199 research outputs found

    Synoptic estimates of air-sea fluxes

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    Synoptic and climatological dynamic studies generally rely on bulk aerodynamic flux formulae to describe air-sea heat and momentum exchange on synoptic and climatological scales. Barometric pressure maps (which involve an intrinsic spatial and temporal averaging of the wind) and wind roses provide two sources of spatial and temporal wind information for flux calculations. Several investigators have shown that time-averaged estimates of the fluxes based on vector-averaged winds systematically underestimate the actual time-averaged fluxes.Using surface meteorological observations from 9 weatherstations in the North Atlantic Ocean and 2 weatherstations in the North Pacific Ocean, the three hourly stresses, latent heat fluxes and sensible heat fluxes were calculated. The sampled data and the calculated fluxes were then averaged over periods up to 28 days. The estimates of the averaged fluxes based on the vector-averaged winds were then compared to the directly averaged values. An upper bound for the difference in the two stresses calculations was directly proportional to the sum of the x and y component wind variances lost through the averaging process (in agreement with Fofonoff, 1960) and inversely proportional to the square of the vector-averaged wind speed. The wind-averaged and directly averaged flux estimates were grouped according to the Beaufort wind speed category and the averaging period. A multivariate regression was then performed to optimize a transformation from the wind-averaged to the directly averaged case. For all fluxes, the transformation dramatically improved the wind-averaged estimates of the climatological means and variances of the directly averaged fluxes. The residual error between the two estimates was decreased up to a factor of 5 over the uncorrected case and the correlation coefficients showed a moderate increase. The regression cofficients showed similar values for all temperate latitude stations.An empirical formula was found which interpolated the wind speed and averaging period dependences and duplicated the multivariate regression results. The data from the ten temperate latitude stations were grouped and a single formula was found which only moderately increased the errors between the wind-averaged and directly averaged estimates. The geographically averaged formula was not applicable at Station N, located at the northern extremity of the North Pacific Trade Wind region.Analysis of the 28 day wind-averaged flux spectral estimates showed that they underestimated the 28 day directly averaged flux spectral estimates. Application of the specific ship empirical formula greatly improved agreement between the two spectral densities and reduced the residual series power density at all frequencies. High latent heat flux errors at Station N were reduced by application of a seasonal correction

    Describing additional fluxes to deep sediment traps and water-column decay in a coastal environment

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    Sediment traps were moored at three stations in Sechelt Inlet, a fjord in southern British Columbia, Canada, for five one-month deployment periods from late January to late June, 1991. On each mooring were traps at three depths; total and constituent fluxes often increased with depth. We present the flux data and describe an analytical model that is based on a set of simultaneous equations for which two unknowns are the decay rate of material representatively caught by two vertically-separated sediment traps and the composition of material causing observed increases in flux with depth. The unknowns are solved in a least-squares sense and the results indicate that 60–71% of organic carbon, 57–62% of nitrogen and 41–48% of biogenic silica were lost from the particulate phase over a 200 m depth interval during the study. The results also suggest that material contributing additional fluxes to deep traps was compositionally similar to material settling from traps above

    Aftereffects Support Opponent Coding of Expression

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    Old Black Joe / music by Ellen H. Baily; words by Stephen Foster

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    https://egrove.olemiss.edu/sharris_a/1015/thumbnail.jp

    Trophic modes of large Antarctic Foraminifera: roles of carnivory, omnivory, and detritivory

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    Astrammina rara, Crithionina delacai, and Notodendrodes hyalinosphaira are 3 of the largest and most abundant members of the foraminiferal assemblage at a shallow-water (28 to 32 m) site in Explorers Cove, Antarctica. This study summarizes observations from 2 decades of research, during which we employed laboratory-based feeding experiments and fatty acid biomarker analysis to characterize trophic dynamics and ecological roles of the 3 species, In feeding experiments, A. rara consumed a variety of co-occurring metazoans (several Crustacea, Mollusca, Echinodermata, and a Nephtys species). C. delacai, N. hyalinosphaira, and a number of other foraminiferal species from Explorers Cove successfully trapped Artemia sp. nauplius prey in a setup designed to examine the efficiency of prey capture. Fatty acid analyses on samples from early (November 7, 2001) and late (January 31, 2002) austral summer revealed that the 3 species contained substantial amounts (33 to 45.5%) of polyunsaturated fatty acids (PUFAs), which are produced by microalgae, indicating the downwards transfer of carbon from sea-ice associated primary production. In the case of A. rara, this may be due to the ingestion of herbivorous metazoa, rather than direct uptake of microalgal material. A. rara contained significantly (p < 0.05) higher amounts of the zooplankton biomarkers 20:1(n-9) and 22:1(n-11), and C. delacai contained more PUFAs early, compared to late, in the season. Two morphotypes of N. hyalinosphaira had different fatty acid Profiles, indicating distinct trophotypes. Our results illustrate specific adaptations to different trophic resources in these protists, and they demonstrate the potential impact that large carnivorous species of Foraminifera may have on the structure of benthic communities where they are abundant

