Stroke thrombolysis given by emergency physicians: The time is here.

Emergency Medicine core clinical privileges include administration of thrombolytic therapy for myocardial infarction and stroke. However, emergency medicine providers have created their own paradigm to rely on neurology specialty consultation to treat acute stroke patients. A 2013 study supported by the American Academy of Neurology showed an 11% shortage of neurologists at that time and projected a 19% shortage by 2025. The lack of neurologists is a worldwide problem. To help ease the shortage, teleneurology and telestroke care has been implemented by neurologists, most notably for acute ischemic stroke (AIS) patients. We present a model in which an Emergency Medicine (EM) Stroke Champion (SC); an EM physician within our Neurologic Emergency Department, directs care for acute stroke patients at our comprehensive hub and primary stroke center spoke hospitals. The SCs independently treat patients with fibrinolytic therapy and provide teleneurology to fellow emergency physicians caring for acute stroke patients at spoke hospitals. Over nineteen months the SCs received 457 phone calls for patients meeting stroke alert criteria. Sixteen patients were deemed eligible for IV alteplase with one hemorrhagic conversion (6.25%). Sixty-four patients required transfer, and this was facilitated by the SCs. The concept of emergency physician SCs providing teleneurology consultation to other fellow emergency physicians was found to be feasible and safe. This model has the potential to be generalized not to just stroke champions, but to all emergency physicians to feel both confident and comfortable treating acute stroke patients.

The End of the Profession as a Sociological Category? Systems-theoretical Remarks on the Relationship between Profession and Society.

Following reflections by Talcott Parsons and Niklas Luhmann, this paper is concerned with the changing meaning of the profession as a sociological category for analyzing modern society. Professions are practical academic occupational groups oriented to certain social values, to which a special significance for society was attributed in the social sciences for a long time, thus marking a connection between professions' research and theory of society. This paper now describes that the causal relationship between profession and society is limited to a historically relatively early period. In the transition to modern society, this close network of relationships begins to dissolve, and now professions operate in the context of some function systems of society whose task is the professional assistance of single clients, such as in the fields of health, law, and pastoral care. However, the professions' highlighted position in the knowledge and action structure of single function systems seems to dissolve more and more today so that one can ask whether we can speak here already of an end of the social form profession. This would correspond with the observation that actually the professions no longer appear at all in the newer theories of society and therefore their function as an important mechanism of social structure formation is no longer attributed to them.

Non-explosivity of Stochastically Modeled Reaction Networks that are Complex Balanced.

We consider stochastically modeled reaction networks and prove that if a constant solution to the Kolmogorov forward equation decays fast enough relatively to the transition rates, then the model is non-explosive. In particular, complex-balanced reaction networks are non-explosive.

Looking forwards and backwards: dynamics and genealogies of locally regulated populations.

We introduce a broad class of mechanistic spatial models to describe how spatially heterogeneous populations live, die, and reproduce. Individuals are represented by points of a point measure, whose birth and death rates can depend both on spatial position and local population density, defined at a location to be the convolution of the point measure with a suitable non-negative integrable kernel centred on that location. We pass to three different scaling limits: an interacting superprocess, a nonlocal partial differential equation (PDE), and a classical PDE. The classical PDE is obtained both by a two-step convergence argument, in which we first scale time and population size and pass to the nonlocal PDE, and then scale the kernel that determines local population density; and in the important special case in which the limit is a reaction-diffusion equation, directly by simultaneously scaling the kernel width, timescale and population size in our individual based model. A novelty of our model is that we explicitly model a juvenile phase. The number of juveniles produced by an individual depends on local population density at the location of the parent; these juvenile offspring are thrown off in a (possibly heterogeneous, anisotropic) Gaussian distribution around the location of the parent; they then reach (instant) maturity with a probability that can depend on the local population density at the location at which they land. Although we only record mature individuals, a trace of this two-step description remains in our population models, resulting in novel limits in which the spatial dynamics are governed by a nonlinear diffusion. Using a lookdown representation, we are able to retain information about genealogies relating individuals in our population and, in the case of deterministic limiting models, we use this to deduce the backwards in time motion of the ancestral lineage of an individual sampled from the population. We observe that knowing the history of the population density is not enough to determine the motion of ancestral lineages in our model. We also investigate (and contrast) the behaviour of lineages for three different deterministic models of a population expanding its range as a travelling wave: the Fisher-KPP equation, the Allen-Cahn equation, and a porous medium equation with logistic growth.

Product-form stationary distributions for deficiency zero chemical reaction networks.

We consider stochastically modeled chemical reaction systems with mass-action kinetics and prove that a product-form stationary distribution exists for each closed, irreducible subset of the state space if an analogous deterministically modeled system with mass-action kinetics admits a complex balanced equilibrium. Feinberg's deficiency zero theorem then implies that such a distribution exists so long as the corresponding chemical network is weakly reversible and has a deficiency of zero. The main parameter of the stationary distribution for the stochastically modeled system is a complex balanced equilibrium value for the corresponding deterministically modeled system. We also generalize our main result to some non-mass-action kinetics.