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Abstract The timing of spring phytoplankton blooms is crucial to many species that have adapted their development to benefit from the enhanced feeding opportunity they offer. Any change to their timing may affect the productivity of an entire ecosystem. This study explores the relationship between the ocean climate, the timing of the spring bloom and the secondary production on the Newfoundland and Labrador shelf. It is found that over interannual cycles, the ocean climate is significantly correlated with the timing of the bloom and the abundance of Calanus finmarchicus, a key zooplankton species for the ecosystem. It also appears that the spring bloom is initiated by the onset of ocean re‐stratification following winter mixing. Understanding how annual variation in climate relates to the timing of the spring bloom and zooplankton abundance, that is, the base of the marine food web, can inform the development of ecosystem‐informed models for higher trophic levels.

By the end of October 2022, the US HL-LHC Accelerator Upgrade Project (AUP) had completed fabrication of ten MQXFA magnets and tested eight of them. The MQXFA magnets are the low-beta quadrupole magnets to be used in the Q1 and Q3 Inner Triplet elements of the High Luminosity LHC. This AUP effort is shared by BNL, Fermilab, and LBNL, with strand verification tests at NHMFL. An important step of the AUP QA plan is the testing of MQXFA magnets in a vertical cryostat at BNL. The acceptance criteria that could be tested at BNL were all met by the first four production magnets (MQXFA03-MQXFA06). Subsequently, two magnets (MQXFA07 and MQXFA08) did not meet some of the criteria and were disassembled. Lessons learned during the disassembly of MQXFA07 caused a revision to the assembly specifications that were used for MQXFA10 and subsequent magnets. In this article, we present a summary of: 1) the fabrication and test data for all the MQXFA magnets; 2) the analysis of MQXFA07/A08 test results with characterization of the limiting mechanism; 3) the outcome of the investigation, including the lessons learned during MQXFA07 disassembly; and 4) the finite element analysis correlating observations with test performance.

Abstract Background Few studies on neonatal severe bacterial infection are available in LMICs. Data are needed in these countries to prioritize interventions and decrease neonatal infections which are a primary cause of neonatal mortality. The BIRDY project (Bacterial Infections and Antimicrobial Drug Resistant among Young Children) was initially conducted in Madagascar, Senegal and Cambodia (BIRDY 1, 2012–2018), and continued in Madagascar only (BIRDY 2, 2018–2021). We present here the BIRDY 2 project whose objectives were (1) to estimate the incidence of neonatal severe bacterial infections and compare these findings with those obtained in BIRDY 1, (2) to identify determinants associated with severe bacterial infection and (3) to specify the antibiotic resistance pattern of bacteria in newborns. Methods The BIRDY 2 study was a prospective community-based mother and child cohort, both in urban and semi-rural areas. All pregnant women in the study areas were identified and enrolled. Their newborns were actively and passively followed-up from birth to 3 months. Data on clinical symptoms developed by the children and laboratory results of all clinical samples investigated were collected. A Cox proportional hazards model was performed to identify risk factors associated with possible severe bacterial infection. Findings A total of 53 possible severe bacterial infection and 6 confirmed severe bacterial infection episodes were identified among the 511 neonates followed-up, with more than half occurring in the first 3 days. For the first month period, the incidence of confirmed severe bacterial infection was 11.7 per 1,000 live births indicating a 1.3 -fold decrease compared to BIRDY 1 in Madagascar (p = 0.50) and the incidence of possible severe bacterial infection was 76.3, indicating a 2.6-fold decrease compared to BIRDY 1 in Madagascar (p

Abstract Photochemical reactions initiated by ultraviolet radiation remove the climate‐active gas dimethylsulfide (DMS) from the ocean's surface layer. Here, we quantified DMS photolysis using a satellite‐based model that accounts for spectral irradiance attenuation in the water column, its absorption by chromophoric dissolved organic matter, and the apparent quantum yields (AQYs) with which absorbed photons degrade DMS. Models with two alternative parameterizations for AQY estimate global DMS photolysis at between 17 and 20 Tg S yr−1, equivalent to 13–15 Tg C yr−1, of which ~ 73% occurs in the Southern hemisphere. This asymmetry results mostly from the high AQYs found south of 40° S, which more than counteract the prevailing low irradiance and deep mixing in that region. Simplified schemes currently used in biogeochemical models, whereby photolysis follows the vertical attenuation of visible radiation, overestimate DMS photolysis by around 150% globally. We propose relevant corrections and simple adjustments to those models.

