Single chamber Mg/Ca analyses of Globigerinoides ruber for paleo-proxy calibration using femtosecond LA-ICP-MS.

Mg/Ca is an independent proxy in paleoceanography to reconstruct past seawater temperature. Femtosecond Laser Ablation Inductively Coupled Plasma Mass Spectrometry (fs-LA-ICP-MS) was employed to determine the Mg/Ca composition of tests (shells) of the planktic foraminifer species Globigerinoides ruber albus (white chromotype) and G. ruber ruber (red/pink chromotype) sampled alive from the temperate to subtropical eastern North Atlantic with the research sailing yacht Eugen Seibold.

Increased prokaryotic diversity in the Red Sea deep scattering layer.

Background: The diel vertical migration (DVM) of fish provides an active transport of labile dissolved organic matter (DOM) to the deep ocean, fueling the metabolism of heterotrophic bacteria and archaea. We studied the impact of DVM on the mesopelagic prokaryotic diversity of the Red Sea focusing on the mesopelagic deep scattering layer (DSL) between 450-600 m.

Results: Despite the general consensus of homogeneous conditions in the mesopelagic layer, we observed variability in physico-chemical variables (oxygen, inorganic nutrients, DOC) in the depth profiles.

Seasonality of top-down control of bacterioplankton at two central Red Sea sites with different trophic status.

The role of bottom-up (nutrient availability) and top-down (grazers and viruses mortality) controls on tropical bacterioplankton have been rarely investigated simultaneously from a seasonal perspective. We have assessed them through monthly samplings over 2 years in inshore and offshore waters of the central Red Sea differing in trophic status. Flow cytometric analysis allowed us to distinguish five groups of heterotrophic bacteria based on physiological properties (nucleic acid content, membrane integrity and active respiration), three groups of cyanobacteria (two populations of Synechococcus and Prochlorococcus), heterotrophic nanoflagellates (HNFs) and three groups of viruses based on nucleic acid content.

Growth dynamics and transcriptional responses of a Red Sea Prochlorococcus strain to varying temperatures.

Prochlorococcus play a crucial role in the ocean's biogeochemical cycling, but it remains controversial how they will respond to global warming. Here we assessed the response to temperature (22-30°C) of the growth dynamics and gene expression profiles of a Red Sea Prochlorococcus strain (RSP50) in a non-axenic culture. Both the specific growth rate (0.

High-Frequency Variability of Bacterioplankton in Response to Environmental Drivers in Red Sea Coastal Waters.

Autotrophic and heterotrophic bacterioplankton are essential to the biogeochemistry of tropical ecosystems. However, the processes that govern their dynamics are not well known. We provide here a high-frequency assessment of bacterial community dynamics and concurrent environmental factors in Red Sea coastal waters.

Heterotrophic Bacterioplankton Growth and Physiological Properties in Red Sea Tropical Shallow Ecosystems With Different Dissolved Organic Matter Sources.

Despite the key role of heterotrophic bacterioplankton in the biogeochemistry of tropical coastal waters, their dynamics have been poorly investigated in relation to the different dissolved organic matter (DOM) pools usually available. In this study we conducted four seasonal incubations of unfiltered and predator-free seawater (Community and Filtered treatment, respectively) at three Red Sea coastal sites characterized by different dominant DOM sources: Seagrass, Mangrove, and Phytoplankton. Bacterial abundance, growth and physiological status were assessed by flow cytometry and community composition by 16S rRNA gene amplicons.

Diel dynamics of dissolved organic matter and heterotrophic prokaryotes reveal enhanced growth at the ocean's mesopelagic fish layer during daytime.

Contrary to epipelagic waters, where biogeochemical processes closely follow the light and dark periods, little is known about diel cycles in the ocean's mesopelagic realm. Here, we monitored the dynamics of dissolved organic matter (DOM) and planktonic heterotrophic prokaryotes every 2 h for one day at 0 and 550 m (a depth occupied by vertically migrating fishes during light hours) in oligotrophic waters of the central Red Sea. We additionally performed predator-free seawater incubations of samples collected from the same site both at midnight and at noon.

Localized effects of offshore aquaculture on water quality in a tropical sea.

