Stochastic Entropy Production Associated with Quantum Measurement in a Framework of Markovian Quantum State Diffusion.

The reduced density matrix that characterises the state of an open quantum system is a projection from the full density matrix of the quantum system and its environment, and there are many full density matrices consistent with a given reduced version. Without a specification of relevant details of the environment, the time evolution of a reduced density matrix is therefore typically unpredictable, even if the dynamics of the full density matrix are deterministic. With this in mind, we investigate a two-level open quantum system using a framework of quantum state diffusion.

Dissipation production in a closed two-level quantum system as a test of the irreversibility of the dynamics.

Irreversible behavior in open stochastic dynamical systems is quantified by stochastic entropy production, a property that measures the difference in likelihoods of forward and subsequent backward system evolution. But for a closed system, governed by deterministic dynamics, such an approach is not appropriate. Instead, we can consider the difference in likelihoods of forward and "obverse" behavior: the latter being a backward trajectory initiated at the same time as the forward trajectory.

Diagnostic value of symptoms for pediatric SARS-CoV-2 infection in a primary care setting.

Purpose: To evaluate the diagnostic value of symptoms used by daycares and schools to screen children and adolescents for SARS-CoV-2 infection, we analyzed data from a primary care setting.

Methods: This cohort study included all patients ≤17 years old who were evaluated at Providence Community Health Centers (PCHC; Providence, U.S.

Urogenital symptoms after sexual abuse vs irritant contact in premenarchal girls.

Objectives: Sexually abused (SA) girls report urogenital symptoms temporally related to inappropriate genital contact. Since girls also experience symptoms following genital irritant exposure and mostly all girls are exposed to genital irritants, we describe overall symptoms reported by girls that disclosed SA compared to those that did not and we compare how girls describe symptoms following a specific episode of contact SA vs a genital irritant exposure.

Design: Cross-sectional study.