryas Reciente o al inicio del Holoceno se produjo una acusada y rápida expansión de los bosques. Esta dinámica sugiere que no hubo refugios glaciares importantes en esta zona de la Meseta durante el “Mystery Interval”, aparentemente el periodo más frío y seco. Los incendios fueron muy escasos, aumentando de forma muy brusca al inicio del Holoceno por el aumento de biomasa y las condiciones relativamente cálidas y secas. A partir de los registros de Ayoó y El Maíllo se consolida la importancia del gradiente oceanicidad-continentalidad en el Sistema Central y la Meseta Norte, que se manifiesta principalmente en la dominancia más prolongada de los pinares hacia el interior. Además, otra de las principales contribuciones de la presente tesis es proporcionar evidencia sobre la sucesión de distintos tipos de bosques en el noroeste de la Meseta, precisando el marco temporal en el que suceden. Así, se ha constatado que hubo un máximo desarrollo del bosque caducifolio durante el Holoceno medio en Ayoó de Vidriales y una baja incidencia del fuego que sugieren que el clima fue más húmedo que en el Holoceno inicial. El estudio de macrofósiles leñosos ha permitido detectar procesos que con el análisis polínico habrían pasado desapercibidos, como la persistencia hasta el Holoceno final de Pinus sylvestris en la sierra del Teleno y la sustitución de P. sylvestris por P. pinaster en la sierra de Francia durante el Holoceno inicial. También el estudio de los carbones procedentes de los arenales de Tierra de Pinares han proporcionado la prueba definitiva de la naturalidad de los pinares de P. pinaster. El impacto humano se detecta temprano en las secuencias del oeste de la cuenca del Duero, durante el Neolítico, aunque ha sido mucho más acusado desde la Edad del Hierro (ca 2700-2500 años cal BP). Para la detección del impacto humano temprano ha sido clave el análisis de esporas de hongos coprófilos, cuyo análisis fue incorporado en la secuencia de Ayoó de Vidriales. Una de sus principales consecuencias fue el establecimiento de comunidades de matorral (brezales, piornales) sobre amplias extensiones del occidente de la cuenca del Duero, vinculado al recrudecimiento de los regímenes de incendios. A pesar de que los incendios han sido ecológicamente importantes desde el inicio del Holoceno, los cambios introducidos por el hombre en sus regímenes sobrepasaron la resiliencia de los bosques originales, lo cual condujo a su sustitución sostenida por matorrales. ABSTRACT The Duero Basin constitutes a vast Iberian territory which is currently strongly disturbed due to human activities, so it is very difficult to find any remnant of the natural vegetation. Vegetation history for the eastern and western sectors of the Basin is relatively well-known but, in contrast, there is an almost complete lack of palaeoecological record in the western area. Consequently, there exists a profound ignorance about vegetation responses to the climatic oscillations occurred since the Last Glacial Maximum, the environmental impact of the different cultures, when a severe disturbance of the natural vegetation took place and fire history. The last question, the role and importance of fire, has a special interest in the Iberian Peninsula due to its geographic and climatic framework, the Mediterranean Basin, where fire is a major ecological factor. The diverse palaeoecological techmiques are the most suitable tools to address all these questions. Thus, vegetation shifts through time have been reconstructed using pollen and macrofossil analyses, human impact has been tracked by means of anthropogenic pollen indicators and dung fungal spores, while fire history has been studied from the quantification of microscopic charcoal particles. The high taxonomic and time resolution attained along with the extensive surface covered by the studied sites provide detailed information very useful to complete the knowledge on landscape dynamics in the Duero Basin. The Lateglacial is recorded for the first time in the Northern Iberian Plateau in the sequence from Ayoó de Vidriales, showing that almost treeless steppic vegetation dominated during the cold periods. Tree expansion (pines, birches) was late and slight during the Bølling/Allerød interstadial and was sharply interrupted by the Younger Dryas (YD) climatic reversal. By the end of the YD or the onset of the Holocene, a rapid forest expansion occurred. This forest dynamics suggests an absence of important glacial refugia for trees in this area of the Plateau during the Mystery Interval, apparently the coldest and driest period. Fires were fairly rare, increasing abruptly at the beginning of the Holocene due to the relatively warm and dry climate and the accumulation of biomass. The records from Ayoó and El Maíllo reinforce the role of the oceanicity-continentality gradient in the vegetation history of the Iberian Central Range and the Iberian Northern Plateau, reflected mainly in the longer dominance of pine forests towards inland areas. Further, another important contribution of this PhD Thesis is providing evidence on the succession of different forest types in the northestern fringe of the Plateau, specifying the chronological framework. A maximum of deciduous forest development and low fire activity have been detected in Ayoó de Vidriales during the mid-Holocene, suggesting that climate was wetter than in the early Holocene. The study of woody macrofossils has allowed detecting processes which would have remained unnoticed using pollen analysis alone, such as the persistence of Pinus sylvestris until the late Holocene in the Teleno Mountains and the early Holocene replacement of P. sylvestris with P. pinaster in the sierra de Francia range. The study of macroscopic charcoal fragments from palaeosols of the Tierra de Pinares has also provided the definitive proof of naturalness for the P. pinaster stands gorwing over this area at present. Early human impact, during the Neolithic, has been detected in the sequences from the western sector of the Duero Basin, although human disturbance has been more severe from the Iron Age onwards (ca 2700-2500 cal yr BP). The analysis of coprophilous fungi incorporated in the sequence of Ayoó de Vidriales has played a key role in recognizing that early human impact. One of the main consequences of human disturbance was the establishment of shrubland communities (heaths, brooms) over huge areas of the western Duero Basin, linked to severe and/or frequent fires. Despite fires has been ecologically important since the onset of the Holocene, human-induced changes in fire regimes have exceeded the resilience of original forests leading to a sustained replacement with shrublands.

