Fe, Zn, Mn and N transfer between size classes in a coastal phytoplankton community: Trace metal and major nutrient recycling compared

Experiments were performed to investigate transfer of 59Fe, 65Zn, 54Mn, and 15N from labeled cyanobacteria to the large (\u3e8 μm or \u3e5 μm) phytoplankton size class from Monterey Bay, California. Transfer of metal isotope activity was measured from and into total (for all isotopes) and intracellular (59Fe only) pools. Results demonstrated rapid and efficient transfer of nitrogen to the large phytoplankton size class; intracellular 59Fe was transferred into the intracellular and total pools of the \u3e8 μm phytoplankton size class 70% and 130% as efficiently as nitrogen, respectively. 65Zn and 54Mn were transferred between size classes 48% and 23% as efficiently as N. Extracellular 59Fe and 65Zn from the added cyanobacteria also appeared quickly in the large size fraction, although most of the Fe transfer appeared to be the result of surface adsorption rather than biological uptake. These data are discussed in relation to the biological recycling efficiencies of the four elements and the resulting implications for biogeochemical cycling of trace and major nutrient elements

The Marine Biogeochemistry of Selenium: A Re-Evaluation

Vertical and horizontal profiles from the North and South Pacific Oceans demonstrate the existence of three species of dissolved selenium: selenite, selenate, and organic selenide (operationally defined). In surface waters, organic selenide makes up about 80% of the total dissolved selenium, selenite concentrations are uniformly low, and selenate concentrations rise with increased vertical mixing. The organic selenide maximum (thought to consist of seleno-amino acids in peptides) coincides with the maxima of primary productivity, pigments, bioluminescence, and dissolved free amino acids. Deep ocean waters are enriched in selenite and selenate, while organic selenide is nondetectable. In suboxic waters of the tropical northeastern Pacific, organic selenide concentrations rise, while selenite values decrease. The downward flux of particulate selenium generally decreases with depth, and fluxing particulate selenium is found to be primarily in the (-2) oxidation state. These data allow a re-evaluation of the internal biogeochemical cycle of selenium. This cycle includes selective uptake, reductive incorporation, particulate transport, a multistep regeneration, and kinetic stabilization of thermodynamically unstable species

Rapid and Noncontaminating Sampling System For Trace Elements in Global Ocean Surveys

A system for the rapid and noncontaminating sampling of trace elements with volumes of up to 36 L per depth and including the dissolved and particulate phases has been developed for ocean sections that are a crucial part of programs such as International GEOTRACES. The system uses commercially available components, including an aluminum Seabird Carousel with all titanium pressure housings for electronics and sensors to eliminate zinc sacrificial anodes and holding twenty-four 12 L GO-FLO bottles, and a 7500 m, 14 mm Vectran conducting cable (passing over an A-frame with nonmetallic sheave) spooled onto a traction winch. The GO-FLO bottles are stored and processed in a clean lab built into a 20\u27 ISO container. To minimize contamination, the GO-FLO bottles are triggered when the carousel is moving upward into clean water at 3 m min super(-1. Analyses of salinity and nutrients in bottle samples from the stopped versus moving carousel show no detectable smearing, whereas the contamination-prone trace elements show the samples are uncontaminated when compared with other clean sampling methods. Based on the use of this system on three major cruises, the launch-sample-recover time for the carousel (2 bottles triggered per depth) is 1 h per 1000 m, and dissolved and particulate sampling time averages 6 h per hydrocast. Thus, the system described here meets all the requirements for ocean basin sampling for trace elements: rapid, good hydrographic fidelity, and noncontaminating

Spatial distances affect temporal prediction and interception.

The more distant two consecutive stimuli are presented, the longer the temporal interstimulus interval (ISI) between their presentations is perceived (kappa effect). The present study aimed at testing whether the kappa effect not only affects perceptual estimates of time, but also motor action, more specifically, interception. In a first step, the original kappa paradigm was adapted to assess the effect in temporal prediction. Second, the task was further modified to an interception task, requiring participants to spatially and temporally predict and act. In two online experiments, a white circle was successively presented at three locations moving from left to right with constant spatial and temporal ISIs in between. Participants were asked to either (i) indicate the time of appearance of the predicted fourth stimulus (Exp. 1) or to (ii) intercept the predicted fourth location at the correct time (Exp. 2). In both experiments the temporal response depended on the spatial intervals. In line with the kappa effect, participants predicted the final stimulus to appear later (Exp. 1) or intercepted it later (Exp. 2), the more distant the stimuli were presented. Together, these results suggest that perceptual biases such as the kappa effect impact motor interception performance. [Abstract copyright: © 2022. The Author(s).

Effects of visual blur and contrast on spatial and temporal precision in manual interception.

