Effect of gaseous and solid simulated jet plumes on a 040A space shuttle launch configuration at Mach numbers from 1.6 to 2.2

An experimental investigation was conducted in a 9- by 7-foot supersonic wind tunnel to determine the effect of plume-induced flow separation and aspiration effects due to operation of both the orbiter and the solid rocket motors on a 0.019-scale model of the launch configuration of the space shuttle vehicle. Longitudinal and lateral-directional stability data were obtained at Mach numbers of 1.6, 2.0, and 2.2 with and without the engines operating. The plumes exiting from the engines were simulated by a cold gas jet supplied by an auxiliary 200 atmosphere air supply system, and by solid body plume simulators. Comparisons of the aerodynamic effects produced by these two simulation procedures are presented. The data indicate that the parameters most significantly affected by the jet plumes are the pitching moment, the elevon control effectiveness, the axial force, and the orbiter wing loads

Implications of future northwest Atlantic bottom temperatures on the American lobster (Homarus americanus) fishery

© The Author(s), 2017. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Journal of Geophysical Research: Oceans 122 (2017): 9387–9398, doi:10.1002/2017JC012949.Sea surface temperatures of the northwest Atlantic have warmed dramatically over the last several decades, while benthic temperatures have increased at a slower pace. Here we analyze a subset of the CMIP5 global Earth system model ensemble using a statistical downscaling approach to determine potential future changes in benthic temperatures on the northwest Atlantic continental shelf and slope (<500 m). We put future changes in the context of possible impacts of ocean warming on the high-value, wild-caught American Lobster (Homarus americanus) fishery. Future bottom temperatures of the northwest Atlantic under a business-as-usual (RCP8.5) and a climate-policy (RCP4.5) scenario are projected to increase by 0–1.5°C and 1.2–2.4°C by 2050 and 0–1.9°C and 2.3–4.3°C by the end of the century for RCP4.5 and RCP8.5, respectively. H. americanus experiences thermal stress at temperatures above 20°C, and projected increases in temperature is likely to result in changes in the distribution of optimal thermal egg hatching and settlement indicators. Inshore regions of southern New England, where H. americanus biomass and catch have been declining historically, will likely become inhospitable under either future scenario, while thermal egg hatching and settlement indicators will expand offshore and in the Gulf of Maine. These changes imply that members of the fishery based in southern New England may need to recapitalize to larger vessels to prepare for potential changes brought on by future climate warming. Results from the downscaling presented here can be useful in preparing for potential changes to other fisheries or in future climate vulnerability analyses.John D. and Catherine T. MacArthur Foundation Grant Number: 14-106159-000-CFP; NASA Grant Number: NNX14AP62A; “National Marine Sanctuaries as Sentinel Sites for a Demonstration Marine Biodiversity Observation Network (MBON)”; National Ocean Partnership Program Grant Number: NOPP RFP NOAA-NOS IOOS-2014-2003803; NOAA Integrated Ocean Observing System (IOOS) Program Offic

Structure and function of human hemoglobin covalently labeled with periodate-oxidized adenosine triphosphate

Periodate-oxidized adenosine triphosphate (o-ATP), a ribose ring-opened dialdehyde derivative of ATP, reacts specifically with human deoxyhemoglobin to give a single major covalently modified product after reduction with sodium borohydride. This product, designated di-ATP Hb, was isolated using ion-exchange chromatography and shown to have incorporated two molecules of o-ATP/tetramer. Peptide mapping and x-ray crystallography at 2.8-A resolution indicate that a covalent adduct is formed between the ligand and residues Lys-82 EF6 of each beta chain in the organic phosphate-binding site of the molecule. di-ATP Hb exhibits a significantly decreased oxygen affinity (P50 = 20.8 mm Hg versus 5.8 mm Hg control; 50 mM 2-[bis(2-hydroxyethyl)amino]-2-(hydroxymethyl)-propane-1,3-diol, pH 7.4, 0.1 M C, 20 degrees C). The subunit cooper-activity of di-ATP Hb is also reduced (nmax = 1.9 versus 2.7 control)

Phytoplankton shading of marine benthic macrophytes: Implications for intertidal community structure