Abstract HIV post- exposure prophylaxis (PEP) is a prevention tool for individuals with a recent potential exposure to HIV. Doravirine has been available since 2019 in combination with tenofovir disoproxil fumarate and lamivudine and has not been evaluated as a PEP. DOR/3TC/TDF is our department’s most commonly prescribed PEP treatment since 2021. This study evaluates the completion rate of the DOR/3TC/TDF as compared to EVG/c/FTC/TAF for PEP, which was the regimen prescribed until 2020 in our hospital. This retrospective observational study was conducted between January 2020 and September 2021. The subjects included consecutively were adults who consulted for an HIV sexual exposure accident and for whom DOR/3TC/TDF in 2021 or EVG/c/FTC/TAF in 2020 was prescribed. The outcomes were the completion rate to the end of treatment (28 days), the seroconversion rate, and the description of side effects. During the study period, 311 people were included: 140 treated with DOR/3TC/TDF and 171 treated with EVGc/FTC/TAF. Considering subjects with a follow-up visit, the completion rate was 96.8% (90/93) in the DOR/3TC/TDF group, and 94.6% (123/130) in the EVG/c/FTC/TAF group (p-value: 0.53). The number of people lost to follow-up was nearly equivalent in both groups: 27.1% (38/140) in the DOR/3TC/TDF group and 23.4% (40/171) in the EVG/c/FTC/TAF group (p-value: 0.45). A side effect was described for 38% (36/94) in the DOR/3TC/TDF group, and 29.7% (38/128) in the EVG/c/FTC/TAF group. No cases of seroconversion were observed. DOR/3TC/TDF appears to have a similar safety profile to EVG/c/FTC/TAF. Due to its lower cost, it seems to be a treatment option for consideration in the context of HIV-exposure accidents.

Summary: Background: Although immunomodulators have established benefit against the new coronavirus disease (COVID-19) in general, it is uncertain whether such agents improve outcomes without increasing the risk of secondary infections in the specific subgroup of previously immunocompromised patients. We assessed the effect of immunomodulators on outcomes of immunocompromised patients hospitalized for COVID-19. Methods: The protocol was prospectively registered with PROSPERO (CRD42022335397). MEDLINE, Cochrane Central Register of Controlled Trials and references of relevant articles were searched up to 01-06-2022. Authors of potentially eligible randomized controlled trials were contacted to provide data on immunocompromised patients randomized to immunomodulators vs control (i.e., placebo or standard-of-care). Findings: Eleven randomized controlled trials involving 397 immunocompromised patients hospitalized for COVID-19 were included. Ten trials had low risk of bias. There was no difference between immunocompromised patients randomized to immunomodulators vs control regarding mortality [30/182 (16.5%) vs 41/215 (19.1%); RR 0.93, 95% CI 0.61–1.41; p = 0.74], secondary infections (RR 1.00, 95% CI 0.64–1.58; p = 0.99) and change in World Health Organization ordinal scale from baseline to day 15 (weighed mean difference 0.27, 95% CI -0.09–0.63; p = 0.15). In subgroup analyses including only patients with hematologic malignancy, only trials with low risk of bias, only trials administering IL-6 inhibitors, or only trials administering immunosuppressants, there was no difference between comparators regarding mortality. Interpretation: Immunomodulators, compared to control, were not associated with harmful or beneficial outcomes, including mortality, secondary infections, and change in ordinal scale, when administered to immunocompromised patients hospitalized for COVID-19. Funding: Hellenic Foundation for Research and Innovation.

Climate warming and related drivers of soil thermal change in the Arctic are expected to modify the distribution and dynamics of carbon contained in perennially frozen grounds. Thawing of permafrost in the Mackenzie River watershed of northwestern Canada, coupled with increases in river discharge and coastal erosion, triggers the release of terrestrial organic matter (OMt) from the largest Arctic drainage basin in North America into the Arctic Ocean. While this process is ongoing and its rate is accelerating, the fate of the newly mobilized organic matter as it transits from the watershed through the delta and into the marine system remains poorly understood. In the framework of the European Horizon 2020 Nunataryuk programme, and as part of the Work Package 4 (WP4) Coastal Waters theme, four field expeditions were conducted in the Mackenzie Delta region and southern Beaufort Sea from April to September 2019. The temporal sampling design allowed the survey of ambient conditions in the coastal waters under full ice cover prior to the spring freshet, during ice breakup in summer, and anterior to the freeze-up period in fall. To capture the fluvial–marine transition zone, and with distinct challenges related to shallow waters and changing seasonal and meteorological conditions, the field sampling was conducted in close partnership with members of the communities of Aklavik, Inuvik and Tuktoyaktuk, using several platforms, namely helicopters, snowmobiles, and small boats. Water column profiles of physical and optical variables were measured in situ, while surface water, groundwater, and sediment samples were collected and preserved for the determination of the composition and sources of OMt, including particulate and dissolved organic carbon (POC and DOC), and colored dissolved organic matter (CDOM), as well as a suite of physical, chemical, and biological variables. Here we present an overview of the standardized datasets, including hydrographic profiles, remote sensing reflectance, temperature and salinity, particle absorption, nutrients, dissolved organic carbon, particulate organic carbon, particulate organic nitrogen, CDOM absorption, fluorescent dissolved organic matter intensity, suspended particulate matter, total particulate carbon, total particulate nitrogen, stable water isotopes, radon in water, bacterial abundance, and a string of phytoplankton pigments including total chlorophyll. Datasets and related metadata can be found in Juhls et al. (2021) (https://doi.org/10.1594/PANGAEA.937587).

