90 research outputs found

    Division of labour and risk taking in the dinosaur ant, Dinoponera quadriceps

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    The success of social insects can be largely attributed to division of labour. In contrast to most social insects, many species with simple societies contain workers which are capable of sexual reproduction. Headed by one or a few reproductive individuals, subordinate workers form a dominance hierarchy, queuing to attain the reproductive role. In these species task allocation may be influenced by individual choice based on future reproductive prospects. Individuals with a better chance of inheriting the colony may be less likely to take risks and high-ranking workers that spend a greater amount of time in proximity to the brood may be able to increase the ability to police egg-laying by cheating subordinates. We investigated division of labour and risk taking in relation to dominance rank in the queenless ponerine ant, Dinoponera quadriceps, a species with relatively simple societies. Using behavioural observations, we show that high-ranking workers spend more time performing egg care, less time foraging and are less likely to defend the nest against attack. High-rankers also spent a greater amount of time guarding and inspecting eggs, behaviours which are likely to improve detection of egg laying by cheating subordinates. We also show that high-ranking workers spend a greater amount of time idle, which may help increase lifespan by reducing energy expenditure. Our results suggest that both risk-taking and egg-care behaviours are related to future reproductive prospects in D. quadriceps. This highlights a mechanism by which effective division of labour could have been achieved during the early stages of eusocial evolution

    #UKRAS21: The 4th UK Robotics and Autonomous Systems Conference

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    © The Author(s) / UK-RAS Network. This is an open access conference paper distributed under the terms of the Creative Commons Attribution License (CC BY), https://creativecommons.org/licenses/by/4.0/This year’s theme focuses on robotics at home. We haveidentified three focus areas to examine robotics and au-tonomous systems within our call for papers that are eachcovered by an inspiring keynote and four oral presentationsfrom authors of accepted papers: The focus area robotics foruse in the home considers aspects of rapid prototyping, safety,assisted living, rehabilitation robotics, technology acceptance,and diverse user groups. Keynote speaker Prof. Ana Paiva (In-stituto Superior T´ecnico, University of Lisbon and coordinatorof GAIPS at INESC-ID) will talk about the engineering ofsociality and collaboration between humans and robots. The oral paper presentations in this area are Exploring Human-Dog Attachment Behaviours and their Translation to a Roboti

    Convergent phenotypes but non-convergent genomes in simple social insect societies

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    Dissertação de Mestrado na área de especialização em Ciências Jurídico-Forenses apresentada à Faculdade de Direito da Universidade de Coimbr

    Development of scalable manufacturing process and GMP-compatible formulation for a novel recombinant schistosomiasis vaccine

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    Schistosomiasis is a parasitic disease spread by fresh water snails. After malaria, schistosomiasis is the deadliest parasitic disease, plaguing an estimated 200 million people worldwide, and causing up to 280,000 fatalities in Africa. This neglected tropical disease has also emerged as an important co-factor in Africa’s HIV/AIDS epidemic, especially among women and adolescent girls. Together with hookworm disease and leishmaniasis, it ranks as the neglected tropical disease with the highest disease burden as defined by disability-adjusted life years (DALYs)1. Although treatments exist, such as praziquantel chemotherapy, a vaccine will likely be needed to prevent infection and re-infection, interrupt disease transmission, and ultimately establish long-term control and elimination of the disease. No such vaccine currently exists, but a promising candidate is currently under development at Texas Children’s Hospital Center for Vaccine Development (TCH-CVD). The Sm-TSP-2 schistosomiasis vaccine comprises a 9 kDa recombinant protein corresponding to the extracellular domain of a unique S. mansoni tetraspanin found in the parasite’s tegumental surface. Sm-TSP-2 was expressed as a recombinant protein secreted by the yeast PichiaPinkTM and purified in a two-step process, which resulted in a protein recovery yield of 31% and a protein purity of 97%.2 The developed processes were suitable for production of purified protein for subsequent formulation and Phase 1 clinical studies. However, improvements in process yield and efficiency, as well as transition of the formulation to GMP-compatible materials, are desirable for the advancement of this candidate through subsequent clinical phases and large-scale manufacturing. TCH-CVD and MilliporeSigma are conducting a collaborative project to optimize the efficiency and scalability of the Sm-STP-2 schistosomiasis vaccine manufacturing process. The overall goal of this work is to develop a safe and low-cost process for the purification of the vaccine antigen. This was accomplished by redesigning the original process, which utilized 750kD hollow fiber and 3kD cellulose membrane tangential flow filtration (TFF) devices for the clarification and concentration of the Pichia pastoris-based vaccine lysate process feed. The level of solids in the fermentation broth (30%) had required a dilution to enable processing through the hollow fiber device, which led to decreased product yield and increased complexity. MilliporeSigma assisted TCH-CVD with studies to eliminate the dilution prior to lysate clarification and to also streamline the process to enable Texas Children’s to simultaneously clarify and concentrate the yeast lysate. 0.1um, open-channel, stacked plate, membrane sheet TFF devices were successfully used to clarify the undiluted lysate. The TFF operating parameters (specifically the feed and permeate flow rates) were optimized to enable the downstream 3kD concentration process to run concurrently in a cascade TFF. Enhancement of the chromatography operations is currently underway as well. This presentation will detail the optimized clarification and concentration process and highlight the economic and process simplification benefits. Work was also performed to optimize the vaccine formulation. Extensive studies were previously conducted to identify excipients and conditions to maximize the stability of soluble recombinant Sm-TSP-2.3 Additional components were tested to find alternative GMP-grade reagents that maintained or improved the stability of the vaccine. REFRENCES 1. Forgotten People, Forgotten Diseases: The Neglected Tropical Diseases and Their Impact on Global Health and Development, Second Edition. Peter J. Hotez. American Society for Microbiology Press, Washington, DC, USA, 2013. 2. Curti E et al. Hum Vaccin Immunother. 2013 Nov;9(11):2342-50. 3. Cheng W et al. Hum Vaccin Immunother. 2013 Nov;9(11):2351-61

