A western route of prehistoric human migration from Africa into the Iberian Peninsula.

Being at the western fringe of Europe, Iberia had a peculiar prehistory and a complex pattern of Neolithization. A few studies, all based on modern populations, reported the presence of DNA of likely African origin in this region, generally concluding it was the result of recent gene flow, probably during the Islamic period. Here, we provide evidence of much older gene flow from Africa to Iberia by sequencing whole genomes from four human remains from northern Portugal and southern Spain dated around 4000 years BP (from the Middle Neolithic to the Bronze Age). We found one of them to carry an unequivocal sub-Saharan mitogenome of most probably West or West-Central African origin, to our knowledge never reported before in prehistoric remains outside Africa. Our analyses of ancient nuclear genomes show small but significant levels of sub-Saharan African affinity in several ancient Iberian samples, which indicates that what we detected was not an occasional individual phenomenon, but an admixture event recognizable at the population level. We interpret this result as evidence of an early migration process from Africa into the Iberian Peninsula through a western route, possibly across the Strait of Gibraltar.

A genomic Neolithic time transect of hunter-farmer admixture in central Poland.

Ancient DNA genome-wide analyses of Neolithic individuals from central and southern Europe indicate an overall population turnover pattern in which migrating farmers from Anatolia and the Near East largely replaced autochthonous Mesolithic hunter-gatherers. However, the genetic history of the Neolithic transition in areas lying north of the European Neolithic core region involved different levels of admixture with hunter-gatherers. Here we analyse genome-wide data of 17 individuals spanning from the Middle Neolithic to the Early Bronze Age (4300-1900 BCE) in order to assess the Neolithic transition in north-central Poland, and the local impacts of hunter-farmer contacts and Late Neolithic steppe migrations. We evaluate the influence of these on local populations and assess if and how they change through time, reporting evidence of recurrent hunter-farmer admixture over three millennia, and the co-existence of unadmixed hunter-gatherers as late as 4300 BCE. During the Late Neolithic we report the appearance of steppe ancestry, but on a lesser scale than previously described for other central European regions, with evidence of stronger affinities to hunter-gatherers than to steppe pastoralists. These results help understand the Neolithic palaeogenomics of another central European area, Kuyavia, and highlight the complexity of population interactions during those times.

Quantifying individual specialization using tracking data: a case study on two species of albatrosses.

Many predictive models of spatial and temporal distribution (e.g. in response to climate change or species introductions) assume that species have one environmental niche that applies to all individuals. However, there is growing evidence that individuals can have environmental preferences that are narrower than the species niche. Such individual specialization has mainly been studied in terms of dietary niches, but a recent increase in the availability of individual movement data opens the possibility of extending these analyses to specialisation in environmental preferences. Yet, no study to date on individual specialisation has considered the environmental niche in its multidimensionality. Here we propose a new method for quantifying individual specialisation in multiple dimensions simultaneously. We compare the hypervolumes in n-dimensional environmental niche space of each individual against that of the population, testing for significant differences against a null model. The same method can be applied to a 2-dimensional geographic space to test for site fidelity. We applied this method to test for individual environmental specialisation (across three dimensions: sea surface temperature, eddy kinetic energy, depth) and for site fidelity among satellite-tracked black-browed albatrosses (Thalassarche melanophris) and grey-headed albatrosses (Thalassarche chrysostoma), during chick-rearing at South Georgia. We found evidence for site fidelity in both species and of environmental specialisation among individual grey-headed but not black-browed albatrosses. Specialisation can affect the resilience of populations affected by natural and anthropogenic changes in the environment, and hence has implications for population dynamics and conservation.

Infections on the move: how transient phases of host movement influence disease spread.

Animal movement impacts the spread of human and wildlife diseases, and there is significant interest in understanding the role of migrations, biological invasions and other wildlife movements in spatial infection dynamics. However, the influence of processes acting on infections during transient phases of host movement is poorly understood. We propose a conceptual framework that explicitly considers infection dynamics during transient phases of host movement to better predict infection spread through spatial host networks. Accounting for host transient movement captures key processes that occur while hosts move between locations, which together determine the rate at which hosts spread infections through networks. We review theoretical and empirical studies of host movement and infection spread, highlighting the multiple factors that impact the infection status of hosts. We then outline characteristics of hosts, parasites and the environment that influence these dynamics. Recent technological advances provide disease ecologists unprecedented ability to track the fine-scale movement of organisms. These, in conjunction with experimental testing of the factors driving infection dynamics during host movement, can inform models of infection spread based on constituent biological processes.

