40 research outputs found
From real-time adaptation to social learning in robot ecosystems
While evolutionary robotics can create novel morphologies and controllers that are well-adapted to their environments, learning is still the most efficient way to adapt to changes that occur on shorter time scales. Learning proposals for evolving robots to date have focused on new individuals either learning a controller from scratch, or building on the experience of direct ancestors and/or robots with similar configurations. Here we propose and demonstrate a novel means for social learning of gait patterns, based on sensorimotor synchronization. Using movement patterns of other robots as input can drive nonlinear decentralized controllers such as CPGs into new limit cycles, hence encouraging diversity of movement patterns. Stable autonomous controllers can then be locked in, which we demonstrate using a quasi-Hebbian feedback scheme. We propose that in an ecosystem of robots evolving in a heterogeneous environment, such a scheme may allow for the emergence of generalist task-solvers from a population of specialists
Estrogen Metabolites in Human Corpus Luteum Physiology: Differential Effects on Angiogenic Activity
OBJECTIVE: To determine tissue concentrations of E2, estrone, P, and estrogens metabolites (EMs) 2-methoxyestradiol, 2-methoxyestrone, 4-hydroxyestrone, and 16-ketoestradiol in corpus luteum (CL) of different ages, and after hCG administration; and to examine the effects of EMs on vascular endothelial growth factor (VEGF) secretion and angiogenic activity released by cultured luteinizing granulosa cells in the presence and absence of hCG.
DESIGN: Experimental study.
SETTING: University.
PATIENT(S): Thirty-two healthy women of reproductive age.
INTERVENTION(S): Corpus luteum was collected at the time of minilaparotomy for tubal sterilization, at varying stages of the luteal phase (LP). Late-LP CL was collected 24 hours after IM administration of 10,000 IU hCG. Granulosa cells were isolated from follicular aspirates obtained from healthy women participating in our IVF program for male factor infertility.
MAIN OUTCOMES MEASURE(S): Estrogen metabolite concentrations were determined in CL tissue, and VEGF was assessed in conditioned medium. The angiogenic activity was analyzed by bioassay.
RESULT(S): Concentrations of EMs with proangiogenic activity (16-ketoestradiol and 4-hydroxyestrone) were higher in early and mid-LP CL vs. late-LP CL. These EMs and hCG increased VEGF production and angiogenic activity. Conversely, late-LP CL had significantly higher levels of 2-methoxyestrone and 2-methoxyestradiol, which have antiangiogenic activity. Administration of hCG reduced the production of these EMs.
CONCLUSION(S): Our findings suggest that the EMs are important paracrine modulators of CL function. Administration of hCG increases the production of EMs with proangiogenic activity and reduces the secretion of those EMs with antiangiogenic action, suggesting a novel mechanism by which the late-LP CL is rescued in conception cycles
Trial protocol for the Building Resilience through Socio-Emotional Training (ReSET) programme: a cluster randomised controlled trial of a new transdiagnostic preventative intervention for adolescents
Background Adolescence is a period of heightened vulnerability to developing mental health problems, and rates of mental health disorder in this age group have increased in the last decade. Preventing mental health problems developing before they become entrenched, particularly in adolescents who are at high risk, is an important research and clinical target. Here, we report the protocol for the trial of the ‘Building Resilience through Socioemotional Training’ (ReSET) intervention. ReSET is a new, preventative intervention that incorporates individual-based emotional training techniques and group-based social and communication skills training. We take a transdiagnostic approach, focusing on emotion processing and social mechanisms implicated in the onset and maintenance of various forms of psychopathology.
Methods A cluster randomised allocation design is adopted with randomisation at the school year level. Five-hundred and forty adolescents (aged 12–14) will be randomised to either receive the intervention or not (passive control). The intervention is comprised of weekly sessions over an 8-week period, supplemented by two individual sessions. The primary outcomes, psychopathology symptoms and mental wellbeing, will be assessed pre- and post-intervention, and at a 1-year follow-up. Secondary outcomes are task-based assessments of emotion processing, social network data based on peer nominations, and subjective ratings of social relationships. These measures will be taken at baseline, post-intervention and 1-year follow-up. A subgroup of participants and stakeholders will be invited to take part in focus groups to assess the acceptability of the intervention.
Discussion This project adopts a theory-based approach to the development of a new intervention designed to target the close connections between young people’s emotions and their interpersonal relationships. By embedding the intervention within a school setting and using a cluster-randomised design, we aim to develop and test a feasible, scalable intervention to prevent the onset of psychopathology in adolescence.
