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Organic-rich whale bones and wood falls occur widely in the deep sea and support diverse faunal communities, contributing to seafloor habitat diversity. Changes in community structure through succession on deep-sea bone/wood substrates are modulated by ecosystem engineers, i.e., bone-eating Osedax annelids, and wood-boring Xylophaga bivalves. Here, we use a comparative experimental approach and Ocean Networks Canada's (ONC) cabled observatory in hypoxic Barkley Canyon to study, at high temporal resolution, colonization and succession on whale-bone, Douglas fir wood, and control carbonate rock over 8.3 mo. Experimental substrates were similar in size and mounted on PVC plates near the seafloor at 890 m depth and monitored by high-definition video camera for 5-min intervals every 6-12 h over a period of 8.3 mo. A broad range of seafloor and sea-surface environmental variables were also monitored at this site over the 8.3 mo to account for environmental variability and food input. Following loss of the high-definition camera, substrates were surveyed approximately annually with lower resolution ROV video for an additional 8.5 y. We find that megafaunal abundances, species diversity, and community structure varied substantially over 8.3 mo on each substrate, with markedly different patterns on whale bones due to the development of extensive white bacterial mats. A combination of seafloor and sea surface variables explained < 35% of bone/wood community variation. Bone-eating Osedax annelids failed to colonize whale bones even after 9.2 years, and boring Xylophaga bivalves colonized the wood at much lower rates than in better oxygenated deep-sea locations. Species diversity on whale-bone and wood substrates appeared to be substantially reduced due to the absence of ecosystem engineers and the low oxygen concentrations. We hypothesize that Osedax/Xylophaga colonization, bone/wood degradation, and bone/wood community development may be limited by oxygen concentrations of 0.22 - 0.33 ml.l on the NE Pacific margin, and that OMZ expansion due to climate change will reduce whale-bone and wood degradation, and the contribution of whale falls and wood falls to beta diversity, on the NE Pacific margin. [ABSTRACT FROM AUTHOR]

Objectives: del Nido cardioplegia is utilized for myocardial protection in adult patients undergoing cardiac surgery; however, no standardized re-dosing protocol exists. We describe perfusion characteristics and clinical outcomes in adult cardiac surgery patients who were re-dosed with del Nido cardioplegia. Methods: Chart review was performed for adult patients undergoing cardiac surgery (specific inclusion/exclusion criteria below) who received exactly two doses of del Nido cardioplegia from 2012 to 2019; n = 542 patients. The main outcome was a composite endpoint comprised of operative mortality, myocardial infarction, post-operative cardiac support device (CSD), and postoperative decrease in ejection fraction (EF), which was analyzed via multivariable logistic regression (MVLR). A secondary analysis evaluated postoperative vasoactive-inotropic scores (VIS) via gamma log link regression (GLLR) as a more physiologic indication of myocardial recovery. Results: MVLR demonstrated that increased total cardiopulmonary bypass (CPB) time was associated with a positive composite outcome (p <.001), whereas time between doses (p =.237) and the volume of each dose was not (p =.626). GLLR also demonstrated that prolonged CBP, decreased EF, congestive heart failure at time of surgery, and low hematocrit at the start of the surgery were all associated with higher VIS. Conclusions: In this retrospective study, variations in re-dosing strategy for del Nido cardioplegia do not affect postoperative outcomes and increased CPB time is associated with increased operative mortality, myocardial infarction, need for post-operative CSDs, and reduced postoperative EF, and increased VIS, irrespective of the re-dosing strategy. Further studies are warranted to to identify additional patient and operative characteristics that predispose to complications. [ABSTRACT FROM AUTHOR]

Glaciomarine fjords dominate the coastal margin of the West Antarctic Peninsula. Studies in similar habitats in the Arctic have shown that benthic biodiversity and ecosystem functioning in inner and middle fjord basins are reduced by turbidity and sedimentation disturbance caused by climate warming–enhanced glacial melting. In contrast, the inner and middle fjord basins along the West Antarctic Peninsula are characterized as productivity and biodiversity hotspots, but benthic ecosystem functions remain unevaluated. In 2015–2016, we conducted sediment respiration and 13C pulse‐chase experiments to assess benthic ecosystem functions along a five‐station transect at ~ 500–600 m depths from the inner Andvord Bay fjord, through to Gerlache Strait, and onto the open continental shelf. Incubation samples from the inner and middle basins of Andvord Bay showed peaks in background seafloor respiration, benthic biomass, and uptake of labeled algal biomass compared to more outlying stations; the continental shelf exhibited the lowest levels of these variables, as well as dissolved inorganic carbon production. Macrofaunal community uptake was responsible for most of the C processing in the inner and middle parts of the fjord (> 45%) while dissolved inorganic carbon was the dominant repository of processed C near the fjord mouth and on the continental shelf (> 80%). The inner parts of Andvord Bay are hotspots of benthic C‐cycling and metabolism, in addition to biodiversity. Ongoing climate warming is likely to negatively impact these inner‐fjord hotspots by increasing meltwater input and sedimentation disturbance, yielding a reduction in the input and recycling of labile detritus at the seafloor in the inner‐middle fjord. [ABSTRACT FROM AUTHOR]