The genetics of an early Neolithic pastoralist from the Zagros, Iran.

The agricultural transition profoundly changed human societies. We sequenced and analysed the first genome (1.39x) of an early Neolithic woman from Ganj Dareh, in the Zagros Mountains of Iran, a site with early evidence for an economy based on goat herding, ca. 10,000 BP. We show that Western Iran was inhabited by a population genetically most similar to hunter-gatherers from the Caucasus, but distinct from the Neolithic Anatolian people who later brought food production into Europe. The inhabitants of Ganj Dareh made little direct genetic contribution to modern European populations, suggesting those of the Central Zagros were somewhat isolated from other populations of the Fertile Crescent. Runs of homozygosity are of a similar length to those from Neolithic farmers, and shorter than those of Caucasus and Western Hunter-Gatherers, suggesting that the inhabitants of Ganj Dareh did not undergo the large population bottleneck suffered by their northern neighbours. While some degree of cultural diffusion between Anatolia, Western Iran and other neighbouring regions is possible, the genetic dissimilarity between early Anatolian farmers and the inhabitants of Ganj Dareh supports a model in which Neolithic societies in these areas were distinct.

Food intake rates of inactive fish are positively linked to boldness in three-spined sticklebacks Gasterosteus aculeatus.

To investigate the link between personality and maximum food intake of inactive individuals, food-deprived three-spined sticklebacks Gasterosteus aculeatus at rest in their home compartments were provided with ad libitum prey items. Bolder individuals ate considerably more than shyer individuals, even after accounting for body size, while sociability did not have an effect. These findings support pace-of-life theory predicting that life-history strategies are linked to boldness.

Ancient Ethiopian genome reveals extensive Eurasian admixture throughout the African continent.

Characterizing genetic diversity in Africa is a crucial step for most analyses reconstructing the evolutionary history of anatomically modern humans. However, historic migrations from Eurasia into Africa have affected many contemporary populations, confounding inferences. Here, we present a 12.5× coverage ancient genome of an Ethiopian male ("Mota") who lived approximately 4500 years ago. We use this genome to demonstrate that the Eurasian backflow into Africa came from a population closely related to Early Neolithic farmers, who had colonized Europe 4000 years earlier. The extent of this backflow was much greater than previously reported, reaching all the way to Central, West, and Southern Africa, affecting even populations such as Yoruba and Mbuti, previously thought to be relatively unadmixed, who harbor 6 to 7% Eurasian ancestry.

Social and ecological change over a decade in a village hunting system, central Gabon.

Despite widespread recognition of the major threat to tropical forest biological diversity and local food security posed by unsustainable bushmeat hunting, virtually no long-term studies tracking the socioecological dynamics of hunting systems have been conducted. We interviewed local hunters and collected detailed hunting data to investigate changes in offtake and hunter characteristics over 10 years (2001-2010) in Dibouka and Kouagna villages, central Gabon, in the context of hunter recollections of longer term trends since the 1950s. To control for changes in hunter behavior, such as trap location and characteristics, we report hunting offtake data per trap. Our results suggest the hunting area was already highly depleted by 2001; local hunters reported that 16 large-bodied prey species had become rare or locally extirpated over the last 60 years. Overall, we observed no significant declines in hunting offtake or changes in species composition from 2001 to 2010, and offtakes per trap increased slightly between 2004 and 2010. However, trapping distance from the villages increased, and there was a switch in hunting techniques; a larger proportion of the catch was hunted with guns in 2010. The number of hunters declined by 20% from 2004 to 2010, and male livelihood activities shifted away from hunting. Hunters with the lowest hunting incomes in 2004 were more likely than successful hunters to have moved away from the village by 2010 (often in response to alternative employment opportunities). Therefore, changes in trap success (potentially related to biological factors) were interacting with system-level changes in hunter number and composition (related to external socioeconomic factors) to produce a relatively static overall offtake. Our results highlight the importance of understanding the small-scale context of hunting to correctly interpret changes or apparent stasis in hunting effort and offtake over time.

Relationship between roving behaviour and the diet and client composition of the cleaner fish Labroides bicolor.