Vegetation and fire history since the last glacial maximum in an inland area of the western Mediterranean Basin (Northern Iberian Plateau, NW Spain)

We reconstructed vegetation responses to climate oscillations, fire and human activities since the last glacial maximum in inland NW Iberia, where previous paleoecological research is scarce. Extremely sparse and open vegetation composed of steppic grasslands and heathlands with scattered pioneer trees suggests very cold and dry conditions during the Oldest Dryas, unsuitable for tree survival in the surroundings of the study site. Slight woodland expansion during the Bolling/Allerod was interrupted by the Younger Dryas cooling. Pinewoods dominated for most of the early Holocene, when a marked increase in fire activity occurred. Deciduous trees expanded later reaching their maximum representation during the mid-Holocene. Enhanced fire activity and the presence of coprophilous fungi around 6400-6000 cal yr BP suggest an early human occupation around the site. However, extensive deforestation only started at 4500 calyrBP, when fire was used to clear the tree canopy. Final replacement of woodlands with heathlands, grasslands and cereal crops occurred from 2700 cal yr BP onwards due to land-use intensification. Our paleoecological record can help efforts aimed at restoring the natural vegetation by indicating which communities were dominant at the onset of heavy human impact, thus promoting the recovery of currently rare oak and alder stands.

Flower color variation: A model for the experimental study of evolution

We review the study of flower color polymorphisms in the morning glory as a model for the analysis of adaptation. The pathway involved in the determination of flower color phenotype is traced from the molecular and genetic levels to the phenotypic level. Many of the genes that determine the enzymatic components of flavonoid biosynthesis are redundant, but, despite this complexity, it is possible to associate discrete floral phenotypes with individual genes. An important finding is that almost all of the mutations that determine phenotypic differences are the result of transposon insertions. Thus, the flower color diversity seized on by early human domesticators of this plant is a consequence of the rich variety of mobile elements that reside in the morning glory genome. We then consider a long history of research aimed at uncovering the ecological fate of these various flower phenotypes in the southeastern U.S. A large body of work has shown that insect pollinators discriminate against white phenotypes when white flowers are rare in populations. Because the plant is self-compatible, pollinator bias causes an increase in self-fertilization in white maternal plants, which should lead to an increase in the frequency of white genes, according to modifier gene theory. Studies of geographical distributions indicate other, as yet undiscovered, disadvantages associated with the white phenotype. The ultimate goal of connecting ecology to molecular genetics through the medium of phenotype is yet to be attained, but this approach may represent a model for analyzing the translation between these two levels of biological organization.

Applications of pox virus vectors to vaccination: an update.