During summer, the Eastern Beaufort Sea beluga whale (Delphinapterus leucas (Pallas, 1776)) population aggregates in the waters of the Mackenzie Estuary and Tarium Niryutait Marine Protected Area (TNMPA). Guided by local communities’ priorities, this study aimed to better understand beluga summer habitat selection and to examine whether shifts in beluga distribution are expected under a changing climate. We used a resource selection function (RSF) based on aerial survey data and satellite remote sensing images to estimate the likelihood of beluga presence as a function of environmental conditions. The RSF revealed that belugas selected warm and turbid waters, with suspended particulate matter concentrations and sea surface temperatures ranging above average estuarine values. These specific conditions support hypotheses on the ecological roles of estuaries for belugas such as providing a thermal advantage for their calves or for beluga epidermal moulting. Using a diachronic analysis, we found a distribution shift towards coastal and inshore waters, areas already experiencing effects of climate change. Thus, the current distribution may reflect beluga responses to a changing climate, selecting warmer and more turbid areas. Our finding provides insight into current and evolving beluga habitat and habitat selection under a changing climate, which may help inform beluga management in the TNMPA.

For the high luminosity upgrade of the CERN large hadron collider, lower β∗ quadrupole magnets based on advanced Nb3Sn conductors will be installed on each side of the ATLAS and compact muon solenoid (CMS) experiment insertion zones. As part of the technological developments needed to achieve the required field gradient of 132.6 T/m within a 150-mm aperture, short length model magnets, named MQXFS, are tested both at the CERN SM18 and Fermilab test facilities. The model magnets rely on two types of Nb3Sn conductors (restack rod process (RRP) and powder-in-tube (PIT)) and on an innovative bladders and keys design to provide mechanical support against the Lorentz forces. In 2016 and 2017, the powering tests of the first two models MQXFS3 (RRP) and MQXFS5 (PIT) proved that nominal performance (16.5 kA) could be reached with excellent memory of the quench current after thermal cycle. However both magnets showed a slow training behavior with clear observations of voltage disturbances before the quench. Besides, only MQXFS5 could reach ultimate current (17.9 kA) whereas erratic behavior was observed on MQXFS3 due to conductor local degradation at the head of one of the coils. In 2018, this limiting coil was changed and the applied azimuthal prestress increased. While ultimate current could then be reached, no stable current could be maintained due to identified defect on the outer layer of the new coil. Finally the outcome of the test of the new model MQXFS4, featuring the final RRP conductors that will be used for the series production and variation on the inner layer quench heater designs are here reported in details.

For the Large Hadron Collider luminosity upgrade, two of the NbTi 8.3 T main bending dipoles will be replaced by two shorter Nb3Sn 11.2 T dipoles to create space for the installation of collimators in the dispersion suppression region. With the aim to verify the design features, several 2 m long 11 T models have been constructed and tested at CERN. During the fabrication and assembly of, so far, seven single and two double aperture short model magnets, several challenges were identified and tackled. These include reproducibility in coil fabrication and assembly procedure, as well as control of mechanical stresses in the conductor and surrounding structure. In order to limit coil over-compression and improve reproducibility, the cable insulation was re-optimized. In addition, a review of the collaring procedure of the 11 T magnet was launched with the goal of reducing the risk of conductor degradation due to excessive stress. In this paper, the main fabrication and assembly steps are described, including the description of the actions taken to resolve the identified weakness.

For the high luminosity upgrade of the CERN large hadron collider, lower β∗ quadrupole magnets based on advanced Nb3Sn conductors will be installed on each side of the ATLAS and compact muon solenoid (CMS) experiment insertion zones. As part of the technological developments needed to achieve the required field gradient of 132.6 T/m within a 150-mm aperture, short length model magnets, named MQXFS, are tested both at the CERN SM18 and Fermilab test facilities. The model magnets rely on two types of Nb3Sn conductors (restack rod process (RRP) and powder-in-tube (PIT)) and on an innovative bladders and keys design to provide mechanical support against the Lorentz forces. In 2016 and 2017, the powering tests of the first two models MQXFS3 (RRP) and MQXFS5 (PIT) proved that nominal performance (16.5 kA) could be reached with excellent memory of the quench current after thermal cycle. However both magnets showed a slow training behavior with clear observations of voltage disturbances before the quench. Besides, only MQXFS5 could reach ultimate current (17.9 kA) whereas erratic behavior was observed on MQXFS3 due to conductor local degradation at the head of one of the coils. In 2018, this limiting coil was changed and the applied azimuthal prestress increased. While ultimate current could then be reached, no stable current could be maintained due to identified defect on the outer layer of the new coil. Finally the outcome of the test of the new model MQXFS4, featuring the final RRP conductors that will be used for the series production and variation on the inner layer quench heater designs are here reported in details.

