342 research outputs found

    Quantifying the Loss of Coral from a Bleaching Event Using Underwater Photogrammetry and AI-Assisted Image Segmentation

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    Detecting the impacts of natural and anthropogenic disturbances that cause declines in organisms or changes in community composition has long been a focus of ecology. However, a tradeoff often exists between the spatial extent over which relevant data can be collected, and the resolution of those data. Recent advances in underwater photogrammetry, as well as computer vision and machine learning tools that employ artificial intelligence (AI), offer potential solutions with which to resolve this tradeoff. Here, we coupled a rigorous photogrammetric survey method with novel AI-assisted image segmentation software in order to quantify the impact of a coral bleaching event on a tropical reef, both at an ecologically meaningful spatial scale and with high spatial resolution. In addition to outlining our workflow, we highlight three key results: (1) dramatic changes in the three-dimensional surface areas of live and dead coral, as well as the ratio of live to dead colonies before and after bleaching; (2) a size-dependent pattern of mortality in bleached corals, where the largest corals were disproportionately affected, and (3) a significantly greater decline in the surface area of live coral, as revealed by our approximation of the 3D shape compared to the more standard planar area (2D) approach. The technique of photogrammetry allows us to turn 2D images into approximate 3D models in a flexible and efficient way. Increasing the resolution, accuracy, spatial extent, and efficiency with which we can quantify effects of disturbances will improve our ability to understand the ecological consequences that cascade from small to large scales, as well as allow more informed decisions to be made regarding the mitigation of undesired impacts

    Regenerative memory in time-delayed neuromorphic photonic resonators

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    We investigate a photonic regenerative memory based upon a neuromorphic oscillator with a delayed self-feedback (autaptic) connection. We disclose the existence of a unique temporal response characteristic of localized structures enabling an ideal support for bits in an optical buffer memory for storage and reshaping of data information. We link our experimental implementation, based upon a nanoscale nonlinear resonant tunneling diode driving a laser, to the paradigm of neuronal activity, the FitzHugh-Nagumo model with delayed feedback. This proof-of-concept photonic regenerative memory might constitute a building block for a new class of neuron-inspired photonic memories that can handle high bit-rate optical signals

    Changes in Employment Uncertainty and the Fertility Intention-Realization Link: An Analysis Based on the Swiss Household Panel.

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    How do changes in employment uncertainty matter for fertility? Empirical studies on the impact of employment uncertainty on reproductive decision-making offer a variety of conclusions, ranging from gender and socio-economic differences in the effect of employment uncertainty on fertility intentions and behaviour, to the effect of employment on changes in fertility intentions. This article analyses the association between a change in subjective employment uncertainty and fertility intentions and behaviour by distinguishing male and female partners' employment uncertainty, and examines the variation in these associations by education. Using a sample of men and women living in a couple from the Swiss Household Panel (SHP 2002-2011), we examine through multinomial analysis how changes in employment uncertainty and selected socio-demographic factors are related to individual childbearing decisions. Our results show strong gendered effects of changes in employment uncertainty on the revision of reproductive decisions among the highly educated population

    Scenario-Based Design Theorizing:The Case of a Digital Idea Screening Cockpit

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    As ever more companies encourage employees to innovate, a surplus of ideas has become reality in many organizations – often exceeding the available resources to execute them. Building on insights from a literature review and a 3-year collaboration with a banking software provider, the paper suggests a Digital Idea Screening Cockpit (DISC) to address this challenge. Following a design science research approach, it suggests a prescriptive design theory that provides practitioner-oriented guidance for implementing a DISC. The study shows that, in order to facilitate the assessment, selection, and tracking of ideas for different stakeholders, such a system needs to play a dual role: It needs to structure decision criteria and at the same be flexible to allow for creative expression. Moreover, the paper makes a case for scenario-based design theorizing by developing design knowledge via scenarios

    Longitudinal Associations Between Perceived Parent-Child Relationship Quality and Depressive Symptoms in Adolescence

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    This longitudinal study examined bidirectional paths between perceived parent-adolescent relationship quality and depressive symptoms, as well as the moderating role of sex, age, and personality type. 1313 Dutch adolescents (51% girls) from two cohorts (923 12-year olds and 390 16-year olds at Wave 1) reported on their personality, depressive symptoms, and perceived relationship quality to parents in four waves. Consistent with a relationship erosion perspective, depressive symptoms negatively predicted perceived relationship quality with parents. Relationship quality to mothers predicted depressive symptoms for boys and girls, but relationship quality to fathers predicted depressive symptoms only for boys. Personality type only moderated initial associations between relationship quality with mothers and depressive symptoms, which were stronger for Overcontrollers and Undercontrollers than for Resilients. Results thus reveal a pattern of mutual influence between perceived relationship quality and depressive symptoms that is moderated by the interplay among parent and adolescent sex and adolescent personality type

    Micromechanical Properties of Injection-Molded Starch–Wood Particle Composites

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    The micromechanical properties of injection molded starch–wood particle composites were investigated as a function of particle content and humidity conditions. The composite materials were characterized by scanning electron microscopy and X-ray diffraction methods. The microhardness of the composites was shown to increase notably with the concentration of the wood particles. In addition,creep behavior under the indenter and temperature dependence were evaluated in terms of the independent contribution of the starch matrix and the wood microparticles to the hardness value. The influence of drying time on the density and weight uptake of the injection-molded composites was highlighted. The results revealed the role of the mechanism of water evaporation, showing that the dependence of water uptake and temperature was greater for the starch–wood composites than for the pure starch sample. Experiments performed during the drying process at 70°C indicated that the wood in the starch composites did not prevent water loss from the samples.Peer reviewe

    Two Conceptions of Democracy in the Council of the EU: Narrow and Broad

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    Since the entry into force of the Lisbon Treaty, the Council is explicitly understood as a democratic actor in a decision-making system that is legitimated on the basis of a democratic rationale. While this formalisation in the Lisbon Treaty of the Council as a democratic actor is to be welcomed as an important step in a longer-standing process, it remains unclear which normative requirements result from it. This point is illustrated in this paper with reference to the principle of transparency. It discerns the role of transparency in two competing conceptions at the Council level, representing a narrow, and a broad perspective on democracy. It is argued that below a minimal threshold of transparency, Council democracy cannot function. Above this threshold, in turn, transparency is likely to make Council democracy function better
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