1,235 research outputs found

    Novel Characteristics of Valveless Pumping

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    This study investigates the occurrence of valveless pumping in a fluidfilled system consisting of two open tanks connected by an elastic tube. We show that directional flow can be achieved by introducing a periodic pinching applied at an asymmetrical location along the tube, and that the flow direction depends on the pumping frequency. We propose a relation between wave propagation velocity, tube length, and resonance frequencies associated with shifts in the pumping direction using numerical simulations. The eigenfrequencies of the system are estimated from the linearized system, and we show that these eigenfrequencies constitute the resonance frequencies and the horizontal slope frequencies of the system; 'horizontal slope frequency' being a new concept. A simple model is suggested, explaining the effect of the gravity driven part of the oscillation observed in response to the tank and tube diameter changes. Results are partly compared with experimental findings.Art. no. 22450

    Lonely but avoidant—the unfortunate juxtaposition of loneliness and self-disgust

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    Loneliness is prevalent worldwide and is a known risk factor for numerous physical and mental health outcomes. The health consequences of chronic loneliness coupled with the cost on public health care has necessitated the development of interventions and campaigns to end loneliness globally. According to a recent meta-analysis, such interventions focus on improving social skills, increasing opportunities for social contact/support (i.e., reducing social isolation) or addressing maladaptive cognition (e.g., irrational thoughts, self-defeating, and self-blame thoughts). The results showed that changing maladaptive thoughts offer “the best chance” for alleviating feelings of loneliness. In accordance with the latter approach, this paper proposes a new paradigm in understanding and treating loneliness that takes into account self-disgust, an aversive self-conscious affective state that reflects disgust directed towards the self. Based on findings from published and unpublished data, it is argued that interventions against loneliness that focus exclusively on improving social skills and increasing opportunities for social contact may be ineffective because lonelier people experience more self-disgust, which makes them more socially inhibited and reluctant to connect with other people. Future interventions should consider self-disgust in the treatment of loneliness and explore ways to counter feelings of self-disgust

    Cardiosphere-derived cells suppress allogeneic lymphocytes by production of PGE2 acting via the EP4 receptor

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    derived cells (CDCs) are a cardiac progenitor cell population, which have been shown to possess cardiac regenerative properties and can improve heart function in a variety of cardiac diseases. Studies in large animal models have predominantly focussed on using autologous cells for safety, however allogeneic cell banks would allow for a practical, cost-effective and efficient use in a clinical setting. The aim of this work was to determine the immunomodulatory status of these cells using CDCs and lymphocytes from 5 dogs. CDCs expressed MHC I but not MHC II molecules and in mixed lymphocyte reactions demonstrated a lack of lymphocyte proliferation in response to MHC-mismatched CDCs. Furthermore, MHC-mismatched CDCs suppressed lymphocyte proliferation and activation in response to Concanavalin A. Transwell experiments demonstrated that this was predominantly due to direct cell-cell contact in addition to soluble mediators whereby CDCs produced high levels of PGE2 under inflammatory conditions. This led to down-regulation of CD25 expression on lymphocytes via the EP4 receptor. Blocking prostaglandin synthesis restored both, proliferation and activation (measured via CD25 expression) of stimulated lymphocytes. We demonstrated for the first time in a large animal model that CDCs inhibit proliferation in allo-reactive lymphocytes and have potent immunosuppressive activity mediated via PGE2

    Climate-resilient development planning for cities: progress from Cape Town.

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    Priorities and programmes in the City of Cape Town's Integrated Development Plan (2022-2027) demonstrate progress towards operationalising local level planning for climate-resilient development. These developments provide lessons of process and focus on transformative outcomes for cities seeking equitable and just development while implementing climate change adaptation and mitigation.fals

    Assessing Graphical Robot Aids for Interactive Co-working

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    The shift towards more collaborative working between humans and robots increases the need for improved interfaces. Alongside robust measures to ensure safety and task performance, humans need to gain the confidence in robot co-operators to enable true collaboration. This research investigates how graphical signage can support human–robot co-working, with the intention of increased productivity. Participants are required to co-work with a KUKA iiwa lightweight manipulator on a manufacturing task. The three conditions in the experiment differ in the signage presented to the participants – signage relevant to the task, irrelevant to the task, or no signage. A change between three conditions is expected in anxiety and negative attitudes towards robots; error rate; response time; and participants’ complacency, suggested by facial expressions. In addition to understanding how graphical languages can support human–robot co-working, this study provides a basis for further collaborative research to explore human–robot co-working in more detail

    Maternal VDR variants rather than 25-hydroxyvitamin D concentration during early pregnancy are associated with type 1 diabetes in the offspring

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    This study was supported by the Finnish Academy (grant 127219), the European Foundation for the Study of Diabetes, the Novo Nordisk Foundation, the Diabetes Research Foundation, the EVO funding of the South Ostrobothnia Central Hospital from the Ministry ofHealthand SocialAffairs (EVO1107), the BiomedicumHelsinki Foun- dation, the Jalmari and Rauha Ahokas Foundation, the Yrjö Jahnsson Foundation, the Suoma Loimaranta-Airila Fund, the Onni and Hilja Tuovinen Foundation and the Juho Vainio Foundation