For the Large Hadron Collider luminosity upgrade, two of the NbTi 8.3 T main bending dipoles will be replaced by two shorter Nb3Sn 11.2 T dipoles to create space for the installation of collimators in the dispersion suppression region. With the aim to verify the design features, several 2 m long 11 T models have been constructed and tested at CERN. During the fabrication and assembly of, so far, seven single and two double aperture short model magnets, several challenges were identified and tackled. These include reproducibility in coil fabrication and assembly procedure, as well as control of mechanical stresses in the conductor and surrounding structure. In order to limit coil over-compression and improve reproducibility, the cable insulation was re-optimized. In addition, a review of the collaring procedure of the 11 T magnet was launched with the goal of reducing the risk of conductor degradation due to excessive stress. In this paper, the main fabrication and assembly steps are described, including the description of the actions taken to resolve the identified weakness.

Elevated surface chlorophyll-a (chl-a) concentration ([chl-a]), an index of phytoplankton biomass, has been previously observed and documented by remote sensing in the waters to the southwest of Sable Island (SI) on the Scotian Shelf in eastern Canada. Here, we present an analysis of this phenomenon using a 21-year time series of satellite-derived [chl-a], paired with information on the particle backscattering coefficient at 443 nm (bbp(443), a proxy for particle suspension) and the detritus/gelbstoff absorption coefficient at 443 nm (adg(443), a proxy to differentiate water masses and presence of dissolved organic matter) in an attempt to explain some possible mechanisms that lead to the increase in surface biomass in the surroundings of SI. We compared the seasonal cycle, 8 d climatology and seasonal trends of surface waters near SI to two control regions located both upstream and downstream of the island, away from terrigenous inputs. Application of the self-organising map (SOM) approach to the time series of satellite-derived [chl-a] over the Scotian Shelf revealed the annual spatio-temporal patterns around SI and, in particular, persistently high phytoplankton biomass during winter and spring in the leeward side of SI, a phenomenon that was not observed in the control boxes. In the vicinity of SI, a significant increase in [chl-a] and adg(443) during the winter months occurred at a rate twice that of the ones observed in the control boxes, while no significant trends were found for the other seasons. In addition to the increase in [chl-a] and adg(443) within the plume southwest of SI, the surface area of the plume itself expanded by a factor of 5 over the last 21 years. While the island mass effect (IME) explained the enhanced biomass around SI, we hypothesised that the large increase in [chl-a] over the last 21 years was partly due to an injection of nutrients by the island's grey seal colony, which has increased by 200 % during the same period. This contribution of nutrients from seals may sustain high phytoplankton biomass at a time of year when it is usually low following the fall bloom. A conceptual model was developed to estimate the standing stock of chl-a that can be sustained by the release of nitrogen (N) by seals. Comparison between satellite observations and model simulations showed a good temporal agreement between the increased abundance of seal on SI during the breeding season and the phytoplankton biomass increase during the winter. We found that about 20 % of chl-a standing stock increase over the last 21 years could be due to seal N fertilisation, the remaining being explained by climate forcing and oceanographic processes. Although without in situ measurements for ground truthing, the satellite data analysis provided evidence of the impact of marine mammals on lower trophic levels through a fertilisation mechanism that is coupled with the IME with potential implications for conservation and fisheries.

The ITER toroidal field (TF) strand procurement initiated the largest Nb3Sn superconducting strand production hitherto. The industrial-scale production started in Japan in 2008 and finished in summer 2015. Six ITER partners (so-called Domestic Agencies, or DAs) are in charge of the procurement and involved eight different strand suppliers all over the world, of which four are using the bronze route (BR) process and four the internal-tin (IT) process. In total more than 500 tons have been produced including excess material covering losses during the conductor manufacturing process, in particular the cabling. The procurement is based on a functional specification where the main strand requirements like critical current, hysteresis losses, Cu ratio and residual resistance ratio are specified but not the strand production process or layout. This paper presents the analysis on the data acquired during the quality control (QC) process that was carried out to ensure the same conductor performance requirements are met by the different strand suppliers regardless of strand design. The strand QC is based on 100% billet testing and on applying statistical process control (SPC) limits. Throughout the production, samples adjacent to the strand pieces tested by the suppliers are cross-checked ('verified') by their respective DAs reference labs. The level of verification was lowered from 100% at the beginning of the procurement progressively to approximately 25% during the final phase of production. Based on the complete dataset of the TF strand production, an analysis of the SPC limits of the critical strand parameters is made and the related process capability indices are calculated. In view of the large-scale production and costs, key manufacturing parameters such as billet yield, number of breakages and piece-length distribution are also discussed. The results are compared among all the strand suppliers, focusing on the difference between BR and IT processes. Following the completion of the largest Nb3Sn strand production, our experience gained from monitoring the execution of the QC activities and from auditing the results from the measurements is summarised for future superconducting strand material procurement activities.

