On restrictions of Besov functions

In this paper, we study the smoothness of restrictions of Besov functions. It is known that for any $f\in B\_{p,q}^s(\mathbb{R}^N)$ with $q\leq p$ we have $f(\cdot,y)\in B\_{p,q}^s(\mathbb{R}^d)$ for a.e. $y\in \mathbb{R}^{N-d}$. We prove that this is no longer true when p\. Namely, we construct a function $f\in B\_{p,q}^s(\mathbb{R}^N)$ such that $f(\cdot,y)\notin B\_{p,q}^s(\mathbb{R}^d)$ for a.e. $y\in \mathbb{R}^{N-d}$. We show that, in fact, $f(\cdot,y)$ belong to $B\_{p,q}^{(s,\Psi)}(\mathbb{R}^d)$ for a.e. $y\in\mathbb{R}^{N-d}$, a Besov space of generalized smoothness, and, when $q=\infty$, we find the optimal condition on the function $\Psi$ for this to hold. The natural generalization of these results to Besov spaces of generalized smoothness is also investigated

Coupling Between the Thermosphere and the Stratosphere: the Role of Nitric Oxide

In order to understand the lower ionosphere and its probable control by dynamical processes, the behavior of nitric oxide below 100 km was investigated. A two dimensional model with coupled chemical and dynamical processes was constructed. Calculations based on the model reveal that the chemical conditions at the stratopause are related to the state of the thermosphere. This coupling mechanism can be partly explained by the downward transport of nitric oxide during the winter season, and consequently depends on the dynamical conditions in the mesosphere and in the lower thermosphere (mean circulation and waves). In summer, the photodissociation of nitric oxide plays an important role and the thermospheric NO abundance modulates the radiation field reaching the upper stratosphere. Perturbations in the nitric oxide concentration above the mesopause could therefore have an impact in the vicinity of the stratopause

Competition between General Practitioners and Specialists in the Primary Health Care Market

In this paper, we study the optimal payment system for the primary health care market when general practitioners are not only in competition between themselves but also with specialists. We define the copayment to impose in order to ensure a good allocation of patients among the two types of physicians. Further, we set the physician reimbursement system that guarantees an appropriate referral of patients to specialists. We prove that the GP's remuneration system is more prospective the larger the competition with specialists. Next, we show that the assumption of risk-averse patients precludes the optimal payment system from being a first-best solution. To conclude, we contrast the results of the analysis with systems of gatekeepers where all patients are required to go to a general practitioner before having access to specialized medicine.health care; competition; gatekeeping; payment system

Modelling habitat preference and estimating the spatial distribution of Australian Sea Lions (Neophoca cinerea); "A first exploration "

Managing the Australian sea lion (Neophoca cinerea) population and mitigating its interactions with commercial fisheries, requires an understanding of their spatial distribution and habitat preference at sea. Numerous wildlife telemetry devices have been attached to individual seals from different colonies, providing a detailed insight into there movement and activities. However, as data are only available from some individuals from 16 of 40 colonies in South Australia, these data represents only a small proportion of the population. Moreover, some colonies are poorly represented. To estimate the spatial distribution of the entire South Australian population, one can first investigate why individuals visit certain places and use this information to predict the spatial distribution for other regions lacking data. In this study we fit Generalized Additive Mixed Models (GAMMs) to wildlife telemetry data collected from adult female Australian sea lions to investigate the species’ habitat preference for the variables distance to the colony, depth and slope. The results show that in general they have a higher preference for shallow areas, places close to the colony and a steep slope, but they also display large individual variability. Preference for these variables does not seem to differ between individuals of different sizes. In some of the most western colonies, some individuals seem to spend more time further away from the colony, but apart from this, there is no apparent effect of the longitudinal capture position on preference. The predicted spatial distribution is largely driven by the distance from the departure colony and the actual distribution of individuals among the different colonies. Although depth and slope does seem to effect their distribution to some extent, the most important variables that explain fine-scale foraging activities at-sea are probably missing. Future studies using GPS transmitters attached to animals, that yield high resolution locations and more detailed environmental data, in combination with the analytical technique presented here, should provide more insight there foraging decisions. This should eventually also improve the spatial prediction of the population as a whole

