Seasonal and interannual variations of Irminger ring formation and boundary–interior heat exchange in FLAME

Author Posting. © American Meteorological Society, 2016. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Journal of Physical Oceanography 46 (2016): 1717-1734, doi:10.1175/JPO-D-15-0124.1.The contribution of warm-core anticyclones shed by the Irminger Current off West Greenland, known as Irminger rings, to the restratification of the upper layers of the Labrador Sea is investigated in the 1/12° Family of Linked Atlantic Models Experiment (FLAME) model. The model output, covering the 1990–2004 period, shows strong similarities to observations of the Irminger Current as well as ring observations at a mooring located offshore of the eddy formation region in 2007–09. An analysis of fluxes in the model shows that while the majority of heat exchange with the interior indeed occurs at the site of the Irminger Current instability, the contribution of the coherent Irminger rings is modest (18%). Heat is provided to the convective region mainly through noncoherent anomalies and enhanced local mixing by the rings facilitating further exchange between the boundary and interior. The time variability of the eddy kinetic energy and the boundary to interior heat flux in the model are strongly correlated to the density gradient between the dense convective region and the more buoyant boundary current. In FLAME, the density variations of the boundary current are larger than those of the convective region, thereby largely controlling changes in lateral fluxes. Synchronous long-term trends in temperature in the boundary and the interior over the 15-yr simulation suggest that the heat flux relative to the temperature of the interior is largely steady on these time scales.The authors were supported in this work by the U.S. National Science Foundation

Sitting time and patterns of activity in post-stroke rehabilitation: week versus weekend activity

Background: High levels of active task practice are recommended after stroke. However, the in-patient rehabilitation day is largely spent sitting. Understanding patterns of sitting across the rehabilitation week may facilitate strategies to promote greater activity. We aimed to compare differences in weekday and weekend sitting time and 24-hour activity patterns during the last week of in patient rehabilitation. Methods: Participants with stroke (n=34) from two rehabilitation units wore an activity monitor continuously during the final 7-days of in-patient rehabilitation. Linear mixed models (adjusted for waking hours) were performed with activity time as the outcome and weekday and weekend as the exposure. Patterns of activity accumulation were determined by averaging patient activity in 60-minute epochs, and then generating a heat map of activity level as a function of time. Results: Participant mean age was 68 [SD 13] years (53% male) mean NIHSS score 7 [SD 5]. There was no significant difference in total sitting time between weekdays and weekends. On the weekend, mean walking time was 8.35 minutes less (95% CI -12.13, -4.56 p ≤0.001), and steps/day were 624 fewer (95% CI -951, -296 p ≤0.001) than during the week. Activity patterns were similar across weekdays and weekends, with more morning than afternoon activity observed. Conclusion: Sitting time did not change in relation to the 7-day rehabilitation week, while walking (time and steps) was less on weekends. Morning activity was observably greater than afternoon activity across the 7-days. Strategies targeting afternoon, evening and weekend activity may increase overall physical activity during rehabilitation

Lagrangian perspective on the origins of Denmark Strait Overflow

Author Posting. © American Meteorological Society, 2020. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Journal of Physical Oceanography 50(8), (2020): 2393-2414, doi:10.1175/JPO-D-19-0210.1.The Denmark Strait Overflow (DSO) is an important contributor to the lower limb of the Atlantic meridional overturning circulation (AMOC). Determining DSO formation and its pathways is not only important for local oceanography but also critical to estimating the state and variability of the AMOC. Despite prior attempts to understand the DSO sources, its upstream pathways and circulation remain uncertain due to short-term (3–5 days) variability. This makes it challenging to study the DSO from observations. Given this complexity, this study maps the upstream pathways and along-pathway changes in its water properties, using Lagrangian backtracking of the DSO sources in a realistic numerical ocean simulation. The Lagrangian pathways confirm that several branches contribute to the DSO from the north such as the East Greenland Current (EGC), the separated EGC (sEGC), and the North Icelandic Jet (NIJ). Moreover, the model results reveal additional pathways from south of Iceland, which supplied over 16% of the DSO annually and over 25% of the DSO during winter of 2008, when the NAO index was positive. The southern contribution is about 34% by the end of March. The southern pathways mark a more direct route from the near-surface subpolar North Atlantic to the North Atlantic Deep Water (NADW), and needs to be explored further, with in situ observations.This work was financially supported by the U.S. National Science Foundation under Grant Numbers OAC-1835640, OCE-1633124, OCE-1433448, and OCE-1259210

