343 research outputs found

    The Costs of Obtaining Environmental Outcomes through Coastal Habitat Restoration

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    Studies examining the costs of coastal habitat restoration have focused on the cost per acre of restoration or on cost efficiency of various restoration methods. On the other hand, studies examining the benefits of restoration have focused on various ecosystem services that more directly affect welfare including amenity value, storm protection, nutrient retention and biodiversity. We examine a set of 133 Gulf of Mexico coastal habitat restoration projects to estimate the cost of obtaining average annual habitat units (AAHUs), a measure which captures the quantity and, importantly, quality of habitat restored, which is one of the more direct ecosystem service benefits from coastal restoration. AAHUs are the environmental outcome considered during the assessment of proposed projects by decision-makers and therefore are a potential measurement unit that can more closely link costs and benefits of restoration

    Multiple light inputs to a simple clock circuit allow complex biological rhythms

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    Circadian clocks are biological timekeepers that allow living cells to time their activity in anticipation of predictable environmental changes. Detailed understanding of the circadian network of higher plants, such as Arabidopsis thaliana, is hampered by the high number of partially redundant genes. However, the picoeukaryotic alga Ostreococcus tauri, which was recently shown to possess a small number of non-redundant clock genes, presents an attractive alternative target for detailed modelling of circadian clocks in the green lineage. Based on extensive time-series data from in vivo reporter gene assays, we developed a model of the Ostreococcus clock as a feedback loop between the genes TOC1 and CCA1. The model reproduces the dynamics of the transcriptional and translational reporters over a range of photoperiods. Surprisingly, the model is also able to predict the transient behaviour of the clock when the light conditions are altered. Despite the apparent simplicity of the clock circuit, it displays considerable complexity in its response to changing light conditions. Systematic screening of the effects of altered day length revealed a complex relationship between phase and photoperiod, which is also captured by the model. The complex light response is shown to stem from circadian gating of light-dependent mechanisms. This study provides insights into the contributions of light inputs to the Ostreococcus clock. The model suggests that a high number of light-dependent reactions are important for flexible timing in a circadian clock with only one feedback loop

    Combined use of the Consolidated Framework for Implementation Research (CFIR) and the Theoretical Domains Framework (TDF): a systematic review

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    Abstract Background Over 60 implementation frameworks exist. Using multiple frameworks may help researchers to address multiple study purposes, levels, and degrees of theoretical heritage and operationalizability; however, using multiple frameworks may result in unnecessary complexity and redundancy if doing so does not address study needs. The Consolidated Framework for Implementation Research (CFIR) and the Theoretical Domains Framework (TDF) are both well-operationalized, multi-level implementation determinant frameworks derived from theory. As such, the rationale for using the frameworks in combination (i.e., CFIR + TDF) is unclear. The objective of this systematic review was to elucidate the rationale for using CFIR + TDF by (1) describing studies that have used CFIR + TDF, (2) how they used CFIR + TDF, and (2) their stated rationale for using CFIR + TDF. Methods We undertook a systematic review to identify studies that mentioned both the CFIR and the TDF, were written in English, were peer-reviewed, and reported either a protocol or results of an empirical study in MEDLINE/PubMed, PsycInfo, Web of Science, or Google Scholar. We then abstracted data into a matrix and analyzed it qualitatively, identifying salient themes. Findings We identified five protocols and seven completed studies that used CFIR + TDF. CFIR + TDF was applied to studies in several countries, to a range of healthcare interventions, and at multiple intervention phases; used many designs, methods, and units of analysis; and assessed a variety of outcomes. Three studies indicated that using CFIR + TDF addressed multiple study purposes. Six studies indicated that using CFIR + TDF addressed multiple conceptual levels. Four studies did not explicitly state their rationale for using CFIR + TDF. Conclusions Differences in the purposes that authors of the CFIR (e.g., comprehensive set of implementation determinants) and the TDF (e.g., intervention development) propose help to justify the use of CFIR + TDF. Given that the CFIR and the TDF are both multi-level frameworks, the rationale that using CFIR + TDF is needed to address multiple conceptual levels may reflect potentially misleading conventional wisdom. On the other hand, using CFIR + TDF may more fully define the multi-level nature of implementation. To avoid concerns about unnecessary complexity and redundancy, scholars who use CFIR + TDF and combinations of other frameworks should specify how the frameworks contribute to their study. Trial registration PROSPERO CRD4201502761

    Innateness as genetic adaptation: Lorenz redivivus (and revised)

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    In 1965, Konrad Lorenz grounded the innate–acquired distinction in what he believed were the only two possible sources of information that can underlie adaptedness: phylogenetic and individual experience. Phylogenetic experience accumulates in the genome by the process of natural selection. Individual experience is acquired ontogenetically through interacting with the environment during the organism's lifetime. According to Lorenz, the adaptive information underlying innate traits is stored in the genome. Lorenz erred in arguing that genetic adaptation is the only means of accumulating information in phylogenetic (i.e., intergenerational) experience. Cultural adaptation also occurs over a phylogenetic time scale, and cultural tradition is a third source from which adaptive information can be extracted. This paper argues that genetic adaptation can be distinguished from individual and cultural adaptation in a species like Homo sapiens, in which even adaptations with a genetic component require cultural inputs and scaffolding to develop and be expressed. Examination of the way in which innateness is used in science suggests that scientists use the term, as Lorenz suggested, to designate genetic adaptations. The search for innate traits plays an essential role in generating hypotheses in ethology and psychology. In addition, designating a trait as innate establishes important facts that apply at the information-processing level of description

    Self domestication and the evolution of language

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    Tissue engineering: state of the art in oral rehabilitation

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/74998/1/j.1365-2842.2009.01939.x.pd

    Looking at handaxes from another angle: Assessing the ergonomic and functional importance of edge form in Acheulean bifaces

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    Edge angle is widely considered to be a morphological attribute that influences the functional performance of lithic technologies. However, the comparative performance capabilities of handaxes that vary in terms of edge angles has never been investigated under experimental conditions. Similarly, detailed accounts of Acheulean handaxe angle variation from archaeological examples have not been reported in the literature. Consequently, it has not previously been possible to assess the extent to which Palaeolithic individuals adhered to specific edge angle ranges during handaxe production or whether resultant artifactual properties may have been in response to varying rates of utility. Here, using a substantial experimental program (n = 500 handaxes), we investigate the impact that edge angle variation has on the cutting efficiency of handaxes at a “whole tool” and “edge-point localized” level. We then examine edge angles in a temporally and geographically wide range of handaxes (n = 643) and assess the extent to which hominins were likely altering tool production choices in response to functional pressures. Our experimental results demonstrate that, up to a certain value, higher edge angles in handaxes can actually increase functional performance. Furthermore, results indicate that edges in the proximal portion of handaxes have the greatest influence over efficiency rates. Combined with examination of archaeological specimens, these results suggest that hominins actively pursued the production of more obtuse edges in the proximal (butt) portion of handaxes in order to increase ergonomic features that facilitated greater efficiency during use. Edge angle values in the proximal portion of the archaeological handaxes were, however, consistently found to be below an efficiency threshold identified at ?70 degrees, above which, an edge’s ability to effectively be applied to cutting tasks decreases markedly. This further suggests that the proximal edges of handaxes, at least occasionally, were required as a functional working edge
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