|\epsilon|-Near-Zero materials in the near-infrared

We consider a mixture of metal coated quantum dots dispersed in a polymer matrix and, using a modified version of the standard Maxwell-Garnett mixing rule, we prove that the mixture parameters (particles radius, quantum dots gain, etc.) can be chosen so that the effective medium permittivity has an absolute value very close to zero in the near-infrared, i.e. |Re(epsilon)|<<1 and |Im (epsilon)|<<1 at the same near-infrared wavelength. Resorting to full-wave simulations, we investigate the accuracy of the effective medium predictions and we relate their discrepancy with rigorous numerical results to the fact that |epsilon|<<1 is a critical requirement. We show that a simple method for reducing this discrepancy, and hence for achieving a prescribed value of |\epsilon|, consists in a subsequent fine-tuning of the nanoparticles volume filling fraction.Comment: 3 pages, 3 figure

ARIA 2016: Care pathways implementing emerging technologies for predictive medicine in rhinitis and asthma across the life cycle

The Allergic Rhinitis and its Impact on Asthma (ARIA) initiative commenced during a World Health Organization workshop in 1999. The initial goals were (1) to propose a new allergic rhinitis classification, (2) to promote the concept of multi-morbidity in asthma a

Inequalities in fruit-removal and seed dispersal: consequences of bird behaviour, neighbourhood density and landscape aggregation

1. Frugivores disperse the seeds of the majority of woody plant species world-wide. Thus, insights on how frugivores influence the dispersal of plants and the variability of this process are crucial for understanding plant population dynamics in a rapidly changing world. 2. We used a spatially explicit, stochastic, individual-based model that simulates fruit-removal and seed dispersal by birds to assess bird density, landscape and neighbourhood effects on the inequalities of within-population fruit-removal rates and seed dispersal. We also compared model predictions with spatially-explicit field data. 3. In our simulations, bird density had a strong effect on the distribution of fruit-removal rates creating large inequalities among plants. Also, for equal bird densities, inequalities increased with the landscape level aggregation of plants. 4. Fruit removal increased with increasing plant neighbourhood density although there was a tendency to decline at the highest densities. Neighbourhood density also changed average dispersal distances, but with shorter distances at higher densities. Plants with few neighbours not only had longer distance dispersal but also a larger variance in seed rain across distances than plants with ten or more neighbours. These relationships between neighbourhood density and fruit removal and dispersal distance were scale-dependent with a peak in correlations at 150-m radius. 5. Similar to model predictions, field data shows an inverse relationship between dispersal distances (inferred from bird movements) and fruiting neighbourhood density. Also, fruit-removal rates observed in the field show large numbers of plants receiving little or zero fruit-removal. Fruit-removal rate distributions were statistically indistinguishable between the simulation and field data. But, distributions were strikingly different from two alternative models that lacked spatial effects. 6. Synthesis. Our model and field data show that as fruiting plants become aggregated, inequalities in fruit-removal rates increase and seed dispersal distance decreases. Both of these processes could help create and maintain plant aggregation and affect genetic structuring. The model also predicts that small-scale neighbourhood effects can be controlled by large-scale processes such as overall frugivore abundance and landscape-level plant aggregation. Most importantly, both simulations and field data shows an interaction between plant spatial pattern and bird foraging, which results in neighbourhood-specific dispersal and rates of fruit removal

The effects of plant distribution and frugivore density on the scale and shape of dispersal kernels

For many plant species, seed dispersal is one of the most important spatial demographic processes. We used a diffusion approximation and a spatially explicit simulation model to explore the mechanisms generating seed dispersal kernels for plants dispersed by frugivores. The simulation model combined simple movement and foraging rules with seed gut passage time, plant distribution, and fruit production. A simulation experiment using plant spatial aggregation and frugivore density as factors showed that seed dispersal scale was largely determined by the degree of plant aggregation, whereas kernel shape was mostly dominated by frugivore density. Kernel shapes ranged from fat tailed to thin tailed, but most shapes were between an exponential and that of the solution of a diffusion equation. The proportion of dispersal kernels with fat tails was highest for landscapes with clumped plant distributions and increased with increasing number of dispersers. The diffusion model provides a basis for models including more behavioral details but can also be used to approximate dispersal kernels once a diffusion rate is estimated from animal movement data. Our results suggest that important characteristics of dispersal kernels will depend on the spatial pattern of plant distribution and on disperser density when frugivores mediate seed dispersal