Diet analyses and observations of cleaning behaviour of two cleaner fishes revealed that Labroides bicolor fed more on client mucus, but Labroides dimidiatus fed more on ectoparasites, and that L. bicolor interacted with fewer species (36 species) compared with L. dimidiatus (44 species). The client species which contributed most to the dissimilarity between cleaner species were the dusky farmerfish Stegastes nigricans and bicolor chromis Chromis margaritifer damselfishes, which L. dimidiatus interacted with more often than L. bicolor, and the striated Ctenochaetus striatus and brown Acanthurus nigrofuscus surgeonfishes, which L. bicolor interacted with more; L. bicolor interacted with all parrotfishes (Scaridae) more. These results confirm the importance of repeated interactions and partner choice in determining the nature of interactions in mutualisms.

Fractura de Cadera en los hospitales públicos de la Argentina / Hip Fracture in Public Hospitals of Argentina

La fractura de cadera en población añosa constituye un problema creciente para los sistemas de salud a nivel mundial debido a su elevado impacto econámico y social. Objetivos: Evaluar los egresos por fractura de cadera en adultos mayores de 55 años informados al Ministerio de Salud de la Nación durante los años 2000, 2006, 2007 y 2008. Analizar el efecto de la edad y sexo sobre la incidencia de fracturas de cadera, los tipos de fractura y su variabilidad en el tiempo. Materiales y Métodos: Se obtuvieron los datos de egresos por fracturas de cadera en pacientes mayores de 55 años registrados en el Ministerio de Salud de la Nación. Se calculá la Tasa de Egresos (TE) por fracturas de cadera, la TE estratificada por sexo (♀: mujer, ♂: varán) y edad; Tasa de Crecimiento Interanual (TCI). Estadística: test de Chi cuadrado y test T de Student para datos no apareados. Resultados y Conclusiones: La fractura de cadera en los hospitales públicos de la Argentina durante los años evaluados, alcanzá un promedio de 5700 egresos/año, con una TE 280/100000. La relación ♀/♂ fue de 2,3. La edad de egreso promedio fue de 78,7 años siendo significativamente menor en los hombres en relación a las mujeres. La relación ♀/♂ aumentá tres veces con la edad. La edad fue un fuerte determinante de las fracturas, siendo la TE de 2800/100000 en los individuos mayores de 75 años. La TCI fue de 1,4 %. La fractura cervical de fémur fue la más frecuente, y fue aumentando progresivamente con la edad; la fractura de trocánter se mantuvo estable en los grupos de menor edad y solo aumentá en los mayores de 75 años. Ambos tipos de fractura predominaron en las mujeres. Este es el primer trabajo que establece datos sobre fractura de cadera en la Argentina. Con el envejecimiento de la población, la fractura de cadera se convertirá en una carga progresivamente mayor para los sistemas de salud.

Hip fracture in the aged population constitutes a growing problem for health systems at a global level because of its economic and social impact. Objectives: to assess discharges for hip fracture in adults over the age of 55 reported to the Ministry of Health of Argentina during the years 2000, 2006, 2007 and 2008; analyze the effect of age and sex on the incidence of hip fractures and its variability over time. Materials and Methods: The discharge data for hip fractures in patients over 55 years were obtained from registers of the Ministry of Health of Argentina. We calculated the Discharge Rate (DR) by hip fractures, DR of fractures stratified by sex (♀: female, ♂: male) and age; the Annual Growth Rate (AGR). Statistics: Student test and Chi square test. Results and Conclusions: Hip fracture in public hospitals in Argentina in the evaluated years reached an average of 5700 discharges per year, with a DR 280/100000. The.♀/♂ ratio was 2.3. The average discharge age was 78.7 years, significantly lower in men in relation to women. The relationship ^/c? increased three times with age. The age was a strong determinant of fracture so the DR was 2800/100000 in people older than 75 years. The AGR was 1.4 %. Cervical fracture was the most frequent, and increased progressively with age; the trochanteric remained stable in the younger age groups and increased in people over 75 years. Both were more common in women. This is the first trial on hip fracture data in Argentina. Given population aging hip fracture will become a progressively larger burden on public health.

