825 research outputs found
Heterogeneity in genetic admixture across different regions of Argentina
The population of Argentina is the result of the intermixing between several groups, including Indigenous American, European and African populations. Despite the commonly held idea that the population of Argentina is of mostly European origin, multiple studies have shown that this process of admixture had an impact in the entire Argentine population. In the present study we characterized the distribution of Indigenous American, European and African ancestry among individuals from different regions of Argentina and evaluated the level of discrepancy between self-reported grandparental origin and genetic ancestry estimates. A set of 99 autosomal ancestry informative markers (AIMs) was genotyped in a sample of 441 Argentine individuals to estimate genetic ancestry. We used non-parametric tests to evaluate statistical significance. The average ancestry for the Argentine sample overall was 65% European (95%CI: 63-68%), 31% Indigenous American (28-33%) and 4% African (3-4%). We observed statistically significant differences in European ancestry across Argentine regions [Buenos Aires province (BA) 76%, 95%CI: 73-79%; Northeast (NEA) 54%, 95%CI: 49-58%; Northwest (NWA) 33%, 95%CI: 21-41%; South 54%, 95%CI: 49-59%; p<0.0001] as well as between the capital and immediate suburbs of Buenos Aires city compared to more distant suburbs [80% (95%CI: 75-86%) versus 68% (95%CI: 58-77%), p = 0.01]. European ancestry among individuals that declared all grandparents born in Europe was 91% (95%CI: 88-94%) compared to 54% (95%CI: 51-57%) among those with no European grandparents (p<0.001). Our results demonstrate the range of variation in genetic ancestry among Argentine individuals from different regions in the country, highlighting the importance of taking this variation into account in genetic association and admixture mapping studies in this population
Towards constraints on the SUSY seesaw from flavour-dependent leptogenesis
We systematically investigate constraints on the parameters of the
supersymmetric type-I seesaw mechanism from the requirement of successful
thermal leptogenesis in the presence of upper bounds on the reheat temperature
of the early Universe. To this end, we solve the
flavour-dependent Boltzmann equations in the MSSM, extended to include
reheating. With conservative bounds on , leading to mildly
constrained scenarios for thermal leptogenesis, compatibility with observation
can be obtained for extensive new regions of the parameter space, due to
flavour-dependent effects. On the other hand, focusing on (normal) hierarchical
light and heavy neutrinos, the hypothesis that there is no CP violation
associated with the right-handed neutrino sector, and that leptogenesis
exclusively arises from the CP-violating phases of the matrix,
is only marginally consistent. Taking into account stricter bounds on
further suggests that (additional) sources of CP violation must
arise from the right-handed neutrino sector, further implying stronger
constraints for the right-handed neutrino parameters.Comment: 42 pages, 12 figures; final version published in JCAP; numerical
results for the efficiency factor can be downloaded from
http://www.newphysics.eu/leptogenesis
BOB-RED queue management for IEEE 802.15.4 wireless sensor networks
This study is aimed at exploring why many economists propose a transfer scheme and debt mutualisation for the Eurozone. This would equip the Eurozone with better tools to deal with an economic shock, like the 2010-2012 sovereign debt crisis, thus making it more financially stable. After the theoretical presentation, the study presents a unique institutional design with an EU Treasury that manages debt mutualisation and a transfer scheme as well as other competences that address other present economic challenges. Crucial to the study are the issues of moral hazard and adverse selection that arise when thinking of European economic integration.L’objectiu del treball és explorar la raó per la qual molts economistes proposen un sistema de transferències fiscals i la mutualització del deute a l’Eurozona. Així se la dotaria amb eines més efectives per pal·liar un xoc econòmic, com la crisi del deute sobirà del 2010-2012. A continuació, es presenta un disseny institucional únic d’un Tresor de l’Euro que gestionaria les competències esmentades (i d’altres) per combatre alguns dels reptes econòmics actuals. El risc moral i de selecció adversa, qüestions que sorgeixen en pensar la drecera que ha de prendre la integració econòmica Europea, són cabdals per aquest estudi
‘Here to support anybody who needs to come’? An investigation of the provision for EAL pupils in secondary school libraries in England
This paper presents the findings of a mixed methods investigation of the effectiveness of provision for
EAL pupils by secondary school libraries in England. Data from a quantitative survey of secondary
school librarians are triangulated with those of qualitative interviews with staff responsible for EAL
provision. A picture emerges of a hybrid environment which addresses a number of the educational,
cultural and social needs of EAL learners, but in which a series of barriers to effective provision are
also identified. Recommendations are made to key stakeholder groups for the short and long term
improvement of EAL provision, and for further research
Can sleep and resting behaviours be used as indicators of welfare in shelter dogs (Canis lupusfamiliaris)?
