Segregation of regulatory polymorphisms with effects on the gluteus medius transcriptome in a purebred pig population

Background: The main goal of the present study was to analyse the genetic architecture of mRNA expression in muscle, a tissue with an outmost economic importance for pig breeders. Previous studies have used F2 crosses to detect porcine expression QTL (eQTL), so they contributed with data that mostly represents the between-breed component of eQTL variation. Herewith, we have analysed eQTL segregation in an outbred Duroc population using two groups of animals with divergent fatness profiles. This approach is particularly suitable to analyse the within-breed component of eQTL variation, with a special emphasis on loci involved in lipid metabolism. Methodology/Principal Findings: GeneChip Porcine Genome arrays (Affymetrix) were used to determine the mRNA expression levels of gluteus medius samples from 105 Duroc barrows. A whole-genome eQTL scan was carried out with a panel of 116 microsatellites. Results allowed us to detect 613 genome-wide significant eQTL unevenly distributed across the pig genome. A clear predominance of trans- over cis-eQTL, was observed. Moreover, 11 trans-regulatory hotspots affecting the expression levels of four to 16 genes were identified. A Gene Ontology study showed that regulatory polymorphisms affected the expression of muscle development and lipid metabolism genes. A number of positional concordances between eQTL and lipid trait QTL were also found, whereas limited evidence of a linear relationship between muscle fat deposition and mRNA levels of eQTL regulated genes was obtained. Conclusions/Significance: Our data provide substantial evidence that there is a remarkable amount of within-breed genetic variation affecting muscle mRNA expression. Most of this variation acts in trans and influences biological processes related with muscle development, lipid deposition and energy balance. The identification of the underlying causal mutations and the ascertainment of their effects on phenotypes would allow gaining a fundamental perspective about how complex traits are built at the molecular level.

Y-chromosome diversity in native mexicans reveals continental transition of genetic structure in the Americas

The genetic characterization of Native Mexicans is important to understand multiethnic based features influencing the medical genetics of present Mexican populations, as well as to the reconstruct the peopling of the Americas. We describe the Y-chromosome genetic diversity of 197 Native Mexicans from 11 populations and 1,044 individuals from 44 Native American populations after combining with publicly available data. We found extensive heterogeneity among Native Mexican populations and ample segregation of Q-M242* (46%) and Q-M3 (54%) haplogroups within Mexico. The northernmost sampled populations falling outside Mesoamerica (Pima and Tarahumara) showed a clear differentiation with respect to the other populations, which is in agreement with previous results from mtDNA lineages. However, our results point toward a complex genetic makeup of Native Mexicans whose maternal and paternal lineages reveal different narratives of their population history, with sex-biased continental contributions and different admixture proportions. At a continental scale, we found that Arctic populations and the northernmost groups from North America cluster together, but we did not find a clear differentiation within Mesoamerica and the rest of the continent, which coupled with the fact that the majority of individuals from Central and South American samples are restricted to the Q-M3 branch, supports the notion that most Native Americans from Mesoamerica southwards are descendants from a single wave of migration. This observation is compatible with the idea that present day Mexico might have constituted an area of transition in the diversification of paternal lineages during the colonization of the Americas.

Moral hazard and dynamics of insider ownership stakes

In this paper, I analyze the ownership dynamics of N strategic risk-averse corporate insiders facing a moral hazard problem. A solution for the equilibrium share price and the dynamics of the aggregate insider stake is obtained in two cases: when agents can crediblycommit to an optimal ownership policy and when they cannot commit (time-consistent case). Inthe latter case, the aggregate stake gradually adjusts towards the competitive allocation. The speed of adjustment increases with N when outside investors are risk-averse, and does not depend on it when investors are risk-neutral. Predictions of the model are consistent with recent empirical findings.

Genetic evidence of heterogeneity in intrahepatic cholestasis of pregnancy

Background and aims: The aim of this study was to investigate the genetic aetiology of intrahepatic cholestasis of pregnancy (ICP) and the impact of known cholestasis genes (BSEP, FIC1, and MDR3) on the development of this disease. Patients and methods: Sixty nine Finnish ICP patients were prospectively interviewed for a family history of ICP, and clinical features were compared in patients with familial ICP (patients with a positive family history, n=11) and sporadic patients (patients with no known family history of ICP, n=58). For molecular genetic analysis, 16 individuals from two independently ascertained Finnish ICP families were genotyped for the flanking markers for BSEP, FIC1, and MDR3. Results: The pedigree structures in 16% (11/69) of patients suggested dominant inheritance. Patients with familial ICP had higher serum aminotransferase levels and a higher recurrence risk (92% v 40%). Both segregation of haplotypes and multipoint linkage analysis excluded BSEP, FIC1, and MDR3 genes in the studied pedigrees. Additionally, the MDR3 gene, previously shown to harbour mutations in ICP patients, was negative for mutations when sequenced in four affected individuals from the two families. Conclusions: These results support the hypothesis that the aetiology of ICP is heterogeneous and that ICP is due to a genetic predisposition in a proportion of patients. The results of molecular genetic analysis further suggest that the previously identified three cholestasis genes are not likely to be implicated in these Finnish ICP families with dominant inheritance.