Trial registration ISRCTN88585916. Trial registration date: 20/04/2023
Expression of Transposable Elements in Neural Tissues during Xenopus Development
Transposable elements comprise a large proportion of animal genomes. Transposons can have detrimental effects on genome stability but also offer positive roles for genome evolution and gene expression regulation. Proper balance of the positive and deleterious effects of transposons is crucial for cell homeostasis and requires a mechanism that tightly regulates their expression. Herein we describe the expression of DNA transposons of the Tc1/mariner superfamily during Xenopus development. Sense and antisense transcripts containing complete Tc1-2_Xt were detected in Xenopus embryos. Both transcripts were found in zygotic stages and were mainly localized in Spemann's organizer and neural tissues. In addition, the Tc1-like elements Eagle, Froggy, Jumpy, Maya, Xeminos and TXr were also expressed in zygotic stages but not oocytes in X. tropicalis. Interestingly, although Tc1-2_Xt transcripts were not detected in Xenopus laevis embryos, transcripts from other two Tc1-like elements (TXr and TXz) presented a similar temporal and spatial pattern during X. laevis development. Deep sequencing analysis of Xenopus tropicalis gastrulae showed that PIWI-interacting RNAs (piRNAs) are specifically derived from several Tc1-like elements. The localized expression of Tc1-like elements in neural tissues suggests that they could play a role during the development of the Xenopus nervous system
Causing a Racket: Unpacking the Elements of Cultural Capital in an Assessment of Urban Noise Control, Live Music, and the Quiet Enjoyment of Private Property
Departure of Tomorrow: A design roadmapping research towards seamless departure journeys
The research was performed in order to design a roadmap for transforming the departure hall, by researching the way KLM could improve the customer departure journey. Hall capacity needs to grow to accommodate for an expected increase in passenger numbers: for welcoming, waiting, check-in, and baggage processing. Design roadmapping methodology is used for performing initial context research, and for mapping user value drivers, new ideas for departure, and pathways to a future vision. The company context is researched by discovering KLM values and by mapping stakeholders in departure. Passengers are the primary stakeholders who interact with staff at the airport, and perform check-in and bag drop tasks in the departure hall. By mapping flow, user routing in the journey is made clear. By combining these insights with literature on waiting, passenger behavior, the perception of waiting, and an action mapping exercise, a journey overview is created. In order to truly understand customer journeys, interviewing with passengers was arranged in the live environment. Journey mapping yielded a journey experience overview and four personas in departure with specific service requirements, motivations for assistance, and needs. Market research in the form of a competitor analysis and DEPEST research provides the trend patterning needed for future visioning. A problem definition of current departure at the airport is established by reflecting on the airline's ambition to be most customer-centric, efficient, and innovative. Most important in design roadmapping are user value drivers; the unmet needs of future customers. Understanding these needs allows forward-looking enterprises to transform processes and services in time to create new value. By introducing the analogous customer experience of upcoming seamless grocery shopping, the design team engaged in a value mapping exercise yielding five key user value drivers: convenience, comprehension, choice, confirmation, and care. An envisioned future departure interaction is explained by imagining the functional and emotional benefits of future solutions according to these five value drivers. A three component future vision statement is provided. While the first half of the research focused on doing research and envisioning an improved future departure, the second part is dedicated to designing the roadmap. At this halfway point of the research, a switch from journey touchpoint research to changed strategic processes for new business development is made. Here, a roadmap offering a strategic pathway to the future is needed. As the five user value drivers were found, what remains is mapping of new ideas for departure, and mapping of pathways to the future vision. For idea mapping, a tech scouting is performed in order to see what technology is available and to learn how these are relevant in reaching the vision. An integral ideation day yielded eight idea concepts spread over three horizons. The ideas aim at simplifying touchpoints, offering journey guidance, providing departure certainty and facilitate purchasing, shortening touchtime, and offering true care and recognition. Implications of horizon developments for a Staff of Tomorrow, and Operations of Tomorrow are explained. These five themes in the mapped ideas shape the pathways to the three component future vision, or alternatively: the roads to follow to achieve the ambition. Here, the decision is made to construct two roadmaps for flexibility in creative dialogue: a strategic roadmap which quickly communicates vision outlook and strategic themes, and a tactical roadmap displaying full background information and concept idea information. The two roadmaps are introduced and the approach and design choices are explained. A reflection on requirements set at the halfway point of the research is provided.Finally, the research is concluded by means of a discussion which provides a brief summary of the work, states the implications of the research, and suggests four follow-up projects, as well as future design sprint HCWs for moving forward with Departure of Tomorrow. The thesis concludes with a reflection on the value of creative dialogue and roadmapping at KLM, and a personal reflection on the project. Strategic Product Desig