Introduction: Physical activity (PA) during pregnancy has numerous benefits, which may be mediated via effects on the immune system. However, supportive evidence is inconsistent and is mainly from studies in high‐risk groups. We estimated the effect of PA during pregnancy on systemic inflammatory markers and cytokines in mothers recruited in the Barwon infant study. Material and Methods: The Barwon infant study is a prebirth cohort of 1064 mothers recruited in the Barwon Region of Victoria, Australia. Participants reported their previous week's PA at their 28‐week antenatal appointment using the International PA Questionnaire. Women were grouped into low, moderate, and high PA categories based on daily duration and weekly frequency of walking, moderate‐ or vigorous‐intensity PA. Women reporting moderate levels of PA, consistent with current recommendations, served as the comparison group. Markers of systemic inflammation, high‐sensitivity C‐reactive protein (hsCRP), glycoprotein acetyls (GlycA), and 17 cytokines were measured at 28 weeks gestation and log transformed as appropriate. Regression analyses adjusted for maternal smoking, gestational diabetes mellitus, prepregnancy BMI, and household size were performed. Results: Compared to women in the moderate group (n = 371, 42%), women reporting low PA (n = 436, 50%) had 10.1% higher hsCRP (95% CI (3.7% to 16.6%), p < 0.01) while women in high PA (n = 76, 9%) had a 14% higher hsCRP (95% CI (3.1% to 24.8%), p = 0.01). Women in the high PA category had higher interleukin (IL)‐4 (q = 0.03) and IL‐9 (q = 0.03) levels compared to those in moderate category. Each vigorous MET minute/week was associated with lower GlycA (β = −0.004, 95% CI (−0.044 to 0.035); p = 0.03). Conclusions: Low and high PA are each associated with higher hsCRP than moderate PA, suggesting that undertaking the recommended moderate PA during pregnancy decreases systemic inflammation. High PA affects T cell‐associated cytokines during pregnancy. Evidence from our study suggests that PA can modulate the immune responses during pregnancy. Studies are now required to assess whether PA during pregnancy impacts maternal and infant clinical outcomes by modifying inflammatory responses. [ABSTRACT FROM AUTHOR]

Understanding and quantifying migration phenology of commercially harvested Pacific salmon (Oncorhynchus spp.) is a cornerstone for managing sustainable populations. Here, we use a multidecadal data time series together with a hypothesis-driven framework to evaluate migration phenology in adult fall and winter ecotype chum salmon (O. keta) in a poorly studied but highly managed system--the South Puget Sound (SPS) of Washington State, USA. Using generalized additive mixed models that accounted for temporal autoregressive dynamics, we examined the effect of commercial harvest, climate variation, intra-specific density dependence, and predator buffering on migration timing and run duration. SPS chum salmon are migrating earlier over time, especially the winter ecotype that showed the strongest temporal shift from historical timing. Migration timing shifts were closely associated with regional marine climate regimes, local scale freshwater availability, and increasing pinniped abundance. We conclude that there is potential for the winter ecotype migration converging with that of the fall ecotype and that directional change in migration phenology may be driven by a unique combination of ecosystem factors. La comprehension et la quantification de la phenologie des migrations des saumons du Pacifique (Oncorhynchus spp.) faisant l'objet d'une exploitation commerciale constituent un des elements essentiels de la gestion de populations perennes. Nous utilisons une serie de donnees multidecennale jumelee a un cadre module par differentes hypotheses pour evaluer la phenologie de la migration de saumons ketas (O. keta) adultes des ecotypes automnal et hivernal dans un systeme peu etudie, mais faisant l'objet d'une gestion intense, le sud du Puget Sound (SPS, Etat de Washington, Etats-Unis). En utilisant des modeles mixtes additifs generalises qui tiennent compte de la dynamique autoregressive temporelle, nous examinons les effets de l'exploitation commerciale, des variations climatiques, de la dependance intraspecifique sur la densite et de la modulation par les predateurs sur le moment et la duree des migrations. Les saumons ketas du SPS migrent de plus en plus tot, en particulier ceux de l'ecotype hivernal, qui presentent le plus grand decalage temporel par rapport aux observations passees. Les changements du moment de la migration sont etroitement associes aux regimes climatiques marins regionaux, a la disponibilite locale d'eau douce et a l'augmentation de l'abondance de pinnipedes. En conclusion, il est possible que la migration de l'ecotype hivernal converge avec celle de l'ecotype automnal et que les changements directionnels de la phenologie des migrations soient modules par une combinaison unique de facteurs ecosystemiques. [Traduit par la Redaction], Introduction Predicting migratory behavior of commercially harvested salmonids is important for managing and maintaining sustainable populations. However, evaluating the underlying biotic and abiotic mechanisms that drive migration phenology remains complex, [...]

