108 research outputs found
Cobalt, manganese, and iron near the Hawaiian Islands : a potential concentrating mechanism for cobalt within a cyclonic eddy and implications for the hybrid-type trace metals
Author Posting. © Elsevier B.V., 2008. This is the author's version of the work. It is posted here by permission of Elsevier B.V. for personal use, not for redistribution. The definitive version was published in Deep Sea Research Part II: Topical Studies in Oceanography 55 (2008): 1473-1490, doi:10.1016/j.dsr2.2008.02.010.The vertical distributions of cobalt, iron, and manganese in the water column were
studied during the E-Flux Program (E-Flux II and III), which focused on the
biogeochemistry of cold-core cyclonic eddies that form in the lee of the Hawaiian
Islands. During E-Flux II (January 2005) and E-Flux III (March 2005), 17 stations were
sampled for cobalt (n =147), all of which demonstrated nutrient-like depletion in surface
waters. During E-Flux III, two depth profiles collected from within a mesoscale coldcore
eddy, Cyclone Opal, revealed small distinct maxima in cobalt at ~100m depth and a
larger inventory of cobalt within the eddy. We hypothesize that this was due to a cobalt
concentrating effect within the eddy, where upwelled cobalt was subsequently associated
with sinking particulate organic carbon (POC) via biological activity and was released at
a depth coincident with nearly complete POC remineralization (Benitez-Nelson et al.
2007). There is also evidence for the formation of a correlation between cobalt and
soluble reactive phosphorus during E-Flux III relative to the E-Flux II cruise that we
suggest is due to increased productivity, implying a minimum threshold of primary
production below which cobalt-phosphate coupling does not occur. Dissolved iron was
measured in E-Flux II and found in somewhat elevated concentrations (~0.5nM) in
surface waters relative to the iron depleted waters of the surrounding Pacific (Fitzwater et
al. 1996), possibly due to island effects associated with the iron-rich volcanic soil from
the Hawaiian Islands and/or anthropogenic inputs. Distinct depth maxima in total
dissolved cobalt were observed at 400 to 600m depth, suggestive of the release of metals
from the shelf area of comparable depth that surrounds these islands.This research was supported by NSF Grants
OCE-0327225, OCE-0452883, OPP-0440840, the Office of Naval Research, the Center
for Environmental Bioinorganic Chemistry at Princeton, and the Center for Microbial
Oceanography and Education
Discriminating relational and perceptual judgments: Evidence from human toddlers
The ability to represent same-different relations is an important condition for abstract thought. However, there is mixed evidence for when this ability develops, both ontogenetically and phylogenetically. Apparent success in relational reasoning may be evidence for genuine conceptual understanding or may be the result of low-level, perceptual strategies. We introduce a method to discriminate these possibilities by pitting two conditions that are perceptually matched but conceptually different: in a "fused" condition, same and different objects are joined, creating single objects that have the same perceptual features as the two object pairs in the "relational" condition. However, the "fused" objects do not provide evidence for the relation 'same.' Using this method with human toddlers in a causal relational reasoning task provides evidence for genuine conceptual understanding. This novel technique offers a simple manipulation that may be applied to a variety of existing match-to-sample procedures used to assess same-different reasoning to include in future research with non-human animals across species, as well as human infants
Trace elements at the intersection of marine biological and geochemical evolution
Life requires a wide variety of bioessential trace elements to act as structural components and reactive centers in metalloenzymes. These requirements differ between organisms and have evolved over geological time, likely guided in some part by environmental conditions. Until recently, most of what was understood regarding trace element concentrations in the Precambrian oceans was inferred by extrapolation, geochemical modeling, and/or genomic studies. However, in the past decade, the increasing availability of trace element and isotopic data for sedimentary rocks of all ages has yielded new, and potentially more direct, insights into secular changes in seawater composition – and ultimately the evolution of the marine biosphere. Compiled records of many bioessential trace elements (including Ni, Mo, P, Zn, Co, Cr, Se, and I) provide new insight into how trace element abundance in Earth's ancient oceans may have been linked to biological evolution. Several of these trace elements display redox-sensitive behavior, while others are redox-sensitive but not bioessential (e.g., Cr, U). Their temporal trends in sedimentary archives provide useful constraints on changes in atmosphere-ocean redox conditions that are linked to biological evolution, for example, the activity of oxygen-producing, photosynthetic cyanobacteria. In this review, we summarize available Precambrian trace element proxy data, and discuss how temporal trends in the seawater concentrations of specific trace elements may be linked to the evolution of both simple and complex life. We also examine several biologically relevant and/or redox-sensitive trace elements that have yet to be fully examined in the sedimentary rock record (e.g., Cu, Cd, W) and suggest several directions for future studies
