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Ten cyanobacterial species ( Nostoc calcicola , Nostoc commune, Nostoc entophytum, Nostoc minutum, Nostoc palndosum, Nostoc passerianum, Nostoc punctiforme, Anabaena ambigua, Anabaena amomala, and Anabaena doliolum ) were isolated from the mangrove region of Ras Mohammed (Sinai, Egypt), and were tested for their allelopathic activities including inhibitory and/or promoting effects against two Gram positive bacteria ( Bacillus subtilis and Staphylococcus aureus ) and two Gram negative bacteria (Escherichia coli and Pseudomonas aeruginosa ). Data suggested two types of allelopathic effects: one type which always appeared in cyanobacterial medium as in the case with N. minutum (medium that inhibits the growth of all tested bacterial species). The other type is induced only when cyanobacteria are in contact with bacteria; this is the case when the growth of both B. subtilis and S. aureus were inhibited in co-culture with N. commune. On the other hand, promotion effects of bacterial growth were observed when grown in cyanobacterial metabolites in most of studied cyanobacterial species. The biological assays for aqueous and methanolic extracts of the two Nostoc species revealed that both extracts for each species were not toxic at concentrations of 0.52 and 0.59 g L -1 water extract for N. commune and N. minutum , respectively and 0.31 and 0.425 g L -1 for methanolic extract for N. commune and N. minutum , respectively. No mortality was observed in tested mice within 72 h.

[Image: see text] The biological reduction of soluble U(VI) complexes to form immobile U(IV) species has been proposed to remediate contaminated sites. It is well established that multiheme c-type cytochromes (MHCs) are key mediators of electron transfer to aqueous phase U(VI) complexes for bacteria such as Shewanella oneidensis MR-1. Recent studies have confirmed that the reduction proceeds via a first electron transfer forming pentavalent U(V) species that readily disproportionate. However, in the presence of the stabilizing aminocarboxylate ligand, dpaea(2–) (dpaeaH(2)=bis(pyridyl-6-methyl-2-carboxylate)-ethylamine), biologically produced U(V) persisted in aqueous solution at pH 7. We aim to pinpoint the role of MHC in the reduction of U(V)-dpaea and to establish the mechanism of solid-phase U(VI)-dpaea reduction. To that end, we investigated U-dpaea reduction by two deletion mutants of S. oneidensis MR-1–one lacking outer membrane MHCs and the other lacking all outer membrane MHCs and a transmembrane MHC–and by the purified outer membrane MHC, MtrC. Our results suggest that solid-phase U(VI)-dpaea is reduced primarily by outer membrane MHCs. Additionally, MtrC can directly transfer electrons to U(V)-dpaea to form U(IV) species but is not strictly necessary, underscoring the primary involvement of outer membrane MHCs in the reduction of this pentavalent U species but not excluding that of periplasmic MHCs.

BACKGROUND: Coronavirus disease 2019 created unintended but significant experiential barriers for surgical learners to interact at the bedside for teaching/case presentations. We hypothesized that an international grand rounds using the Microsoft HoloLens 2 extended reality (XR) headset would create an improved bedside-learning experience compared to traditional grand rounds formats. STUDY DESIGN: From December 2020 to March 2021, the world’s first 2 international mixed reality grand rounds events using the HoloLens 2 headset were held, broadcasting transatlantically (between the University of Michigan and the Imperial College of London) bedside rounding experiences on 5 complex surgical patients to an international audience of 325 faculty, residents, and medical trainees. Participants completed pre- and post-event surveys to assess their experience. RESULTS: Of the 325 participants, 267 (80%) completed pre-surveys, and 95 (29%) completed both the pre- and post-surveys. Respondents (average age, 38 y; 44% women, 56% men; 211 US, 56 UK) included 92 (34%) medical students and residents and 175 faculty and staff. In the pre-event survey, 76% had little or no earlier experience with XR devices, and 94% thought implementation of XR into medical curricula was valuable. In the post-survey, 96% thought telerounding using XR technology was important for the current era, and 99% thought the ability to visualize the examination, imaging, and laboratory results at bedside via XR rounding was highly valuable and that this format was superior to traditional grand rounds. CONCLUSIONS: Almost all of the participants in the mixed reality international grand rounds felt the immersive XR experiences—allowing visualization of clinical findings, imaging, and laboratory results at the patient’s bedside—were superior to a traditional grand rounds format, and that it could be a valuable tool for surgical teaching and telerounding.

How does specific information about contamination in a household's drinking water affect water handling behavior? We randomly split a sample of households in rural Andhra Pradesh, India. The treatment group observed a contamination test of the drinking water in their own household storage vessel; while they were waiting for their results, they were also provided with a list of actions that they could take to remedy contamination if they tested positive. The control group received no test or guidance. The drinking water of nearly 90% of tested households showed evidence of contamination by fecal bacteria. They reacted by purchasing more of their water from commercial sources but not by making more time-intensive adjustments. Providing salient evidence of risk increases demand for commercial clean water.

Dental biomechanics based on finite element (FE) analysis is attracting enormous interest in dentistry, biology, anthropology and palaeontology. Nonetheless, several shortcomings in FE modeling exist, mainly due to unrealistic loading conditions. In this contribution we used kinematics information recorded in a virtual environment derived from occlusal contact detection between high resolution models of an upper and lower human first molar pair (M1 and M1, respectively) to run a non-linear dynamic FE crash colliding test.MicroCT image data of a modern human skull were segmented to reconstruct digital models of the antagonistic right M1 and M1 and the dental supporting structures. We used the Occlusal Fingerprint Analyser software to reconstruct the individual occlusal pathway trajectory during the power stroke of the chewing cycle, which was applied in a FE simulation to guide the M1 3D-path for the crash colliding test.FE analysis results showed that the stress pattern changes considerably during the power stroke, demonstrating that knowledge about chewing kinematics in conjunction with a morphologically detailed FE model is crucial for understanding tooth form and function under physiological conditions.Results from such advanced dynamic approaches will be applicable to evaluate and avoid mechanical failure in prosthodontics/endodontic treatments, and to test material behavior for modern tooth restoration in dentistry. This approach will also allow us to improve our knowledge in chewing-related biomechanics for functional diagnosis and therapy, and it will help paleoanthropologists to illuminate dental adaptive processes and morphological modifications in human evolution.

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Many manufacturing processes involved in the fabrication and assembly of “high-tech” components have highly variable yields that complicate the planning and control of production. We develop a procedure to determine optimal input quantities at each stage of a serial production system in which process yields at each stage of production may be stochastic. The procedure is applied to an example in the manufacture of a light-emitting diode (LED) display using actual yield data. We also provide a brief analysis of the quantifiable savings obtained by reducing the variability of the yield at one production stage.