The visual system is said to be especially sensitive towards spatial but lesser so towards temporal information. To test this, in two experiments, we systematically reduced the acuity and contrast of a visual stimulus and examined the impact on spatial and temporal precision (and accuracy) in a manual interception task. In Experiment 1, we blurred a virtual, to-be-intercepted moving circle (ball). Participants were asked to indicate (i.e., finger tap) on a touchscreen where and when the virtual ball crossed a ground line. As a measure of spatial and temporal accuracy and precision, we analyzed the constant and variable errors, respectively. With increasing blur, the spatial and temporal variable error, as well as the spatial constant error increased, while the temporal constant error decreased. Because in the first experiment, blur was potentially confounded with contrast, in Experiment 2, we re-ran the experiment with one difference: instead of blur, we included five levels of contrast matched to the blur levels. We found no systematic effects of contrast. Our findings confirm that blurring vision decreases spatial precision and accuracy and that the effects were not mediated by concomitant changes in contrast. However, blurring vision also affected temporal precision and accuracy, thereby questioning the generalizability of the theoretical predictions to the applied interception task. [Abstract copyright: © 2021. The Author(s).

Examination of precipitation chemistry and improvements in precision using the Mg(OH)2 preconcentration ICP-MS method for high-throughput analysis of open-ocean Fe and Mn in seawater

Author Posting. © Elsevier B.V., 2006. 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 Analytica Chimica Acta 565 (2006): 222-233, doi:10.1016/j.aca.2006.02.028.The chemistry of magnesium precipitation preconcentration of Fe, Mn and Co from seawater was investigated, and this analytical technique was adapted for use with the Element-2 inductively coupled plasma mass spectrometer (E2 ICP-MS). Experiments revealed that the scavenging efficiency of Mn using the precipitation protocol described here was ~95% and similar to that previously observed with Fe. In contrast, the scavenging efficiency of Co was three-fold lower than that of Fe and Mn, resulting in poor recovery. An increase in sample size to 13mL led to several desired effects: 1) an increase in the Fe and Mn signals allowing a final dilution of samples to 0.5mL and the use of an autosampler, 2) an increase in precision to ~1-2.5% RSD, 3) an increase in signal relative to the blank. Experiments suggest metal concentration from seawater occurs during the formation of Mg(OH)2 precipitate, whereas P was scavenged by adsorption onto the Mg(OH)2 particles. Example vertical profiles are shown for dissolved Fe and Mn from the Equatorial Pacific.This research was supported by NSF grants OCE-0327225, OCE-0452883, and the Center for Environmental Bioinorganic Chemistry at Princeton

Converging Technologies - Shaping the Future of European Societies

The European Commission and Member States are called upon to recognise the novel potential of Converging Technologies (CTs) to advance the Lisbon Agenda. Wise investment in CTs stimulates science and technology research, strengthens economic competitiveness, and addresses the needs of European societies and their citizens. Preparatory action should be taken to implement CT as a thematic research priority, to develop Converging Technologies for the European Knowledge Society (CTEKS) as a specifically European approach to CTs, and to establish a CTEKS research communit

Improvement measures to achieve sustainable construction labor performance

Construction industry is the largest industrial employer of the world. However, construction labor suffers from declining productivity, job satisfaction and wellbeing. Given its volume and labor extensiveness, measures undertaken to improve labor sustainability of the construction industry would have high impact for the future. To improve the sustainability of labor performance, this paper suggests decision-making measures at the strategic, tactical, and operational levels. Data is generated through targeted interviews of the top management of the five biggest Norwegian construction contractors. The measures suggested by the interviewees are analyzed and complemented with theory through a systematic literature review, resulting in the development of 45 measures to achieve sustainable labor performance at strategic, tactical, and operational decision-making levels. Due to strict labor laws and regulations, some frequently reported measures in literature do not hold relevance to the Norwegian construction industry. However, the quality of data and unique position of the Norwegian construction industry magnifies its relevance to the global construction industry

Alkaline phosphatase in metastatic castration-resistant prostate cancer: reassessment of an older biomarker

Since most patients with metastatic castration-resistant prostate cancer (mCRPC) have bone metastases, it is important to understand the potential impact of therapies on prognostic biomarkers, such as ALP. Clinical studies involving mCRPC life-prolonging agents (i.e., sipuleucel-T, abiraterone, enzalutamide, docetaxel, cabazitaxel, and radium-223) have shown that baseline ALP level is prognostic for overall survival, and may be a better prognostic marker for overall survival than prostate-specific antigen in patients with bone-dominant mCRPC. Mechanism of action differences between therapies may partly explain ALP dynamics during treatment. ALP changes can be interpreted within the context of other parameters while monitoring disease activity to better understand the underlying pathology. This review evaluates the current role of ALP in mCRPC