    Electron Antineutrino Search at the Sudbury Neutrino Observatory

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    Upper limits on the \nuebar flux at the Sudbury Neutrino Observatory have been set based on the \nuebar charged-current reaction on deuterium. The reaction produces a positron and two neutrons in coincidence. This distinctive signature allows a search with very low background for \nuebar's from the Sun and other potential sources. Both differential and integral limits on the \nuebar flux have been placed in the energy range from 4 -- 14.8 MeV. For an energy-independent \nu_e --> \nuebar conversion mechanism, the integral limit on the flux of solar \nuebar's in the energy range from 4 -- 14.8 MeV is found to be \Phi_\nuebar <= 3.4 x 10^4 cm^{-2} s^{-1} (90% C.L.), which corresponds to 0.81% of the standard solar model 8B \nu_e flux of 5.05 x 10^6 cm^{-2} s^{-1}, and is consistent with the more sensitive limit from KamLAND in the 8.3 -- 14.8 MeV range of 3.7 x 10^2 cm^{-2} s^{-1} (90% C.L.). In the energy range from 4 -- 8 MeV, a search for \nuebar's is conducted using coincidences in which only the two neutrons are detected. Assuming a \nuebar spectrum for the neutron induced fission of naturally occurring elements, a flux limit of Phi_\nuebar <= 2.0 x 10^6 cm^{-2} s^{-1}(90% C.L.) is obtained.Comment: submitted to Phys. Rev.

    Emerging concepts of shear stress in placental development and function.

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    Blood flow, and the force it generates, is critical to placental development and function throughout pregnancy. This mechanical stimulation of cells by the friction generated from flow is called shear stress (SS) and is a fundamental determinant of vascular homeostasis, regulating remodelling and vasomotor tone. This review describes how SS is fundamental to the establishment and regulation of the blood flow through the uteroplacental and fetoplacental circulations. Amongst the most recent findings is that alongside the endothelium, embryonic stem cells and the villous trophoblast are mechanically sensitive. A complex balance of forces is required to enable effective establishment of the uteroplacental circulation, whilst protecting the embryo and placental villi. SS also generates flow-mediated vasodilatation through the release of endothelial nitric oxide, a process vital for adequate placental blood flow. The identification of SS sensors and the mechanisms governing how the force is converted into biochemical signals is a fast-paced area of research, with multiple cellular components under investigation. For example, the Piezo1 ion channel is mechanosensitive in a variety of tissues including the fetoplacental endothelium. Enhanced Piezo1 activity has been demonstrated in response to the Yoda1 agonist molecule, suggesting the possibility for developing tools to manipulate these channels. Whether such agents might progress to novel therapeutics to improve blood flow through the placenta requires further consideration and research

    Attachment, infidelity, and loneliness in college students involved in a romantic relationship: the role of relationship satisfaction, morbidity and prayer for partner

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    This study examined the mediating effects of relationship satisfaction, prayer for a partner, and morbidity in the relationship between attachment and loneliness, infidelity and loneliness, and psychological morbidity and loneliness, in college students involved in a romantic relationship. Participants were students in an introductory course on family development. This study examined only students (n = 345) who were involved in a romantic relationship. The average age of participants was 19.46 (SD = 1.92) and 25 % were males. Short-form UCLA Loneliness Scale (ULS-8), (Hays and DiMatteo in J Pers Assess 51:69–81, doi:10.1207/s15327752jpa5101_6, 1987); Relationship Satisfaction Scale (Funk and Rogge in J Fam Psychol 21:572–583, doi:10.1037/0893-3200.21.4.572, 2007); Rotterdam Symptom Checklist (De Haes et al. in Measuring the quality of life of cancer patients with the Rotterdam Symptom Checklist (RSCL): a manual, Northern Centre for Healthcare Research, Groningen, 1996); Prayer for Partner Scale, (Fincham et al. in J Pers Soc Psychol 99:649–659, doi:10.1037/a0019628, 2010); Infidelity Scale, (Drigotas et al. in J Pers Soc Psychol 77:509–524, doi:10.1037/0022-3514.77.3.509, 1999); and the Experiences in Close Relationship Scale-short form (Wei et al. in J Couns Psychol 52(4):602–614, doi:10.1037/0022-0167.52.4.602, 2005). Results showed that relationship satisfaction mediated the relationship between avoidance attachment and loneliness and between infidelity and loneliness. Physical morbidity mediated the relationship between anxious attachment and psychological morbidity. Psychological morbidity mediated the relationship between anxious attachment and physical morbidity. The present results expand the literature on attachment by presenting evidence that anxious and avoidant partners experience loneliness differently. Implications for couple’s therapy are addressed. Future research should replicate these results with older samples and married couples.Acknowledgments This research was supported by Grant Number 90FE0022 from the United States Department of Health and Human Services awarded to the last author
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