Plant-frugivore interactions as spatially explicit networks: integrating frugivore foraging with fruiting plant spatial patterns

In this chapter, an attempt to fit diffuse characteristics of frugivore-plant interactions into a framework that provides new ideas about frugivory and seed dispersal patterns, plant community associations and evolution. Specifically, it is proposed that frugivory and seed dispersal patterns should be examined in a spatially explicit manner that will help explain variability at the levels of both plant individuals and species. It is argued that the framework can shed light on fruiting plant community structure, diversity and evolution

When Hope Is All There Is Left

One particular patient who was facing the fact that she would die from cancer reveals an important lesson for the oncologist about listening and caring. Medical oncologists have a role beyond offering new treatments to patients with incurable disease: the role of supporter, and of witness, supporting a patient, especially in the last stages of illness, when hope is all there is left

Atomistic simulation of the electronic transport in organic nanostructures: Electron-phonon and electron-electron interactions

Non-equilibrium Green's functions formalism is used to study the influence of molecular vibrations on the current through a benzodithiolate molecule sandwiched in between Cu contacts. Incoherent tunneling and power dissipation in the molecular junction is analyzed in detail. We develop an efficient scheme for quasiparticle correction to the DFT states based on the GW theory. The method is applied to the investigation of tunneling current through the same molecule. We show that the HOMO-LUMO gap renormalization results in a decrease of tunneling current by up to one order of magnitude. The importance of quasiparticle corrections in conjunction to power dissipation analysis is discusse

Alterations in polyunsaturated fatty acid composition of cardiac membrane phospholipids and α1 adrenoceptor mediated phosphatidylinositol turnover

Study objective - The aim of the study was to investigate the steps at which polyunsaturated fatty acids are involved in α1 adrenoceptor mediated phosphatidylinositol turnover. Design - Phosphatidylinositol turnover rates were investigated after preincubating neonatal rat ventricular myocytes with culture media enriched with linoleic acid (18:2n-6) or eicosapentaenoic acid (20:5n-3) to change the polyunsaturated fatty acid composition of their membrane phospholipids. Experimental material - Cardiomyocytes were isolated from ventricles of 2-4 d old Wistar rats by trypsinization and were then cultured. Experiments were started 48 h after seeding, when there was a confluent monolayer of beating cardiomyocytes. Measurements and results - In 18:2n-6 treated cells the 18:2n-6 content in the total phospholipid fraction rose from 45 to 68 nmol·mg-1 protein; in 20:5n-6 treated cells the 20:5n-3 content rose from 1.5 to 12.5 nmol·mg-1 protein, and the docosapentaenoic acid (22:5n-3) content rose from 5.1 to 14.7 nmol·mg-1protein. The major n-3 fatty acid, 22:6n-3 (11.4 nmol·mg-1 protein), did not change after 20:5n-3 treatment. Although the phosphatidylinositol fraction showed changes paralleling those in the total phospholipids, none were significant. In this fraction the major n-3 fatty acid appeared to be 22:5n-3 (0.4 nmol·mg-1 protein). The fatty acid treated cells were prelabelled with [3H]-inositol to estimate the rate of phosphatidylinositol-4,5-bisphosphate turnover. There were no differences in the rate of [3H]-inositolphosphate formation between control, 18:2n-6 treated cells, and 20:5n-3 treated cells. Prolonged α1 adrenergic stimulation of control and treated cells did not change the polyunsaturated fatty acid composition of the total phospholipid and phosphatidylinositol fractions. Conclusions - The α1 adrenoceptor mediated phosphatidylinositol turnover rate is not affected by changes in polyunsaturated fatty acid composition of membrane phospholipids, neither does prolonged α1 adrenergic stimulation lead to significant depletion of any specific or total polyunsaturated fatty acids in the phosphatidylinositol lipids