Past and present deepwater contour-current bedforms at the base of the Sigsbee Escarpment, northern Gulf of Mexico

Using a high-resolution deep-towed seismic system, we have discovered a series of contour-current bedforms at the base of the Sigsbee Escarpment in the Bryant Canyon region of the northern Gulf of Mexico. We identify a continuum of bedforms that include furrows, meandering furrows, flutes and fully eroded seafloor. These contourcurrent bedforms are linked to current velocities ranging from 20 to upwards of 60 cm/s based on nearby current meter measurements and similar flume generated bedforms (Allen, 1969). We identify erosion and non-deposition of up to 25 meters of surface sediment at the base of Sigsbee Escarpment. Using 3-D and high-resolution seismic data, sediment samples, and submersible observations from the Green Knoll area, we further define contour-current bedforms along the Sigsbee Escarpment. The study area is divided into eleven zones based on bedform morphology, distribution, and formation processes. We identify a contourcurrent bedform continuum similar to that of the Bryant Canyon region, while the data reveals additional features that result from the interaction between topography and contour-currents. Three regional seismic marker horizons are identified, and we establish an age of ~19 kyr on the deepest horizon. The seismic horizons are correlated with very subtle changes in sediment properties, which in turn define the maximum depth of erosion for each of the individual bedforms. Finally, we show for the first time that furrowed horizons can be acoustically imaged in three dimensions below seafloor. Analysis of imagery of several horizons obtained from 3-D seismic data from the Green Knoll region establishes the existence of multiple paleo-furrow events. The contour current pattern preserved by the paleofurrows is similar to the presently active seafloor furrows. And, based on the morphology and development that we establish for the active seafloor furrows, we show that paleo-furrows are likely formed by currents that are in the same range as those measured today (20-60 cm/s), that erode into sediments with similar physical properties to the fine-grained hemipelagic sediments of the present-day seafloor. We further suggest the possibility that furrows are formed during inter-glacial highstands and buried during glacial lowstands

Past and present deepwater contour-current bedforms at the base of the Sigsbee Escarpment, northern Gulf of Mexico

Using a high-resolution deep-towed seismic system, we have discovered a series of contour-current bedforms at the base of the Sigsbee Escarpment in the Bryant Canyon region of the northern Gulf of Mexico. We identify a continuum of bedforms that include furrows, meandering furrows, flutes and fully eroded seafloor. These contourcurrent bedforms are linked to current velocities ranging from 20 to upwards of 60 cm/s based on nearby current meter measurements and similar flume generated bedforms (Allen, 1969). We identify erosion and non-deposition of up to 25 meters of surface sediment at the base of Sigsbee Escarpment. Using 3-D and high-resolution seismic data, sediment samples, and submersible observations from the Green Knoll area, we further define contour-current bedforms along the Sigsbee Escarpment. The study area is divided into eleven zones based on bedform morphology, distribution, and formation processes. We identify a contourcurrent bedform continuum similar to that of the Bryant Canyon region, while the data reveals additional features that result from the interaction between topography and contour-currents. Three regional seismic marker horizons are identified, and we establish an age of ~19 kyr on the deepest horizon. The seismic horizons are correlated with very subtle changes in sediment properties, which in turn define the maximum depth of erosion for each of the individual bedforms. Finally, we show for the first time that furrowed horizons can be acoustically imaged in three dimensions below seafloor. Analysis of imagery of several horizons obtained from 3-D seismic data from the Green Knoll region establishes the existence of multiple paleo-furrow events. The contour current pattern preserved by the paleofurrows is similar to the presently active seafloor furrows. And, based on the morphology and development that we establish for the active seafloor furrows, we show that paleo-furrows are likely formed by currents that are in the same range as those measured today (20-60 cm/s), that erode into sediments with similar physical properties to the fine-grained hemipelagic sediments of the present-day seafloor. We further suggest the possibility that furrows are formed during inter-glacial highstands and buried during glacial lowstands

Anticoagulation for atrial fibrillation in people with serious mental illness in the general hospital setting

