251 research outputs found
Reducing the health effect of particles from agriculture
This autumn, the European Union (EU) Parliament will have a crucial vote on the future of air pollution policy in Europe. For discussion is a commission proposal for new national emission ceilings, as amended by the European Parliament Environment Committee in July, 2015. The proposed emission ceilings cover not only emissions of primary, directly emitted particulate matter but also emissions from precursor gases. These gases include ammonia, sulphur dioxide, and nitrogen oxides, which react in the atmosphere to form solid (particulate) ammonium sulphates and nitrates
Non-invasive laminar inference with MEG: comparison of methods and source inversion algorithms
Magnetoencephalography (MEG) is a direct measure of neuronal current flow; its anatomical resolution is therefore not constrained by physiology but rather by data quality and the models used to explain these data. Recent simulation work has shown that it is possible to distinguish between signals arising in the deep and superficial cortical laminae given accurate knowledge of these surfaces with respect to the MEG sensors. This previous work has focused around a single inversion scheme (multiple sparse priors) and a single global parametric fit metric (free energy). In this paper we use several different source inversion algorithms and both local and global, as well as parametric and non-parametric fit metrics in order to demonstrate the robustness of the discrimination between layers. We find that only algorithms with some sparsity constraint can successfully be used to make laminar discrimination. Importantly, local t-statistics, global cross-validation and free energy all provide robust and mutually corroborating metrics of fit. We show that discrimination accuracy is affected by patch size estimates, cortical surface features, and lead field strength, which suggests several possible future improvements to this technique. This study demonstrates the possibility of determining the laminar origin of MEG sensor activity, and thus directly testing theories of human cognition that involve laminar- and frequency-specific mechanisms. This possibility can now be achieved using recent developments in high precision MEG, most notably the use of subject-specific head-casts, which allow for significant increases in data quality and therefore anatomically precise MEG recordings
On the measurement of leptonic CP violation
We show that the simultaneous determination of the leptonic CP-odd phase
and the angle from the subleading transitions
and results generically, at
fixed neutrino energy and baseline, in two degenerate solutions. In light of
this, we refine a previous analysis of the sensitivity to leptonic CP violation
at a neutrino factory, in the LMA-MSW scenario, by exploring the full range of
and .
Furthermore, we take into account the expected uncertainties on the solar and
atmospheric oscillation parameters and in the average Earth matter density
along the neutrino path. An intermediate baseline of O(3000) km is still the
best option to tackle CP violation, although a combination of two baselines
turns out to be very important in resolving degeneracies.Comment: 19 pages, 14 figures, uses epsfi
Measurement of CP violation at a Neutrino Factory
The prospects of measuring CP violation in the leptonic sector using the
intense neutrino beams arising from muon decay in the straight sections of a
muon accumulator ring (the so-called neutrino factory) are discussed.Comment: Invited talk given at the CP2000 Conference in Ferrara, September,
200
Prenatal hormones alter antioxidant enzymes and lung histology in rats with congenital diaphragmatic hernia.
Prenatal administration of dexamethasone (Dex) and thyrotropin-releasing hormone
(TRH) synergistically enhances lung maturity, but TRH suppresses the antioxidant
enzyme activity. Prenatal hormonal therapy improves alveolar surfactant content
and lung compliance in rats with congenital diaphragmatic hernia (CDH). In full
term neonatal rats with CDH we studied the effects of prenatal Dex or Dex+TRH on
antioxidant enzyme activity at birth, on survival, and on lung morphometry after
4 h of ventilation with 100% O2. CDH was induced by administration of
2,4-dichlorophenyl-p-nitro-phenylether (Nitrofen) on gestational day 10.