Previous observations of light levels and phytoplankton abundances along the Oregon coast demonstrated that phytoplankton attenuated light sufficiently to potentially limit the growth of intertidal macrophytes and therefore structure local intertidal communities. Inspired by this observation, in spring 2004, I initiated a study to quantify the direct and indirect benthic community response to different light regimes. Frames supporting plastic mesh were installed to shade macroalgae in the Hedophyllum zone. With unshaded treatments, the shade treatment manipulated the light levels available to benthic algal species at two sites differing in historic pelagic productivity. Treatments included shaded, unshaded, and manipulation control plots that were 0.25 m2 in area. The experiment began in mid June and ran through the end of August, 2004. The direct response variables were the growth rate and abundance accumulation of the perennial intertidal kelp Hedophyllum sessile. The indirect responses measured were the changes in abundance of understory red algae. Results indicated that shade decreased growth rates of Hedophyllum and that the extent of growth rate reduction varied between sites. The response of total cover of understory algae was not strongly different between treatments and the response of individual algal groups differed between treatments and between sites. At Fogarty Creek, an area of historically high macroalgal abundance and comparatively low phytoplankton abundance, the primary response to increased shade was an increase in foliose red algae. At Strawberry Hill, an area of lower macroalgal abundance, the primary response was an increase in dominance of coralline algae. The response of algal diversity to different canopy treatments also differed between sites. Diversity of understory algae was highest beneath the artificial shades at Fogarty Creek whereas at Strawberry Hill, the diversity was the highest beneath intact canopy. The difference in responses of the understory assemblage at the two sites was interpreted to signify potential differences in the ecological role of the canopy. At Fogarty Creek, the canopy appears to reduce algal abundance and diversity, presumably through competitive inhibition, whereas at Strawberry Hill the canopy appears to facilitate increased algal abundance and diversity, presumably through habitat amelioration. While underscoring the need to include parameters of environmental stress when modeling changes in total production, these results are consistent with estuarine studies that demonstrate that as nutrient loading increases, the community shifts from a mixed autotroph assemblage to one dominated by phytoplankton. Thus in open coast systems where annual benthic production can exceed the pelagic production by a factor of 5-10, increased nutrients may also shift these systems towards greater dominance by phytoplankton and reduced macrophytes. As perennial macrophytes such as kelp and sea grasses are also extraordinarily important habitat modifiers and provide nursery habitat for several species of fish and invertebrates, large-scale reduction of macrophytes could also lead to profound modifications of coastal ecosystem dynamics.Keywords: community production, light limitation, kelp canopy understory dynamics, autoecology, marine ecology, Hedophyllum sessil

Dynamic seascapes : a quantitative framework for scaling pelagic ecology and biogeochemistry

