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Health-relevant microorganisms present in natural surface waters and engineered treatment systems that are exposed to sunlight can be inactivated by a complex set of interacting mechanisms. The net impact of sunlight depends on the solar spectral irradiance, the susceptibility of the specific microorganism to each mechanism, and the water quality; inactivation rates can vary by orders of magnitude depending on the organism and environmental conditions. Natural organic matter (NOM) has a large influence, as it can attenuate radiation and thus decrease inactivation by endogenous mechanisms. Simultaneously NOM sensitizes the formation of reactive intermediates that can damage microorganisms via exogenous mechanisms. To accurately predict inactivation and design engineered systems that enhance solar inactivation, it is necessary to model these processes, although some details are not yet sufficiently well understood. In this critical review, we summarize the photo-physics, -chemistry, and -biology that underpin sunlight-mediated inactivation, as well as the targets of damage and cellular responses to sunlight exposure. Viruses that are not susceptible to exogenous inactivation are only inactivated if UVB wavelengths (280-320 nm) are present, such as in very clear, open waters or in containers that are transparent to UVB. Bacteria are susceptible to slightly longer wavelengths. Some viruses and bacteria (especially Gram-positive) are susceptible to exogenous inactivation, which can be initiated by visible as well as UV wavelengths. We review approaches to model sunlight-mediated inactivation and illustrate how the environmental conditions can dramatically shift the inactivation rate of organisms. The implications of this mechanistic understanding of solar inactivation are discussed for a range of applications, including recreational water quality, natural treatment systems, solar disinfection of drinking water (SODIS), and enhanced inactivation via the use of sensitizers and photocatalysts. Finally, priorities for future research are identified that will further our understanding of the key role that sunlight disinfection plays in natural systems and the potential to enhance this process in engineered systems.

Confined Periodic Turbulence (CPT) is numerical homogeneous turbulence with periodic conditions, over an extended time until the eddy size is only limited by the period L. With large or infinite Reynolds number, this allows a self-similar decaying state with a constant spectrum shape and turbulent kinetic energy k asymptotically equal to $ C_{CPT}L^2/t^2 $ C CPT L 2 / t 2 where t is time and $ C_{CPT} $ C CPT is a constant, as predicted by Skrbek & Stalp. This setting may provide a long inertial range for a given resolution and is free of inputs such as initial spectra or forcing devices. Outside the viscous range, it generates the same spectra as the Linear Forcing proposed by Lundgren and exercised by Rosales & Meneveau. We conduct DNS, with the viscosity artificially decreasing in time to keep the Reynolds number $ Re \equiv L\sqrt{k}/\nu $ Re ≡ L k / ν approximately constant, and LES at infinite Reynolds number, with resolution 10243. The solutions indeed lose memory of initial conditions. Both agree well with Rosales & Meneveau and with the $ L^2/t^2 $ L 2 / t 2 conjecture although with modulations; $ C_{CPT} $ C CPT is about 0.5. Kovasznay's extension of Kolmogorov's theory, based on the local energy-transfer rate across wavenumbers, predicts the spectrum well even for intermediate wavenumbers, with the Kolmogorov constant $ C_K $ C K at 1.65. [ABSTRACT FROM AUTHOR]

Metacognition and quality of life (QoL) are both adversely affected by traumatic brain injury (TBI), but the relation between them is not fully understood. As such, the purpose of this study was to determine the degree to which metacognitive accuracy predicts QoL in individuals with TBI. Eighteen participants with moderate-to-severe TBI completed a stimulus-response task requiring the discrimination of emotions depicted in pictures of faces and then provided a retrospective confidence judgment after each response. Metacognitive accuracy was calculated using participants' response accuracy and confidence judgment accuracy. Participants also completed the Quality of Life After Brain Injury (QOLIBRI) questionnaire to assess QoL in various areas of functioning. Performance of a linear regression analysis revealed that higher metacognitive accuracy significantly predicted lower overall QoL. Additionally, higher metacognitive accuracy significantly predicted lower QoL related to cognition and physical limitations. The study results provide evidence of an inverse relation between metacognitive performance and QoL following TBI. Metacognitive changes associated with TBI and their relation to QoL have several clinical implications for TBI rehabilitation. [ABSTRACT FROM AUTHOR]

In the present article, we describe a course exercise in which students were administered four course evaluation forms throughout the semester, on which they provided their overall impressions of the class as well as their desire to change certain aspects of the course. Critically, during the semester, a total of three changes were made to the structure of the course as voted on by the students. Compared to the previous semester where students completed only end-of-semester evaluations, improvements in exam performance as well as instructor ratings were observed. Furthermore, students indicated that the changes made throughout the semester improved the course, and they hoped that other classes would adopt a similar classroom developmental strategy. This supports a growing body of evidence, suggesting that midsemester feedback is crucial for optimizing the learning environment for the student, particularly when concrete changes are made after the administration of course feedback.