Mineral exploitation has spread from land to shallow coastal waters and is now planned for the offshore, deep seabed. Large seafloor areas are being approved for exploration for seafloor mineral deposits, creating an urgent need for regional environmental management plans. Networks of areas where mining and mining impacts are prohibited are key elements of these plans. We adapt marine reserve design principles to the distinctive biophysical environment of mid-ocean ridges, offer a framework for design and evaluation of these networks to support conservation of benthic ecosystems on mid-ocean ridges, and introduce projected climate-induced changes in the deep sea to the evaluation of reserve design. We enumerate a suite of metrics to measure network performance against conservation targets and network design criteria promulgated by the Convention on Biological Diversity. We apply these metrics to network scenarios on the northern and equatorial Mid-Atlantic Ridge, where contractors are exploring for seafloor massive sulfide (SMS) deposits. A latitudinally distributed network of areas performs well at (i) capturing ecologically important areas and 30 to 50% of the spreading ridge areas, (ii) replicating representative areas, (iii) maintaining along-ridge population connectivity, and (iv) protecting areas potentially less affected by climate-related changes. Critically, the network design is adaptive, allowing for refinement based on new knowledge and the location of mining sites, provided that design principles and conservation targets are maintained. This framework can be applied along the global mid-ocean ridge system as a precautionary measure to protect biodiversity and ecosystem function from impacts of SMS mining.

Spectral structures due to the instrument response is the current limiting factor for the experiments attempting to detect the redshifted 21 cm signal from the Epoch of Reionization (EoR). Recent advances in the delay spectrum methodology for measuring the redshifted 21 cm EoR power spectrum brought new attention to the impact of an antenna’s frequency response on the viability of making this challenging measurement. The delay spectrum methodology provides a somewhat straightforward relationship between the time-domain response of an instrument that can be directly measured and the power spectrum modes accessible to a 21 cm EoR experiment. In this paper, we derive the explicit relationship between antenna reflection coefficient (S11) measurements made by a Vector Network Analyzer (VNA) and the extent of additional foreground contaminations in delay space. In the light of this mathematical framework, we examine the chromaticity of a prototype antenna element that will constitute the Hydrogen Epoch of Reionization Array (HERA) between 100 and 200 MHz. These reflectometry measurements exhibit additional structures relative to electromagnetic simulations, but we find that even without any further design improvement, such an antenna element will support measuring spatial k modes with line-of-sight components of k∥ > 0.2h Mpc− 1. We also find that when combined with the powerful inverse covariance weighting method used in optimal quadratic estimation of redshifted 21 cm power spectra the HERA prototype elements can successfully measure the power spectrum at spatial modes as low as k∥ > 0.1h Mpc− 1. This work represents a major step toward understanding the HERA antenna element and highlights a straightforward method for characterizing instrument response for future experiments designed to detect the 21 cm EoR power spectrum.

Sulfenyl dipyrroles feature two pyrroles linked via a sulfenyl bridge. The synthesis of sulfenyl dipyrroles has typically involved [SCl.sub.2] as the sulfur source. However, [SCl.sub.2] is no longer readily available within North America and Europe. Herein we report a new synthesis of sulfenyl dipyrroles using [SOCl.sub.2] as the sulfur source and reductant. Although five new sulfenyl dipyrroles were synthesized and isolated via this route, functional group tolerance proved limited. A potential mechanism for the reaction, involving reduction of a sulfinyl moiety by [SOCl.sub.2], is briefly explored. Key words: sulfur, pyrrole, organic synthesis, in-situ reduction of sulfinyl dipyrroles. Les sulfenyldipyrroles sont constituees de deux pyrroles relies par un pont sulfenyle. Dans la synthese des sulfenyldipyrroles, le [SCl.sub.2] est habituellement employe comme source de soufre. Or, le [SCl.sub.2] n'est plus facilement accessible en Amerique du Nord et en Europe. Dans cet article, nous presentons une nouvelle synthese des sulfenyldipyrroles qui fait intervenir le [SOCl.sub.2] comme source de soufre et comme agent reducteur. Bien que nous soyons parvenus a synthetiser et a isoler cinq nouveaux sulfenyldipyrroles par cette methode, la tolerance des groupes fonctionnels s'est revelee limitee. Nous avons explore un mecanisme de reaction possible, qui impliquerait la reduction d'une fraction sulfinyle par le [SOCl.sub.2]. [Traduit par la Redaction] Mots-cles : soufre, pyrrole, synthese organique, reduction in situ des sulfinyldipyrroles., Introduction The sulfenyl dipyrrolic motif, featuring two pyrroles linked via a sulfenyl bridge (1, V = S, Fig.1), has been known since the 1930s. (1) The most common application of [...]