A comparison of rapid bioassessment protocols used in 2 regions with Mediterranean climates, the Iberian Peninsula and South Africa

Abstract. The ability of 2 Rapid Bioassessment Protocols (RBPs) to assess stream water quality was compared in 2 Mediterranean-climate regions. The most commonly used RBPs in South Africa (SAprotocol) and the Iberian Peninsula (IB-protocol) are both multihabitat, field-based methods that use macroinvertebrates. Both methods use preassigned sensitivity weightings to calculate metrics and biotic indices. The SA- and IB-protocols differ with respect to sampling equipment (mesh size: 1000 lm vs 250 300 lm, respectively), segregation of habitats (substrate vs flow-type), and sampling and sorting procedures (variable time and intensity). Sampling was undertaken at 6 sites in South Africa and 5 sites in the Iberian Peninsula. Forty-four and 51 macroinvertebrate families were recorded in South Africa and the Iberian Peninsula, respectively; 77.3% of South African families and 74.5% of Iberian Peninsula families were found using both protocols. Estimates of community similarity compared between the 2 protocols were .60% similar among sites in South Africa and .54% similar among sites in the Iberian Peninsula (BrayCurtis similarity), and no significant differences were found between protocols (Multiresponse Permutation Procedure). Ordination based on Non-metric Multidimensional Scaling grouped macroinvertebrate samples on the basis of site rather than protocol. Biotic indices generated with the 2 protocols at each site did not differ. Thus, both RBPs produced equivalent results, and both were able to distinguish between biotic communities (mountain streams vs foothills) and detect water-quality impairment, regardless of differences in sampling equipment, segregation of habitats, and sampling and sorting procedures. Our results indicate that sampling a single habitat may be sufficient for assessing water quality, but a multihabitat approach to sampling is recommended where intrinsic variability of macroinvertebrate assemblages is high (e.g., in undisturbed sites in regions with Mediterranean climates). The RBP of choice should depend on whether the objective is routine biomonitoring of water quality or autecological or faunistic studies.

Suburbanisation and international immigration: The case of The Barcelona Metropolitan Region (1998-2009)

This last decade, main Spanish urban areas have received large amounts of international immigrants, modifying (sub)urban dynamics. The paper specifically explores the Metropolitan Region of Barcelona (RMB), where, between 1998 and 2009, foreign nationality residents rose from 1.8 to 14.9% of total population.Research focuses on the impact of foreign immigration on three specific dynamics: population growth and distribution/segregation of both Spanish and foreign populations within the metropolitan area; their respective residential mobility patterns; and consequences on their age and sex structure. Results show that there are remarkable differences between the two populations: foreign immigrants have preferably settled in the core city"s least affluent neighbourhoods and, in a second phase, in inner ring municipalities, while the Spanish population continues to move to suburban municipalities

Effects of exercise on mitochondrial DNA content in skeletal muscle of patients with COPD

Background Exhausting exercise reduces the mitochondrial DNA (mtDNA) content in the skeletal muscle of healthy subjects due to oxidative damage. Since patients with chronic obstructive pulmonary disease (COPD) suffer enhanced oxidative stress during exercise, it was hypothesised that the mtDNA content will be further reduced. Objective To investigate the effects of exercise above and below the lactate threshold (LT) on the mtDNA content of skeletal muscle of patients with COPD. Methods Eleven patients with COPD (676 8 years; forced expiratory volume in 1s (FEV1)456 8%ref) and 10 healthy controls (666 4 years; FEV1 906 7% ref) cycled 45 min above LT (65% peak oxygen uptake (V9O2 peak)and another 7 patients (656 6 years; FEV1 506 4%ref)and 7 controls (566 9 years;FEV1 926 6%ref) cycled 45 min below their LT (50% V9O2 peak). Biopsies from the vastus lateralis muscle were obtained before exercise, immediately after and 1 h, 1 day and 1 week later to determine by PCR the mtDNA/nuclear DNA (nDNA) ratio (a marker of mtDNA content) and the expression of the peroxisome proliferator-activated receptor- g coactivator-1 a (PGC-1a)mRNA and the amount of reactive oxygen species produced during exercise was estimated from total V9O2. Results Skeletal muscle mtDNA/nDNA fell significantly after exercise above the LT both in controls and in patients with COPD, but the changes were greater in those with COPD. These changes correlated with production of reactive oxygen species, increases in manganese superoxide dismutase and PGC-1 a mRNA and returned to baseline values 1 week later. This pattern of response wa was also observed, albeit minimised, in patients exercising below the LT. Conclusions In patients with COPD, exercise enhances the decrease in mtDNA content of skeletal muscle and the expression of PGC-1 a mRNA seen in healthy subjects probably due to oxidative stress.

