2,289 research outputs found

    Expulsion of Symbiotic Algae during Feeding by the Green Hydra – a Mechanism for Regulating Symbiont Density?

    Get PDF
    Background: Algal-cnidarian symbiosis is one of the main factors contributing to the success of cnidarians, and is crucial for the maintenance of coral reefs. While loss of the symbionts (such as in coral bleaching) may cause the death of the cnidarian host, over-proliferation of the algae may also harm the host. Thus, there is a need for the host to regulate the population density of its symbionts. In the green hydra, Chlorohydra viridissima, the density of symbiotic algae may be controlled through host modulation of the algal cell cycle. Alternatively, Chlorohydra may actively expel their endosymbionts, although this phenomenon has only been observed under experimentally contrived stress conditions. Principal Findings: We show, using light and electron microscopy, that Chlorohydra actively expel endosymbiotic algal cells during predatory feeding on Artemia. This expulsion occurs as part of the apocrine mode of secretion from the endodermal digestive cells, but may also occur via an independent exocytotic mechanism. Significance: Our results demonstrate, for the first time, active expulsion of endosymbiotic algae from cnidarians under natural conditions. We suggest this phenomenon may represent a mechanism whereby cnidarians can expel excess symbiotic algae when an alternative form of nutrition is available in the form of prey

    BIM Research in Irish Academic Institutions 2015-19

    Get PDF
    The use of BIM in the Irish construction industry has become pervasive in the last decade and it is an essential element in improving productivity in the market. The developments in BIM education and training in supporting the increase in Ireland’s BIM maturity has been well documented in recent years, principally through the proceedings of the BIM Gatherings and the BIM in Ireland 2017 and 2019 reviews. Similarly, the public and private sectors have been surveyed to establish their readiness for digital transformation on their BIM journey. However, BIM research undertaken by Irish academics, while individually strong, has not been strategic at national level nor has it yet met all the needs of industry. This paper will review the learned publications of all research-active academics on this island in the various aspects of the field of BIM-related research in the last 5 years. It will categorise and analyse their achievements, acting as a national reference source for all parties in this industry. It will also suggest areas where further research opportunities exist in support of the continuing fast-paced evolution of this digital technology in the construction industry, nationally and internationally

    Romantic Partnerships and the Dispersion of Social Ties: A Network Analysis of Relationship Status on Facebook

    Full text link
    A crucial task in the analysis of on-line social-networking systems is to identify important people --- those linked by strong social ties --- within an individual's network neighborhood. Here we investigate this question for a particular category of strong ties, those involving spouses or romantic partners. We organize our analysis around a basic question: given all the connections among a person's friends, can you recognize his or her romantic partner from the network structure alone? Using data from a large sample of Facebook users, we find that this task can be accomplished with high accuracy, but doing so requires the development of a new measure of tie strength that we term `dispersion' --- the extent to which two people's mutual friends are not themselves well-connected. The results offer methods for identifying types of structurally significant people in on-line applications, and suggest a potential expansion of existing theories of tie strength.Comment: Proc. 17th ACM Conference on Computer Supported Cooperative Work and Social Computing (CSCW), 201

    Digital Construction and BIM Research in Ireland 2016-2020

    Get PDF
    As the construction industry opens up post pandemic, new and significant challenges will demand considerable expertise, not least in financial viability, solving the housing crisis and facing the very significant climate change pressures to make the industry less wasteful and less carbon intensive. This presents an excellent opportunity to further inculcate aspects of lean construction, particularly BIM into many aspects of construction not traditionally associated with digital construction, provided the necessary expertise is available and known to exist. Following a well-received recent conference paper summarising BIM-related research published by academics in Ireland’s higher education institutions in 2020, this paper will review and identify noteworthy publications in digital technologies, including BIM, by academics of this island’s third level institutions in the last five years. Areas of expertise of individuals will be identified to act as a useful directory for both industry and fellow researchers as well as providing a valuable national resource to identify research gaps which need funding if the ambitions of the national plan for the digitisation of the industry are to be realised. Using an already proven methodology, a survey of the 16 academic institutions in Ireland will be conducted through identified representatives in each institution, seeking all conference and journal papers published in the 2016-2020 period. The assembled database will be categorised, sorted and analysed to identify academic individuals in the workforce with extant research strengths in the various themes to establish the available expertise and areas for growth in the next five years