Seasonal and inter-annual absorption properties of phytoplankton and non-algal particulate matter were studied in relation to phytoplankton biomass, as indexed by chlorophyll-a concentration, and presence of diatoms, as indexed by fucoxanthin concentration, using a 20-year time series of in situ data collected in the Northwest Atlantic. We found significant differences in the spatiotemporal variations of the bio-optical properties for three oceanic regimes: mesotrophic (Scotian Shelf), oligotrophic (Northwest Atlantic Basin, NAB), and subartic (Labrador Sea). The Scotian Shelf and NAB exhibited similar phenology with the spring and autumn blooms associated with low phytoplankton specific absorption, while only relatively high fucoxanthin concentration occurred in spring. The NAB showed a smaller seasonal variation than the Scotian Shelf in agreement with its oceanic conditions. The Labrador Sea showed a single phytoplankton bloom in spring followed by a continuous decrease in biomass the rest of the year. The relationship between phytoplankton absorption coefficient at 443 nm and chlorophyll-a concentration was consistent with other studies with coefficients that were region-dependent. Absorption by non-algal particulate matter remained between 5% and 60% of phytoplankton absorption with a mean of 15%. The slope of the non-algal particulate absorption varied with seasons and regions and appeared to depend on the trophic status with high values (i.e., up to 0.04) occurring during bloom conditions. We also introduced a new index, the phytoplankton apparent absorption wavelength (PAAW), a wavelength-weighted sum of absorption expressed in nanometers that provides information on the phytoplankton biomass and assemblage in a simple manner. Time series analysis of the PAAW revealed a decrease of this property in spring on the Scotian Shelf, NAB, and Labrador Sea and an increase in autumn on the Scotian Shelf and NAB, suggesting a shift in these ecosystems.

Satellite observations are an integral component of long-term Arctic Ocean monitoring and help identifying changes resulting from climate warming. A Self-Organizing Maps (SOM) approach was applied to four-day composite satellite images of the Eastern Beaufort Sea (EBS) acquired by the MODerate resolution Imaging Spectroradiometer over the period 2003–2019. Using sea-surface temperature (SST), suspended particulate matter concentration (SPM) and chlorophyll-a concentration (Chl-a) as input the EBS was partitioned into six biogeochemical regions. The SOM approach revealed region-specific mean conditions and seasonal cycles for all properties, particularly for SPM and Chl-a. Three of the six regions, located on the continental shelf, had the highest SST, SPM and Chl-a with earlier maxima compared to the remaining three regions which comprised the shelf edge, Canada Basin and Amundsen Gulf. While mean and maximum SST did not exhibit significant trends over the 17 years of observations, the annual maximum SST in Amundsen Gulf was reached significantly earlier in recent years compared to the start of the time series. With the exception of Amundsen Gulf, sea-ice concentration (SIC) derived from microwave satellites declined throughout the study area; monthly trends showed dramatic SIC declines in regions on the shelf during May and June, and in Canada Basin during August. Correlation analysis of properties within and between regions showed that SST and SIC were driven by large scale processes while SPM and Chl-a showed regional features. SST and Chl-a in the regions nearest the Mackenzie River showed a strong relationship during seasonal warming. The SOM approach, applied to 17 years of satellite data, revealed spatially distinct marine units with unique characteristics, emphasizing the need for regional considerations when assessing the impact of climate warming in the Arctic Ocean.

By varying the precursor ratios, cobalt doped manganese oxide nanocluster catalysts with different cobalt contents were prepared using the colloidal method. Catalysts were applied to a gas phase benzene oxidation reaction. Among them, the catalyst with a Mn:Co ratio of 90:10 showed the highest conversion. The addition of cobalt changing the valence of manganese was observed by XANES analysis, and that is thought to be the reason for the high activity. [ABSTRACT FROM AUTHOR]

The North Atlantic current has been suspected to trigger intrusions of temperate marine species in the Arctic. Here, Oziel and colleagues reveal the link between the poleward intrusion of the temperate coccolithophore Emiliania huxleyi and the North Atlantic current, showing evidence for bio-advection as an important mechanism.

Microtubule targeting agents (MTA) are anti-cancer molecules that bind tubulin and interfere with the microtubule functions, eventually leading to cell death. In the present study, we used an in vitro microtubule polymerization assay to screen several venom families for the presence of anti-microtubule activity. We isolated myotoxin-3, a peptide of the crotamine family, and three isoforms from the venom of the Northern Pacific rattlesnake Crotalus oreganus oreganus, which was able to increase tubulin polymerization. Myotoxin-3 turned out to be a cell-penetrating peptide that slightly diminished the viability of U87 glioblastoma and MCF7 breast carcinoma cells. Myotoxin 3 also induced remodeling of the U87 microtubule network and decreased MCF-7 microtubule dynamic instability. These effects are likely due to direct interaction with tubulin. Indeed, we showed that myotoxin-3 binds to tubulin heterodimer with a Kd of 5.3 µM and stoichiometry of two molecules of peptide per tubulin dimer. Our results demonstrate that exogenous peptides are good candidates for developing new MTA and highlight the richness of venoms as a source of pharmacologically active molecules.

Abstract Insights into tau molecular structures have advanced significantly in recent years. This field has been the subject of recent breakthroughs, including the first cryo-electron microscopy structures of tau filaments from Alzheimer’s and Pick’s disease inclusions, as well as the structure of the repeat regions of tau bound to microtubules. Tau structure covers various species as the tau protein itself takes many forms. We will here address a range of studies that help to define the many facets of tau protein structures and how they translate into pathogenic forms. New results shed light on previous data that need now to be revisited in order to up-date our knowledge of tau molecular structure. Finally, we explore how these data can contribute the important medical aspects of this research - diagnosis and therapeutics.