Trophic versus geographic structure in stable isotope signatures of pelagic seabirds breeding in the northeast Atlantic

Feeding ecology and geographic location are 2 major factors influencing animal stable isotope signatures, but their relative contributions are poorly understood, which limits the usefulness of stable isotope analysis in the study of animal ecology. To improve our knowledge of the main sources of isotopic variability at sea, we determined δ15N and δ13C signatures in the first primary feather of adult birds from 11 Procellariiform species (n = 609) across 16 northeast Atlantic localities, from Cape Verde (20°N) to Iceland (60°N). Post-breeding areas (where the studied feather is thought to be grown) were determined using light-level geolocation for 6 of the 11 species. Isotopic variability was geographically unstructured within the mid-northeast Atlantic (Macaronesian archipelagos), but trophically structured according to species and regardless of the breeding location, presumably as a result of trophic segregation among species. Indeed, the interspecific isotopic overlap resulting from combining δ15N and δ13C signatures of seabirds was low, which suggests that most species exploited exclusive trophic resources consistently across their geographic range. Species breeding in north temperate regions (Iceland, Scotland and Northern Ireland) showed enriched δ15N compared to the same or similar species breeding in tropical and subtropical regions, suggesting some differences in baseline levels between these regions. The present study illustrates a noticeable trophic segregation of northeast Atlantic Procellariiformes. Our results show that the isotopic approach has limited applicability for the study of animal movements in the northeast Atlantic at a regional scale, but is potentially useful for the study of long-distance migrations between large marine systems

The long run development of Chile and the Natural Resources curse. Linkages, policy and growth, 1850-1950

This chapter analyses the effects of Natural Resources on the Chilean economy in the long run -1850-1950-. Specifically, the authors focus their attention on the mining cycles -nitrates and copper- and their impact on the mining activity. We also compare it with the evolution of the industry and whole economy, and how this has affected the economic growth of the country. In that sense, the industrial performance in Chile at the end of the 19th century until the Great Depression is still under debate. The optimistic view of Kirsch -1977- forehead the pessimistic view of Lagos -1966- and Palma -1979-. The new data and its analyses shows a neutral effect of the Natural Resources in the industrial development.

Labour segregation and immigrant and native-born wage distributions in Spain: an analysis using matched employer-employee data

This article carries out an empirical examination of the origin of the differences between immigrant and native-born wage structures in the Spanish labour market. Especial attention is given in the analysis to the role played by occupational and workplace segregation of immigrants. Legal immigrants from developing countries exhibit lower mean wages and a more compressed wage structure than native-born workers. By contrast, immigrants from developed countries display higher mean wages and a more dispersed wage structure. The main empirical finding is that the disparities in the wage distributions for the native-born and both groups of immigrants are largely explained by their different observed characteristics, with a particularly important influence in this context of workplace and, particularly, occupational segregation.

Població i família als Andes en el temps de la colònia: parroquia de Toacazo, Cotopaxi, Equador (s. XVIII-XIX )

Estudi elaborat a partir d’una estada a la Facultad Latinoamericana de Ciencias Sociales, durant l’ octubre del 2006. L’estudi de les haciendas creades a partir de la colonització espanyola als territoris americans no pot ser mai complet si no es pot entrar en la vida quotidiana de les persones que les constitueixen. La millor manera de fer-ho és a través d’assolir d’un exhaustiu estudi dels comportaments demogràfics –natalitat, nupcialitat, mortalitat, migracions—i familiars. L’objectiu d’aquest estudi ha estat localitzar una tipologia documental que permeti aquest treball a la parròquia de Toacazo a Cotopaxi (Equador) i, un cop assolida aquesta fita, fotografiar exhaustivament els registres parroquials, altrament dits registre civil antic. El període treballat va des de l’ 1720, any de fundació de la parròquia fins a 1857, any on s’acaba el tributo de indios o règim que regulava les normes de segregació racial de les poblacions.

