Assessment of the realisation of the right to adequate food in the Blue Crane Route (Eastern Cape, South Africa)

To assess whether the right to adequate food (RtF) is realised by children and primary caregivers and what actions are required to fully realise this right.A cross-sectional, descriptive study was undertaken using a mixed-methods approach.Rural and urban primary caregivers of children (one to five years old) were recruited if they had resided in the Blue Crane Route (Eastern Cape) for at least six months. Purposefully selected key informants (KIs) involved in nutrition and food security, health or governance participated in in-depth interviews.Primary caregivers responded to interviewer-administered questionnaires (IAQ) (N = 161), which investigated various indicators supporting the realisation of the RtF. Statistical analysis of quantitative data examined relationships between urban and rural participants. Significance was considered at p < 0.05. In-depth interviews with key informants (KIs) examined the perceptions of 11 prominent community leaders. Qualitative data were coded deductively and common themes identified

Coexpression of Two Functional Odor Receptors in One Neuron

SummaryOne of the most fundamental tenets in the field of olfaction is that each olfactory receptor neuron (ORN) expresses a single odorant receptor. However, the one receptor-one neuron principle is difficult to establish rigorously. Here we construct a receptor-to-neuron map for an entire olfactory organ in Drosophila and find that two receptor genes are coexpressed in one class of ORN. Both receptors are functional in an in vivo expression system, they are only 16% identical in amino acid sequence, and the genes that encode them are unlinked. Most importantly, their coexpression has been conserved for >45 million years. Expression of multiple odor receptors in a cell provides an additional degree of freedom for odor coding

Solvent and conformation dependence of amide I vibrations in peptides and proteins containing proline

We present a mixed quantum-classical model for studying the amide I vibrational dynamics (predominantly CO stretching) in peptides and proteins containing proline. There are existing models developed for determining frequencies of and couplings between the secondary amide units. However, these are not applicable to proline because this amino acid has a tertiary amide unit. Therefore, a new parametrization is required for infrared-spectroscopic studies of proteins that contain proline, such as collagen, the most abundant protein in humans and animals. Here, we construct the electrostatic and dihedral maps accounting for solvent and conformation effects on frequency and coupling for the proline unit. We examine the quality and the applicability of these maps by carrying out spectral simulations of a number of peptides with proline in D2O and compare with experimental observations.Netherlands Organization for Scientific Research (VIDI grant)National Science Foundation (U.S.) ((NSF) CHE-0911107

Melting of a beta-Hairpin Peptide Using Isotope-Edited 2D IR Spectroscopy and Simulations

Item does not contain fulltextIsotope-edited two-dimensional infrared spectroscopy has been used to characterize the conformational heterogeneity of the beta-hairpin peptide TrpZip2 (TZ2) across its thermal unfolding transition. Four isotopologues were synthesized to probe hydrogen bonding and solvent exposure of the beta-turn (K8), the N-terminus (S1), and the midstrand region (T10 and T3T10). Isotope-shifts, 2D lineshapes, and other spectral changes to the amide I 2D IR spectra of labeled TZ2 isotopologues were observed as a function of temperature. Data were interpreted on the basis of structure-based spectroscopic modeling of conformers obtained from extensive molecular dynamics simulations. The K8 spectra reveal two unique turn geometries, the type I' beta-turn observed in the NMR structure, and a less populated disordered or bulged loop. The data indicate that structures at low temperature resemble the folded NMR structure with typical cross-strand hydrogen bonds, although with a subpopulation of misformed turns. As the temperature is raised from 25 to 85 degrees C, the fraction of population with a type I' turn increases, but the termini also fray. Hydrogen bonding contacts in the midstrand region remain at all temperatures although with increasing thermal disorder. Our data show no evidence of an extended chain or random coil state for the TZ2 peptide at any temperature. The methods demonstrated here offer an approach to characterizing conformational variation within the folded or unfolded states of proteins and peptides

Kinetic effects on the 660 km-phase transition in mantle upstreams and seismological implications