Neuronal calcium sensors (NCSs) are the family of EF-hand proteins mediating Ca2+-dependent signaling pathways in healthy neurons and neurodegenerative diseases. It was hypothesized that the calcium sensor activity of NCSs can be complemented by sensing fluctuation of intracellular zinc, which could further diversify their function. Here, using a set of biophysical techniques, we analyzed the Zn2+-binding properties of five proteins belonging to three different subgroups of the NCS family, namely, VILIP1 and neurocalcin-δ/NCLD (subgroup B), recoverin (subgroup C), as well as GCAP1 and GCAP2 (subgroup D). We demonstrate that each of these proteins is capable of coordinating Zn2+ with a different affinity, stoichiometry, and structural outcome. In the absence of calcium, recoverin and VILIP1 bind two zinc ions with submicromolar affinity, and the binding induces pronounced conformational changes and regulates the dimeric state of these proteins without significant destabilization of their structure. In the presence of calcium, recoverin binds zinc with slightly decreased affinity and moderate conformational outcome, whereas VILIP1 becomes insensitive to Zn2+. NCALD binds Zn2+ with micromolar affinity, but the binding induces dramatic destabilization and aggregation of the protein. In contrast, both GCAPs demonstrate low-affinity binding of zinc independent of calcium, remaining relatively stable even at submillimolar Zn2+ concentrations. Based on these data, and the results of structural bioinformatics analysis, NCSs can be divided into three categories: (1) physiological Ca2+/Zn2+ sensor proteins capable of binding exchangeable (signaling) zinc (recoverin and VILIP1), (2) pathological Ca2+/Zn2+ sensors responding only to aberrantly high free zinc concentrations by denaturation and aggregation (NCALD), and (3) Zn2+-resistant, Ca2+ sensor proteins (GCAP1, GCAP2). We suggest that NCS proteins may therefore govern the interconnection between Ca2+-dependent and Zn2+-dependent signaling pathways in healthy neurons and zinc cytotoxicity-related neurodegenerative diseases, such as Alzheimer’s disease and glaucoma.

Sentinel-2 satellite imagery has been successfully used to map submerged seagrasses in clear waters, and surface-canopy forming seaweed habitats in a range of water types. We examined the ability to use Sentinel-2 remote sensing reflectance to classify fully submerged seagrass and seaweed habitats in optically complex, temperate waters within a high priority management region in Atlantic Canada. To do so, we determined the “best” Sentinel-2 image available between 2015 and 2019 based on tidal height, absence of sun glint and clouds, and water transparency. Using the full Sentinel-2 tile, we atmospherically corrected the image using ACOLITE’s dark spectrum fitting method. Our classification goal was a two-class prediction of vegetation presence and absence. Using information obtained from drop-camera surveys, the image was first partially classified using simple band thresholds based on the normalized difference vegetation index (NDVI), red/green ratio and the blue band. A random forest model was built to classify the remaining areas to a maximum depth of 10 m, the maximum depth at which field surveys were performed. The resulting habitat map had an overall accuracy of 79% and ∼231 km2 of vegetated habitat were predicted to occur (total area 345.15 km2). As expected, the classification performed best in regions dominated by bright sandy bare substrate, and dense dark vegetated beds. The classification performed less well in regions dominated by dark bare muddy substrate, whose spectra were similar to vegetated habitat, in pixels where vegetation density was low and mixed with other substrates, and in regions impacted by freshwater input. The maximum depth that bottom habitat was detectable also varied across the image. Leveraging the full capacity of the freely available Sentinel-2 satellite series with its high spatial resolution and resampling frequency, provides a new opportunity to generate large scale vegetation habitat maps, and examine how vegetation extent changes over time in Atlantic Canada, providing essential data layers to inform monitoring and management of macrophyte dominated habitats and the resulting ecosystem functions and services.

Satellite remote sensing is a valuable tool to map and monitor the distribution of marine macrophytes such as seagrass and seaweeds that perform many ecological functions and services in coastal habitats. Various satellites have been used to map the distribution of these coastal bottom habitat-forming species, with each sensor providing unique benefits. In this study, we first explored optimal methods to create bottom habitat maps using WorldView-3 satellite imagery. We secondly compared the WorldView-3 bottom habitat maps to previously produced Sentinel-2 maps in a temperate, optically complex environment in Nova Scotia, Canada to identify the top performing classification and the advantages and disadvantages of each sensor. Sentinel-2 provides a global, freely accessible dataset where four bands are available at a 10-m spatial resolution in the visible and near infrared spectrum. Conversely, WorldView-3 is a commercial satellite where eight bands are available at a 2-m spatial resolution in the visible and near infrared spectrum, but data catalogs are costly and limited in scope. Our optimal WorldView-3 workflow processed images from digital numbers to habitat classification maps, and included a semiautomatic stripe correction. Our comparison of bottom habitat maps explored the impact of improved WorldView-3 spatial resolution in isolation, and the combined advantage of both WorldView’s increased spatial and spectral resolution relative to Sentinel-2. We further explored the effect of tidal height on classification success, and relative changes in water clarity between images collected at different dates. As expected, both sensors are suitable for bottom habitat mapping. The value of WorldView-3 came from both its increased spatial and spectral resolution, particularly for fragmented vegetation, and the value of Sentinel-2 imagery comes from its global dataset that readily allows for large scale habitat mapping. Given the variation in scale, cost and resolution of the two sensors, we provide recommendations on their use for mapping and monitoring marine macrophyte habitat in Atlantic Canada, with potential applications to other coastal areas of the world.