Aquaculture production has increased steadily in many tropical countries over the past few decades, although impact assessments have been frequently neglected. We investigated the impacts of an offshore barramundi fish farm on water quality in the southern-central Red Sea, a traditionally understudied tropical, oligotrophic, and semi-enclosed basin. Inorganic nutrients, particulate matter, chlorophyll-a, and heterotrophic bacteria were measured periodically over 8 months around the farm.

Fine-scale metabolic discontinuity in a stratified prokaryote microbiome of a Red Sea deep halocline.

Deep-sea hypersaline anoxic basins are polyextreme environments in the ocean's interior characterized by the high density of brines that prevents mixing with the overlaying seawater, generating sharp chemoclines and redoxclines up to tens of meters thick that host a high concentration of microbial communities. Yet, a fundamental understanding of how such pycnoclines shape microbial life and the associated biogeochemical processes at a fine scale, remains elusive. Here, we applied high-precision sampling of the brine-seawater transition interface in the Suakin Deep, located at 2770 m in the central Red Sea, to reveal previously undocumented fine-scale community structuring and succession of metabolic groups along a salinity gradient only 1 m thick.

High summer temperatures amplify functional differences between coral- and algae-dominated reef communities.

Shifts from coral to algal dominance are expected to increase in tropical coral reefs as a result of anthropogenic disturbances. The consequences for key ecosystem functions such as primary productivity, calcification, and nutrient recycling are poorly understood, particularly under changing environmental conditions. We used a novel in situ incubation approach to compare functions of coral- and algae-dominated communities in the central Red Sea bimonthly over an entire year.

Heterotrophic bacterioplankton responses in coral- and algae-dominated Red Sea reefs show they might benefit from future regime shift.

In coral reefs, dissolved organic matter (DOM) cycling is a critical process for sustaining ecosystem functioning. However, global and local stressors have caused persistent shifts from coral- to algae-dominated benthic communities. The influence of such phase shifts on DOM nature and its utilization by heterotrophic bacterioplankton remains poorly studied.

Exploring the Association Between Emphysema Phenotypes and Low Bone Mineral Density in Smokers with and without COPD.

Rationale: Emphysema and osteoporosis are tobacco-related diseases. Many studies have shown that emphysema is a strong and independent predictor of low bone mineral density (BMD) in smokers; however, none of them explored its association with different emphysema subtypes.

Objective: To explore the association between the different emphysema subtypes and the presence of low bone mineral density in a population of active or former smokers with and without chronic obstructive pulmonary disease (COPD).

Weekly variations of viruses and heterotrophic nanoflagellates and their potential impact on bacterioplankton in shallow waters of the central Red Sea.

Bacterioplankton play a pivotal role in marine ecosystems. However, their temporal dynamics and underlying control mechanisms are poorly understood in tropical regions such as the Red Sea. Here, we assessed the impact of bottom-up (resource availability) and top-down (viruses and heterotrophic nanoflagellates) controls on bacterioplankton abundances by weekly sampling a coastal central Red Sea site in 2017.

Seasonal variability and vertical distribution of autotrophic and heterotrophic picoplankton in the Central Red Sea.

The Red Sea is characterized by higher temperatures and salinities than other oligotrophic tropical regions. Here, we investigated the vertical and seasonal variations in the abundance and biomass of autotrophic and heterotrophic picoplankton. Using flow cytometry, we consistently observed five groups of autotrophs (, two populations of separated by their relative phycoerythrin fluorescence, low (LF-Syn) and high (HF-Syn), and two differently-sized groups of picoeukaryotes, small (Speuk) and large (Lpeuk)) and two groups of heterotrophic prokaryotes of low and high nucleic acid content (LNA and HNA, respectively).

Factors Regulating the Relationship Between Total and Size-Fractionated Chlorophyll- in Coastal Waters of the Red Sea.

Phytoplankton biomass and size structure are recognized as key ecological indicators. With the aim to quantify the relationship between these two ecological indicators in tropical waters and understand controlling factors, we analyzed the total chlorophyll- concentration, a measure of phytoplankton biomass, and its partitioning into three size classes of phytoplankton, using a series of observations collected at coastal sites in the central Red Sea. Over a period of 4 years, measurements of flow cytometry, size-fractionated chlorophyll- concentration, and physical-chemical variables were collected near Thuwal in Saudi Arabia.

