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Internal water in cold-water and tropical coral skeletons was extracted and measured for its oxygen and hydrogen isotope ratios. Water was extracted by crushing pieces of coral hard tissue in a percussion device connected to either a cavity ring-down spectroscopy (CRDS) system or an isotope ratio mass spectrometry (IRMS) system. Despite most samples yielding sufficient water, each analytical system produces distinct isotope patterns. Experiments show that several characteristics specific to biominerals give rise to discrepancies and analytical artefacts that preclude the acquisition of reproducible isotope data. The main complication is that internal water in biogenic carbonates is distributed in an open interconnected micro-network that readily exchanges with external water and potentially facilitates interaction with hydration water in the finely dispersed organic matrix in the coral skeleton. Furthermore, only an isotopically fractionated part of the internal water is released from the coral skeletons upon crushing. Altogether, isotope ratio measurement of internal water in corals with bulk crushing techniques does not give primary fluid isotope ratios useful for (palaeo-)environmental or microbiological studies. As the resulting isotope patterns can show systematic behaviour per technique, isotope data may be erroneously interpreted to reflect the original calcifying fluid when using only a single technique to isotopically characterise internal fluids in coral skeletons., Geostandards and Geoanalytical Research, 46 (3), ISSN:1639-4488, ISSN:1751-908X

International audience; The frequency response of a vaporizing pastille-shaped droplet subjected to small standing acoustic oscillations is examined. The motionless droplet is continuously fed so that its volume remains constant during the process. The feeding can be realized with the same liquid at different heat exchange coefficients h and both heat convection and conduction effects inside the droplet are considered. Variation in coefficient h value effects on the evaporating mass response factor and on the liquid thermal field are studied.; On examine la réponse en fréquence d’une goutte en évaporation en forme de pastille soumise aux oscillations acoustiques. La pastille fixe est alimentée de façon continue de telle manière qu’elle garde un volume constant durant le processus. L’alimentation par le même liquide est réalisée avec différents coefficients d’échange thermique h et il est tenu compte des effets de la convection et de la conduction de chaleur dans la phase liquide. Les effets de la variation du coefficient h sur la réponse en fréquence du taux d’évaporation et sur le champ thermique dans la gouttelette sont étudiés.

International audience; For pure substances, the liquid-vapor phase separation interface disappears at the critical point. This property and others have attracted the interest of many scientists. This article is an update of the text of the invited conference on Critical Fluids presented at a seminar of Saint-Gobain-Recherche Aubervilliers on June 14, 2007. Thermostatics is first presented; then successively the thermodynamics of fluids near the critical point; the piston effect, a specific mode of heat transfer; the expansion of a "drop" at the critical pressure; the behavior of a supercritical fluid pocket immersed in a high temperature environment; finally boiling near the critical point. It is partly a resumption of texts issued by various authors cited.; Pour les corps purs, l'interface de séparation de phases liquide-vapeur disparait au point critique. Cette propriété et d'autres encore ont suscité l'intérêt de nombreux scientifiques. Cet article est une mise à jour du texte de la conférence invitée sur les Fluides Critiques présentée à un séminaire de Saint-Gobain-Recherche Aubervilliers le 14 juin 2007. Sont présentés successivement : la thermostatique, puis la thermodynamique des fluides au voisinage du point critique ; l'effet piston, mode spécifique de transmission de la chaleur ; l'expansion d'une "goutte" a la pression critique ; le comportement d'une poche de fluide supercritique plongée dans un environnement à haute température ; enfin l'ébullition près du point critique. Il s'agit pour partie d'une reprise de textes émis par différents auteurs cités.