Dex+TRH-treated CDH rats had lower activity of glutathione reductase after birth
than did sham-treated CDH pups. Dex-treated and sham-treated pups had similar
antioxidant enzyme activity. Hormonal treatment did not change survival during
ventilation. The average airspace volume increased in Dex-treated CDH pups after
ventilation, with a small synergistic effect after addition of TRH. On the basis
of our findings, we speculate that prenatal administration of Dex is the best
choice to improve lung maturity and airspace volume in CDH patients
High-affinity prorenin binding to cardiac man-6-P/IGF-II receptors precedes proteolytic activation to renin
Mannose-6-phosphate (man-6-P)/insulin-like growth factor-II
(man-6-P/IgF-II) receptors are involved in the activation of recombinant
human prorenin by cardiomyocytes. To investigate the kinetics of this
process, the nature of activation, the existence of other prorenin
receptors, and binding of native prorenin, neonatal rat cardiomyocytes
were incubated with recombinant, renal, or amniotic fluid prorenin with or
without man-6-P. Intact and activated prorenin were measured in cell
lysates with prosegment- and renin-specific antibodies, respectively. The
dissociation constant (K(d)) and maximum number of binding sites (B(max))
for prorenin binding to man-6-P/IGF-II receptors were 0.6 +/- 0.1 nM and
3,840 +/- 510 receptors/myocyte, respectively. The capacity for prorenin
internalization was greater than 10 times B(max). Levels of internalized
intact prorenin decreased rapidly (half-life = 5 +/- 3 min) indicating
proteolytic prosegment removal. Prorenin subdivision into man-6-P-free and
man-6-P-containing fractions revealed that only the latter was bound.
Cells also bound and activated renal but not amniotic fluid prorenin. We
concluded that cardiomyocytes display high-affinity binding of renal but
not extrarenal prorenin exclusively via man-6-P/IGF-II receptors. Binding
precedes internalization and proteolytic activation to renin thereby
supporting the concept of cardiac angiotensin formation by renal prorenin
Microscopic mechanisms of spin-dependent electric polarization in 3d oxides
We present a short critical overview of different microscopic models for
nonrelativistic and relativistic magnetoelectric coupling including the
so-called "spin current scenario", ab-initio calculations, and several recent
microscopic approaches to a spin-dependent electric polarization in 3d oxides.Comment: 8 pages, 3 figure
Thin-Film Metamaterials called Sculptured Thin Films
Morphology and performance are conjointed attributes of metamaterials, of
which sculptured thin films (STFs) are examples. STFs are assemblies of
nanowires that can be fabricated from many different materials, typically via
physical vapor deposition onto rotating substrates. The curvilinear--nanowire
morphology of STFs is determined by the substrate motions during fabrication.
The optical properties, especially, can be tailored by varying the morphology
of STFs. In many cases prototype devices have been fabricated for various
optical, thermal, chemical, and biological applications.Comment: to be published in Proc. ICTP School on Metamaterials (Augsut 2009,
Sibiu, Romania
Superbeams plus Neutrino Factory: the golden path to leptonic CP violation
Superbeams (SB) and neutrino factories (NF) are not alternative facilities for exploring neutrino oscillation physics, but successive steps. The correct strategy is to contemplate the combination of their expected physics results. We show its important potential on the disappearance of fake degenerate solutions in the simultaneous measurement Of theta(13) and leptonic CP violation. Intrinsic, sign (Deltam(13)(2)) and theta(23) degeneracies are shown to be extensively eliminated when the results from one NF baseline and a SB facility are combined. A key point is the different average neutrino energy and baseline of the facilities. For values of theta(13) near its present limit, the short NF baseline, e.g., L = 732 km, becomes, after such a combination, a very interesting distance. For smaller theta(13), an intermediate NF baseline of O (3000 km) is still required
Residential exposure to microbial emissions from livestock farms: Implementation and evaluation of land use regression and random forest spatial models
Adverse health effects have been linked with exposure to livestock farms, likely due to airborne microbial agents. Accurate exposure assessment is crucial in epidemiological studies, however limited studies have modelled bioaerosols. This study used measured concentrations in air of livestock commensals (Escherichia coli (E. coli) and Staphylococcus species (spp.)), and antimicrobial resistance genes (tetW and mecA) at 61 residential sites in a livestock-dense region in the Netherlands. For each microbial agent, land use regression (LUR) and random forest (RF) models were developed using Geographic Information System (GIS)-derived livestock-related characteristics as predictors. The mean and standard deviation of annual average concentrations (gene copies/m3) of E. coli, Staphylococcus spp., tetW and mecA were as follows: 38.9 (±1.98), 2574 (±3.29), 20991 (±2.11), and 15.9 (±2.58). Validated through 10-fold cross-validation (CV), the models moderately explained spatial variation of all microbial agents. The best performing model per agent explained respectively 38.4%, 20.9%, 33.3% and 27.4% of the spatial variation of E. coli, Staphylococcus spp., tetW and mecA. RF models had somewhat better performance than LUR models. Livestock predictors related to poultry and pig farms dominated all models. To conclude, the models developed enable enhanced estimates of airborne livestock-related microbial exposure in future epidemiological studies. Consequently, this will provide valuable insights into the public health implications of exposure to specific microbial agents
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