Previous research on humans and animals suggests that the analysis of sleep patterns
may reliably inform us about welfare status, but little research of this kind has been carried
out for non-human animals in an applied context. This study explored the use of sleep and
resting behaviour as indicators of welfare by describing the activity patterns of dogs (Canis
lupus familiaris) housed in rescue shelters, and comparing their sleep patterns to other
behavioural and cognitive measures of welfare. Sleep and activity patterns were observed
over five non-consecutive days in a population of 15 dogs. Subsequently, the characteristics
of sleep and resting behaviour were described and the impact of activity on patterns of
sleep and resting behaviour analysed. Shelter dogs slept for 2.8% of the day, 14.3% less
than previously reported and experienced less sleep fragmentation at night (32 sleep
bouts). There were no statistically significant relationships between behaviours exhibited
during the day and sleep behaviour. A higher proportion of daytime resting behaviour was
significantly associated with a positive judgement bias, less repetitive behaviour and
increased time spent coded as ‘relaxed’ across days by shelter staff. These results suggest
that, in the context of a busy shelter environment, the ability to rest more during the day
could be a sign of improved welfare. Considering the non-linear relationship between sleep
and welfare in humans, the relationship between sleep and behavioural indicators of welfare,
including judgement bias, in shelter dogs may be more complex than this study could
detect
Standardisation of magnetic nanoparticles in liquid suspension
Suspensions of magnetic nanoparticles offer diverse opportunities for technology innovation, spanning a large number of industry sectors from imaging and actuation based applications in biomedicine and biotechnology, through large-scale environmental remediation uses such as water purification, to engineering-based applications such as position-controlled lubricants and soaps. Continuous advances in their manufacture have produced an ever-growing range of products, each with their own unique properties. At the same time, the characterisation of magnetic nanoparticles is often complex, and expert knowledge is needed to correctly interpret the measurement data. In many cases, the stringent requirements of the end-user technologies dictate that magnetic nanoparticle products should be clearly defined, well characterised, consistent and safe; or to put it another way—standardised. The aims of this document are to outline the concepts and terminology necessary for discussion of magnetic nanoparticles, to examine the current state-of-the-art in characterisation methods necessary for the most prominent applications of magnetic nanoparticle suspensions, to suggest a possible structure for the future development of standardisation within the field, and to identify areas and topics which deserve to be the focus of future work items. We discuss potential roadmaps for the future standardisation of this developing industry, and the likely challenges to be encountered along the way
Rubber-Modified Glassy Amorphous Polymers Prepared via Chemically Induced Phase Separation. 4. Comparison of Properties of Semi- and Full-IPNs, and Copolymers of Acrylate−Aliphatic Epoxy Systems
Integrated population models poorly estimate the demographic contribution of immigration
Estimating the contribution of demographic parameters to changes in population growth is essential for understanding why populations fluctuate. Integrated population models (IPMs) offer a possibility to estimate the contributions of additional demographic parameters, for which no data have been explicitly collected—typically immigration. Such parameters are often subsequently highlighted as important drivers of population growth. Yet, accuracy in estimating their temporal variation, and consequently their contribution to changes in population growth rate, has not been investigated.
To quantify the magnitude and cause of potential biases when estimating the contribution of immigration using IPMs, we simulated data (using northern wheatear Oenanthe oenanthe population estimates) from controlled scenarios to examine potential biases and how they depend on IPM parameterization, formulation of priors, the level of temporal variation in immigration and sample size. We also used empirical data on populations with known rates of immigration: Soay sheep Ovis aries and Mauritius kestrel Falco punctatus with zero immigration and grey wolf Canis lupus in Scandinavia with near-zero immigration.
IPMs strongly overestimated the contribution of immigration to changes in population growth in scenarios when immigration was simulated with zero temporal variation (proportion of variance attributed to immigration = 63% for the more constrained formulation and real sample size) and in the wild populations, where the true number of immigrants was zero or near-zero (kestrel 19.1%–98.2%, sheep 4.2%–36.1% and wolf 84.0%–99.2%). Although the estimation of the contribution of immigration in the simulation study became more accurate with increasing temporal variation and sample size, it was often not possible to distinguish between an accurate estimation from data with high temporal variation versus an overestimation from data with low temporal variation. Unrealistically, large sample sizes may be required to estimate the contribution of immigration well.
To minimize the risk of overestimating the contribution of immigration (or any additional parameter) in IPMs, we recommend to: (a) look for evidence of variation in immigration before investigating its contribution to population growth, (b) simulate and model data for comparison to the real data and (c) use explicit data on immigration when possible
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