Ryegrass (Lolium perenne L.) regrowth after defoliation results from the mobilization of sugar reserves (mainly fructans) and, simultaneously, the efficient lateral transport of sucrose toward growing tissues. However, as for grasses overall, it is not yet known if the induction of this transport is solely linked to the sugar demand of growing tissues via the modification of sugar content at the tissue or cellular level or if it could be triggered by a wounding signal due to the defoliation itself. Ryegrass plants were therefore submitted to total or partial defoliation, pinning of the leaf blades to simulate wounding, or to leaf spraying with 100 μM methyl jasmonate (MeJA), a phytohormone related to wounding. As a response to total or partial defoliation, fructans were mobilized, and the expression of the sucrose lateral transporter LpSUT1 was induced. This highlights an efficient intra-plant compensatory partitioning of sugar resources between defoliated and intact tillers, resulting in the adaptation to regrow after moderate to severe defoliation. The MeJA treatment strongly decreased fructan content. Pinning and especially MeJA largely and quickly increased sucrose content and LpSUT1 transcript levels in leaf sheaths and elongating leaf bases, suggesting a direct effect of wounding on the upregulation of the sucrose lateral transporter. The overall results suggest that sucrose transport capacity and fructan degradation are induced by defoliation through the modification of source-sink relationships for sugars at the plant level and are mediated by phytohormones associated with wounding, such as jasmonates.

Aims To identify nurse staffing groups in acute care facilities. Design This retrospective descriptive study used a configurational approach. Methods Data from a two‐month target period from January–March 2016 were collected for 40 facilities in four different hospitals in one of the largest regions of Quebec. Multiple factorial analysis and hierarchical ascendant classification were used to generate a limited number of nurse staffing groups. Results/Findings Four distinct nurse staffing groups emerged from this study. The least resourced model relied mainly on less qualified personnel and agency staff. The moderately resourced basic model was assessed as average across all staffing dimensions, but employed less overtime, relying mostly on auxiliary nurses. The moderately resourced professional group, also moderate in most variables, involved more overtime and fewer less qualified personnel. The most resourced group maximized highly qualified personnel and minimized instability in the nursing team. Conclusion This study covered multiple staffing groups with widely varying characteristics. Most groups entailed risks for quality of care at one or more levels. Few care units approached the theoretical staffing ideal.

The encapsulation of therapeutics into nanocarriers with specialized surface chemistries for targeting applications in the body is a major goal in the field of drug delivery. Here the encapsulation of an antitubercular peptide, ecumicin, into monodisperse nanocarriers 60 nm in diameter using a combination of Flash NanoPrecipitation and hydrophobic ion pairing is demonstrated. The lead formulation achieves 70% ecumicin encapsulation efficiency and 24% loading by mass. In vivo single-dose oral (PO), subcutaneous (SC), and intraperitoneal (IP) pharmacokinetics (PK) are measured in mice, and the dose-normalized area under the curve (AUC) of ecumicin nanocarriers dosed IP exceeded the dose-normalized AUC of unencapsulated ecumicin dosed IP by a factor of 2.5. Next, variations of the lead formulation stabilized with a custom-synthesized poly(caprolactone)-block-poly(ethylene glycol)-hexamannose polymer at three levels of mannose surface coverage (0%, 4%, and 74% of polymer chains terminating in hexamannose) for targeting to macrophages are prepared. These formulations are evaluated against Mycobacterium tuberculosis in a macrophage culture at multiple concentrations and found to reduce colony-forming units (CFU) counts by up to 3.8-log10 units, with greater antitubercular ecumicin activity measured from formulations prepared with higher amounts of surface mannose coverage. Taken together, these results suggest that Flash NanoPrecipitation with hydrophobic ion pairing is an effective method for encapsulating ionizable peptide therapeutics into macrophage-targeted formulations for improved PK and targeted macrophage uptake in the body.

It is unknown if solid organ transplant recipients are at higher risk for severe COVID-19. The management of a lung transplantation (LTx) program and the therapeutic strategies to adapt the immunosuppressive regimen and antiviral measures is a major issue in the COVID-19 era, but little is known about worldwide practice. We sent out to 180 LTx centers worldwide in June 2020 a survey with 63 questions, both regarding the management of a LTx program in the COVID-19 era and the therapeutic strategies to treat COVID-19 LTx recipients. We received a total of 78 responses from 15 countries. Among participants, 81% declared a reduction of the activity and 47% restricted LTx for urgent cases only. Sixteen centers observed deaths on waiting listed patients and eight centers performed LTx for COVID-19 disease. In 62% of the centers, COVID-19 was diagnosed in LTx recipients, most of them not severe cases. The most common immunosuppressive management included a decreased dose or pausing of the cell cycle inhibitors. Remdesivir, hydroxychloroquine, and azithromycin were the most proposed antiviral strategies. Most of the centers have been affected by the COVID-19 pandemic and proposed an active therapeutic strategy to treat LTx recipients with COVID-19.