    The Telehealth Skills, Training, and Implementation Project: An evaluation protocol

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    External stabilization is reported to improve reliability of hand held dynamometry, yet this has not been tested in burns. We aimed to assess the reliability of dynamometry using an external system of stabilization in people with moderate burn injury and explore construct validity of strength assessment using dynamometry. Participants were assessed on muscle and grip strength three times on each side. Assessment occurred three times per week for up to four weeks. Within session reliability was assessed using intraclass correlations calculated for within session data grouped prior to surgery, immediately after surgery and in the sub-acute phase of injury. Minimum detectable differences were also calculated. In the same timeframe categories, construct validity was explored using regression analysis incorporating burn severity and demographic characteristics. Thirty-eight participants with total burn surface area 5 – 40% were recruited. Reliability was determined to be clinically applicable for the assessment method (intraclass correlation coefficient \u3e0.75) at all phases after injury. Muscle strength was associated with sex and burn location during injury and wound healing. Burn size in the immediate period after surgery and age in the sub-acute phase of injury were also associated with muscle strength assessment results. Hand held dynamometry is a reliable assessment tool for evaluating within session muscle strength in the acute and sub-acute phase of injury in burns up to 40% total burn surface area. External stabilization may assist to eliminate reliability issues related to patient and assessor strength

    Correlation of baseline biomarkers with clinical outcomes and response to fulvestrant with vandetanib or placebo in patients with bone predominant metastatic breast cancer: An OCOG ZAMBONEY sub-study

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    AbstractBackgroundBone metastases are common in women with breast cancer and often result in skeletal related events (SREs). As the angiogenic factor vascular endothelial growth factor (VEGF) regulates osteoclast activity and is associated with more extensive bone metastases and SRE risk in metastatic breast cancer, we hypothesized that blockade of VEGF signaling could be a therapeutic strategy for inhibiting bone metastases progression and possibly prolonging overall (OS) or progression-free survival (PFS). The Zamboney trial was a randomized placebo-controlled study designed to assess whether patients with bone predominant metastatic breast cancer benefited from addition of the VEGF receptor (VEGFR) targeting agent, vandetanib, to endocrine therapy with fulvestrant. As a companion study, evaluation of biomarkers and their potential association with response to vandetanib or SRE risk was performed.MethodsBaseline overnight fasted serum from enrolled patients was analyzed for levels of various putative biomarkers including; VEGF-A, soluble (s)VEGFR2, sVEGFR3, transforming growth factor (TGF)-β1 and activinA by ELISA. Spearman correlation coefficients and Wilcoxon rank sum tests were used to investigate potential relationships between biomarker values and baseline clinical parameters. Prognostic and predictive ability of each marker was investigated using Cox proportional hazards regression with adjustments for treatment and baseline strata of serum CTx (<400 versus ≥400ng/L).ResultsOf 129 enrolled patients, serum was available for analysis in 101; 51 in vandetanib and 50 in placebo arm. Mean age amongst consenting patients was 59.8 years. Clinical characteristics were not significantly different between patients with or without serum biomarker data and serum markers were similar for patients by treatment arm. Baseline sVEGFR2 was prognostic for OS (HR=0.77, 95% CI=0.61–0.96, p=0.020), and although a modest association was observed, it was not significant for PFS (HR=0.90, 95% CI=0.80–1.01, p=0.085) nor time to first SRE (HR=0.82, 95% CI=0.66–1.02, p=0.079). When interaction terms were evaluated, sVEGFR2 was not found to be predictive of response to vandetanib, although a modest association remained with respect to PFS (interaction p=0.085). No other marker showed any significant prognostic or predictive ability with any measured outcome.ConclusionsIn this clinical trial, sVEGFR2 appeared prognostic for OS, hence validation of sVEGFR2 should be conducted. Moreover, the role of sVEGFR2 in breast cancer bone metastasis progression should be elucidated

    Evaluating presentation formats of local climate change in community planning with regard to process and outcomes

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    This study synthesizes two evaluations of a local climate change planning process in a rural town in British Columbia (Canada), which was supported through landscape visualizations. First, the impact of the visualizations, based on scientific environmental modeling and presented in three different presentation formats, verbal/visual presentation, posters and a virtual globe, was evaluated with regard to immediate impacts during the process. Second, the long-term impacts on decision-making and actual outcomes were evaluated in a retrospective evaluation 22 months after the end of the initial planning process. Two results are highlighted: according to the quantitative pre-/post-questionnaires, the visualizations contributed to increased awareness and understanding. Most importantly, the retrospective evaluation indicated that the process informed policy, operational and built changes in Kimberley, in which the landscape visualizations played a role. The post interviews with key decision-makers showed that they remembered most of the visualizations and some decision-makers were further using them, particularly the posters. The virtual globe seemed to be not a "sustainable" display format suitable for formal decision-making processes such as council meetings though. That may change with the further mainstreaming of visualization technologies or mobile devices. Until then, we recommend using display formats that can be re-used following a specific planning event such as an Open House, to ensure on-going support for effective decision-making over the longer-term
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