Fractura de Cadera en los hospitales públicos de la Argentina / Hip Fracture in Public Hospitals of Argentina

La fractura de cadera en población añosa constituye un problema creciente para los sistemas de salud a nivel mundial debido a su elevado impacto econámico y social. Objetivos: Evaluar los egresos por fractura de cadera en adultos mayores de 55 años informados al Ministerio de Salud de la Nación durante los años 2000, 2006, 2007 y 2008. Analizar el efecto de la edad y sexo sobre la incidencia de fracturas de cadera, los tipos de fractura y su variabilidad en el tiempo. Materiales y Métodos: Se obtuvieron los datos de egresos por fracturas de cadera en pacientes mayores de 55 años registrados en el Ministerio de Salud de la Nación. Se calculá la Tasa de Egresos (TE) por fracturas de cadera, la TE estratificada por sexo (♀: mujer, ♂: varán) y edad; Tasa de Crecimiento Interanual (TCI). Estadística: test de Chi cuadrado y test T de Student para datos no apareados. Resultados y Conclusiones: La fractura de cadera en los hospitales públicos de la Argentina durante los años evaluados, alcanzá un promedio de 5700 egresos/año, con una TE 280/100000. La relación ♀/♂ fue de 2,3. La edad de egreso promedio fue de 78,7 años siendo significativamente menor en los hombres en relación a las mujeres. La relación ♀/♂ aumentá tres veces con la edad. La edad fue un fuerte determinante de las fracturas, siendo la TE de 2800/100000 en los individuos mayores de 75 años. La TCI fue de 1,4 %. La fractura cervical de fémur fue la más frecuente, y fue aumentando progresivamente con la edad; la fractura de trocánter se mantuvo estable en los grupos de menor edad y solo aumentá en los mayores de 75 años. Ambos tipos de fractura predominaron en las mujeres. Este es el primer trabajo que establece datos sobre fractura de cadera en la Argentina. Con el envejecimiento de la población, la fractura de cadera se convertirá en una carga progresivamente mayor para los sistemas de salud.(AU)

Hip fracture in the aged population constitutes a growing problem for health systems at a global level because of its economic and social impact. Objectives: to assess discharges for hip fracture in adults over the age of 55 reported to the Ministry of Health of Argentina during the years 2000, 2006, 2007 and 2008; analyze the effect of age and sex on the incidence of hip fractures and its variability over time. Materials and Methods: The discharge data for hip fractures in patients over 55 years were obtained from registers of the Ministry of Health of Argentina. We calculated the Discharge Rate (DR) by hip fractures, DR of fractures stratified by sex (♀: female, ♂: male) and age; the Annual Growth Rate (AGR). Statistics: Student test and Chi square test. Results and Conclusions: Hip fracture in public hospitals in Argentina in the evaluated years reached an average of 5700 discharges per year, with a DR 280/100000. The.♀/♂ ratio was 2.3. The average discharge age was 78.7 years, significantly lower in men in relation to women. The relationship ^/c? increased three times with age. The age was a strong determinant of fracture so the DR was 2800/100000 in people older than 75 years. The AGR was 1.4 %. Cervical fracture was the most frequent, and increased progressively with age; the trochanteric remained stable in the younger age groups and increased in people over 75 years. Both were more common in women. This is the first trial on hip fracture data in Argentina. Given population aging hip fracture will become a progressively larger burden on public health.(AU)

Distribution and use of income from bushmeat in a rural village, central Gabon.

Bushmeat hunting is an activity integral to rural forest communities that provides a high proportion of household incomes and protein requirements. An improved understanding of the relationship between bushmeat hunting and household wealth is vital to assess the potential effects of future policy interventions to regulate an increasingly unsustainable bushmeat trade. We investigated the relationship between hunting offtake and household wealth, gender differences in spending patterns, and the use of hunting incomes in two rural forest communities, Central Gabon, from 2003 to 2005. Households in which members hunted (hunting households) were significantly wealthier than households in which no one hunted (nonhunting households), but within hunting households offtakes were not correlated with household wealth. This suggests there are access barriers to becoming a hunter and that hunting offtakes may not be the main driver of wealth accumulation. Over half of the money spent by men in the village shop was on alcohol and cigarettes, and the amount and proportion of income spent on these items increased substantially with increases in individual hunting offtake. By contrast, the majority of purchases made by women were of food, but their food purchases decreased actually and proportionally with increased household hunting offtake. This suggests that the availability of bushmeat as a food source decreases spending on food, whereas hunting income may be spent in part on items that do not contribute significantly to household food security. Conservation interventions that aim to reduce the commercial bushmeat trade need to account for likely shifts in individual spending that may ensue and the secondary effects on household economies.

How accurate is the current picture of human genetic variation?