Recombinant pox viruses have been generated for vaccination against heterologous pathogens. Amongst these, the following are notable examples. (i) The engineering of the Copenhagen strain of vaccinia virus to express the rabies virus glycoprotein. When applied in baits, this recombinant has been shown to vaccinate the red fox in Europe and raccoons in the United States, stemming the spread of rabies virus infection in the wild. (ii) A fowlpox-based recombinant expressing the Newcastle disease virus fusion and hemagglutinin glycoproteins has been shown to protect commercial broiler chickens for their lifetime when the vaccine was administered at 1 day of age, even in the presence of maternal immunity against either the Newcastle disease virus or the pox vector. (iii) Recombinants of canarypox virus, which is restricted for replication to avian species, have provided protection against rabies virus challenge in cats and dogs, against canine distemper virus, feline leukemia virus, and equine influenza virus disease. In humans, canarypox virus-based recombinants expressing antigens from rabies virus, Japanese encephalitis virus, and HIV have been shown to be safe and immunogenic. (iv) A highly attenuated vaccinia derivative, NYVAC, has been engineered to express antigens from both animal and human pathogens. Safety and immunogenicity of NYVAC-based recombinants expressing the rabies virus glycoprotein, a polyprotein from Japanese encephalitis virus, and seven antigens from Plasmodium falciparum have been demonstrated to be safe and immunogenic in early human vaccine studies.

Narrativa digital e infancia. La generación de los creadores colaborativos

La naturaleza de los medios y lenguajes digitales ha posibilitado el desarrollo de diferentes técnicas que, en el canon del mundo analógico, se veían limitadas. Esta combinación ha originado, en los primeros años de vida del ser humano, nuevas formas de aprender envueltas en una nueva realidad. Las técnicas de creación que adquieren los niños en espacios alejados de cualquier currículo escolar, son desarrolladas gracias a su condición de ciudadanos de un contexto de sabios digitales; condición que trae intrínseco un conocimiento en el manejo tecnológico como de manera innata, convirtiendo la narrativa digital en el medio que ellos utilizan para aprender y comunicarse. Como consecuencia, en el modelo EMEREC más individualista se abre paso una generación de creadores colaborativos otorgando, por medio de la participación infantil, una mayor potencialidad a la ley de los tres tercios.

Application and evaluation of classification trees for screening unwanted plants

Risk assessment systems for introduced species are being developed and applied globally, but methods for rigorously evaluating them are still in their infancy. We explore classification and regression tree models as an alternative to the current Australian Weed Risk Assessment system, and demonstrate how the performance of screening tests for unwanted alien species may be quantitatively compared using receiver operating characteristic (ROC) curve analysis. The optimal classification tree model for predicting weediness included just four out of a possible 44 attributes of introduced plants examined, namely: (i) intentional human dispersal of propagules; (ii) evidence of naturalization beyond native range; (iii) evidence of being a weed elsewhere; and (iv) a high level of domestication. Intentional human dispersal of propagules in combination with evidence of naturalization beyond a plants native range led to the strongest prediction of weediness. A high level of domestication in combination with no evidence of naturalization mitigated the likelihood of an introduced plant becoming a weed resulting from intentional human dispersal of propagules. Unlikely intentional human dispersal of propagules combined with no evidence of being a weed elsewhere led to the lowest predicted probability of weediness. The failure to include intrinsic plant attributes in the model suggests that either these attributes are not useful general predictors of weediness, or data and analysis were inadequate to elucidate the underlying relationship(s). This concurs with the historical pessimism that we will ever be able to accurately predict invasive plants. Given the apparent importance of propagule pressure (the number of individuals of an species released), future attempts at evaluating screening model performance for identifying unwanted plants need to account for propagule pressure when collating and/or analysing datasets. The classification tree had a cross-validated sensitivity of 93.6% and specificity of 36.7%. Based on the area under the ROC curve, the performance of the classification tree in correctly classifying plants as weeds or non-weeds was slightly inferior (Area under ROC curve = 0.83 +/- 0.021 (+/- SE)) to that of the current risk assessment system in use (Area under ROC curve = 0.89 +/- 0.018 (+/- SE)), although requires many fewer questions to be answered.

Peat Bog Ecosystems: Tracks across peatlands

Tracks have been made across peatlands for as long as human society has existed. Un - made tracks (i.e. those created simply by regular use, with no construction involved) were probably first created by grazing animals and then presumably also used by early human communities. F ind ing these increasingly impassable with regular use , human societies began to construct ' corduroy roads ' during Neolithic, Bronze and Iron Age times. These first constructed tracks were made from cut timbers ( below ) . Across Europe, ma ny examples of these corduroy roads have been found preserved in lowland bogs, perhaps most famously in the Somerset Levels and more recently at Hatfield Moors on the Humberhead Levels.