Impact of Irminger Rings on Deep Convection in the Labrador Sea : mooring instrument, cruise CTD, and APEX data report September 2007 – September 2009

This is the final data report of all hydrographic station, mooring, and subsurface float data collected by the Woods Hole Oceanographic Institution in 2007-2009 during the Impact of Irminger Rings on Deep Convection in the Labrador Sea experiment (IRINGS). The objectives of IRINGS were to (1) to determine the full water column hydrographic and velocity structure of newlyformed Irminger Rings that have entered the interior Labrador Sea; (2) to observe how Irminger Ring core properties are modified by atmospheric forcing over their lifetime; and (3) to improve the interpretation of sea surface height (SSH) anomalies in terms of newly formed coherent heat containing Irminger Rings. The mooring deployment and recovery cruises were both on the R/V Knorr: KN192-01 in September 2007 and KN196-01 in September 2009, respectively. The single mooring held eight Aanderaa current meters (RCM-11), two Submerged Autonomous Launch Platforms (SALPs), and nine Seabird microcats (SBE37), deployed from 26 September 2007 through 27 September 2009, yeilding full water column (100-3000 meters) records of temperature, salinity, pressure, and velocity data for the two year period. The two SALP cages contained eleven APEX floats, and released some of these floats according to local oceanographic conditions, so as to seed the floats in passing Irminger Rings, and the remainder of floats as timed releases. Thirteen conductivity-temperature-depth (CTD) stations were taken on the mooring recovery cruise, creating a boundary current cross-section from the mooring site to Nuuk, Greenland.Funding was provided by the National Science Foundation Grant OCE-0623192

Triple Combination of Amantadine, Ribavirin, and Oseltamivir Is Highly Active and Synergistic against Drug Resistant Influenza Virus Strains In Vitro

The rapid emergence and subsequent spread of the novel 2009 Influenza A/H1N1 virus (2009 H1N1) has prompted the World Health Organization to declare the first pandemic of the 21st century, highlighting the threat of influenza to public health and healthcare systems. Widespread resistance to both classes of influenza antivirals (adamantanes and neuraminidase inhibitors) occurs in both pandemic and seasonal viruses, rendering these drugs to be of marginal utility in the treatment modality. Worldwide, virtually all 2009 H1N1 and seasonal H3N2 strains are resistant to the adamantanes (rimantadine and amantadine), and the majority of seasonal H1N1 strains are resistant to oseltamivir, the most widely prescribed neuraminidase inhibitor (NAI). To address the need for more effective therapy, we evaluated the in vitro activity of a triple combination antiviral drug (TCAD) regimen composed of drugs with different mechanisms of action against drug-resistant seasonal and 2009 H1N1 influenza viruses. Amantadine, ribavirin, and oseltamivir, alone and in combination, were tested against amantadine- and oseltamivir-resistant influenza A viruses using an in vitro infection model in MDCK cells. Our data show that the triple combination was highly synergistic against drug-resistant viruses, and the synergy of the triple combination was significantly greater than the synergy of any double combination tested (P<0.05), including the combination of two NAIs. Surprisingly, amantadine and oseltamivir contributed to the antiviral activity of the TCAD regimen against amantadine- and oseltamivir-resistant viruses, respectively, at concentrations where they had no activity as single agents, and at concentrations that were clinically achievable. Our data demonstrate that the TCAD regimen composed of amantadine, ribavirin, and oseltamivir is highly synergistic against resistant viruses, including 2009 H1N1. The TCAD regimen overcomes baseline drug resistance to both classes of approved influenza antivirals, and thus may represent a highly active antiviral therapy for seasonal and pandemic influenza

