Excavaciones en el conjunto funerario de época hispano-visigoda de la Cabeza (La Cabrera, Madrid)

La presencia visigoda en la actual Comunidad de Madrid está ampliamente constatada a través de las innumerables necrópolis conocidas. El pequeño conjunto funerario de la Cabeza, excavado con carácter de urgencia, ofrece una serie de características que le hacen particularmente interesante: número de tumbas, situación geográfica, ubicación topográfica, tipología del conjunto, etc. Tanto por su arquitectura funeraria como, y sobre todo, por el material hallado, hemos fechado el conjunto dentro del siglo VII

Temporal and spatial instability in neutral and adaptive (MHC) genetic variation in marginal salmon populations

The role of marginal populations for the long-term maintenance of species’ genetic diversity and evolutionary potential is particularly timely in view of the range shifts caused by climate change. The Centre-Periphery hypothesis predicts that marginal populations should bear reduced genetic diversity and have low evolutionary potential. We analysed temporal stability at neutral microsatellite and adaptive MHC genetic variation over five decades in four marginal Atlantic salmon populations located at the southern limit of the species’ distribution with a complicated demographic history, which includes stocking with foreign and native salmon for at least 2 decades. We found a temporal increase in neutral genetic variation, as well as temporal instability in population structuring, highlighting the importance of temporal analyses in studies that examine the genetic diversity of peripheral populations at the margins of the species’ range, particularly in face of climate change

Metabolic modelling in a dynamic evolutionary framework predicts adaptive diversification of bacteria in a long-term evolution experiment

Background: Predicting adaptive trajectories is a major goal of evolutionary biology and useful for practical applications. Systems biology has enabled the development of genome-scale metabolic models. However, analysing these models via flux balance analysis (FBA) cannot predict many evolutionary outcomes including adaptive diversification, whereby an ancestral lineage diverges to fill multiple niches. Here we combine in silico evolution with FBA and apply this modelling framework, evoFBA, to a long-term evolution experiment with Escherichia coli. Results: Simulations predicted the adaptive diversification that occurred in one experimental population and generated hypotheses about the mechanisms that promoted coexistence of the diverged lineages. We experimentally tested and, on balance, verified these mechanisms, showing that diversification involved niche construction and character displacement through differential nutrient uptake and altered metabolic regulation. Conclusion: The evoFBA framework represents a promising new way to model biochemical evolution, one that can generate testable predictions about evolutionary and ecosystem-level outcomes

Environmental variables, habitat discontinuity and life history shaping the genetic structure of Pomatoschistus marmoratus

Coastal lagoons are semi-isolated ecosystems exposed to wide fluctuations of environmental conditions and showing habitat fragmentation. These features may play an important role in separating species into different populations, even at small spatial scales. In this study, we evaluate the concordance between mitochondrial (previous published data) and nuclear data analyzing the genetic variability of Pomatoschistus marmoratus in five localities, inside and outside the Mar Menor coastal lagoon (SE Spain) using eight microsatellites. High genetic diversity and similar levels of allele richness were observed across all loci and localities, although significant genic and genotypic differentiation was found between populations inside and outside the lagoon. In contrast to the FST values obtained from previous mitochondrial DNA analyses (control region), the microsatellite data exhibited significant differentiation among samples inside the Mar Menor and between lagoonal and marine samples. This pattern was corroborated using Cavalli-Sforza genetic distances. The habitat fragmentation inside the coastal lagoon and among lagoon and marine localities could be acting as a barrier to gene flow and contributing to the observed genetic structure. Our results from generalized additive models point a significant link between extreme lagoonal environmental conditions (mainly maximum salinity) and P. marmoratus genetic composition. Thereby, these environmental features could be also acting on genetic structure of coastal lagoon populations of P. marmoratus favoring their genetic divergence. The mating strategy of P. marmoratus could be also influencing our results obtained from mitochondrial and nuclear DNA. Therefore, a special consideration must be done in the selection of the DNA markers depending on the reproductive strategy of the species

No additional value of conventional and high-sensitivity cardiac troponin over clinical scoring systems in the differential diagnosis of type 1 versus type 2 myocardial infarction.

BACKGROUND: The distinction of type 1 and type 2 myocardial infarction (MI) is of major clinical importance. Our aim was to evaluate the diagnostic ability of absolute and relative conventional cardiac troponin I (cTnI) and high-sensitivity cardiac troponin T (hs-cTnT) in the distinction between type 1 and type 2 MI in patients presenting at the emergency department with non-ST-segment elevation acute chest pain within the first 12 h. METHODS: We measured cTnI (Dimension Vista) and hs-cTnT (Cobas e601) concentrations at presentation and after 4 h in 200 patients presenting with suspected acute MI. The final diagnosis, based on standard criteria, was adjudicated by two independent cardiologists. RESULTS: One hundred and twenty-five patients (62.5%)were classified as type 1 MI and 75 (37.5%) were type 2 MI. In a multivariable setting, age (relative risk [RR]=1.43, p=0.040), male gender (RR=2.22, p=0.040), T-wave inversion (RR=8.51, p<0.001), ST-segment depression (RR=8.71, p<0.001) and absolute delta hs-cTnT (RR=2.10, p=0.022) were independently associated with type 1 MI. In a receiver operating characteristic curve analysis, the discriminatory power of absolute delta cTnI and hs-cTnT was significantly higher compared to relative c-TnI and hs-cTnT changes. The additive information provided by cTnI and hs-cTnT over and above the information provided by the "clinical" model was only marginal. CONCLUSIONS: The diagnostic information provided by serial measurements of conventional or hs-cTnT is not better than that yielded by a simple clinical scoring model. Absolute changes are more informative than relative troponin changes

Constraints on the χ_(c1) versus χ_(c2) polarizations in proton-proton collisions at √s = 8 TeV

The polarizations of promptly produced χ_(c1) and χ_(c2) mesons are studied using data collected by the CMS experiment at the LHC, in proton-proton collisions at √s=8  TeV. The χ_c states are reconstructed via their radiative decays χ_c → J/ψγ, with the photons being measured through conversions to e⁺e⁻, which allows the two states to be well resolved. The polarizations are measured in the helicity frame, through the analysis of the χ_(c2) to χ_(c1) yield ratio as a function of the polar or azimuthal angle of the positive muon emitted in the J/ψ → μ⁺μ⁻ decay, in three bins of J/ψ transverse momentum. While no differences are seen between the two states in terms of azimuthal decay angle distributions, they are observed to have significantly different polar anisotropies. The measurement favors a scenario where at least one of the two states is strongly polarized along the helicity quantization axis, in agreement with nonrelativistic quantum chromodynamics predictions. This is the first measurement of significantly polarized quarkonia produced at high transverse momentum