Validation of the Body Concealment Scale for Scleroderma (BCSS): Replication in the Scleroderma Patient-centered Intervention Network (SPIN) Cohort
© 2016 Elsevier Ltd Body concealment is an important component of appearance distress for individuals with disfiguring conditions, including scleroderma. The objective was to replicate the validation study of the Body Concealment Scale for Scleroderma (BCSS) among 897 scleroderma patients. The factor structure of the BCSS was evaluated using confirmatory factor analysis and the Multiple-Indicator Multiple-Cause model examined differential item functioning of SWAP items for sex and age. Internal consistency reliability was assessed via Cronbach's alpha. Construct validity was assessed by comparing the BCSS with a measure of body image distress and measures of mental health and pain intensity. Results replicated the original validation study, where a bifactor model provided the best fit. The BCSS demonstrated strong internal consistency reliability and construct validity. Findings further support the BCSS as a valid measure of body concealment in scleroderma and provide new evidence that scores can be compared and combined across sexes and ages
Global patient outcomes after elective surgery: prospective cohort study in 27 low-, middle- and high-income countries.
BACKGROUND: As global initiatives increase patient access to surgical treatments, there remains a need to understand the adverse effects of surgery and define appropriate levels of perioperative care. METHODS: We designed a prospective international 7-day cohort study of outcomes following elective adult inpatient surgery in 27 countries. The primary outcome was in-hospital complications. Secondary outcomes were death following a complication (failure to rescue) and death in hospital. Process measures were admission to critical care immediately after surgery or to treat a complication and duration of hospital stay. A single definition of critical care was used for all countries. RESULTS: A total of 474 hospitals in 19 high-, 7 middle- and 1 low-income country were included in the primary analysis. Data included 44 814 patients with a median hospital stay of 4 (range 2-7) days. A total of 7508 patients (16.8%) developed one or more postoperative complication and 207 died (0.5%). The overall mortality among patients who developed complications was 2.8%. Mortality following complications ranged from 2.4% for pulmonary embolism to 43.9% for cardiac arrest. A total of 4360 (9.7%) patients were admitted to a critical care unit as routine immediately after surgery, of whom 2198 (50.4%) developed a complication, with 105 (2.4%) deaths. A total of 1233 patients (16.4%) were admitted to a critical care unit to treat complications, with 119 (9.7%) deaths. Despite lower baseline risk, outcomes were similar in low- and middle-income compared with high-income countries. CONCLUSIONS: Poor patient outcomes are common after inpatient surgery. Global initiatives to increase access to surgical treatments should also address the need for safe perioperative care. STUDY REGISTRATION: ISRCTN5181700
If You Build It, They Will Come: Nest Site Selection of Ospreys (Pandion haliaetus) in West-central Idaho
Ospreys (Pandion haliaetus) are fish-eating, top predators of aquatic ecosystems that serve as useful sentinel species for monitoring environmental contaminants and ecosystem health. Ospreys further appear highly adaptable to human-dominated landscapes and readily nest on artificial structures that occur within an array of land use and land cover (LULC) types and human settlement regimes. In Long Valley Idaho, the abundance of breeding Ospreys has declined slightly since the late 1970’s while the distribution of nests and nest substrate use has changed dramatically. To evaluate if changes in nest structure availability and use, coupled with increasing anthropogenic landscape conversion, could be changing osprey nest site selection, we evaluated relationships among nest site characteristics. We used multivariate generalized linear models with model selection procedures to evaluate the relative importance of LULC composition and nest site characteristics associated with nest occupancy.https://digitalcommons.humboldt.edu/wildlife_posters/1005/thumbnail.jp
- …