The effects of reaction kinetics of bridgmanite and ferropericlase transforming to ringwoodite on elastic properties in upwelling mantle are investigated using data of kinetic experiments and internally self-consistent thermodynamic modelling of density and seismic velocities. The kinetic experiments show inhibited grain growth of ringwoodite. At the initiation of ringwoodite growth, bridgmanite completely transforms to a metastable pyrope-bearing garnet. Ringwoodite then gradually grows from the metastable assemblage of ferropericlase and garnet. The changes in mineralogy result in a low-velocity zone directly above the 660 km seismic discontinuity due to the lower seismic velocities and densities of ferropericlase and garnet compared to ringwoodite and bridgmanite. The modelling of the effects of reaction kinetics and its effect on seismic structure at ∼660 km depth shows more sensitivity to grain size than to temperature and upwelling rate. Modelling 1-D synthetic seismograms of PP (SS) underside reflections off the kinetically inhibited backward reaction to ringwoodite shows advanced travel times of underside reflections off ∼660 km depth of 0.2 - 0.8 s (1.2 - 1.6 s) for upwelling rates of 50 cm/yr and initial grain sizes between 5 and 20 cm due to the low-velocity zone above the 660 km discontinuity. The finite width of the low-velocity layer results in frequency-dependent behaviour of PP and SS underside reflection amplitudes, with higher amplitudes towards shorter periods. The effect on the travel times of P-to-s conversions used for receiver function is small (< 0.7 s) but the inhibited backward reaction leads to strong amplitude changes and significant waveform variations. The effects of reaction kinetics in mantle upwellings might serve as an additional means to map regions of large-scale upwellings and to constrain grain size in the lower mantle

Structural Ceramic Composites for Nuclear Applications

A research program has been established to investigate fiber reinforced ceramic composites to be used as control rod components within a Very High Temperature Reactor. Two candidate systems have been identified, carbon fiber reinforced carbon (Cf/C) and silicon carbide fiber reinforced silicon carbide (SiCf/SiC) composites. Initial irradiation stability studies to determine the maximum dose for each composite type have been initiated within the High Flux Isotope Reactor at Oak Ridge National Laboratory. Test samples exposed to 10 dpa irradiation dose have been completed with future samples to dose levels of 20 and 30 dpa scheduled for completion in following years. Mechanical and environmental testing is being conducted concurrently at the Idaho National Laboratory and at Pacific Northwest National Laboratory. High temperature test equipment, testing methodologies, and test samples for high temperature (up to 1600º C) tensile strength and long duration creep studies have been established. Specific attention was paid to the architectural fiber preform design as well as the materials used in construction of the composites. Actual testing of both tubular and flat, "dog-bone" shaped tensile composite specimens will begin next year. Since there is no precedence for using ceramic composites within a nuclear reactor, ASTM standard test procedures will be established from these mechanical and environmental tests. Close collaborations between the U.S. national laboratories and international collaborators (i.e. France and Japan) are being forged to establish both national and international test standards to be used to qualify ceramic composites for nuclear reactor applications

The pursuit of happiness: the social and scientific origins of Hans Selye’s natural philosophy of life

© The Author(s) 2012. Open access article.In 1956, Hans Selye tentatively suggested that the scientific study of stress could ‘help us to formulate a precise program of conduct’ and ‘teach us the wisdom to live a rich and meaningful life’. Nearly two decades later, Selye expanded this limited vision of social order into a full-blown philosophy of life. In Stress without Distress, first published in 1974, he proposed an ethical code of conduct designed to mitigate personal and social problems. Basing his arguments on contemporary understandings of the biological processes involved in stress reactions, Selye referred to this code as ‘altruistic egotism’. This article explores the origins and evolution of Selye’s ‘natural philosophy of life’, analysing the links between his theories and adjacent intellectual developments in biology, psychosomatic and psychosocial medicine, cybernetics and socio-biology, and situating his work in the broader cultural framework of modern western societies.Wellcome Trus