Estudis funcionals i de plegament dels dominis d'activació de les procarboxipeptidases

Els dominis d’activació (ADs) de les procarboxipeptidases de la subfamília A/B sempre han sorprès ja que representen una quarta part del proenzim. S’han realitzat alguns estudis per intentar descobrir-ne alguna possible funció alternativa, però no han estat fructífers. El descobriment de l’elevada velocitat de plegament del domini d’activació de la procarboxipeptidasa A2 humana, (ADA2h), emperò, va portar a proposar la possibilitat de que realitzessin una funció d’assistència al plegament del domini enzimàtic. Posteriorment, l’anàlisi del plegament d’ADA2h a pH baix va revelar la capacitat d’aquest domini per formar fibres amiloides, a més de demostrar que un increment de l’estabilitat proteica podia prevenir la formació d’aquests agregats. La profunda caracterització del plegament d’ADA2h va fer que aquesta proteïna fos un bon model amiloidogènic, de manera que es van proposar un seguit d’experiments que s’han desenvolupat en el present treball per tal de conèixer millor aquest procés. S’han dut a terme estudis cinètics d’agregació per tal de valorar la contribució dels diferents aminoàcids de la seqüència polipeptídica, utilitzant 29 variants puntuals d’ADA2h. Es va eliminar la contribució de l’estabilitat mitjançant la utilització d’urea, i per dicroïsme circular conjuntament amb un aparell de flux detingut, es van obtenir dues velocitats diferents, v1 i v2, que corresponen a la formació d’un intermediari i a la seva reorganització, respectivament. Experiments complementaris utilitzant espectroscòpia d’infraroig (IR) revelaren la reorganització de l’estat natiu (en aquest cas) per a donar la forma agregada. Les cinètiques d’IR van mostrar que ADA2h forma l’estructura _ típica de les fibres amiloides, previ desplegament les seves hèlixs-_. Finalment, s’han realitzat estudis de biocomputació per tal d’esbrinar possibles funcions alternatives dels ADs. Les superposicions estructurals semblen mostrar similaritat dels ADs amb dominis de reconeixement d’RNA (RRM). Aquesta hipòtesi s’ha comprovat experimentalment amb ADA4h, mostrant una dèbil, però existent, unió a RNA.

Indicadores cuantitativos de segregación residencial. El caso de la población inmigrante en Barcelona

La segregación residencial en una ciudad indica el nivel de desigualdad de la distribución de la población entre las diferentes zonas. Es interesante obtener una visión cuantitativa de la segregación residencial para prever y actuar sobre los territorios más afectados por este proceso. En este artículo se propone medir la segregación de los colectivos de inmigrantes desde diferentes ópticas, utilizando la estadística espacial y los sistemas de información geográfica. Con estas herramientas se realiza un estudio sobre la distribución de la población inmigrante para la ciudad de Barcelona. Los resultados apuntan a una disminución en la segregación entre 1996 y 2001. Aunque se aprecian diferencias significativas según la procedencia de cada grupo estudiado.

Población inmigrante y espacio urbano. Indicadores de segregación y pautas de localización

Given the importance of immigrant population growth in Spain, it would be interesting to study its distribution throughout the urban area. The field of statistics suggests different indicators that have a long tradition and permit the quantification of segregation of minority population groups. Through the application of these tools in the Metropolitan Region of Barcelona, this paper demonstrates the utility of analyzing segregation patterns within a city and detecting local patterns of this phenomenon. A new perspective of segregation can be obtained with the use of indicators designed for spatial statistics. The combination of these measures represents a useful procedure for the analysis of the distribution of the immigrant population in urban areas and its extension to different areas such as sociology, economics, urban studies, and housing policy.

Structural factors impacting carrier transport and electroluminescence from Si nanocluster-sensitized Er ions.

We present an analysis of factors influencing carrier transport and electroluminescence (EL) at 1.5 µm from erbium-doped silicon-rich silica (SiOx) layers. The effects of both the active layer thickness and the Si excess content on the electrical excitation of erbium are studied. We demonstrate that when the thickness is decreased from a few hundred to tens of nanometers the conductivity is greatly enhanced. Carrier transport is well described in all cases by a Poole-Frenkel mechanism, while the thickness-dependent current density suggests an evolution of both density and distribution of trapping states induced by Si nanoinclusions. We ascribe this observation to stress-induced effects prevailing in thin films, which inhibit the agglomeration of Si atoms, resulting in a high density of sub-nm Si inclusions that induce traps much shallower than those generated by Si nanoclusters (Si-ncs) formed in thicker films. There is no direct correlation between high conductivity and optimized EL intensity at 1.5 µm. Our results suggest that the main excitation mechanism governing the EL signal is impact excitation, which gradually becomes more efficient as film thickness increases, thanks to the increased segregation of Si-ncs, which in turn allows more efficient injection of hot electrons into the oxide matrix. Optimization of the EL signal is thus found to be a compromise between conductivity and both number and degree of segregation of Si-ncs, all of which are governed by a combination of excess Si content and sample thickness. This material study has strong implications for many electrically driven devices using Si-ncs or Si-excess mediated EL.