STEM materials: a new frontier for an intelligent sustainable world

Materials are addressed as possible enablers for solutions to many global societal challenges. A foresight exercise has been conducted to identify research paths to design, with a new approach, a generation of materials which can provide multi-functionalities. These material systems have been named ???stem???, in analogy to living cells where a base of primitive units can be designed and assembled for self-reacting to external inputs. These materials will embed a concept of ???internet in things???, where their processing capacity will enable the systems to interact with the environment and express diverse functionalities. Stem materials do not exist yet, but many clues from diferent theoretical and experimental results suggest they can be developed, and because living organisms exist. This article aims at launching this new approach and promoting the structuring of a multi-disciplinary community to fll the research gaps

Skin- and gut-homing molecules on human circulating gamma delta T cells and their dysregulation in inflammatory bowel disease

Changes in phenotype and function of γδ T cells have been reported in inflammatory bowel disease (IBD), including Crohn's disease (CD) and ulcerative colitis (UC). Dysregulation of lymphocyte migration plays a key role in IBD pathogenesis; however, data on migratory properties of γδ T cells are scarce. Human circulating γδ T cells from healthy controls (n = 27), patients with active CD (n = 15), active UC (n = 14) or cutaneous manifestations of IBD (n = 2) were characterized by flow cytometry. Circulating γδ T cells in healthy controls were CD3(hi) and expressed CD45RO. They expressed gut-homing molecule β7 but not gut-homing molecule corresponding chemokine receptors (CCR)9, or skin-homing molecules cutaneous lymphocyte-associated antigen (CLA) and CCR4, despite conventional T cells containing populations expressing these molecules. CCR9 expression was increased on γδ T cells in CD and UC, while skin-homing CLA was expressed aberrantly on γδ T cells in patients with cutaneous manifestations of IBD. Lower levels of CD3 expression were found on γδ T cells in CD but not in UC, and a lower proportion of γδ T cells expressed CD45RO in CD and UC. Enhanced expression of gut-homing molecules on circulating γδ T cells in IBD and skin-homing molecules in cutaneous manifestations of IBD may be of clinical relevance

On the stability of high-speed milling with spindle speed variation

Spindle speed variation is a well-known technique to suppress regenerative machine tool vibrations, but it is usually considered to be effective only for low spindle speeds. In this paper, the effect of spindle speed variation is analyzed in the high-speed domain for spindle speeds corresponding to the first flip (period doubling) and to the first Hopf lobes. The optimal amplitudes and frequencies of the speed modulations are computed using the semidiscre- tization method. It is shown that period doubling chatter can effectively be suppressed by spindle speed variation, although, the technique is not effective for the quasiperiodic chatter above the Hopf lobe. The results are verified by cutting tests. Some special cases are also discussed where the practical behavior of the system differs from the predicted one in some ways. For these cases, it is pointed out that the concept of stability is understood on the scale of the principal period of the system—that is, the speed modulation period for variable spindle speed machining and the tooth passing period for constant spindle speed machining

Ferritins: furnishing proteins with iron

Ferritins are a superfamily of iron oxidation, storage and mineralization proteins found throughout the animal, plant, and microbial kingdoms. The majority of ferritins consist of 24 subunits that individually fold into 4-α-helix bundles and assemble in a highly symmetric manner to form an approximately spherical protein coat around a central cavity into which an iron-containing mineral can be formed. Channels through the coat at inter-subunit contact points facilitate passage of iron ions to and from the central cavity, and intrasubunit catalytic sites, called ferroxidase centers, drive Fe2+ oxidation and O2 reduction. Though the different members of the superfamily share a common structure, there is often little amino acid sequence identity between them. Even where there is a high degree of sequence identity between two ferritins there can be major differences in how the proteins handle iron. In this review we describe some of the important structural features of ferritins and their mineralized iron cores and examine in detail how three selected ferritins oxidise Fe2+ in order to explore the mechanistic variations that exist amongst ferritins. We suggest that the mechanistic differences reflect differing evolutionary pressures on amino acid sequences, and that these differing pressures are a consequence of different primary functions for different ferritins

Rotating black holes with equal-magnitude angular momenta in d=5 Einstein-Gauss-Bonnet theory

We construct rotating black hole solutions in Einstein-Gauss-Bonnet theory in five spacetime dimensions. These black holes are asymptotically flat, and possess a regular horizon of spherical topology and two equal-magnitude angular momenta associated with two distinct planes of rotation. The action and global charges of the solutions are obtained by using the quasilocal formalism with boundary counterterms generalized for the case of Einstein-Gauss-Bonnet theory. We discuss the general properties of these black holes and study their dependence on the Gauss-Bonnet coupling constant $\alpha$. We argue that most of the properties of the configurations are not affected by the higher derivative terms. For fixed $\alpha$ the set of black hole solutions terminates at an extremal black hole with a regular horizon, where the Hawking temperature vanishes and the angular momenta attain their extremal values. The domain of existence of regular black hole solutions is studied. The near horizon geometry of the extremal solutions is determined by employing the entropy function formalism.Comment: 25 pages, 7 figure

Symmetry restoring bifurcation in collective decision-making.