OBJECTIVE: People with serious mental illnesses (SMI) have an increased risk of stroke compared to the general population. This study aims to evaluate oral anticoagulation prescription trends in atrial fibrillation (AF) patients with and without a comorbid SMI. METHODS: An open-source retrieval system for clinical data (CogStack) was used to identify a cohort of AF patients with SMI who ever had an inpatient admission to King's College Hospital from 2011 to 2020. A Natural Language Processing pipeline was used to calculate CHA2DS2-VASc and HASBLED risk scores from Electronic Health Records free text. Antithrombotic prescriptions of warfarin and Direct acting oral anti-coagulants (DOACs) (apixaban, rivaroxaban, dabigatran, edoxaban) were extracted from discharge summaries. RESULTS: Among patients included in the study (n = 16 916), 2.7% had a recorded co-morbid SMI diagnosis. Compared to non-SMI patients, those with SMI had significantly higher CHA2DS2-VASc (mean (SD): 5.3 (1.96) vs 4.7 (2.08), p < 0.001) and HASBLED scores (mean (SD): 3.2 (1.27) vs 2.5 (1.29), p < 0.001). Among AF patients having a CHA2DS2-VASc ≥2, those with co-morbid SMI were less likely than non-SMI patients to be prescribed an OAC (44% vs 54%, p < 0.001). However, there was no evidence of a significant difference between the two groups since 2019. CONCLUSION: Over recent years, DOAC prescription rates have increased among AF patients with SMI in acute hospitals. More research is needed to confirm whether the introduction of DOACs has reduced OAC treatment gaps in people with serious mental illness and to assess whether the use of DOACs has improved health outcomes in this population

ADAMTS5 is a critical regulator of virus-specific T cell immunity

The extracellular matrix (ECM) provides physical scaffolding for cellular constituents and initiates biochemical and biomechanical cues that are required for physiological activity of living tissues. The ECM enzyme ADAMTS5, a member of the ADAMTS (A Disintegrin-like and Metalloproteinase with Thrombospondin-1 motifs) protein family, cleaves large proteoglycans such as aggrecan, leading to the destruction of cartilage and osteoarthritis. However, its contribution to viral pathogenesis and immunity is currently undefined. Here, we use a combination of in vitro and in vivo models to show that ADAMTS5 enzymatic activity plays a key role in the development of influenza-specific immunity. Influenza virus infection of Adamts5-/- mice resulted in delayed virus clearance, compromised T cell migration and immunity and accumulation of versican, an ADAMTS5 proteoglycan substrate. Our research emphasises the importance of ADAMTS5 expression in the control of influenza virus infection and highlights the potential for development of ADAMTS5-based therapeutic strategies to reduce morbidity and mortality

Strongly aligned gas-phase molecules at Free-Electron Lasers

We demonstrate a novel experimental implementation to strongly align molecules at full repetition rates of free-electron lasers. We utilized the available in-house laser system at the coherent x-ray imaging beamline at the Linac Coherent Light Source. Chirped laser pulses, i. e., the direct output from the regenerative amplifier of the Ti:Sa chirped pulse amplification laser system, were used to strongly align 2,5-diiodothiophene molecules in a molecular beam. The alignment laser pulses had pulse energies of a few mJ and a pulse duration of 94 ps. A degree of alignment of \left = 0.85 was measured, limited by the intrinsic temperature of the molecular beam rather than by the available laser system. With the general availability of synchronized chirped-pulse-amplified near-infrared laser systems at short-wavelength laser facilities, our approach allows for the universal preparation of molecules tightly fixed in space for experiments with x-ray pulses.Comment: 10 pages, 5 figure

Mycobacterium tuberculosis Type VII Secreted Effector EsxH Targets Host ESCRT to Impair Trafficking

Mycobacterium tuberculosis (Mtb) disrupts anti-microbial pathways of macrophages, cells that normally kill bacteria. Over 40 years ago, D'Arcy Hart showed that Mtb avoids delivery to lysosomes, but the molecular mechanisms that allow Mtb to elude lysosomal degradation are poorly understood. Specialized secretion systems are often used by bacterial pathogens to translocate effectors that target the host, and Mtb encodes type VII secretion systems (TSSSs) that enable mycobacteria to secrete proteins across their complex cell envelope; however, their cellular targets are unknown. Here, we describe a systematic strategy to identify bacterial virulence factors by looking for interactions between the Mtb secretome and host proteins using a high throughput, high stringency, yeast two-hybrid (Y2H) platform. Using this approach we identified an interaction between EsxH, which is secreted by the Esx-3 TSSS, and human hepatocyte growth factor-regulated tyrosine kinase substrate (Hgs/Hrs), a component of the endosomal sorting complex required for transport (ESCRT). ESCRT has a well-described role in directing proteins destined for lysosomal degradation into intraluminal vesicles (ILVs) of multivesicular bodies (MVBs), ensuring degradation of the sorted cargo upon MVB-lysosome fusion. Here, we show that ESCRT is required to deliver Mtb to the lysosome and to restrict intracellular bacterial growth. Further, EsxH, in complex with EsxG, disrupts ESCRT function and impairs phagosome maturation. Thus, we demonstrate a role for a TSSS and the host ESCRT machinery in one of the central features of tuberculosis pathogenesis