Dissolved organic carbon contribution to oxygen respiration in the central Red Sea.

In oligotrophic waters, dissolved organic carbon (DOC) is mostly produced in the surface layers by phytoplankton and remineralized by heterotrophic prokaryotes throughout the water column. DOC surface excess is subducted and exported to deeper layers where a semi-labile fraction is further processed contributing to oxygen consumption. How this cycling of DOC occurs in the Red Sea, one of the warmest oligotrophic marine basins, is virtually unknown.

Trabecular bone score in active or former smokers with and without COPD.

Background: Smoking is a recognized risk factor for osteoporosis. Trabecular bone score (TBS) is a novel texture parameter to evaluate bone microarchitecture. TBS and their main determinants are unknown in active and former smokers.

Low Abundances but High Growth Rates of Coastal Heterotrophic Bacteria in the Red Sea.

Characterized by some of the highest naturally occurring sea surface temperatures, the Red Sea remains unexplored regarding the dynamics of heterotrophic prokaryotes. Over 16 months, we used flow cytometry to characterize the abundance and growth of four physiological groups of heterotrophic bacteria: membrane-intact (), high and low nucleic acid content (HNA and LNA) and actively respiring (CTC+) cells in shallow coastal waters. Chlorophyll , dissolved organic matter (DOC and DON) concentrations, and their fluorescent properties were also measured as proxies of bottom-up control.

Diel dynamics and coupling of heterotrophic prokaryotes and dissolved organic matter in epipelagic and mesopelagic waters of the central Red Sea.

The ecological status of an ecosystem can be approached by the taxa present but also by the size of individual organisms. In aquatic ecosystems, flow cytometry (FC) allows to study the individual size spectra and broad community composition through the evaluation of cytometric categories. The Red Sea represents a warm oligotrophic environment with a strong diel signal of vertically migrating mesopelagic fish, which feed at night at the surface and release dissolved organic carbon (DOC) at depth during day-time.

A quality improvement project to improve the Medicare and Medicaid Services (CMS) sepsis bundle compliance rate in a large healthcare system.

Sepsis is a leading cause of mortality and morbidity in hospitalised patients. The Centers for Medicare and Medicaid Services (CMS) mandated that US hospitals report sepsis bundle compliance rate as a quality process measure in October 2015. The specific aim of our study was to improve the CMS sepsis bundle compliance rate from 30% to 40% across 20 acute care hospitals in our healthcare system within 1 year.

Major hydrogeochemical processes in an acid mine drainage affected estuary.

This study provides geochemical data with the aim of identifying and quantifying the main processes occurring in an Acid Mine Drainage (AMD) affected estuary. With that purpose, water samples of the Huelva estuary were collected during a tidal half-cycle and ion-ion plots and geochemical modeling were performed to obtain a general conceptual model. Modeling results indicated that the main processes responsible for the hydrochemical evolution of the waters are: (i) the mixing of acid fluvial water with alkaline ocean water; (ii) precipitation of Fe oxyhydroxysulfates (schwertmannite) and hydroxides (ferrihydrite); (iii) precipitation of Al hydroxysulfates (jurbanite) and hydroxides (amorphous Al(OH)3); (iv) dissolution of calcite; and (v) dissolution of gypsum.

Pulmonary-renal vasculitic disorders: differential diagnosis and management.

Pulmonary-renal syndrome (PRS) is a combination of diffuse pulmonary hemorrhage and glomerulonephritis. Pulmonary-renal syndrome is not a single entity and is caused by a variety of conditions, including Goodpasturés syndrome associated with autoantibodies to the glomerular and alveolar basement membranes, various forms of primary systemic vasculitis associated with serum positivity for antineutrophil cytoplasmic antibodies (ANCA), cryoglobulinemia, systemic lupus erythematosus, systemic sclerosis, antiphospholipid syndrome, environmental factors, and drugs. The majority of cases of PRS are associated with ANCAs.