Our understanding of the distribution of worldwide human genomic diversity has greatly increased over recent years thanks to the availability of large data sets derived from short tandem repeats (STRs), insertion deletion polymorphisms (indels) and single nucleotide polymorphisms (SNPs). A concern, however, is that the current picture of worldwide human genomic diversity may be inaccurate because of biases in the selection process of genetic markers (so-called 'ascertainment bias'). To evaluate this problem, we first compared the distribution of genomic diversity between these three types of genetic markers in the populations from the HGDP-CEPH panel for evidence of bias or incongruities. In a second step, using a very relaxed set of criteria to prevent the intrusion of bias, we developed a new set of unbiased STR markers and compared the results against those from available panels. Contrarily to recent claims, our results show that the STR markers suffer from no discernible bias, and can thus be used as a baseline reference for human genetic diversity and population differentiation. The bias on SNPs is moderate compared to that on the set of indels analysed, which we recommend should be avoided for work describing the distribution of human genetic diversity or making inference on human settlement history.

Determinants of reproductive success in dominant female meerkats.

1. In cooperative societies with high reproductive skew, selection on females is likely to operate principally through variation in the probability of acquiring dominant status and variation in reproductive success while dominant. Despite this, few studies of cooperative societies have investigated the factors that influence which females become dominant, and/or their reproductive output while in the dominant position. 2. Here we use long-term data from a wild meerkats population to describe variation in the breeding success of dominant female meerkats Suricata suricatta and investigate its causes. 3. Female meerkats compete intensely for breeding positions, and the probability of acquiring the breeding role depends upon a female's age in relation to competitors and her weight, both at the time of dominance acquisition and early in life. 4. Once dominant, individual differences in breeding success depend principally on the duration of dominance tenure. Females remain for longer in the dominant position if they are heavier than their competitors at the start of dominance, and if the number of adult female competitors at the start is low. 5. Female breeding success is also affected by variation in fecundity and pup survival, both of which increase with group size. After controlling for these effects, female body weight has a positive influence on breeding rate and litter size, while the number of adult female competitors reduces litter survival. 6. These findings suggest that selection for body weight and competitive ability will be high in female meerkats, which may moderate their investment in cooperative activities. We suggest that similar consequences of competition may occur among females in other cooperative societies where the benefits of attaining dominance status are high.

Genome-wide characterisation of hepatitis B mutations involved in clinical outcome.

Infection with the hepatitis B virus (HBV) leads to different disease outcomes, which can be broadly divided into three categories: acute mild infection, 'fulminant' and chronic hepatitis (long-term persistent form of the infection). The factors that influence the development of these different disease states are poorly understood and may include viral polymorphisms. To investigate this possibility, we analysed 116 published complete HBV genomes for which we knew disease outcome and had access to associated information on patients (age, sex and geographic origin). Our best statistical model correctly classified 72% of the cases and retained age and sex of the patient, as well as 29 candidate mutations. With the exception of one mutation in the X gene, all were located in the viral polymerase, suggesting this gene plays a critical role in clinical outcome. Our results highlight the importance of the genetics of HBV strains in the evolution of the disease and demonstrate that disease outcome can be predicted to a surprisingly large extent with a limited number of host and viral factors.

[Mycoplasma pneumoniae pneumonia: clinical and radiological features] / Diferentes apresentações clínico-radiológicas da pneumonia.

OBJECTIVE: To alert about the great variability of clinical and radiological features of Mycoplasma pneumoniae pneumonia in pediatric patients. Although it has been referred as a prevalent entity in children, its diagnosis is, many times, retarded due to the lack of a pattern that can really be considered classic.METHODS: The authors present 5 cases of mycoplasma pneumonia in children. Diagnostic difficulties, clinical features, radiological findings and evolution after treatment are discussed. The cases have their significant peculiarities confronted with the findings of medical literature of the last two decades, obtained through a bibliographic research in Medline about the subject.RESULTS: All the patients were between 6 and 9 years old, characteristically the most prevalent age group for this infection. In none of the cases the possibility of mycoplasma infection was considered at first. Clinical hypothesis like sinusal aspirative pneumonia, tuberculosis, and asthma were initially considered, but later on discarded. Except for one, all the other patients referred previous treatment with antibiotics. The initial radiological findings were different among the cases: bronchopneumonic consolidations, pleural effusion, perihilar adenopathy with interstitial infiltrated, and atelectasic areas. After the institution of specific therapy, clinical and radiological evolution was favorable in all cases.CONCLUSIONS: Mycoplasma pneumoniae pneumonia has a great sort of clinical presentations. In the same way the complementary radiological investigation may also demonstrate different patterns of presentation. Due to its great variability, mycoplasma is not commonly considered as the first diagnosis, even though it is a prevalent disease at pediatric age. This may lead to a delay in the diagnosis and institution of an appropriate treatment.