The Drivers of Pathology in Zoonotic Avian Influenza: The Interplay Between Host and Pathogen

The emergence of zoonotic strains of avian influenza (AI) that cause high rates of mortality in people has caused significant global concern, with a looming threat that one of these strains may develop sustained human-to-human transmission and cause a pandemic outbreak. Most notable of these viral strains are the H5N1 highly pathogenic AI and the H7N9 low pathogenicity AI viruses, both of which have mortality rates above 30%. Understanding of their mechanisms of infection and pathobiology is key to our preparation for these and future viral strains of high consequence. AI viruses typically circulate in wild bird populations, commonly infecting waterfowl and also regularly entering commercial poultry flocks. Live poultry markets provide an ideal environment for the spread AI and potentially the selection of mutants with a greater propensity for infecting humans because of the potential for spill over from birds to humans. Pathology from these AI virus infections is associated with a dysregulated immune response, which is characterized by systemic spread of the virus, lymphopenia, and hypercytokinemia. It has been well documented that host/pathogen interactions, particularly molecules of the immune system, play a significant role in both disease susceptibility as well as disease outcome. Here, we review the immune/virus interactions in both avian and mammalian species, and provide an overview or our understanding of how immune dysregulation is driven. Understanding these susceptibility factors is critical for the development of new vaccines and therapeutics to combat the next pandemic influenza

CMBPol Mission Concept Study: Probing Inflation with CMB Polarization

We summarize the utility of precise cosmic microwave background (CMB) polarization measurements as probes of the physics of inflation. We focus on the prospects for using CMB measurements to differentiate various inflationary mechanisms. In particular, a detection of primordial B-mode polarization would demonstrate that inflation occurred at a very high energy scale, and that the inflaton traversed a super-Planckian distance in field space. We explain how such a detection or constraint would illuminate aspects of physics at the Planck scale. Moreover, CMB measurements can constrain the scale-dependence and non-Gaussianity of the primordial fluctuations and limit the possibility of a significant isocurvature contribution. Each such limit provides crucial information on the underlying inflationary dynamics. Finally, we quantify these considerations by presenting forecasts for the sensitivities of a future satellite experiment to the inflationary parameters.Comment: 107 pages, 14 figures, 17 tables; Inflation Working Group contribution to the CMBPol Mission Concept Study; v2: typos fixed and references adde

Coherent diffraction of single Rice Dwarf virus particles using hard X-rays at the Linac Coherent Light Source

Single particle diffractive imaging data from Rice Dwarf Virus (RDV) were recorded using the Coherent X-ray Imaging (CXI) instrument at the Linac Coherent Light Source (LCLS). RDV was chosen as it is a wellcharacterized model system, useful for proof-of-principle experiments, system optimization and algorithm development. RDV, an icosahedral virus of about 70 nm in diameter, was aerosolized and injected into the approximately 0.1 mu m diameter focused hard X-ray beam at the CXI instrument of LCLS. Diffraction patterns from RDV with signal to 5.9 angstrom ngstrom were recorded. The diffraction data are available through the Coherent X-ray Imaging Data Bank (CXIDB) as a resource for algorithm development, the contents of which are described here.11Ysciescopu

Exposure and Effect Assessment of Aerosolized Red Tide Toxins (Brevetoxins) and Asthma

addresses: National Science Foundation National Institute of Environmental Health Sciences Oceans and Human Health Center, University of Miami Rosenstiel School of Marine and Atmospheric Sciences, Miami, Florida 33136, USA. [email protected]: PMCID: PMC2717136types: Journal Article; Research Support, N.I.H., Extramural; Research Support, Non-U.S. Gov't; Research Support, U.S. Gov't, Non-P.H.S.; Research Support, U.S. Gov't, P.H.S.'Reproduced with permission from Environmental Health Perspectives'Copyright © 2009 National Institute of Environmental Health SciencesIn previous studies we demonstrated statistically significant changes in reported symptoms for lifeguards, general beach goers, and persons with asthma, as well as statistically significant changes in pulmonary function tests (PFTs) in asthmatics, after exposure to brevetoxins in Florida red tide (Karenia brevis bloom) aerosols