Rapid rhythmic entrainment in bio-inspired central pattern generators
Entrainment of movement to a periodic stimulus is a characteristic
intelligent behaviour in humans and an important goal for adaptive robotics. We
demonstrate a quadruped central pattern generator (CPG), consisting of modified
Matsuoka neurons, that spontaneously adjusts its period of oscillation to that
of a periodic input signal. This is done by simple forcing, with the aid of a
filtering network as well as a neural model with tonic input-dependent
oscillation period. We first use the NSGA3 algorithm to evolve the CPG
parameters, using separate fitness functions for period tunability, limb
homogeneity and gait stability. Four CPGs, maximizing different weighted
averages of the fitness functions, are then selected from the Pareto front and
each is used as a basis for optimizing a filter network. Different numbers of
neurons are tested for each filter network. We find that period tunability in
particular facilitates robust entrainment, that bounding gaits entrain more
easily than walking gaits, and that more neurons in the filter network are
beneficial for pre-processing input signals. The system that we present can be
used in conjunction with sensory feedback to allow low-level adaptive and
robust behaviour in walking robots.Comment: 7 pages, 6 figures. To appear in Proceedings of the IEEE
International Joint Conference on Neural Networks 202
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Photobiodulation Inhibits Long-Term Structural and Functional Lesions of Diabetic Retinopathy
Previous studies demonstrated that brief (3 to 4 min) daily application of light at 670 nm to diabetic rodents inhibited molecular and pathophysiologic processes implicated in the pathogenesis of diabetic retinopathy (DR) and reversed diabetic macular edema in small numbers of patients studied. Whether or not this therapy would inhibit the neural and vascular lesions that characterize the early stages of the retinopathy was unknown. We administered photobiomodulation (PBM) therapy daily for 8 months to streptozotocin-diabetic mice and assessed effects of PBM on visual function, retinal capillary permeability, and capillary degeneration using published methods. Vitamin D receptor and Cyp24a1 transcripts were quantified by quantitative real-time PCR, and the abundance of c-Kit+ stem cells in blood and retina were assessed. Long-term daily administration of PBM significantly inhibited the diabetes-induced leakage and degeneration of retinal capillaries and also significantly inhibited the diabetes-induced reduction in visual function. PBM also inhibited diabetes-induced reductions in retinal Cyp24a1 mRNA levels and numbers of circulating stem cells (CD45-/c-Kit+), but these effects may not account for the beneficial effects of PBM on the retinopathy. PBM significantly inhibits the functional and histopathologic features of early DR, and these effects likely are mediated via multiple mechanisms
Characterization of In Vitro and In Vivo Metabolic Pathways of the Investigational Anticancer Agent, 2-Methoxyestradiol
The aim of this study was to characterize the metabolic pathways of 2-methoxyestradiol (2ME2), an investigational anticancer drug. In vitro metabolism studies were performed by incubation of 2ME2 with human liver microsomes under various conditions and metabolite identification was performed using liquid chromatography-tandem mass spectrometry. In microsomal mixtures, four major oxidative metabolites and two glucuronic acid conjugates were observed originating from 2ME2. Human liver S9 protein fraction was used to screen for in vitro sulfation but no prominent conjugates were observed. The total hepatic clearance as estimated using the well-stirred model was approximately 712 mL/min. In vivo metabolism, assessed using 24-h collections of urine from cancer patients treated with 2ME2 revealed tha
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Transducin1, Phototransduction and the Development of Early Diabetic Retinopathy.
PURPOSE: Recent evidence suggests that retinal photoreceptor cells have an important role in the pathogenesis of retinal microvascular lesions in diabetes. We investigated the role of rod cell phototransduction on the pathogenesis of early diabetic retinopathy (DR) using Gnat1-/- mice (which causes permanent inhibition of phototransduction in rod cells without degeneration). METHODS: Retinal thickness, oxidative stress, expression of inflammatory proteins, electroretinograms (ERG) and optokinetic responses, and capillary permeability and degeneration were evaluated at up to 8 months of diabetes. RESULTS: The diabetes-induced degeneration of retinal capillaries was significantly inhibited in the Gnat1-/- diabetics. The effect of the Gnat1 deletion on the diabetes-induced increase in permeability showed a nonuniform accumulation of albumin in the neural retina; the defect was inhibited in diabetic Gnat1-/- mice in the inner plexiform layer (IPL), but neither in the outer plexiform (OPL) nor inner nuclear (INL) layers. In Gnat1-deficient animals, the diabetes-induced increase in expression of inflammatory associated proteins (iNOS and ICAM-1, and phosphorylation of IĸB) in the retina, and the leukocyte mediated killing of retinal endothelial cells were inhibited, however the diabetes-mediated induction of oxidative stress was not inhibited. CONCLUSIONS: In conclusion, deletion of transducin1 (and the resulting inhibition of phototransduction in rod cells) inhibits the development of retinal vascular pathology in early DR