Consultation/Liaison Psychiatry During Covid-19

Consultation/liaison psychiatrists care for people with co-existing medical and psychologic difficulties. The coronavirus pandemic is stressful for patients and their psychiatric caregivers. Patients have lost support systems and harbor fears about exposing family to the virus. COVID-19 sometimes exacerbates previous psychiatric conditions, while diminishing intimacy with physicians. Everyone is oversaturated with COVID-19-related news focusing on rising concerns about the illness and about jobs, school, and housing insecurities. The psychiatrist maintains a hospital presence despite fear of contracting the disease. Challenges include addressing staff morale, evidencing empathy despite telecommunication devices, and treating anxiety, depression, sleep phobias, post intubation flashbacks, COVID-19-induced cognitive disorders, and/or drug and alcohol addiction or withdrawal. They also provide support to patients who otherwise would die alone. The consultant must value small clinical successes, debrief beleaguered colleagues, offer support to hospital staff, and deliver psychotherapies to bolster patient comfort and autonomy. They prescribe pharmacotherapies that address psychiatric concerns without adversely affecting medical conditions. To decrease professional burnout from COVID-19-related issues, psychiatrists should attend to self-care and precautions designed to maintain the safety of their family

Static electric fields in an infinite plane condensor with one or three homogeneous layers

Various expressions are derived for the Green's functions for a point charge in an infinite plane condensor comprising one or three homogeneous isolating parallel dielectric layers. In view of numerical evaluations needed for calculating space charge effects in detectors (e.g. RPC's) the merits of these (series and integral) representations are discussed. It turns out that in most cases the integral representations are more favourable after their convergence has been improved. This is done by subtracting simple terms having the same asymptotic behaviour as certain too slowly converging terms and adding closed expressions resulting from the integration of the simple terms. The method is demonstrated in some detail. In addition analytic expressions for the weighting field of a strip electrode are derived which allow calculation of induced signals and crosstalk

Analytic expressions for static electric fields in an infinite plane condenser with one or three homogeneous layers

Expressions for the electrostatic field of a point charge in an infinite plane condenser comprising one or three homogeneous isolating parallel dielectric layers are presented. These solutions are essential for detector physics simulations of Parallel Plate Chambers (PPCs) and Resistive Plate Chambers (RPCs). In addition, expressions for the weighting field of a strip electrode are presented which allow calculation of induced signals and crosstalk in these detectors. A detailed discussion of the derivation of these solutions can be found in \cite{schnizer}

Ray-optical refraction with confocal lenslet arrays

Two parallel lenslet arrays with focal lengths f1 and f2 that share a common focal plane (that is, which are separated by a distance f1+f2) can refract transmitted light rays according to Snell's law, but with the 'sin's replaced with 'tan's. This is the case for a limited range of input angles and other conditions. Such confocal lenslet arrays can therefore simulate the interface between optical media with different refractive indices, n1 and n2, whereby the ratio η=-f2/f1 plays the role of the refractive-index ratio n2/n1. Suitable choices of focal lengths enable positive and negative refraction. In contrast to Snell's law, which leads to nontrivial geometric imaging by a planar refractive-index interface only for the special case of n1=±n2, the modified refraction law leads to geometric imaging by planar confocal lenslet arrays for any value of η. We illustrate some of the properties of confocal lenslet arrays with images rendered using ray-tracing software