    The Irish Construction Industry’s State of Readiness for a BIM mandate in 2020

    Get PDF
    It was recently announced that a BIM mandate for the Irish public sector is not imminent, suggesting that the sector is not yet ready for what such a mandate implies. Following on from a forward-looking BIM Roadmap for Ireland in 2017 and the publication by the authors of a detailed BIM in Ireland study in 2017 and 2019, what is the actual state of readiness for a more general BIM mandate in Ireland? This paper will review recent publications, seminars and industry initiatives on this topic of interest supported by an online survey to assess the current state of readiness for a BIM mandate in Ireland. An assessment will be made of what deficits, if any, need to be addressed before the introduction of a BIM mandate would be a practical proposition. Reflections on the success of other similar-sized economies will be referred to in identifying the priorities for Ireland in its preparation for a full BIM mandate, in addition to the relative importance of BIM given the ongoing impact of the CoVID-19 global pandemic on Ireland’s economy

    Acute effect of repeated sprints on inter-limb asymmetries during unilateral jumping

    Get PDF
    The aim of the present study was to investigate the effects of multiple repeated sprints on unilateral jump performance and inter-limb asymmetries. Eighteen recreationally active males performed three single leg countermovement jumps (SLCMJ) as baseline data. The repeated sprint protocol was 6 x 40 m with 20 seconds of passive rest between each sprint. This protocol was conducted four times, each set separated by four minutes of rest. Within that rest period, subjects performed one SLCMJ on each limb after two minutes of rest. A one-way ANOVA showed significant reductions (p < 0.05; ES = -0.52 to -0.99) in jump height on both limbs after each set relative to baseline. Inter-limb asymmetries increased at each time point and ranged from 7.62-14.67%, with significant increases in asymmetry seen after sets three (p = 0.046) and four (p = 0.002). Significant increases in sprint time were shown between sprints one and six in each set (p ≤ 0.01). A fatigue index (%) was also calculated and showed an exponential increase from 5.74% (set one) to 13.50% (set four), with significant differences between all sets (p < 0.001) with the exception of sets three and four. Results from this study show that a 6 x 40 m repeated sprint protocol is a sufficient dose for implementing acute fatigue in recreationally active subjects. This was manifested by reductions in jump height at all time points and jump height asymmetries after the third and fourth sets. These findings indicate that jump height from unilateral jump testing may be a useful metric to use during the monitoring process in recreationally trained athletes

    FLICK: developing and running application-specific network services

    Get PDF
    Data centre networks are increasingly programmable, with application-specific network services proliferating, from custom load-balancers to middleboxes providing caching and aggregation. Developers must currently implement these services using traditional low-level APIs, which neither support natural operations on application data nor provide efficient performance isolation. We describe FLICK, a framework for the programming and execution of application-specific network services on multi-core CPUs. Developers write network services in the FLICK language, which offers high-level processing constructs and application-relevant data types. FLICK programs are translated automatically to efficient, parallel task graphs, implemented in C++ on top of a user-space TCP stack. Task graphs have bounded resource usage at runtime, which means that the graphs of multiple services can execute concurrently without interference using cooperative scheduling. We evaluate FLICK with several services (an HTTP load-balancer, a Memcached router and a Hadoop data aggregator), showing that it achieves good performance while reducing development effort

    Effects of a DVD-delivered randomized controlled physical activity intervention on functional health in cancer survivors

    Get PDF
    BACKGROUND: Supervised physical activity interventions improve functional health during cancer survivorship, but remain costly and inaccessible for many. We previously reported on the benefits of a DVD-delivered physical activity program (FlexToBa™) in older adults. This is a secondary analysis of the intervention effects among cancer survivors in the original sample. METHODS: Low active, older adults who self-reported a history of cancer (N = 46; M time since diagnosis = 10.7 ± 9.4 years) participated in a 6-month, home-based physical activity intervention. Participants were randomized to either the DVD-delivered physical activity program focused on flexibility, toning, and balance (FlexToBa™; n = 22) or an attentional control condition (n = 24). Physical function was assessed by the Short Physical Performance Battery (SPPB) at baseline, end of intervention, and at 12 and 24 months after baseline. RESULTS: Repeated measures linear mixed models indicated a significant group*time interaction for the SPPB total score (β = - 1.14, p = 0.048), driven by improved function from baseline to six months in the FlexToBa™ group. The intervention group also had improved balance (β = - 0.56, p = 0.041) compared with controls. Similar trends emerged for the SPPB total score during follow-up; the group*time interaction from 0 to 12 months approached significance (β = - 0.97, p = 0.089) and was significant from 0 to 24 months (β = - 1.84, p = 0.012). No significant interactions emerged for other outcomes (ps \u3e 0.11). CONCLUSIONS: A DVD-delivered physical activity intervention designed for cancer-free older adults was capable of eliciting and maintaining clinically meaningful functional improvements in a subgroup of cancer survivors, with similar effects to the original full sample. These findings inform the dissemination of evidence-based physical activity programs during survivorship. TRIAL REGISTRATION: ClinicalTrials.gov NCT01030419 . Registered 11 December 2009
    • …
    corecore