A Direct Detection of Dust in the Outer Disks of Nearby Galaxies

We measure the extent of 100 micron galactic emission in two independent galaxy samples using the IRAS 100 micron Sky Survey images and constrain the distribution of dust at large (\ltsim30 kpc) radii. The first sample consists of 90 nearby (v < 6000 km/s) galaxies from the RC3 catalog with similar angular sizes and absolute luminosities (5 arcmin $\leq$D$_{25} \leq$ 10 arcmin and $-22.5 \leq$M$_{B} \leq -18$) that are isolated in the 100 micron images. The second sample consists of 24 local galaxies (v < 1500 km/s, 10 arcmin $\leq$D$_{25} \leq$ 30 arcmin). We rescale the 100 micron images of these galaxies using their optical diameters, D$_{25}$, rotate the images using their optical major axis position angle, construct the mean and median image, and rebin the final images into polar coordinates to study the 100 micron emission as a function of radius and azimuthal angle. We find that the 100 micron emission extends at least to radii of 27 kpc (2$\sigma$ detection) for the typical galaxy in the 5 arcmin - 10 arcmin sample and to 21 kpc (2$\sigma$ detection) in the 10 arcmin - 30 arcmin sample (H$_{0} =$75 km/s/Mpc). In both samples, the emission is preferentially elongated along the optical major axis. We fit an exponential to the 100 micron emission along the major axis and measure a scale length of $2.5 \pm$ 0.8 kpc (90% confidence interval). Using a simple model that relates the far-IR emission to the stellar distribution, we examine the range of acceptable dust mass distributions allowed by our data and conclude that the dust is more extended than the starlight.Comment: 31 pages, 9 figures, AASTEX (aaspp4), accepted for publication in the Astronomical Journa

The amphioxus genome and the evolution of the chordate karyotype

Lancelets ('amphioxus') are the modern survivors of an ancient chordate lineage, with a fossil record dating back to the Cambrian period. Here we describe the structure and gene content of the highly polymorphic approx520-megabase genome of the Florida lancelet Branchiostoma floridae, and analyse it in the context of chordate evolution. Whole-genome comparisons illuminate the murky relationships among the three chordate groups (tunicates, lancelets and vertebrates), and allow not only reconstruction of the gene complement of the last common chordate ancestor but also partial reconstruction of its genomic organization, as well as a description of two genome-wide duplications and subsequent reorganizations in the vertebrate lineage. These genome-scale events shaped the vertebrate genome and provided additional genetic variation for exploitation during vertebrate evolution

The multidimensional causal factors of ‘wet litter’ in chicken-meat production

The problem of ‘wet litter’, which occurs primarily in grow-out sheds for meat chickens (broilers), has been recognised for nearly a century. Nevertheless, it is an increasingly important problem in contemporary chicken-meat production as wet litter and associated conditions, especially footpad dermatitis, have developed into tangible welfare issues. This is only compounded by the market demand for chicken paws and compromised bird performance. This review considers the multidimensional causal factors of wet litter. While many causal factors can be listed it is evident that the critical ones could be described as micro-environmental factors and chief amongst them is proper management of drinking systems and adequate shed ventilation. Thus, this review focuses on these environmental factors and pays less attention to issues stemming from health and nutrition. Clearly, there are times when related avian health issues of coccidiosis and necrotic enteritis cannot be overlooked and the development of efficacious vaccines for the latter disease would be advantageous. Presently, the inclusion of phytate-degrading enzymes in meat chicken diets is routine and, therefore, the implication that exogenous phytases may contribute to wet litter is given consideration. Opinion is somewhat divided as how best to counter the problem of wet litter as some see education and extension as being more beneficial than furthering research efforts. However, it may prove instructive to assess the practice of whole grain feeding in relation to litter quality and the incidence of footpad dermatitis. Additional research could investigate the relationships between dietary concentrations of key minerals and the application of exogenous enzymes with litter quality

Overturning in the Subpolar North Atlantic Program: A New International Ocean Observing System

For decades oceanographers have understood the Atlantic meridional overturning circulation (AMOC) to be primarily driven by changes in the production of deep-water formation in the subpolar and subarctic North Atlantic. Indeed, current Intergovernmental Panel on Climate Change (IPCC) projections of an AMOC slowdown in the twenty-first century based on climate models are attributed to the inhibition of deep convection in the North Atlantic. However, observational evidence for this linkage has been elusive: there has been no clear demonstration of AMOC variability in response to changes in deep-water formation. The motivation for understanding this linkage is compelling, since the overturning circulation has been shown to sequester heat and anthropogenic carbon in the deep ocean. Furthermore, AMOC variability is expected to impact this sequestration as well as have consequences for regional and global climates through its effect on the poleward transport of warm water. Motivated by the need for a mechanistic understanding of the AMOC, an international community has assembled an observing system, Overturning in the Subpolar North Atlantic Program (OSNAP), to provide a continuous record of the transbasin fluxes of heat, mass, and freshwater, and to link that record to convective activity and water mass transformation at high latitudes. OSNAP, in conjunction with the Rapid Climate Change–Meridional Overturning Circulation and Heatflux Array (RAPID–MOCHA) at 26°N and other observational elements, will provide a comprehensive measure of the three-dimensional AMOC and an understanding of what drives its variability. The OSNAP observing system was fully deployed in the summer of 2014, and the first OSNAP data products are expected in the fall of 2017