How social groups and organisms decide between alternative feeding sites or shelters has been extensively studied both experimentally and theoretically. One key result is the existence of a symmetry-breaking bifurcation at a critical system size, where there is a switch from evenly distributed exploitation of all options to a focussed exploitation of just one. Here we present a decision-making model in which symmetry-breaking is followed by a symmetry restoring bifurcation, whereby very large systems return to an even distribution of exploitation amongst options. The model assumes local positive feedback, coupled with a negative feedback regulating the flow toward the feeding sites. We show that the model is consistent with three different strains of the slime mold Physarum polycephalum, choosing between two feeding sites. We argue that this combination of feedbacks could allow collective foraging organisms to react flexibly in a dynamic environment

Minimum length effects in black hole physics

We review the main consequences of the possible existence of a minimum measurable length, of the order of the Planck scale, on quantum effects occurring in black hole physics. In particular, we focus on the ensuing minimum mass for black holes and how modified dispersion relations affect the Hawking decay, both in four space-time dimensions and in models with extra spatial dimensions. In the latter case, we briefly discuss possible phenomenological signatures.Comment: 29 pages, 12 figures. To be published in "Quantum Aspects of Black Holes", ed. X. Calmet (Springer, 2014

Photo-antagonism of the GABAA receptor

Neurotransmitter receptor trafficking is fundamentally important for synaptic transmission and neural network activity. GABAA receptors and inhibitory synapses are vital components of brain function, yet much of our knowledge regarding receptor mobility and function at inhibitory synapses is derived indirectly from using recombinant receptors, antibody-tagged native receptors and pharmacological treatments. Here we describe the use of a set of research tools that can irreversibly bind to and affect the function of recombinant and neuronal GABAA receptors following ultraviolet photoactivation. These compounds are based on the competitive antagonist gabazine and incorporate a variety of photoactive groups. By using site-directed mutagenesis and ligand-docking studies, they reveal new areas of the GABA binding site at the interface between receptor β and α subunits. These compounds enable the selected inactivation of native GABAA receptor populations providing new insight into the function of inhibitory synapses and extrasynaptic receptors in controlling neuronal excitation

Measurement of the inclusive and dijet cross-sections of b-jets in pp collisions at sqrt(s) = 7 TeV with the ATLAS detector

The inclusive and dijet production cross-sections have been measured for jets containing b-hadrons (b-jets) in proton-proton collisions at a centre-of-mass energy of sqrt(s) = 7 TeV, using the ATLAS detector at the LHC. The measurements use data corresponding to an integrated luminosity of 34 pb^-1. The b-jets are identified using either a lifetime-based method, where secondary decay vertices of b-hadrons in jets are reconstructed using information from the tracking detectors, or a muon-based method where the presence of a muon is used to identify semileptonic decays of b-hadrons inside jets. The inclusive b-jet cross-section is measured as a function of transverse momentum in the range 20 < pT < 400 GeV and rapidity in the range |y| < 2.1. The bbbar-dijet cross-section is measured as a function of the dijet invariant mass in the range 110 < m_jj < 760 GeV, the azimuthal angle difference between the two jets and the angular variable chi in two dijet mass regions. The results are compared with next-to-leading-order QCD predictions. Good agreement is observed between the measured cross-sections and the predictions obtained using POWHEG + Pythia. MC@NLO + Herwig shows good agreement with the measured bbbar-dijet cross-section. However, it does not reproduce the measured inclusive cross-section well, particularly for central b-jets with large transverse momenta.Comment: 10 pages plus author list (21 pages total), 8 figures, 1 table, final version published in European Physical Journal

Association between egg consumption and cardiovascular disease events, diabetes and all-cause mortality

Purpose The association between egg consumption and cardiovascular disease (CVD) or type 2 diabetes (T2D) remains controversial. We investigated the association between egg consumption and risk of CVD (primary outcome), T2D and mortality in the Caerphilly prospective cohort study (CAPS) and National Diet and Nutritional Survey (NDNS). Methods CAPS included 2512 men aged 45–59 years (1979–1983). Dietary intake, disease incidence and mortality were updated at 5-year intervals. NDNS included 754 adults aged 19–64 years from 2008 to 2012. Results Men free of CVD (n = 1781) were followed up for a mean of 22.8 years, egg consumption was not associated with new incidence of CVD (n = 715), mortality (n = 1028) or T2D (n = 120). When stroke (n = 248), MI (n = 477),heart failure (n = 201) were investigated separately, no associations between egg consumption and stroke and MI were identified, however, increased risk of stroke in subjects with T2D and/or impaired glucose tolerance (IGT, fasting plasma glucose ≥ 6.1 mmol/L), adjusted hazard ratios (95% CI) were 1.0 (reference), 1.09 (0.41, 2.88), 0.96 (0.37, 2.50), 1.39 (0.54, 3.56) and 2.87 (1.13, 7.27) for egg intake (n) of 0 ≤ n ≤ 1, 1 < n ≤ 2, 2 < n ≤ 3, 3 < n < 5, and n ≥ 5 eggs/wk, respectively (P = 0.01). In addition, cross-sectional analyses revealed that higher egg consumption was significantly associated with elevated fasting glucose in those with T2D and/or IGT (CAPS: baseline P = 0.02 and 5-year P = 0.04; NDNS: P = 0.05). Conclusions Higher egg consumption was associated with higher blood glucose in subjects with T2D and/or IGT. The increased incidence of stroke with higher egg consumption among T2D and/or IGT sub-group warrants further investigation