Understanding and modeling microbial responses and feedbacks to climate change is hampered by a lack of a framework in the pelagic environment by which to link local mechanism to large scale patterns. Where terrestrial ecology draws from landscape theory and practice to address issues of scale, the pelagic seascape concept is still in its infancy. We have applied the patch mosaic paradigm of landscape ecology to the study of the seasonal and interannual variability of the North Pacific to facilitate comparative analysis between pelagic ecosystems and provide spatiotemporal context for eulerian time-series studies. Using multivariate, 13-year climatologies of sea surface temperature, photosynthetically active radiation, and chlorophyll a derived from remote sensing observations, we classified hierarchical seascapes at monthly and interannual scales. These dynamic, objectively-determined seascapes offer improved hydrographic coherence relative to oceanic regions with subjectively defined and static boundaries (Chapter 2) and represent unique biogeochemical functioning (Chapter 2) and microbial communities (Chapter3). Furthermore they provide consilience between satellite studies and in situ observations (Chapter 4) and allow for objective comparison of ecosystem forcing (Chapters, 4 and 5). In Chapter 2, we rigorously tested the assumption that satellite-derived seascapes describe regions of biogeochemical coherence. The seasonal cycle of the North Pacific was characterized at three levels of spatiotemporal hierarchy and broader relevance of monthly –resolved seascapes was assessed through analysis of variance (ANOVA) and multiple linear regression (MLR) analyses of nutrient, primary productivity, and pCO₂ data. Distinct nutrient and primary productivity regimes were well-characterized in the coarsest two levels of hierarchy (ANOVA, R² = 0.5-0.7). Finer scale partitioning was more relevant for pCO₂. MLR analyses revealed differential forcing on pCO₂ across seascapes and hierarchical levels and a 33 % reduction in mean model error with increased partitioning (from 18.5 µatm to 12.0 µatm pCO₂). In Chapter 3 we verified the seascapes with in situ collections of microbial abundance and structure. Flow cytometry data was collected from two long term time series and several cruises spanning thousand kilometers of the NE Pacific; these data allowed us to quantify spatiotemporal patterns. In addition, multiple response permutation analysis revealed differences in community structure across discrete seascapes, in terms of both absolute and relative abundances. Principal component analysis of the assemblage supported seascape divisions and revealed structure along environmental gradients with strong associations with chlorophyll a and sea surface temperature and, to a lesser extent, with mixed layer depth and mean photosynthetically active radiation in the mixed layer. Differences of assemblage structure between seascapes and strength of environmental forcing were strong in the subarctic and transition zones, but less pronounced in the subtropics, suggesting satellite-detected changes in bulk properties that may be associated with local physiology or interannual shifts in seascape boundaries. Based on the work presented in Chapter 4, we discovered that interannual shifts in the boundaries of a transition seascape and two distinct oligotrophic subtropical seascapes affect the variability observed at benchmark time series Station ALOHA; the latter two seascapes oscillate in their contributions to the expansion of the entire subtropics. On interannual scales, in situ phytoplankton abundance (as measured by chl-a), net primary productivity (NPP), and the relative abundance of eukaryotic phytoplankton and Synechococcus sp. increased during periods of encroachment by the transition seascape. Conversely, the relative abundance of Prochlorococcus increased and chl –a and NPP decreased when the highly oligotrophic seascape encroached on Station ALOHA. The dynamic range (~6 million km²) of subtropical expansion is born almost entirely by the transition zone - resulting in a transfer of ~1.2 Pg of total primary C production between a system primed for export production and one dominated by the microbial loop. In Chapter 5, we investigated multiple factors that contribute to the effectiveness of the biological pump in the transition seascape. Near-continuous measurements of net primary production (NPP), net community production (NCP) and several ecophysiological variables were collected in across subarctic, transition, and subtropical seascapes of the Northeast Pacific during August and September of 2008. Mesoscale processes and shifts in community structure contributed to high export efficiency in the subtropical seascape; the convergence of assemblage structure, high biomass, moderate NPP: NCP and high NCP contributed to biologically mediated air-sea exchange in the transition seascape. Furthermore, NPP and NCP were strongly spatially coupled in both the transition (r[subscript 1, 39]=0.70; p<0.0001) and subtropical seascapes (r[subscript 1, 45]= 0.68, p<0.0001), suggesting the possibility for empirical modeling efforts. This dissertation provides a first step to characterize the seascape variability in the NE Pacific and to understand the modulation of primary and export production in a critical transition region. The multivariate seascape approach described here provides spatiotemporal context for in situ studies and allows objective comparisons of systems' responses to climatic forcing. An integrated ocean observing system will require insight from in situ observations and experiments, ecosystem models, and satellite remote sensing. The results highlighted in this dissertation suggest that the pelagic seascape framework, through its capacity to scale both context and mechanism, may serve as an important and unifying component of such an observing system

Variability in the mechanisms controlling Southern Ocean phytoplankton bloom phenology in an ocean model and satellite observations

