Chiroptical Properties and Conformation of 4,5-Saturated Derivatives of 5-Aryl-1,4-benzodiazepin-2-ones

CD spectra of a series of 5-aryl-7-chloro-l,3,4,5-tetrahydro- 2H-l,4-benzodiazepin-2-one derivatives having different substituents at positions 1, 3, 4, and 5 were studied. The absolute configuration at C-5 of two homochiral analogues, 1 and 2, having enantiomorphous ring conformations was determined on the basis of chiroptical correlations and theoretical calculations. The latter have shown that the optical activity mainly originates from the one-electron mechanism and is determined by the helicity of the diazepine ring, i. e. by the inherent chirality of the partial chromophore 4-chloro-N,2-dimethyl-formanilide. Exciton inter action s between transitions of the two arornatic chromophores A and C also give a significant contribution to chiroptical properties. By applying simple chiroptical rules dedueed from experimental spectra and supported by calculations, the stereochemistry (absolute conformation and configuration), of 3,5-disubstituted cis and trans epimeric pairs (7-17) was revealed

CD99-positive undifferentiated round cell sarcoma diagnosed on fine needle aspiration cytology, later found to harbour a CIC-DUX4 translocation: a recently described entity

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A stakeholder-guided marine heatwave hazard index for fisheries and aquaculture

Marine heatwaves pose an increasing threat to fisheries and aquaculture around the world under climate change. However, the threat has not been estimated for the coming decades in a form that meets the needs of these industries. Tasmanian fisheries and aquaculture in southeast Australia have been severely impacted by marine heatwaves in recent years, especially the oyster, abalone, and salmon industries. In a series of semi-structured interviews with key Tasmanian fishery and aquaculture stakeholders, information was gathered about the following: (i) the impacts they have experienced to date from marine heatwaves, (ii) their planning for future marine heatwaves, and (iii) the information that would be most useful to aid planning. Using CMIP6 historical and future simulations of sea surface temperatures around Tasmania, we developed a marine heatwave hazard index guided by these stakeholder conversations. The region experienced a severe marine heatwave during the austral summer of 2015/16, which has been used here as a reference point to define the index. Our marine heatwave hazard index shows that conditions like those experienced in 2015/16 are projected to occur approximately 1-in-5 years by the 2050s under a low emissions scenario (SSP1-2.6) or 1-in-2 years under a high emissions scenario (SSP5-8.5). Increased frequency of marine heatwaves will likely reduce productivity by both direct (mortality) and in-direct (ecosystem change, greater incidence of disease) impacts on target species. The illustrative hazard index is one step towards a marine heatwave risk index, which would also need to consider aspects of exposure and vulnerability to be of greater utility to stakeholders

Predictability of marine heatwaves off Western Australia using a linear inverse model

Marine heatwaves (MHWs) off Western Australia (110°E−116°E, 22°S−32°S; hereafter, WA MHWs) can cause devastating ecological impacts, as was evidenced by the 2011 extreme event. Previous studies suggest that La Niña is the major large-scale driver of WA MHWs, while Indian Ocean Dipole (IOD) may also play a role. Here, we investigate historical WA MHWs and their connections to these large-scale climate modes in an ocean model (ACCESS−OM2) simulation driven by a prescribed atmosphere from JRA55−do over 1959–2018. Rather than analysing sea surface temperature, the WA MHWs and climate mode indices were characterized and investigated in vertically averaged temperature (VAT) to ~300m depth to afford the longer ocean dynamic time scales, including remote oceanic connections. We develop a cyclostationary linear inverse model (CS-LIM; from 35°S−10°N, across the Indo-Pacific Ocean), to investigate the relative contributions of La Niña VAT and positive IOD VAT to the predictability of WA VAT MHWs. Using a large ensemble of CSLIM simulations, we found that ~50% of WA MHWs were preceded about 5 months by La Niña, and 30% of the MHWs by positive IOD about 20 months prior. While precursor La Niña or positive IOD, on their own, were found to correspond with increased WA MHW likelihood in the months following (~2.7 times or ~1.5 times more likely than by chance, respectively), in combination these climate mode phases were found to produce the largest enhancement in MHW likelihood (~3.2 times more likely than by chance). Additionally, we found that stronger and longer La Niña and/or positive IOD tend to lead stronger and longer WA MHWs

Impacts of marine heatwaves on tropical western and central Pacific Island nations and their communities

Marine heatwaves can have devastating impacts on marine species and habitats, often with flow-on effects to human communities and livelihoods. This is of particular importance to Pacific Island countries that rely heavily on coastal and ocean resources, and for which projected increases in future marine heatwave (MHW) frequency, intensity, and duration could be detrimental across the Pacific Island region. In this study, we investigate MHWs in the tropical western and central Pacific Ocean region, focusing on observed MHWs, their associated impacts, and future projections using Coupled Model Intercomparison Project phase 6 (CMIP6) simulations under a low (SSP1–2.6) and a high (SSP5–8.5) greenhouse gas emissions scenario. Documented impacts from “Moderate” mean intensity MHW events in Fiji, Samoa, and Palau, that were categorised as “Strong” at their peak, included fish and invertebrate mortality and coral bleaching. Based on CMIP6 multi-model mean estimates, and relative to current baselines, “Moderate” intensity MHWs are projected to increase from recent historical (1995–2014) values of 10–50 days per year (dpy) across the region to the equivalent of >100 dpy by the year 2050 under the low emissions scenario, and > 200 dpy nearer the equator. Under the high emissions scenario, 200 dpy of Moderate MHW intensities are projected across most of the region by 2050, with >300 dpy nearer the equator. For the most intense “Extreme” category of MHW, estimates range from 50 dpy projected under the high emissions scenario by 2050. In contrast, “Extreme” MHWs are projected to increase to <5 dpy by 2050 under the low emissions scenario, highlighting the importance for Pacific Island nations that global emissions more closely follow the low emissions scenario trajectory