398 research outputs found
Living Shorelines Support Nearshore Benthic Communities in Upper and Lower Chesapeake Bay
Human population growth and sea-level rise are increasing the demand for protection of coastal property against shoreline erosion. Living shorelines are designed to provide shoreline protection and are constructed or reinforced using natural elements. While living shorelines are gaining popularity with homeowners, their ability to provide ecological services (e.g., habitat provision and trophic transfer) is not well understood, and information is needed to improve coastal and resource management decision-making. We examined benthic community responses to living shorelines in two case-study subestuaries of Chesapeake Bay using a before-after control-impact study design. At Windy Hill, a bulkhead was removed and replaced by three tombolos, sand fill, and native marsh vegetation. At Lynnhaven, 25 m of eroding marsh shoreline was stabilized with coir logs, sand fill, and native marsh vegetation. Communities of large (\u3e 3 mm) infauna adjacent to living shorelines at both locations tended to increase in biomass by the end of the study period. Community compositions changed significantly following living shoreline construction at Windy Hill, reflecting a trend toward higher density and biomass of large bivalves at living shorelines compared to pre-construction. Increasing trends in density and biomass of clams and simultaneously decreasing density and decreasing trends in biomass of polychaetes suggest a transition toward stable infaunal communities at living shorelines over time, though longer-term studies are warranted
Human Influence at the Coast: Upland and Shoreline Stressors Affect Coastal Macrofauna and Are Mediated by Salinity
Anthropogenic stressors can affect subtidal communities within the land-water interface. Increasing anthropogenic activities, including upland and shoreline development, threaten ecologically important species in these habitats. In this study, we examined the consequences of anthropogenic stressors on benthic macrofaunal communities in 14 subestuaries of Chesapeake Bay. We investigated how subestuary upland use (forested, agricultural, developed land) and shoreline development (riprap and bulkhead compared to marsh and beach) affected density, biomass, and diversity of benthic infauna. Upland and shoreline development were parameters included in the most plausible models among a candidate set compared using corrected Akaike\u27s Information Criterion. For benthic macrofauna, density tended to be lower in subestuaries with developed or mixed compared to forested or agricultural upland use. Benthic biomass was significantly lower in subestuaries with developed compared to forested upland use, and biomass declined exponentially with proportion of near-shore developed land. Benthic density did not differ significantly among natural marsh, beach, and riprap habitats, but tended to be lower adjacent to bulkhead shorelines. Including all subestuaries, there were no differences in diversity by shoreline type. In low salinities, benthic Shannon (H\u27) diversity tended to be higher adjacent to natural marshes compared to the other habitats, and lower adjacent to bulkheads, but the pattern was reversed in high salinities. Sediment characteristics varied by shoreline type and contributed to differences in benthic community structure. Given the changes in the infaunal community with anthropogenic stressors, subestuary upland and shoreline development should be minimized to increase benthic production and subsequent trophic transfer within the food web
How citation boosts promote scientific paradigm shifts and Nobel Prizes
Nobel Prizes are commonly seen to be among the most prestigious achievements
of our times. Based on mining several million citations, we quantitatively
analyze the processes driving paradigm shifts in science. We find that
groundbreaking discoveries of Nobel Prize Laureates and other famous scientists
are not only acknowledged by many citations of their landmark papers.
Surprisingly, they also boost the citation rates of their previous
publications. Given that innovations must outcompete the rich-gets-richer
effect for scientific citations, it turns out that they can make their way only
through citation cascades. A quantitative analysis reveals how and why they
happen. Science appears to behave like a self-organized critical system, in
which citation cascades of all sizes occur, from continuous scientific progress
all the way up to scientific revolutions, which change the way we see our
world. Measuring the "boosting effect" of landmark papers, our analysis reveals
how new ideas and new players can make their way and finally triumph in a world
dominated by established paradigms. The underlying "boost factor" is also
useful to discover scientific breakthroughs and talents much earlier than
through classical citation analysis, which by now has become a widespread
method to measure scientific excellence, influencing scientific careers and the
distribution of research funds. Our findings reveal patterns of collective
social behavior, which are also interesting from an attention economics
perspective. Understanding the origin of scientific authority may therefore
ultimately help to explain, how social influence comes about and why the value
of goods depends so strongly on the attention they attract.Comment: 6 pages, 6 figure
Attention on Weak Ties in Social and Communication Networks
Granovetter's weak tie theory of social networks is built around two central
hypotheses. The first states that strong social ties carry the large majority
of interaction events; the second maintains that weak social ties, although
less active, are often relevant for the exchange of especially important
information (e.g., about potential new jobs in Granovetter's work). While
several empirical studies have provided support for the first hypothesis, the
second has been the object of far less scrutiny. A possible reason is that it
involves notions relative to the nature and importance of the information that
are hard to quantify and measure, especially in large scale studies. Here, we
search for empirical validation of both Granovetter's hypotheses. We find clear
empirical support for the first. We also provide empirical evidence and a
quantitative interpretation for the second. We show that attention, measured as
the fraction of interactions devoted to a particular social connection, is high
on weak ties --- possibly reflecting the postulated informational purposes of
such ties --- but also on very strong ties. Data from online social media and
mobile communication reveal network-dependent mixtures of these two effects on
the basis of a platform's typical usage. Our results establish a clear
relationships between attention, importance, and strength of social links, and
