Com la covariància evolutiva ens va fer respirar malament

S'ha suggerit que la morfologia i mida dels individus de les poblacions humanes presenta una correlació amb el clima i el gradient latitudinal. Seguint la regla d'Allen, per tal d'evitar la transferència de calor amb l'entorn, en latituds més equatorials els humans tendeixen a ser alts i esvelts, mentre que als pols és el contrari per tal de conservar la calor corporal. En relació amb aquesta idea, la morfologia de la cavitat nasal també seguiria aquesta teoria iestaria vinculada a la forma en la qual se condiciona l'aire per arribar al pulmó en condicions òptimes de temperatura i humitat. Els individus en climes freds o secs haurien de tenir una major superfície de la mucosa nasal en relació amb el volum d'aire de les fosses nasals que els individus en climes càlids i humits, ja que les superfícies més grans afavoreixen l'intercanvi de calor amb l'aire que entra, escalfant-lo. Es teoritza que, a mesura que les primeres poblacions d'Homo es van traslladar cap als climes més freds d'Euràsia, els nassos van evolucionar per escalfar l'aire inhalat, fent-se més prims i estrets. Malgrat això, estudis recents han trobat que la cavitat nasal en si mateixa pot no ser suficient per condicionar l'aire que entra als pulmons, pot ser la morfologia nasal podria no estar seleccionada amb el gradient ecològic sinó amb l'evolutiu. Si és així, com es fa l'aire condicionat a l'Homo de cara plana? I hi ha un motiu conegut per al canvi de forma del nas

Examining the generalizability of research findings from archival data

This initiative examined systematically the extent to which a large set of archival research findings generalizes across contexts. We repeated the key analyses for 29 original strategic management effects in the same context (direct reproduction) as well as in 52 novel time periods and geographies; 45% of the reproductions returned results matching the original reports together with 55% of tests in different spans of years and 40% of tests in novel geographies. Some original findings were associated with multiple new tests. Reproducibility was the best predictor of generalizability—for the findings that proved directly reproducible, 84% emerged in other available time periods and 57% emerged in other geographies. Overall, only limited empirical evidence emerged for context sensitivity. In a forecasting survey, independent scientists were able to anticipate which effects would find support in tests in new samples

Centrality evolution of the charged-particle pseudorapidity density over a broad pseudorapidity range in Pb-Pb collisions at root s(NN)=2.76TeV

Peer reviewe

Neuromorphological and wiring pattern alterations effects on brain function: a mixed experimental and computational approach.

Fundamental laws governing the wiring of neuronal networks in the brain are still largely unknown. Understanding both the role and importance of the connectivity patterns that can be observed at different scales in the central nervous system are of crucial interest for advancing our knowledge on neuroscience in health and disease. Intellectual disability pathologies provide an excellent opportunity to address these questions due to their characteristic alterations in neuronal structure and connectivity that induce relative changes of the neuronal network dynamics and, eventually, in their function. Our aim is to identify what are the essential properties of brain connectivity and how they constrain cognitive functions such as information processing, learning and memory. Our approach is based on a mixed experimental and computational approach, addressing different scales of interest ranging from the local connectivity in neuronal modules to the long-range connectomes of mammal brains. Specifically we use Down syndrome mouse models (Ts65Dn and TgDyrk1A) that recapitulate both cognitive impairments and neuromorphological alterations observed in the human chromosome 21 trisomy. Homogeneous neuronal cultures provide a simple enough framework to study spontaneous electrical activity and its dependence on specific structural parameters (dendritic arborisation, axonal path length, connectivity density and excitatory-inhibitory balance). This allows to link concepts such as information processing efficiency or percept storage capacity with the observed connectivity patterns detected in well-controlled in vitro experiments where the biological constraints are minimal. In addition, the study of fixed intact brains (by means of the state of the art CLARITY technique) brings us closer to biologically and medically relevant situations, allowing not only to confirm whether the functional links in neuronal cultures are also present in vivo, but also enabling the introduction of functional information (like behavioral studies and functional imaging) and another layer of structural alterations such as brain region morphology, neuronal density, and long-range connectivity. Taking together the experimental information from these systems we want to feed self-developed computational models that allow us to understand what are the fundamental characteristics of the observed connectivity patterns and the impact of each of the alterations on neuronal network function. These models will also provide a framework able to account for the emergent properties that bridge the gap between spontaneous electrical activity arousal/transmission and higher order information processing and memory storage capacities in the brain. As an additional part of the project we are now working on the application of the clearing, labeling and imaging protocols to human biopsy samples. Our aim is to obtain neuronal architecture and connectivity information from focal cortical dysplasia microcircuits using samples from intractable temporal lobe epilepsy patients that undergo deep-brain electrode recording diagnosis and posterior surgical extraction of the tissue. Our computational models can allow us to discern the contributions of the observed abnormalities to neuronal hyperactivity and epileptic seizure generation

A joint numerical study of multi-regime turbulent combustion

info:eu-repo/semantics/publishe

Inclusive J/ψ production in pp collisions at √s=2.76 TeV

The ALICE Collaboration has measured inclusive J/ψ production in pp collisions at a center-of-mass energy √s=2.76 TeV at the LHC. The results presented in this Letter refer to the rapidity ranges |y|<0.9 and 2.5<y<4 and have been obtained by measuring the electron and muon pair decay channels, respectively. The integrated luminosities for the two channels are Linte=1.1 nb−1 and Lintμ=19.9 nb−1, and the corresponding signal statistics are NJ/ψe+e−=59±14 and NJ/ψμ+μ−=1364±53. We present dσJ/ψ/dy for the two rapidity regions under study and, for the forward-y range, d2σJ/ψ/dydpt in the transverse momentum domain 0<pt<8 GeV/c. The results are compared with previously published results at s=7 TeV and with theoretical calculations

Freeze-out radii extracted from three-pion cumulants in pp, p–Pb and Pb–Pb collisions at the LHC

In high-energy collisions, the spatio-temporal size of the particle production region can be measured using the Bose-Einstein correlations of identical bosons at low relative momentum. The source radii are typically extracted using two-pion correlations, and characterize the system at the last stage of interaction, called kinetic freeze-out. In low-multiplicity collisions, unlike in high-multiplicity collisions, two-pion correlations are substantially altered by background correlations, e.g. mini-jets. Such correlations can be suppressed using three-pion cumulant correlations. We present the first measurements of the size of the system at freeze-out extracted from three-pion cumulant correlations in pp, p-Pb and Pb-Pb collisions at the LHC with ALICE. At similar multiplicity, the invariant radii extracted in p-Pb collisions are found to be 5-15% larger than those in pp, while those in Pb-Pb are 35-55% larger than those in p-Pb. Our measurements disfavor models which incorporate substantially stronger collective expansion in p-Pb as compared to pp collisions at similar multiplicity

Coherent J/ψ photoproduction in ultra-peripheral Pb–Pb collisions at √sNN=2.76 TeV

The ALICE Collaboration has made the first measurement at the LHC of J/ψ photoproduction in ultra-peripheral Pb–Pb collisions at sNN=2.76 TeV. The J/ψ is identified via its dimuon decay in the forward rapidity region with the muon spectrometer for events where the hadronic activity is required to be minimal. The analysis is based on an event sample corresponding to an integrated luminosity of about 55 μb−1. The cross section for coherent J/ψ production in the rapidity interval −3.6<y<−2.6 is measured to be dσJ/ψcoh/dy=1.00±0.18(stat)−0.26+0.24(syst) mb. The result is compared to theoretical models for coherent J/ψ production and found to be in good agreement with those models which include nuclear gluon shadowing