Plan d'aménagement et de développement de la municipalité de Saint-Basile au Nouveau-Brunswick

Résumé : L'organisation de l'espace basilien est le reflet culturel de ses habitants. Le paysage humanisé actuel est la résultante de divers artefacts culturels. Pour mieux comprendre l'occupation du sol basilien, il convient de percevoir le milieu physique et humain dans son ensemble, d'examiner à fond les séquences de l'établissement humain et d'identifier les déséquilibres spatiaux temporels qui compromettent l'évolution rationnelle du territoire. L'identification des contraintes et des potentiels du territoire favorise l'élaboration et la conceptualisation d'un plan d'aménagement du territoire équilibré, qui met en valeur l'intégrité de la composante culturelle basilienne. En outre, cette recherche tente d'élucider et de corriger certaines lacunes perceptibles dans le territoire de la municipalité de Saint-Basile.||Abstract : The built up area of Saint-Basile represents the cultural iconography of his inhabitants. Apparently, the cultural landscape is set up from former man made modifications. For a better understanding of the Saint-Basile urban land use, it is a must to perceive and recognize distincly the physical and the human factors abroad; to scrutinize the human settlements sequences since the colonization and to identify the internal land use patterns components who jeopardize the rational developpment of the community. The establishement and the identification of the restreints and the potentiels within the town of Saint-Basile will lead to a design and a better urban land use planning which will preserved the cultural identity of his inhabitants. Therefore, the research tends to light up and rectify some visibles linkages of the Saint-Basile urban land use.

Action and perception: Neural indices of learning in infants

Early human development offers a unique perspective in investigating the potential cognitive and social implications of action and perception. Specifically, during infancy, action production and action perception undergo foundational developments. One essential component to examine developments in action processing is the analysis of others’ actions as meaningful and goal-directed. Little research, however, has examined the underlying neural systems that may be associated with emerging action and perception abilities, and infants’ learning of goal-directed actions. The current study examines the mu rhythm—a brain oscillation found in the electroencephalogram (EEG)—that has been associated with action and perception. Specifically, the present work investigates whether the mu signal is related to 9-month-olds’ learning of a novel goal-directed means-end task. The findings of this study demonstrate a relation between variations in mu rhythm activity and infants’ ability to learn a novel goal-directed means-end action task (compared to a visual pattern learning task used as a comparison task). Additionally, we examined the relations between standardized assessments of early motor competence, infants’ ability to learn a novel goal-directed task, and mu rhythm activity. We found that: 1a) mu rhythm activity during observation of a grasp uniquely predicted infants’ learning on the cane training task, 1b) mu rhythm activity during observation and execution of a grasp did not uniquely predict infants’ learning on the visual pattern learning task (comparison learning task), 2) infants’ motor competence did not predict infants’ learning on the cane training task, 3) mu rhythm activity during observation and execution was not related to infants’ measure of motor competence, and 4) mu rhythm activity did not predict infants’ learning on the cane task above and beyond infants’ motor competence. The results from this study demonstrate that mu rhythm activity is a sensitive measure to detect individual differences in infants’ action and perception abilities, specifically their learning of a novel goal-directed action.

Global distribution of Y-chromosome haplogroup C reveals the prehistoric migration routes of African exodus and early settlement in East Asia

The regional distribution of an ancient Y-chromosome haplogroup C-M130 (Hg C) in Asia provides an ideal tool of dissecting prehistoric migration events. We identified 465 Hg C individuals out of 4284 males from 140 East and Southeast Asian populations. We genotyped these Hg C individuals using 12 Y-chromosome biallelic markers and 8 commonly used Y-short tandem repeats (Y-STRs), and performed phylogeographic analysis in combination with the published data. The results show that most of the Hg C subhaplogroups have distinct geographical distribution and have undergone long-time isolation, although Hg C individuals are distributed widely across Eurasia. Furthermore, a general south-to-north and east-to-west cline of Y-STR diversity is observed with the highest diversity in Southeast Asia. The phylogeographic distribution pattern of Hg C supports a single coastal 'Out-of-Africa' route by way of the Indian subcontinent, which eventually led to the early settlement of modern humans in mainland Southeast Asia. The northward expansion of Hg C in East Asia started similar to 40 thousand of years ago (KYA) along the coastline of mainland China and reached Siberia similar to 15 KYA and finally made its way to the Americas. Journal of Human Genetics (2010) 55, 428-435; doi:10.1038/jhg.2010.40; published online 7 May 2010