Can environmental conditions at North Atlantic deep-sea habitats be predicted several years ahead? - Taking sponge habitats as an example

Predicting the ambient environmental conditions in the coming several years to one decade is of key relevance for elucidating how deep-sea habitats, like for example sponge habitats, in the North Atlantic will evolve under near-future climate change. However, it is still not well known to what extent the deep-sea environmental properties can be predicted in advance. A regional downscaling prediction system is developed to assess the potential predictability of the North Atlantic deep-sea environmental factors. The large-scale climate variability predicted with the coupled Max Planck Institute Earth System Model with low-resolution configuration (MPI-ESM-LR) is dynamically downscaled to the North Atlantic by providing surface and lateral boundary conditions to the regional coupled physical-ecosystem model HYCOM-ECOSMO. Model results of two physical fields (temperature and salinity) and two biogeochemical fields (concentrations of silicate and oxygen) over 21 sponge habitats are taken as an example to assess the ability of the downscaling system to predict the interannual to decadal variations of the environmental properties based on ensembles of retrospective predictions over the period from 1985 to 2014. The ensemble simulations reveal skillful predictions of the environmental conditions several years in advance with distinct regional differences. In areas closely tied to large-scale climate variability and ice dynamics, both the physical and biogeochemical fields can be skillfully predicted more than 4 years ahead, while in areas under strong influence of upper oceans or open boundaries, the predictive skill for both fields is limited to a maximum of 2 years. The simulations suggest higher predictability for the biogeochemical fields than for the physical fields, which can be partly attributed to the longer persistence of the former fields. Predictability is improved by initialization in areas away from the influence of Mediterranean outflow and areas with weak coupling between the upper and deep oceans. Our study highlights the ability of the downscaling regional system to predict the environmental variations at deep-sea benthic habitats on time scales of management relevance. The downscaling system therefore will be an important part of an integrated approach towards the preservation and sustainable exploitation of the North Atlantic benthic habitats

Skilful prediction of cod stocks in the North and Barents Sea a decade in advance

Reliable information about the future state of the ocean and fish stocks is necessary for informed decision-making by fisheries scientists, managers and the industry. However, decadal regional ocean climate and fish stock predictions have until now had low forecast skill. Here, we provide skilful forecasts of the biomass of cod stocks in the North and Barents Seas a decade in advance. We develop a unified dynamical-statistical prediction system wherein statistical models link future stock biomass to dynamical predictions of sea surface temperature, while also considering different fishing mortalities. Our retrospective forecasts provide estimates of past performance of our models and they suggest differences in the source of prediction skill between the two cod stocks. We forecast the continuation of unfavorable oceanic conditions for the North Sea cod in the coming decade, which would inhibit its recovery at present fishing levels, and a decrease in Northeast Arctic cod stock compared to the recent high levels. North Sea cod stock may not recover in the decade 2020-2030 while Northeast Arctic cod biomass is also predicted to decline but will be better able to recover, according to an integration of statistical fisheries models and climate predictionspublishedVersio

Seasonal Prediction of Arabian Sea Marine Heatwaves

Marine heatwaves are known to have a detrimental impact on marine ecosystems, yet predicting when and where they will occur remains a challenge. Here, using a large ensemble of initialized predictions from an Earth System Model, we demonstrate skill in predictions of summer marine heatwaves over large marine ecosystems in the Arabian Sea seven months ahead. Retrospective forecasts of summer (June to August) marine heatwaves initialized in the preceding winter (November) outperform predictions based on observed frequencies. These predictions benefit from initialization during winters of medium to strong El Niño conditions, which have an impact on marine heatwave characteristics in the Arabian Sea. Our probabilistic predictions target spatial characteristics of marine heatwaves that are specifically useful for fisheries management, as we demonstrate using an example of Indian oil sardine (Sardinella longiceps)

Molecular Routes to Two-Dimensional Metal Dichalcogenides MX2 (M = Mo, W; X = S, Se)

New synthetic access to two-dimensional trapsition metal dichalcogenides (TMDCs) is highly desired to exploit their extraordinary semiconducting and optoelectronic properties for practical applications. We introduce here an entirely novel class of molecular precursors, [M-IV (XEtN(Me)- Etx)(2)] (M-IV= mo(IV),W-IV,X =S, Se), enabling chemical vapor deposition of TMDC thin films. Molybdenum and tungsten complexes of dianionic tridentate pincer-type ligands (HXEt)(2)NR (R = methyl, tert-butyl, phenyl) produced air-stable monomeric dichalcogenide complexes, [W(SEtN(Me)EtS)(2)] and [Mo(SEtN(Me)EtS)(2)], displaying W and Mo centers in an octahedral environment of 4 S and 2 N donor atoms. Owing to their remarkable volatility and clean thermal decomposition, both Mo and W complexes, when used in the chemical vapor deposition (CVD) process, produced crystalline MoS2 and WS2 thin films. X-ray diffraction analysis and atomic-scale imaging confirmed the phase purity and 2D structural characteristics of MoS2 and WS2 films. The new set of ligands presented in this work open ups convenient access to a scalable and precursor-based synthesis of 2D transition metal dichalcogenides