The marine biogenic gas dimethylsulfide (DMS) modulates climate by enhancing aerosol light scattering and seeding cloud formation. However, the lack of time- and space-resolved estimates of DMS concentration and emission hampers the assessment of its climatic effects. Here we present DMSSAT, a new remote sensing algorithm that relies on macroecological relationships between DMS, its phytoplanktonic precursor dimethylsulfoniopropionate (DMSPt) and plankton light exposure. In the first step, planktonic DMSPt is estimated from satellite-retrieved chlorophyll a and the light penetration regime as described in a previous study (Galí et al., 2015). In the second step, DMS is estimated as a function of DMSPt and photosynthetically available radiation (PAR) at the sea surface with an equation of the form: log10DMS = α + βlog10DMSPt + γPAR. The two-step DMSSAT algorithm is computationally light and can be optimized for global and regional scales. Validation at the global scale indicates that DMSSAT has better skill than previous algorithms and reproduces the main climatological features of DMS seasonality across contrasting biomes. The main shortcomings of the global-scale optimized algorithm are related to (i) regional biases in remotely sensed chlorophyll (which cause underestimation of DMS in the Southern Ocean) and (ii) the inability to reproduce high DMS ∕ DMSPt ratios in late summer and fall in specific regions (which suggests the need to account for additional DMS drivers). Our work also highlights the shortcomings of interpolated DMS climatologies, caused by sparse and biased in situ sampling. Time series derived from MODIS-Aqua in the subpolar North Atlantic between 2003 and 2016 show wide interannual variability in the magnitude and timing of the annual DMS peak(s), demonstrating the need to move beyond the classical climatological view. By providing synoptic time series of DMS emission, DMSSAT can leverage atmospheric chemistry and climate models and advance our understanding of plankton–aerosol–cloud interactions in the context of global change.

S100A1 is a member of the S100 family of small ubiquitous Ca2+-binding proteins, which participates in the regulation of cell differentiation, motility, and survival. It exists as homo- or heterodimers. S100A1 has also been shown to bind Zn2+, but the molecular mechanisms of this binding are not yet known. In this work, using ESI-MS and ITC, we demonstrate that S100A1 can coordinate 4 zinc ions per monomer, with two high affinity (KD~4 and 770 nm) and two low affinity sites. Using competitive binding experiments between Ca2+ and Zn2+ and QM/MM molecular modeling we conclude that Zn2+ high affinity sites are located in the EF-hand motifs of S100A1. In addition, two lower affinity sites can bind Zn2+ even when the EF-hands are saturated by Ca2+, resulting in a 2Ca2+:S100A1:2Zn2+ conformer. Finally, we show that, in contrast to calcium, an excess of Zn2+ produces a destabilizing effect on S100A1 structure and leads to its aggregation. We also determined a higher affinity to Ca2+ (KD~0.16 and 24 μm) than was previously reported for S100A1, which would allow this protein to function as a Ca2+/Zn2+-sensor both inside and outside cells, participating in diverse signaling pathways under normal and pathological conditions.

In this study, a bio-derived precipitating agent/ligand, palm kernel oil, has been used as an alternative route for the green synthesis of nanoparticles of Fe-doped Co3O4 via the co-precipitation reaction. The palm oil was extracted from dried palm kernel seeds by crushing, squeezing and filtration. The reaction of the palm kernel oil with potassium hydroxide, under reflux, yielded a solution containing a mixture of potassium carboxylate and excess hydroxide ions, irrespective of the length of saponification. The as-obtained solution reacts with an aqueous solution containing iron and cobalt ions to yield the desired metallo-organic precursor, iron cobalt carboxylate. Characterization of the precursors by IR and gas chromatography (GC) attests to the presence of carboxylate fatty acids in good agreement with the proportion contained in the oil, and ICP confirms that the metallic ratios are in the proportion used during the synthesis. Analysis of the products thermally decomposed between 400 °C and 600 °C by XRD, EDX, TEM and ToF-SIMS, established that cobalt iron oxide nanoparticles (Co(1−x)Fex)3O4 were obtained for x ≤ 0.2 and a nanocomposite material (Co(1−x)Fex)3O4/Fe3O4 for x ≥ 0.2, with sizes between 22 and 9 nm. ToF-SIMS and XRD provided direct evidence of the progressive substitution of cobalt by iron in the Co3O4 crystal structure for x ≤ 0.2.