Members of the Binder of SPerm (BSP) superfamily have been identified in both human and mouse epididymis. These proteins are known to bind sperm membrane and promote sperm capacitation. Studies suggest that BSPH2 might play a different role in sperm functions from its counterparts; however, the role of BSPH2 remains mainly unexplored. To investigate whether the absence of one member of the BSP family could affect fertility, mice lacking Bsph2 expression were generated using clustered regularly interspaced short palindromic repeats (CRISPR) associated 9 (Cas9) technology. Knockout (KO) male mice were mated with wild-type (WT) females, and the number and weight of the pups were determined. Sperm motility in WT and KO was assessed using sperm class analyzer (SCA). Liquid chromatography tandem mass spectrometry (LC-MS/MS) was used for protein identification. Fertility analysis of null Bsph2 mice did not reveal any phenotype. No differences were noticed on average litter size or average pup weight. Normal testis weight and morphology were observed in Bsph2+/- and Bsph2-/- compared to the WT. Quantitative polymerase chain reaction analyses revealed that Bsph1 messenger RNA expression was increased in mutant mice, whereas LC-MS/MS analysis displayed no increase in protein expression level. Taken together, we show the existence of redundant function for murine BSPH2 and the lack of BSPH2 itself does not lead to sterility.

Earthworm calcite granules (ECG) are secreted by several earthworm species, mostly Lumbricus terrestris and Lumbricus rubellus, which release them at the surface and in the upper part of soil horizons. For a long time, they have been found in various calcareous Quaternary deposits, but more recently in Western European loess sequences where they can be abundant in specific layers. In this study, we present the first continuous record of ECG abundance variations from two loess sequences in northern France dating from the last glacial period. The aim of this research is to evaluate the reliability of ECG as a new palaeoenvironmental proxy for the study of loess environments. ECG counts reveal a link between their abundance and the nature of stratigraphic units, i.e. very high abundances in tundra gley and boreal brown soil horizons and almost none in typical calcareous loess. These abundance variations are similar to those of terrestrial molluscs. The ECG signal thus suggests, along with sedimentological parameters (grain size index, calcium carbonate, total organic carbon), that milder climatic conditions occurred during the development of tundra gleys during the Upper Pleniglacial (∼20–35 ka), and of boreal brown soils during the Middle Pleniglacial (∼35–40 ka).

Deciphering the complex interplays between climate, uplift and erosion is not straightforward and estimating present-day erosion rates can provide useful insights. Glaciers are thought to be powerful erosional agents, but most published ‘glacial’ erosion rates combine periglacial, subglacial and proglacial erosion processes. Within a glaciated catchment, sediments found in subglacial streams originate either from glacial erosion of substratum or from the rock walls above the glacier that contribute to the supraglacial load. Terrestrial cosmogenic nuclides (TCN) are produced by interactions between cosmic ray particles and element targets at the surface of the Earth, but their concentration becomes negligible under 15 m of ice. Measuring TCN concentrations in quartz sand sampled in subglacial streams and in supraglacial channels is statistically compliant with stochastic processes (e.g. rockfalls) and may be used to discriminate subglacial and periglacial erosion. Results for two subglacial streams of the Bossons glacier (Mont Blanc massif, France) show that the proportion of sediments originating from glacially eroded bedrock is not constant: it varies from 50% to 90% (n = 6). The difference between the two streams is probably linked to the presence or absence of supraglacial channels and sinkholes, which are common features of alpine glaciers. Therefore, most of the published mean catchment glacial erosion rates should not be directly interpreted as subglacial erosion rates. In the case of catchments with efficient periglacial erosion and particularly rockfalls, the proportion of sediments in the subglacial stream originating from the supraglacial load could be considerable and the subglacial erosion rate overestimated. Here, we estimate warm-based subglacial and periglacial erosion rates to be of the same order of magnitude: 0.39 ± 0.33 and 0.29 ± 0.17 mm a−1, respectively.