    Near-infrared Thermal Emission Detections of a number of hot Jupiters and the Systematics of Ground-based Near-infrared Photometry

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    We present detections of the near-infrared thermal emission of three hot Jupiters and one brown-dwarf using the Wide-field Infrared Camera (WIRCam) on the Canada-France-Hawaii Telescope (CFHT). These include Ks-band secondary eclipse detections of the hot Jupiters WASP-3b and Qatar-1b and the brown dwarf KELT-1b. We also report Y-band, KCONTK_{CONT}-band, and two new and one reanalyzed Ks-band detections of the thermal emission of the hot Jupiter WASP-12b. We present a new reduction pipeline for CFHT/WIRCam data, which is optimized for high precision photometry. We also describe novel techniques for constraining systematic errors in ground-based near-infrared photometry, so as to return reliable secondary eclipse depths and uncertainties. We discuss the noise properties of our ground-based photometry for wavelengths spanning the near-infrared (the YJHK-bands), for faint and bright-stars, and for the same object on several occasions. For the hot Jupiters WASP-3b and WASP-12b we demonstrate the repeatability of our eclipse depth measurements in the Ks-band; we therefore place stringent limits on the systematics of ground-based, near-infrared photometry, and also rule out violent weather changes in the deep, high pressure atmospheres of these two hot Jupiters at the epochs of our observations.Comment: 27 pages, 23 figures, ApJ submitted June 16th, 2014. Version revised to address referee comment

    First radial velocity results from the MINiature Exoplanet Radial Velocity Array (MINERVA)

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    The MINiature Exoplanet Radial Velocity Array (MINERVA) is a dedicated observatory of four 0.7m robotic telescopes fiber-fed to a KiwiSpec spectrograph. The MINERVA mission is to discover super-Earths in the habitable zones of nearby stars. This can be accomplished with MINERVA's unique combination of high precision and high cadence over long time periods. In this work, we detail changes to the MINERVA facility that have occurred since our previous paper. We then describe MINERVA's robotic control software, the process by which we perform 1D spectral extraction, and our forward modeling Doppler pipeline. In the process of improving our forward modeling procedure, we found that our spectrograph's intrinsic instrumental profile is stable for at least nine months. Because of that, we characterized our instrumental profile with a time-independent, cubic spline function based on the profile in the cross dispersion direction, with which we achieved a radial velocity precision similar to using a conventional "sum-of-Gaussians" instrumental profile: 1.8 m s1^{-1} over 1.5 months on the RV standard star HD 122064. Therefore, we conclude that the instrumental profile need not be perfectly accurate as long as it is stable. In addition, we observed 51 Peg and our results are consistent with the literature, confirming our spectrograph and Doppler pipeline are producing accurate and precise radial velocities.Comment: 22 pages, 9 figures, submitted to PASP, Peer-Reviewed and Accepte

    Characteristics of outdoor falls among older people: A qualitative study

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    Background Falls are a major threat to older people’s health and wellbeing. Approximately half of falls occur in outdoor environments but little is known about the circumstances in which they occur. We conducted a qualitative study to explore older people’s experiences of outdoor falls to develop understanding of how they may be prevented. Methods We conducted nine focus groups across the UK (England, Wales, and Scotland). Our sample was from urban and rural settings and different environmental landscapes. Participants were aged 65+ and had at least one outdoor fall in the past year. We analysed the data using framework and content analyses. Results Forty-four adults aged 65 – 92 took part and reported their experience of 88 outdoor falls. Outdoor falls occurred in a variety of contexts, though reports suggested the following scenarios may have been more frequent: when crossing a road, in a familiar area, when bystanders were around, and with an unreported or unknown attribution. Most frequently, falls resulted in either minor or moderate injury, feeling embarrassed at the time of the fall, and anxiety about falling again. Ten falls resulted in fracture, but no strong pattern emerged in regard to the contexts of these falls. Anxiety about falling again appeared more prevalent among those that fell in urban settings and who made more visits into their neighbourhood in a typical week. Conclusions This exploratory study has highlighted several aspects of the outdoor environment that may represent risk factors for outdoor falls and associated fear of falling. Health professionals are recommended to consider outdoor environments as well as the home setting when working to prevent falls and increase mobility among older people

    Establishing a core outcome set for peritoneal dialysis : report of the SONG-PD (standardized outcomes in nephrology-peritoneal dialysis) consensus workshop

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    Outcomes reported in randomized controlled trials in peritoneal dialysis (PD) are diverse, are measured inconsistently, and may not be important to patients, families, and clinicians. The Standardized Outcomes in Nephrology-Peritoneal Dialysis (SONG-PD) initiative aims to establish a core outcome set for trials in PD based on the shared priorities of all stakeholders. We convened an international SONG-PD stakeholder consensus workshop in May 2018 in Vancouver, Canada. Nineteen patients/caregivers and 51 health professionals attended. Participants discussed core outcome domains and implementation in trials in PD. Four themes relating to the formation of core outcome domains were identified: life participation as a main goal of PD, impact of fatigue, empowerment for preparation and planning, and separation of contributing factors from core factors. Considerations for implementation were identified: standardizing patient-reported outcomes, requiring a validated and feasible measure, simplicity of binary outcomes, responsiveness to interventions, and using positive terminology. All stakeholders supported inclusion of PD-related infection, cardiovascular disease, mortality, technique survival, and life participation as the core outcome domains for PD
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