Molecular Precursors to Group IV Dichalcogenides MS2 (M=Ti, Zr, Hf)

New chemical routes to synthesize layered 2D transition metal dichalcogenides (TMDCs) are highly desired. We report here a new class of molecular precursors of general formula [M-IV(SC2H4N(Me)C2H4S)(2)] (M-IV=Ti, Zr, Hf) that offers a reliable synthetic access to 2D TMDC materials as demonstrated in the representative case of TiS2 synthesis. The complexation of the TM centers by the chelating tridentate ligand (HSC2H4)(2)NMe produced stable monomeric complexes, [Ti(SC2H4N(Me)C2H4S)(2)], [Zr(SC2H4N(Me)C2H4S)(2)] and [Hf(SC2H4N(Me)C2H4S)(2)], displaying a distorted octahedral environment around metal centers formed by four S and two N donor atoms of the ligand moiety. The characterization of molecular precursors by NMR, single-crystal diffraction analysis, IR spectroscopy and elemental analysis confirmed the presence of metal-sulfur bonds that are crucial in facilitating the formation of MS2 phases. Thermal decomposition behaviour of the three molecular compounds was investigated by TG-DCS measurements that confirmed their decomposition into solid phases. Interestingly, the preorganized M-S bonds in the precursor molecules also influenced the formation of titanium disulfide thin films by chemical vapor phase deposition. The solid thin films of TiS2 were characterized by X-ray spectroscopy analysis and atomic scale imaging. The complexes presented in this work represent a promising chemistry driven approach towards reproducible and scalable synthesis of van der Waals 2D heterostructures

Unusual Reactivity of Silicon Grease Towards Metal Alkoxides: Serendipity for Structural Chemistry

Controlled synthesis of moisture sensitive metal alkoxides demands the use of silicon grease for the inert synthetic manipulation of starting materials using glass apparatus to avoid adventitious hydrolysis. Spontaneous reaction of the siloxane units (-OSi(Me-3)(2))(n)) with the synthesized alkoxides often leads to molecular metal alkoxides based siloxane frameworks. These spontaneous incorporation of siloxane units into homo- and heterometallic alkoxide building blocks lead to the new multinuclear homo- and heterometallic alkoxide-siloxide compounds [Ce-2(OtBu)(4){Me2Si(OtBu)O}(2)(NO3)(2)] (1), [Zr{(OiPr)(2){Me2SiO2}Sr{Zr-2(OiPr)(8)}}(2)] (2) and [Sn2In2O2{Me2Si(OiPr)O}(OiPr)(5)](2) (3). Multifunctional coordination properties of these siloxane units enable the molecular approach to synthetically demanding polymetallic complexes for potential MOx-SiOx nanocomposites fabrication

Unusual Reactivity of Silicon Grease Towards Metal Alkoxides: Serendipity for Structural Chemistry

Controlled synthesis of moisture sensitive metal alkoxides demands the use of silicon grease for the inert synthetic manipulation of starting materials using glass apparatus to avoid adventitious hydrolysis. Spontaneous reaction of the siloxane units (-OSi(Me-3)(2))(n)) with the synthesized alkoxides often leads to molecular metal alkoxides based siloxane frameworks. These spontaneous incorporation of siloxane units into homo- and heterometallic alkoxide building blocks lead to the new multinuclear homo- and heterometallic alkoxide-siloxide compounds [Ce-2(OtBu)(4){Me2Si(OtBu)O}(2)(NO3)(2)] (1), [Zr{(OiPr)(2){Me2SiO2}Sr{Zr-2(OiPr)(8)}}(2)] (2) and [Sn2In2O2{Me2Si(OiPr)O}(OiPr)(5)](2) (3). Multifunctional coordination properties of these siloxane units enable the molecular approach to synthetically demanding polymetallic complexes for potential MOx-SiOx nanocomposites fabrication

Skilful prediction of cod stocks in the North and Barents Sea a decade in advance

Reliable information about the future state of the ocean and fish stocks is necessary for informed decision-making by fisheries scientists, managers and the industry. However, decadal regional ocean climate and fish stock predictions have until now had low forecast skill. Here, we provide skilful forecasts of the biomass of cod stocks in the North and Barents Seas a decade in advance. We develop a unified dynamical-statistical prediction system wherein statistical models link future stock biomass to dynamical predictions of sea surface temperature, while also considering different fishing mortalities. Our retrospective forecasts provide estimates of past performance of our models and they suggest differences in the source of prediction skill between the two cod stocks. We forecast the continuation of unfavorable oceanic conditions for the North Sea cod in the coming decade, which would inhibit its recovery at present fishing levels, and a decrease in Northeast Arctic cod stock compared to the recent high levels.North Sea cod stock may not recover in the decade 2020-2030 while Northeast Arctic cod biomass is also predicted to decline but will be better able to recover, according to an integration of statistical fisheries models and climate predictionshttps://www.thuenen.de/en/sf/projects/a-physical-statistical-model-of-hydrography-for-fishery-and-ecology-studies-ahoi/https://www.metoffice.gov.uk/hadobs/hadisst/index.htmlhttp://cera-www.dkrz.de/WDCC/ui/Compact.jsp?acronym=DKRZ_LTA_1075_ds0000

