1,185 research outputs found
Policy instruments in the Common Agricultural Policy
Policy changes in the Common Agricultural Policy (CAP) can be explained in terms of the exhaustion and long-term contradictions of policy instruments. Changes in policy instruments have reoriented the policy without any change in formal Treaty goals. The social and economic efficacy of instruments in terms of evidence-based policy analysis was a key factor in whether they were delegitimized. The original policy instruments were generally dysfunctional, but reframing the policy in terms of a multifunctionality paradigm permitted the development of more efficacious instruments. A dynamic interaction takes place between the instruments and policy informed by the predominant discourses
Electric field control of multiferroic domains in NiVO imaged by X-ray polarization enhanced topography
The magnetic structure of multiferroic NiVO has been investigated
using non-resonant X-ray magnetic scattering. Incident circularly polarized
X-rays combined with full polarization analysis of the scattered beam is shown
to yield high sensitivity to the components of the cycloidal magnetic order,
including their relative phases. New information on the magnetic structure in
the ferroelectric phase is obtained, where it is found that the magnetic
moments on the "cross-tie" sites are quenched relative to those on the "spine"
sites. This implies that the onset of ferroelectricity is associated mainly
with spine site magnetic order. We also demonstrate that our technique enables
the imaging of multiferroic domains through polarization enhanced topography.
This approach is used to image the domains as the sample is cycled by an
electric field through its hysteresis loop, revealing the gradual switching of
domains without nucleation.Comment: 9 pages, 6 figure
Spin Dynamics at Very Low Temperature in Spin Ice DyTiO
We have performed AC susceptibility and DC magnetic relaxation measurements
on the spin ice system DyTiO down to 0.08 K. The relaxation time of
the magnetization has been estimated below 2 K down to 0.08 K. The spin
dynamics of DyTiO is well described by using two relaxation times
( (short time) and (long time)). Both and increase on cooling. Assuming the Arrhenius law in the
temperature range 0.5-1 K, we obtained an energy barrier of 9 K. Below 0.5 K,
both and show a clear deviation from the thermal
activated dynamics toward temperature independent relaxation, suggesting a
quantum dynamics.Comment: 4 page
Hydrotalcite-derived copper-based oxygen carrier materials for efficient chemical-looping combustion of solid fuels with CO2 capture
Chemical-looping combustion (CLC) is a promising technology that utilizes metal oxides as oxygen carriers for the combustion of fossil fuels to CO2 and H2O, with CO2 readily sequestrated after the condensation of steam. Thermally stable and reactive metal oxides are desirable as oxygen carrier materials for the CLC processes. Here, we report the performance of Cu-based mixed oxides derived from hydrotalcite (also known as layered double hydroxides) precursors as oxygen carriers for the combustion of solid fuels. Two types of CLC processes were demonstrated, including chemical looping oxygen uncoupling (CLOU) and in situ gasification (iG-CLC) in the presence of steam. The Cu-based oxygen carriers showed high performance for the combustion of two solid fuels (a lignite and a bituminous coal), maintaining high thermal stability, fast reaction kinetics, and reversible oxygen release and storage over multiple redox cycles. Slight deactivation and sintering of the oxygen carrier occurred after redox cycles at an very high operation temperature of 985 °C. We expect that our material design strategy will inspire the development of better oxygen carrier materials for a variety of chemical looping processes for the clean conversion of fossil fuels with efficient CO2 capture
PNAS plus: plasmodium falciparum responds to amino acid starvation by entering into a hibernatory state
The human malaria parasite Plasmodium falciparum is auxotrophic for most amino acids. Its amino acid needs are met largely through the degradation of host erythrocyte hemoglobin; however the parasite must acquire isoleucine exogenously, because this amino acid is not present in adult human hemoglobin. We report that when isoleucine is withdrawn from the culture medium of intraerythrocytic P. falciparum, the parasite slows its metabolism and progresses through its developmental cycle at a reduced rate. Isoleucine-starved parasites remain viable for 72 h and resume rapid growth upon resupplementation. Protein degradation during starvation is important for maintenance of this hibernatory state. Microarray analysis of starved parasites revealed a 60% decrease in the rate of progression through the normal transcriptional program but no other apparent stress response. Plasmodium parasites do not possess a TOR nutrient-sensing pathway and have only a rudimentary amino acid starvation-sensing eukaryotic initiation factor 2α (eIF2α) stress response. Isoleucine deprivation results in GCN2-mediated phosphorylation of eIF2α, but kinase-knockout clones still are able to hibernate and recover, indicating that this pathway does not directly promote survival during isoleucine starvation. We conclude that P. falciparum, in the absence of canonical eukaryotic nutrient stress-response pathways, can cope with an inconsistent bloodstream amino acid supply by hibernating and waiting for more nutrient to be provided
Can majority support save an endangered language? A case study of language attitudes in Guernsey
Many studies of minority language revitalisation focus on the attitudes and perceptions of minorities, but not on those of majority group members. This paper discusses the implications of these issues, and presents research into majority andf minority attitudes towards the endangered indigenous vernacular of Guernsey, Channel Islands. The research used a multi-method approach (questionnaire and interview) to obtain attitudinal data from a representative sample of the population that included politicians and civil servants (209 participants). The findings suggested a shift in language ideology away from the post-second world war âculture of modernisationâ and monolingual ideal, towards recognition of the value of a bi/trilingual linguistic heritage. Public opinion in Guernsey now seems to support the maintenance of the indigenous language variety, which has led to a degree of official support. The paper then discusses to what extent this âattitude shiftâ is reflected in linguistic behaviour and in concrete language planning measures
Ordered Phase of the Dipolar Spin Ice under [110]-Magnetic Fields
We find that the true ground state of the dipolar spin ice system under
[110]-magnetic fields is the ``Q=X'' structure, which is consistent with both
experiments and Monte Carlo simulations. We then perform a Monte Carlo
simulation to confirm that there exists a first order phase transition under
the [110]-field. In particular this result indicates the existence of the first
order phase transition to the ``Q=X'' phase in the field above 0.35 T for
Dy2Ti2O7. We also show the magnetic field-temperature phase diagram to
summarize the ordered states of this system.Comment: 4 pages, 5 figures, in RevTex4, submitted to J. Phys. Soc. Jp
In Situ Measurement of Dynamic Mixing in Gas-Solid Fluidized Beds Using Magnetic Resonance
Three magnetic resonance techniques were implemented to study solids mixing in a fluidized bed. Ultra-fast FLASH imaging was utilised to measure the dispersion of a tracer particle in real time. A novel MR sequence for measurement of the time-averaged mixing of solids in a fluidized bed was developed. Finally images of the velocity of solids were obtained to measure directly the pattern of solids flow
- âŠ