15,317 research outputs found

    Environmental impacts of alternative cement binders.

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    Cement production is among the most difficult industrial activities to decarbonize. Various measures have been proposed and explored to reduce its CO2 emissions. Among these measures, the substitution of portland cement (PC) clinker with alternative materials is arguably the most effective, and consequently is an area of high research and commercial interest. However, few studies have systematically quantified environmental impacts of alternative, i.e., non-PC, clinkers. Here, we quantify and compare environmental impacts arising from the production of binders derived from several of the most commonly investigated alternative cement systems. We show that binders derived from most of these alternative cements result in lower greenhouse gas (GHG) emissions as well as other indicators of environmental impacts relative to the PC binder. The extent of these reductions varies as a function of energy requirements for production, process-related emissions from clinker formation, and raw materials demand. While utilization of alternative cements can be environmentally beneficial, similar reductions in GHG emissions can be achieved through use of partial replacement of PC with mineral admixtures. In this work, we quantitatively demonstrate the potential for alternative binders to mitigate environmental burdens and highlight the need to consider trade-offs among environmental impact categories when assessing these products

    On passion and moral behavior in achievement settings: The mediating role of pride

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    The Dualistic Model of Passion (Vallerand et al., 2003) distinguishes two types of passion: harmonious passion (HP) and obsessive passion (OP) that predict adaptive and less adaptive outcomes, respectively. In the present research, we were interested in understanding the role of passion in the adoption of moral behavior in achievement settings. It was predicted that the two facets of pride (authentic and hubristic; Tracy & Robins, 2007) would mediate the passion-moral behavior relationship. Specifically, because people who are passionate about a given activity are highly involved in it, it was postulated that they should typically do well and thus experience high levels of pride when engaged in the activity. However, it was also hypothesized that while both types of passion should be conducive to authentic pride, only OP should lead to hubristic pride. Finally, in line with past research on pride (Carver, Sinclair, & Johnson, 2010; Tracy et al., 2009), only hubristic pride was expected to negatively predict moral behavior, while authentic pride was expected to positively predict moral behavior. Results of two studies conducted with paintball players (N=163, Study 1) and athletes (N=296, Study 2) supported the proposed model. Future research directions are discussed in light of the Dualistic Model of Passion

    Surface functionalisation of nanodiamonds for human neural stem cell adhesion and proliferation.

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    Biological systems interact with nanostructured materials on a sub-cellular level. These interactions may govern cell behaviour and the precise control of a nanomaterial's structure and surface chemistry allow for a high degree of tunability to be achieved. Cells are surrounded by an extra-cellular matrix with nano-topographical properties. Diamond based materials, and specifically nanostructured diamond has attracted much attention due to its extreme electrical and mechanical properties, chemical inertness and biocompatibility. Here the interaction of nanodiamond monolayers with human Neural Stem Cells (hNSCs) has been investigated. The effect of altering surface functionalisation of nanodiamonds on hNSC adhesion and proliferation has shown that confluent cellular attachment occurs on oxygen terminated nanodiamonds (O-NDs), but not on hydrogen terminated nanodiamonds (H-NDs). Analysis of H and O-NDs by Atomic Force Microscopy, contact angle measurements and protein adsorption suggests that differences in topography, wettability, surface charge and protein adsorption of these surfaces may underlie the difference in cellular adhesion of hNSCs reported here

    Towards formal models of psychopathological traits that explain symptom trajectories

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    BACKGROUND: A dominant methodology in contemporary clinical neuroscience is the use of dimensional self-report questionnaires to measure features such as psychological traits (e.g., trait anxiety) and states (e.g., depressed mood). These dimensions are then mapped to biological measures and computational parameters. Researchers pursuing this approach tend to equate a symptom inventory score (plus noise) with some latent psychological trait. MAIN TEXT: We argue this approach implies weak, tacit, models of traits that provide fixed predictions of individual symptoms, and thus cannot account for symptom trajectories within individuals. This problem persists because (1) researchers are not familiarized with formal models that relate internal traits to within-subject symptom variation and (2) rely on an assumption that trait self-report inventories accurately indicate latent traits. To address these concerns, we offer a computational model of trait depression that demonstrates how parameters instantiating a given trait remain stable while manifest symptom expression varies predictably. We simulate patterns of mood variation from both the computational model and the standard self-report model and describe how to quantify the relative validity of each model using a Bayesian procedure. CONCLUSIONS: Ultimately, we would urge a tempering of a reliance on self-report inventories and recommend a shift towards developing mechanistic trait models that can explain within-subject symptom dynamics

    Simulating bottom-up effects on predator productivity and consequences for the rebuilding timeline of a depleted population