Abstract Aggregation of TDP-43 (transactive response DNA binding protein 43 kDa) is a hallmark of certain forms of amyotrophic lateral sclerosis (ALS) and frontotemporal lobar degeneration (FTLD). Moreover, intracellular TDP-43-positive inclusions are often found in other neurodegenerative diseases. Recently it was shown that zinc ions can provoke the aggregation of endogenous TDP-43 in cells, allowing to assume a direct interaction of TDP-43 with zinc ions. In this work, we investigated zinc binding to the 102–269 TDP-43 fragment, which comprise the two RNA recognition motifs. Using isothermal titration calorimetry, mass spectrometry, and differential scanning fluorimetry, we showed that zinc binds to this TDP-43 domain with a dissociation constant in the micromolar range and modifies its tertiary structure leading to a decrease of its thermostability. Moreover, the study by dynamic light scattering and negative stain electron microscopy demonstrated that zinc ions induce auto-association process of this TDP-43 fragment into rope-like structures. These structures are thioflavin-T-positive allowing to hypothesize the direct implication of zinc ions in pathological aggregation of TDP-43.

Microtubules (MTs) play a fundamental role in many vital processes such as cell division and neuronal activity. They are key structural and functional elements in axons, supporting neurite differentiation and growth, as well as transporting motor proteins along the axons, which use MTs as support tracks. Tau is a stabilizing MT associated protein, whose functions are mainly regulated by phosphorylation. A disruption of the MT network, which might be caused by Tau loss of function, is observed in a group of related diseases called tauopathies, which includes Alzheimer’s disease (AD). Tau is found hyperphosphorylated in AD, which might account for its loss of MT stabilizing capacity. Since destabilization of MTs after dissociation of Tau could contribute to toxicity in neurodegenerative diseases, a molecular understanding of this interaction and its regulation is essential.

Dans le cadre de l’agrandissement du port de Dunkerque, plus de 170 hectares de la plaine maritime ont été explorés sur la future « Zone Grande Industrie », dans l’ancien estuaire de la Denna (ou Déna, ou L’Enna), sous-bassin du petite fleuve côtier Aa. Le diagnostic d’archéologie préventive classique par ouverture de tranchées a été accompagnée de recherches en archives, de prospections géophysiques, de levés géomorphologiques en sondages en puits (profonds de 3 m) et en coupes. L’intégration des études de nature différente permet d’aboutir à une compréhension du secteur meilleure que ne l’eût fait chaque discipline séparément. Les dépôts sont essentiellement des sables tidaux recoupés par des chenaux de marée. Les décimètres supérieurs sont parfois plus limoneux. Les mesures de conductivité apparente permettent de spatialiser les données lithostratigraphiques ponctuelles. Leur confrontation, ainsi que des indices venant du réseau parcellaire, permet la mise en évidence d’un bord ouest de l’estuaire, contemporain d’occupations humaines. De même, la confrontation des vestiges archéologiques levés lors du diagnostic avec une zonation basée sur la géophysique et la stratigraphie permet d’appréhender l’évolution du paysage, notamment l’expansion et la contraction de l’habitat du secteur, depuis les premières interventions aux environs des Xe–XIIe siècles sur la bordure ouest de l’estuaire. Depuis ce dernier, l’habitat a progressé vers le nord-est, jusqu’à un bras de la Denna resté longtemps actif et dont l’axe correspond au système de drainage actuel. La cartographie de conductivité électrique permet également de mettre en évidence des anomalies qui se sont révélées être de larges et profondes structures anthropiques (jusqu’à environ 40 m de diamètre et plus de 5 m de profondeur, soit −2,5 m sous la cote zéro). Bien que nombreuses, ces structures peuvent passer facilement inaperçues lors des diagnostics archéologiques. Plusieurs ont été testées. Leur remplissage est variable mais présente comme point commun une étanchéification du fond et des parois par des mottes d’argile. Ces structures sont interprétées comme des mares endiguées dont quelques exemples subsistent sur la côte de la mer du Nord (en Frise, en Zélande et en Allemagne). Elles permettaient de recueillir l’eau douce et leur couronne de remblais en élévation s’élevaient au-dessus des plus fortes marées.

Carbon dioxide has become an environmental challenge, where the emissions have reached higher level than can be handled. In this regard, conversion of CO2 to value-added chemicals and thus recycling of CO2 appear a viable option. Prior to valorization, CO2 must be purified. Among several opportunities, oxyfuel combustion is a process in rapid development. However, the gases resulting from this process contain some traces of impurities that can hinder the recovery of CO2 such as NO and CO. This work has, therefore, focused on the study of the NO-CO reaction in an oxidizing medium, using heterogeneous catalytic materials based on various supported noble metals. These materials were extensively characterized by a variety of methods including Brunauer–Emmett–Teller (BET) surface area measurements, hydrogen chemisorption, transmission electron microscopy (TEM) and H2 temperature programmed reduction (H2-TPR). The results obtained show that the catalytic behavior of M/Al2O3 catalysts in CO oxidation and NO reduction with CO in oxidative conditions depends mainly on the nature of the metal. The best result for both reactions is obtained with Pt/Al2O3 catalyst. The Pt nanoparticles in their metallic form (Pt°) as evidenced by TPR could explain the activity.