Author Posting. © American Geophysical Union, 2017. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Global Biogeochemical Cycles 31 (2017): 922–940, doi:10.1002/2016GB005615.A coupled global numerical simulation (conducted with the Community Earth System Model) is used in conjunction with satellite remote sensing observations to examine the role of top-down (grazing pressure) and bottom-up (light, nutrients) controls on marine phytoplankton bloom dynamics in the Southern Ocean. Phytoplankton seasonal phenology is evaluated in the context of the recently proposed “disturbance-recovery” hypothesis relative to more traditional, exclusively “bottom-up” frameworks. All blooms occur when phytoplankton division rates exceed loss rates to permit sustained net population growth; however, the nature of this decoupling period varies regionally in Community Earth System Model. Regional case studies illustrate how unique pathways allow blooms to emerge despite very poor division rates or very strong grazing rates. In the Subantarctic, southeast Pacific small spring blooms initiate early cooccurring with deep mixing and low division rates, consistent with the disturbance-recovery hypothesis. Similar systematics are present in the Subantarctic, southwest Atlantic during the spring but are eclipsed by a subsequent, larger summer bloom that is coincident with shallow mixing and the annual maximum in division rates, consistent with a bottom-up, light limited framework. In the model simulation, increased iron stress prevents a similar summer bloom in the southeast Pacific. In the simulated Antarctic zone (70°S–65°S) seasonal sea ice acts as a dominant phytoplankton-zooplankton decoupling agent, triggering a delayed but substantial bloom as ice recedes. Satellite ocean color remote sensing and ocean physical reanalysis products do not precisely match model-predicted phenology, but observed patterns do indicate regional variability in mechanism across the Atlantic and Pacific.NDSEG Graduate Fellowship; National Aeronautics and Space Administration Ocean Biology and Biogeochemistry Program Grant Number: NNX14L86G; NSF Poloar Programs Award Grant Number: 1440435; National Aeronautics and Space Administration Grant Number: NNX14AL86G; NDSEG; National Science Foundation Grant Number: 14404352017-11-3

Thirty-three years of ocean benthic warming along the U.S. Northeast Continental Shelf and Slope : patterns, drivers, and ecological consequences

© The Author(s), 2017. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Journal of Geophysical Research: Oceans 122 (2017): 9399–9414, doi:10.1002/2017JC012953.The U.S. Northeast Continental Shelf is experiencing rapid warming, with potentially profound consequences to marine ecosystems. While satellites document multiple scales of spatial and temporal variability on the surface, our understanding of the status, trends, and drivers of the benthic environmental change remains limited. We interpolated sparse benthic temperature data along the New England Shelf and upper Slope using a seasonally dynamic, regionally specific multiple linear regression model that merged in situ and remote sensing data. The statistical model predicted nearly 90% of the variability of the data, resulting in a synoptic time series spanning over three decades from 1982 to 2014. Benthic temperatures increased throughout the domain, including in the Gulf of Maine. Rates of benthic warming ranged from 0.1 to 0.4°C per decade, with fastest rates occurring in shallow, nearshore regions and on Georges Bank, the latter exceeding rates observed in the surface. Rates of benthic warming were up to 1.6 times faster in winter than the rest of the year in many regions, with important implications for disease occurrence and energetics of overwintering species. Drivers of warming varied over the domain. In southern New England and the mid-Atlantic shallow Shelf regions, benthic warming was tightly coupled to changes in SST, whereas both regional and basin-scale changes in ocean circulation affect temperatures in the Gulf of Maine, the Continental Shelf, and Georges Banks. These results highlight data gaps, the current feasibility of prediction from remotely sensed variables, and the need for improved understanding on how climate may affect seasonally specific ecological processes.John D. and Catherine T. MacArthur Foundation Grant Number: 14–106159-000-CFP; National Aeronautics and Space Administration Grant Number: NNX14AP62

Secukinumab, a human anti-interleukin-17A monoclonal antibody, in patients with psoriatic arthritis (FUTURE 2): a randomised, double-blind, placebo-controlled, phase 3 trial