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    Bottom-up control within ecosystems is characterized, in part, by predator populations exhibiting growth and recruitment changes in response to variability in prey density or production. Annual prey availability can vary more than 10-fold in marine ecosystems, with prey experiencing a dramatic increase or pulse in production within some years. To assess the bottom-up effects of such pulses on predator growth, production, and fisheries management, we developed an age-specific, predator-prey simulation model (parameterized for summer flounder, Paralichthys dentatus) based on simple hypothesized mechanisms for consumption, growth, and population dynamics. Pulses in each of the three modeled prey groups (small crustaceans, forage fish, larger fish prey) generated different magnitudes of change in predator weight-at-age (w), spawning stock biomass (S), fishery yield (Y), and recruitment (R), due to ontogenetic differences in growth potential and dietary composition across predator age classes. Increases in productivity of small forage fishes generated the greatest gains in predator w, S, Y, and R, relative to pulses of the other prey groups. Median increases in R following a prey pulse were minimal (\u3c 4%) except under high fishing rates that stimulated a stronger compensatory response in the population (8-11% increase in R), demonstrating the interactive role of top-down and bottom-up effects on predator productivity. Seasonal migration patterns determined the degree of spatiotemporal overlap of predators with the spatially constrained pulses in prey production. Prey pulses reduced the median time required for depleted populations to be rebuilt by 0-5% following declines in fishing pressure. Reductions in time to recovery were highly variable due to recruitment stochasticity, but stock recovery was more sensitive to the severity of harvest control measures than to availability of the non-limiting prey. Understanding the relative magnitudes of such bottom-up processes, particularly in the presence of varied fishing pressure can aid in developing ecosystem approaches to fisheries management that account for such ecological interactions more explicitly. (C) 2015 Elsevier B.V. All rights reserved

    Investigating the association of rs2910164 with cancer predisposition in an Irish cohort.

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    IntroductionMicroRNAs (miRNAs) are small noncoding RNA molecules that exert post-transcriptional effects on gene expression by binding with cis-regulatory regions in target messenger RNA (mRNA). Polymorphisms in genes encoding miRNAs or in miRNA-mRNA binding sites confer deleterious epigenetic effects on cancer risk. miR-146a has a role in inflammation and may have a role as a tumour suppressor. The polymorphism rs2910164 in the MIR146A gene encoding pre-miR-146a has been implicated in several inflammatory pathologies, including cancers of the breast and thyroid, although evidence for the associations has been conflicting in different populations. We aimed to further investigate the association of this variant with these two cancers in an Irish cohort.MethodsThe study group comprised patients with breast cancer (BC), patients with differentiated thyroid cancer (DTC) and unaffected controls. Germline DNA was extracted from blood or from saliva collected using the DNA Genotek Oragene 575 collection kit, using crystallisation precipitation, and genotyped using TaqMan-based PCR. Data were analysed using SPSS, v22.ResultsThe total study group included 1516 participants. This comprised 1386 Irish participants; 724 unaffected individuals (controls), 523 patients with breast cancer (BC), 136 patients with differentiated thyroid cancer (DTC) and three patients with dual primary breast and thyroid cancer. An additional cohort of 130 patients with DTC from the South of France was also genotyped for the variant. The variant was detected with a minor allele frequency (MAF) of 0.19 in controls, 0.22 in BC and 0.27 and 0.26 in DTC cases from Ireland and France, respectively. The variant was not significantly associated with BC (per allele odds ratio = 1.20 (0.98-1.46), P  = 0.07), but was associated with DTC in Irish patients (per allele OR = 1.59 (1.18-2.14), P = 0.002).ConclusionThe rs2910164 variant in MIR146A is significantly associated with DTC, but is not significantly associated with BC in this cohort

    Spatial and temporal dynamics of Atlantic menhaden (Brevoortia tyrannus) recruitment in the Northwest Atlantic Ocean

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    Atlantic menhaden, Brevoortia tyrannus, is an abundant, schooling pelagic fish that is widely distributed in the coastal Northwest Atlantic. It supports the largest single-species fishery by volume on the east coast of the United States. However, relatively little is known about factors that control recruitment, and its stock- recruitment relationship is poorly defined. Atlantic menhaden is managed as a single unit stock, but fisheries and environmental variables likely act regionally on recruitments. To better understand spatial and temporal variability in recruitment, fishery-independent time-series (1959-2013) of young-of-year (YOY) abundance indices from the Mid-Atlantic to Southern New England (SNE) were analysed using dynamic factor analysis and generalized additive models. Recruitment time-series demonstrated low-frequency variability and the analyses identified two broad geographical groupings, the Chesapeake Bay (CB) and SNE. Each of these two regions exhibited changes in YOY abundance and different periods of relatively high YOY abundance that were inversely related to each other; CB indices were highest from ca. 1971 to 1991, whereas SNE indices were high from ca. 1995 to 2005. Wetested for effects of climatic, environmental, biological, and fishing-related variables that have been documented or hypothesized to influence stock productivity. Abroad-scale indicator of climate, the Atlantic Multidecadal Oscillation, was the best single predictor of coast-wide recruitment patterns, and had opposing effects on the CB and SNE regions. Underlying mechanisms of spatial and interannual variability in recruitment likely derive from interactions among climatology, larval transport, adult menhaden distribution, and habitat suitability. The identified regional patterns and climatic effects have implications for the stock assessment of Atlantic menhaden, particularly given the geographically constrained nature of the existing fishery and the climatic oscillations characteristic of the coastal ocean
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