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Light pollution is an environmental stressor of global extent that is growing exponentially in area and intensity. Artificial skyglow, a form of light pollution with large range, is hypothesized to have environmental impact at ecosystem level. However, testing the impact of skyglow at large scales and in a controlled fashion under in situ conditions has remained elusive so far. Here we present the first experimental setup to mimic skyglow at ecosystem level outdoors in an aquatic environment. Spatially diffuse and homogeneous surface illumination that is adjustable between 0.01 and 10 lx, resembling rural to urban skyglow levels, was achieved with white light-emitting diodes at a large-scale lake enclosure facility. The illumination system was enabled by optical modeling with Monte-Carlo raytracing and validated by measurements. Our method can be adapted to other outdoor and indoor skyglow experiments, urgently needed to understand the impact of skyglow on ecosystems., (© 2021. The Author(s).)

Introduction: Coronavirus disease 2019 (COVID-19) infections have strained hospital resources worldwide. As a result, many facilities have suspended elective operations and ambulatory procedures. As the incidence of new cases of COVID-19 decreases, hospitals will need policies and algorithms to facilitate safe and orderly return of normal activities. We describe the recommendations of a task force established in a multi-institutional healthcare system for resumption of elective operative and ambulatory procedures applicable to all hospitals and service lines., Methods: MedStar Health created a multidisciplinary task force to develop guidelines for resumption of elective surgeries/procedures. The primary focus areas included the establishment of a governance structure at each healthcare facility, prioritization of elective cases, preoperative severe acute respiratory syndrome coronavirus 2 testing, and an assessment of the needs and availability of staff, personal protective equipment, and other essential resources., Results: Each hospital president was tasked with establishing a local perioperative leadership team answering directly to them and granted the authority to prioritize elective surgery and ambulatory procedures. An elective surgery algorithm was established using a simplified Medically Necessary Time Sensitive score, with multiple steps requiring a "go/no-go" assessment based on local resources. In addition, mandatory preoperative COVID testing policies were developed and operationalized., Conclusions: Even when the COVID pandemic has passed, hospitals and surgical centers will require COVID screening and testing, case prioritization, and supply chain management to provide care essential to the surgical patient while protecting their safety and that of staff. Our guidelines consider these factors and are applicable to both tertiary academic medical centers and smaller community facilities., Competing Interests: Disclosure: The authors declare that they have nothing to disclose., (Copyright © 2020 The Author(s). Published by Wolters Kluwer Health, Inc.)

Cell lines matching the source epithelium are indispensable for investigating porcine intestinal transport and barrier properties on a subcellular or molecular level and furthermore help to reduce animal usage. The porcine jejunal cell line IPEC-J2 is established as an in vitro model for porcine infection studies but exhibits atypically high transepithelial resistances (TER) and only low active transport rates so that the effect of nutritional factors cannot be reliably investigated. This study aimed to properly remodel IPEC-J2 and then to re-characterize these cells regarding epithelial architecture, expression of barrier-relevant tight junction (TJ) proteins, adequate TER and transport function, and reaction to secretagogues. For this, IPEC-J2 monolayers were cultured on permeable supports, either under conventional (fetal bovine serum, FBS) or species-specific (porcine serum, PS) conditions. Porcine jejunal mucosa was analyzed for comparison. Main results were that under PS conditions (IPEC-J2/PS), compared to conventional FBS culture (IPEC-J2/FBS), the cell height increased 6-fold while the cell diameter was reduced by 50%. The apical cell membrane of IPEC-J2/PS exhibited typical microvilli. Most importantly, PS caused a one order of magnitude reduction of TER and of trans- and paracellular resistance, and a 2-fold increase in secretory response to forskolin when compared to FBS condition. TJ ultrastructure and appearance of TJ proteins changed dramatically in IPEC-J2/PS. Most parameters measured under PS conditions were much closer to those of typical pig jejunocytes than ever reported since the cell line's initial establishment in 1989. In conclusion, IPEC-J2, if cultured under defined species-specific conditions, forms a suitable model for investigating porcine paracellular intestinal barrier function.

Angiogenesis is a multi-step process involving migration, proliferation, and a specific spatial arrangement of endothelial cells. On the basis of a model of cultured microvascular endothelial cells derived from the bovine corpus luteum, all stages of in vitro angiogenesis as well as intussusceptive remodeling were characterized by scanning and transmission electron microscopy. To preserve the delicate three-dimensional cellular structures for electron microscopy, modified processing techniques for both transmission and scanning electron microscopy including micro-corrosion casting of cultured cells were established. The detailed results on morphological alterations and cellular interactions confirmed and complemented earlier studies of in vitro angiogenesis. Electron microscopy proved to be an efficient tool for detection and supervision of all major endothelial differentiation processes resembling in vivo conditions that are generally considered important in a realistic in vitro model of angiogenesis: occurrence of function-related cellular junctions; development of specific surface features indicating cellular polarity; production of extracellular matrix material; mechanisms leading to the formation of an internal lumen; specific spatial arrangement of endothelial cells within capillary-like networks; detachment of apoptotic cells as well as intussusception of specific cells within the course of vascular remodeling. The abundance of quickly available information provided by electron microscopic approaches may be useful for subsequent, e.g., biochemical or molecular, studies and thus delivers important controls for further experimental designs., ((c) 2005 Wiley-Liss, Inc.)

While controversy exists as to the relationship between maternal position in labor and such measures as the labor duration, subjective discomfort, and fetal outcome, little appears to be known about the positions women assume in labor when they are permitted to do so without coercion or instruction. To learn more about maternal position in labor, we observed 80 consecutive patients with uncomplicated normal spontaneous vaginal delivery over the course of labor to ascertain the positions volitionally chosen by each. Data were collected on position preferences and phase of labor. All labors were analyzed; a codified lexicon was established to describe the position pattern in each phase and the principal positions the patient assumed over the course of labor. The frequencies and distributions were determined for nulliparas and multiparas separately and rates of position change were assessed. It was found that gravidas chose a number of different principal positions in the early phases of labor, but that they became more narrowly selective in the deceleration phase and second stage; at the same time, they tended to change position more often in late labor.