Background: Interleukin 17A is a proinflammatory cytokine that is implicated in the pathogenesis of psoriatic arthritis. We assessed the efficacy and safety of subcutaneous secukinumab, a human anti-interleukin-17A monoclonal antibody, in patients with psoriatic arthritis. Methods: In this phase 3, double-blind, placebo-controlled study undertaken at 76 centres in Asia, Australia, Canada, Europe, and the USA, adults (aged &#8805;18 years old) with active psoriatic arthritis were randomly allocated in a 1:1:1:1 ratio with computer-generated blocks to receive subcutaneous placebo or secukinumab 300 mg, 150 mg, or 75 mg once a week from baseline and then every 4 weeks from week 4. Patients and investigators were masked to treatment assignment. The primary endpoint was the proportion of patients achieving at least 20% improvement in the American College of Rheumatology response criteria (ACR20) at week 24. Analysis was by intention to treat. This study is registered with ClinicalTrials.gov, number NCT01752634. Findings: Between April 14, and Nov 25, 2013, 397 patients were randomly assigned to receive secukinumab 300 mg (n=100), 150 mg (n=100), 75 mg (n=99), or placebo (n=98). A significantly higher proportion of patients achieved an ACR20 at week 24 with secukinumab 300 mg (54 [54%] patients; odds ratio versus placebo 6·81, 95% CI 3·42–13·56; p&#60;0·0001), 150 mg (51 [51%] patients; 6·52, 3·25–13·08; p&#60;0·0001), and 75 mg (29 [29%] patients; 2·32, 1·14–4·73; p=0·0399) versus placebo (15 [15%] patients). Up to week 16, the most common adverse events were upper respiratory tract infections (four [4%], eight [8%], ten [10%], and seven [7%] with secukinumab 300 mg, 150 mg, 75 mg, and placebo, respectively) and nasopharyngitis (six [6%], four [4%], six [6%], and eight [8%], respectively). Serious adverse events were reported by five (5%), one (1%), and four (4%) patients in the secukinumab 300 mg, 150 mg, and 75 mg groups, respectively, compared with two (2%) in the placebo group. No deaths were reported. Interpretation: Subcutaneous secukinumab 300 mg and 150 mg improved the signs and symptoms of psoriatic arthritis, suggesting that secukinumab is a potential future treatment option for patients with this disorder

Persistence of low disease activity after tumour necrosis factor inhibitor (TNFi) discontinuation in patients with psoriatic arthritis.

OBJECTIVE: To determine the duration of clinical benefit among patients with psoriatic arthritis (PsA) discontinuing tumour necrosis factor inhibitor (TNFi) therapy while in low disease activity (LDA), and to identify patient characteristics associated with prolonged clinical benefit. METHODS: We performed an observational cohort study assessing patients with PsA from the Consortium of Rheumatology Researchers of North America (CORRONA) registry who had discontinued TNFi after achieving LDA, defined as clinical disease activity index (CDAI) score ≤10 and physician\u27s global assessment (PGA) of skin psoriasis ≤20/100. Kaplan-Meier method was used to estimate the duration of clinical benefit. RESULTS: Of the 5945 patients with PsA in CORRONA, 302 patients had discontinued TNFi (n=325) while in LDA and had follow-up data available. At time of discontinuation, mean PsA duration was 9.8 years, mean CDAI was 3.9, and mean duration of TNFi use was 1.5 years; 52.6% of patients had discontinued their first TNFi. Median time to loss of benefit was 29.2 months. 179 (55.1%) patients had persistent benefit at their previous clinic visit. An increased risk of losing clinical benefit was seen among patients with higher disease activity at discontinuation (CDAI≥3.2 vs CONCLUSIONS: Patients with PsA who achieve LDA may maintain clinical benefit after discontinuation of TNFi therapy

Treatment recommendations for psoriatic arthritis

Objective: To develop comprehensive recommendations for the treatment of the various clinical manifestations of psoriatic arthritis (PsA) based on evidence obtained from a systematic review of the literature and from consensus opinion. Methods: Formal literature reviews of treatment for the most significant discrete clinical manifestations of PsA (skin and nails, peripheral arthritis, axial disease, dactylitis and enthesitis) were performed and published by members of the Group for Research and Assessment of Psoriasis and Psoriatic Arthritis (GRAPPA). Treatment recommendations were drafted for each of the clinical manifestations by rheumatologists, dermatologists and PsA patients based on the literature reviews and consensus opinion. The level of agreement for the individual treatment recommendations among GRAPPA members was assessed with an online questionnaire. Results: Treatment recommendations were developed for peripheral arthritis, axial disease, psoriasis, nail disease, dactylitis and enthesitis in the setting of PsA. In rotal, 19 recommendations were drafted, and over 80% agreement was obtained on 16 of them. In addition, a grid that factors disease severity into each of the different disease manifestations was developed to help the clinician with treatment decisions for the individual patient from an evidenced-based perspective. Conclusions: Treatment recommendations for the cardinal physical manifestations of PsA were developed based on a literature review and consensus between rheumatologists and dermatologists. In addition, a grid was established to assist in therapeutic reasoning and decision making for individual patients. It is anticipated that periodic updates will take place using this framework as new data become available