Seasonal Prediction of Arabian Sea Marine Heatwaves

AbstractMarine heatwaves are known to have a detrimental impact on marine ecosystems, yet predicting when and where they will occur remains a challenge. Here, using a large ensemble of initialized predictions from an Earth System Model, we demonstrate skill in predictions of summer marine heatwaves over large marine ecosystems in the Arabian Sea seven months ahead. Retrospective forecasts of summer (June to August) marine heatwaves initialized in the preceding winter (November) outperform predictions based on observed frequencies. These predictions benefit from initialization during winters of medium to strong El Niño conditions, which have an impact on marine heatwave characteristics in the Arabian Sea. Our probabilistic predictions target spatial characteristics of marine heatwaves that are specifically useful for fisheries management, as we demonstrate using an example of Indian oil sardine (Sardinella longiceps).Plain Language Summary: Marine heatwaves (MHWs) are prolonged extreme events associated with exceptionally high ocean water temperatures. Such events impose heat stress on marine life, and thus predicting such events is beneficial for management applications. In this work we show that the occurrence of MHWs in summer in the Arabian Sea can be skilfully predicted seven month in advance. Our prediction system benefits from the information of sea surface temperature anomalies in the eastern Pacific Ocean in the preceding winter, among other aspects. Our predictions suggest potential for using climate information in fisheries management in this region.Key Points: Summer marine heatwaves in the Arabian Sea are predictable seven months in advance The prediction skill in summer is mainly associated with a preceding El Niño event in winter Probabilistic predictions of Arabian Sea area under heatwave can be tailored to benefit fisheries DFGUniversität Hamburg http://dx.doi.org/10.13039/501100005711Cedars‐Sinai Medical Center http://dx.doi.org/10.13039/100013015Marine Institute http://dx.doi.org/10.13039/501100001627Copernicus Climate Change ServiceAigéin, Aeráid, agus athrú AtlantaighEUhttp://dx.doi.org/10.7289/V5SQ8XB5http://hdl.handle.net/hdl:21.14106/f2fdc61b13828ed5284f4e4ab41e63f8a84c6e52http://hdl.handle.net/hdl:21.14106/27e73ed39cd59d2033e018a494e342383db53a0

Human Macrophages Escape Inhibition of Major Histocompatibility Complex-Dependent Antigen Presentation by Cytomegalovirus and Drive Proliferation and Activation of Memory CD4+ and CD8+ T Cells

Human cytomegalovirus (HCMV) persistently infects 40–90% of the human population but in the face of a normal immune system, viral spread and dissemination are efficiently controlled thus preventing clinically signs and disease. HCMV-infected hosts produce a remarkably large amount of HCMV-specific CD4+ and CD8+ T cells that can even reach 20–50% of total T memory cells in the elderly. How HCMV may elicit such large and long-lasting T-cell responses in the absence of detectable viremia has not been elucidated yet. Additionally, HCMV is known to encode several gene products that potently inhibit T-cell recognition of infected cells. The best characterized are the four immune evasive US2, US3, US6, and US11 genes that by different mechanisms account for major histocompatibility complex (MHC) class I and class II degradation and intracellular retention in infected cells. By infecting M1 and M2 human macrophages (Mφ) with the wild-type HCMV strain TB40E or a mutant virus deleted of the four immune evasive genes US2, US3, US6, and US11, we demonstrated that human Mφ counteract the inhibitory potential of the US2-11 genes and remain capable to present peptides via MHC class I and class II molecules. Moreover, by sorting the infected and bystander cells, we provide evidence that both infected and bystander Mφ contribute to antigen presentation to CD4+ and CD8+ T cells. The T cells responding to TB40E-infected Mφ show markers of the T effector memory compartment, produce interferon-γ, and express the lytic granule marker CD107a on the cell surface, thus mirroring the HCMV-specific T cells present in healthy seropositive individuals. All together, our findings reveal that human Mφ escape inhibition of MHC-dependent antigen presentation by HCMV and continue to support T cell proliferation and activation after HCMV infection. Taking into account that Mφ are natural targets of HCMV infection and a site of viral reactivation from latency, our findings support the hypothesis that Mφ play crucial roles for the lifelong maintenance and expansion of HCMV-committed T cells in the human host