could lead to improved algorithms to prioritize social media content
A Methodological approach to supporting organisational learning
Many organizations need to respond quickly to change and their workers need to regularly develop new knowledge and skills. The prevailing approach to meeting these demands is on-the-job training, but this is known to be highly ineffective, cause stress and devalue workplace autonomy. Conversely, organizational learning is a process through which workers learn gradually in the work context through experience, reflection on work practice and collaboration with colleagues. Our approach aims to support and enhance organizational learning around enriched work representations. Work representations are tools and documents used to support collaborative working and learning. These are enriched through associations with formal knowledge models and informal discourse. The work representations, informal discourse and associated knowledge models together form on organizational memory from which knowledge can be retrieved later. Our methodological approach to supporting organizational learning is drawn from three industrial case studies concerned with machine maintenance, team planning and hotline support. The methodology encompasses development and design activities, a description of the roles and duties required to sustain the long-term use of the tools, and applicability criteria outlining the kind of organizations that can benefit from this approach
Impact of associated injuries in the Floating knee: A retrospective study
<p>Abstract</p> <p>Background</p> <p>Floating knee injuries are usually associated with other significant injuries. Do these injuries have implications on the management of the floating knee and the final outcome of patients? Our study aims to assess the implications of associated injuries in the management and final outcome of floating knee.</p> <p>Methods</p> <p>29 patients with floating knees were assessed in our institution. A retrospective analysis of medical records and radiographs were done and all associated injuries were identified. The impact of associated injuries on delay in initial surgical management, delay in rehabilitation & final outcome of the floating knee were assessed.</p> <p>Results</p> <p>38 associated injuries were noted. 7 were associated with ipsilateral knee injuries. Lower limb injuries were most commonly associated with the floating knee. Patients with some associated injuries had a delay in surgical management and others a delay in post-operative rehabilitation. Knee ligament and vascular injuries were associated with poor outcome.</p> <p>Conclusion</p> <p>The associated injuries were quite frequent with the floating knee. Some of the associated injuries caused a delay in surgical management and post-operative rehabilitation. In assessment of the final outcome, patients with associated knee and vascular injuries had a poor prognosis. Majority of the patients with associated injuries had a good or excellent outcome.</p
The Internet as a Small Business E-Commerce Ecosystem.
The purpose of this chapter is to analyse how the ecosystem concept can be applied to small businesses and how the Internet and e-commerce can help SMEs harness the required resources to enhance their competitive performance in
the marketplace. The chapter will investigate the wide variety of e-commerce applications that are available to small businesses to help address the issue of limited resources. It will provide an ecosystem map illustrating how each functional area of a small business can utilise Internet e-commerce applications to enhance their resource base. The chapter also explores the opportunities and
threats that the e-commerce ecosystem model poses for small, medium-sized enterprises (SMEs). This is based upon empirical research consisting of three focus group interviews undertaken with small and medium-sized retail service firms located in the Herefordshire and Worcestershire regions of the United Kingdom in January–February 2014
Key stages of mammary gland development: Molecular mechanisms involved in the formation of the embryonic mammary gland
The development of the embryonic mammary gland involves communication between the epidermis and mesenchyme and is coordinated temporally and spatially by various signaling pathways. Although many more genes are likely to control mammary gland development, functional roles have been identified for Wnt, fibroblast growth factor, and parathyroid hormone-related protein signaling. This review describes what is known about the molecular mechanisms that regulate embryonic mammary gland development
Valvular involvement in ANCA-associated systemic vasculitis: a case report and literature review
Jellyfish Support High Energy Intake of Leatherback Sea Turtles (Dermochelys coriacea): Video Evidence from Animal-Borne Cameras
The endangered leatherback turtle is a large, highly migratory marine predator that inexplicably relies upon a diet of low-energy gelatinous zooplankton. The location of these prey may be predictable at large oceanographic scales, given that leatherback turtles perform long distance migrations (1000s of km) from nesting beaches to high latitude foraging grounds. However, little is known about the profitability of this migration and foraging strategy. We used GPS location data and video from animal-borne cameras to examine how prey characteristics (i.e., prey size, prey type, prey encounter rate) correlate with the daytime foraging behavior of leatherbacks (n = 19) in shelf waters off Cape Breton Island, NS, Canada, during August and September. Video was recorded continuously, averaged 1:53 h per turtle (range 0:08–3:38 h), and documented a total of 601 prey captures. Lion's mane jellyfish (Cyanea capillata) was the dominant prey (83–100%), but moon jellyfish (Aurelia aurita) were also consumed. Turtles approached and attacked most jellyfish within the camera's field of view and appeared to consume prey completely. There was no significant relationship between encounter rate and dive duration (p = 0.74, linear mixed-effects models). Handling time increased with prey size regardless of prey species (p = 0.0001). Estimates of energy intake averaged 66,018 kJ•d−1 but were as high as 167,797 kJ•d−1 corresponding to turtles consuming an average of 330 kg wet mass•d−1 (up to 840 kg•d−1) or approximately 261 (up to 664) jellyfish•d-1. Assuming our turtles averaged 455 kg body mass, they consumed an average of 73% of their body mass•d−1 equating to an average energy intake of 3–7 times their daily metabolic requirements, depending on estimates used. This study provides evidence that feeding tactics used by leatherbacks in Atlantic Canadian waters are highly profitable and our results are consistent with estimates of mass gain prior to southward migration
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