Some monotonicity results for general systems of nonlinear elliptic PDEs

In this paper we show that minima and stable solutions of a general energy functional of the form $$\int_{\Omega} F(\nabla u,\nabla v,u,v,x)dx$$ enjoy some monotonicity properties, under an assumption on the growth at infinity of the energy. Our results are quite general, and comprise some rigidity results which are known in the literature

The potential impact on atmospheric ozone and temperature of increasing trace gas concentrations

The response of the atmosphere to emissions of chlorofluorocarbons (CFCs) and other chlorocarbons, and to increasing concentrations of other radiatively active trace gases such as CO2, CH4, and N2O is calculated by a coupled chemical-radiative transport one-dimensional model. It is shown that significant reductions in the ozone concentration and in the temperature are expected in the upper stratosphere as a result of increasing concentrations of active chlorine produced by photodecomposition of the CFCs. The ozone content is expected to increase in the troposphere, as a consequence of increasing concentrations of methane and nitrogen oxides. Due to enhanced greenhouse effects, the Earth's surface should warm up by several degrees. The amplitude and even the sign of future changes in the ozone column are difficult to predict as they are strongly scenario-dependent. An early detection system to prevent noticeable ozone changes as a result of increasing concentrations of source gases should thus be based on a continuous monitoring of the ozone amount in the upper stratosphere rather than on measurements of the ozone column only. Measurements of NOx, Clx, and HOx are also required for unambiguous trend detection and interpretation

The Invalidity of the Laplace Law for Biological Vessels and of Estimating Elastic Modulus from Total Stress vs. Strain: a New Practical Method

The quantification of the stiffness of tubular biological structures is often obtained, both in vivo and in vitro, as the slope of total transmural hoop stress plotted against hoop strain. Total hoop stress is typically estimated using the "Laplace law." We show that this procedure is fundamentally flawed for two reasons: Firstly, the Laplace law predicts total stress incorrectly for biological vessels. Furthermore, because muscle and other biological tissue are closely volume-preserving, quantifications of elastic modulus require the removal of the contribution to total stress from incompressibility. We show that this hydrostatic contribution to total stress has a strong material-dependent nonlinear response to deformation that is difficult to predict or measure. To address this difficulty, we propose a new practical method to estimate a mechanically viable modulus of elasticity that can be applied both in vivo and in vitro using the same measurements as current methods, with care taken to record the reference state. To be insensitive to incompressibility, our method is based on shear stress rather than hoop stress, and provides a true measure of the elastic response without application of the Laplace law. We demonstrate the accuracy of our method using a mathematical model of tube inflation with multiple constitutive models. We also re-analyze an in vivo study from the gastro-intestinal literature that applied the standard approach and concluded that a drug-induced change in elastic modulus depended on the protocol used to distend the esophageal lumen. Our new method removes this protocol-dependent inconsistency in the previous result.Comment: 34 pages, 13 figure

The Demand for Physician Services. Evidence from a Natural Experiment

This study exploits a natural experiment in Belgium to estimate the effect of co-payment increases on the demand for physician services. It shows how a differences-in-differences estimator of the price effects can be decomposed into effects induced by the common average proportional price increase (income effects) and by the change in relative prices (substitution effects). The price elasticity of a uniform proportional price increase is relatively small (-.13 for mean and -.03 for woman). Substitution effects are large, especially for women, but imprecisely estimated. Despite the substantial price increases, the efficiency gain of the reform, if any, is modesthealth care; physician service; co-payment; moral hazard; demand system; differences-in-differences estimator

Comparison between observed and calculated distributions of trace species in the middle atmosphere

The purpose is to identify major discrepancies between empirical models and theoretical models and to stress the need for additional observations in the atmosphere and for further laboratory work, since these differences suggest either problems associated with observation techniques or errors in chemical kinetics data (or the existence of unknown processes which appear to play an important role). The model used for this investigation extends from the earth's surface to the lower thermosphere. It includes the important chemical and photochemical processes related to the oxygen, hydrogen, carbon, nitrogen and chlorine families. The chemical code is coupled with a radiative scheme which provides the heating rate due to absorption of solar radiation by ozone and the cooling rate due to the emission and absorption of terrestrial radiation by CO2, H2O and O3. The vertical transport of the species is expressed by an eddy diffusion parameterization