223 research outputs found

    Modelling polarity-driven laminar patterns in bilayer tissues with mixed signalling mechanisms

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    Recent advances in high-resolution experimental methods have highlighted the significance of cell signal pathway crosstalk and localised signalling activity in the development and disease of numerous biological systems. The investigation of multiple signal pathways often introduces different methods of cell-cell communication, i.e. contact-based or diffusive signalling, which generates both a spatial and temporal dependence on cell behaviours. Motivated by cellular mechanisms that control cell-fate decisions in developing bilayer tissues, we use dynamical systems coupled with multilayer graphs to analyse the role of signalling polarity and pathway crosstalk in fine-grain pattern formation of protein activity. Specifically, we study how multilayer graph edge structures and weights influence the layer-wise (laminar) patterning of cells in bilayer structures, which are commonly found in glandular tissues. We present sufficient conditions for existence, uniqueness and instability of homogeneous cell states in the large-scale spatially discrete dynamical system. Using methods of pattern templating by graph partitioning to generate quotient systems in combination with concepts from monotone dynamical systems, we exploit the extensive dimensionality reduction to provide existence conditions for the polarity required to induce fine-grain laminar patterns with multiple spatially dependent intracellular components. We then explore the spectral links between the quotient and large-scale dynamical systems to extend the laminar patterning criteria from existence to convergence for sufficiently large amounts of cellular polarity in the large-scale dynamical system, independent of spatial dimension and number of cells in the tissue

    The Impact of Cognitive Style Diversity on Implicit Learning in Teams

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    Organizations are increasingly looking for ways to reap the benefits of cognitive diversity for problem solving. A major unanswered question concerns the implications of cognitive diversity for longer-term outcomes such as team learning, with its broader effects on organizational learning and productivity. We study how cognitive style diversity in teams-or diversity in the way that team members encode, organize and process information-indirectly influences team learning through collective intelligence, or the general ability of a team to work together across a wide array of tasks. Synthesizing several perspectives, we predict and find that cognitive style diversity has a curvilinear-inverted U-shaped-relationship with collective intelligence. Collective intelligence is further positively related to the rate at which teams learn, and is a mechanism guiding the indirect relationship between cognitive style diversity and team learning. We test the predictions in 98 teams using ten rounds of the minimum-effort tacit coordination game. Overall, this research advances our understanding of the implications of cognitive diversity for organizations and why some teams demonstrate high levels of team learning in dynamic situations while others do not. Keywords: teams; team learning; implicit coordination; collective intelligence; cognitive diversityNational Science Foundation (U.S.) (Grant IIS-0963451

    Reading the Mind in the Eyes or Reading between the Lines? Theory of Mind Predicts Collective Intelligence Equally Well Online and Face-To-Face

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    Recent research with face-to-face groups found that a measure of general group effectiveness (called “collective intelligence”) predicted a group’s performance on a wide range of different tasks. The same research also found that collective intelligence was correlated with the individual group members’ ability to reason about the mental states of others (an ability called “Theory of Mind” or “ToM”). Since ToM was measured in this work by a test that requires participants to “read” the mental states of others from looking at their eyes (the “Reading the Mind in the Eyes” test), it is uncertain whether the same results would emerge in online groups where these visual cues are not available. Here we find that: (1) a collective intelligence factor characterizes group performance approximately as well for online groups as for face-to-face groups; and (2) surprisingly, the ToM measure is equally predictive of collective intelligence in both face-to-face and online groups, even though the online groups communicate only via text and never see each other at all. This provides strong evidence that ToM abilities are just as important to group performance in online environments with limited nonverbal cues as they are face-to-face. It also suggests that the Reading the Mind in the Eyes test measures a deeper, domain-independent aspect of social reasoning, not merely the ability to recognize facial expressions of mental states.National Science Foundation (U.S.) (Grant IIS-0963285)National Science Foundation (U.S.) (Grant ACI-1322254)National Science Foundation (U.S.) (Grant IIS-0963451)United States. Army Research Office (Grant 56692-MA)United States. Army Research Office (Grant 64079-NS)Cisco Systems, Inc. Massachusetts Institute of Technology. Center for Collective Intelligenc

    Further development of spinal cord retreatment dose estimation: including radiotherapy with protons and light ions

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    Purpose A graphical user interface (GUI) was developed to aid in the assessment of changes in the radiation tolerance of spinal cord/similar central nervous system tissues with time between two individual treatment courses. Methods The GUI allows any combination of photons, protons (or ions) to be used as the initial, or retreatment, radiotherapy courses. Allowances for clinical circumstances, of reduced tolerance, can also be made. The radiobiological model was published previously and has been incorporated with additional checks and safety features, to be as safe to use as possible. The proton option includes use of a fixed RBE of 1.1 (set as the default), or a variable RBE, the latter depending on the proton linear energy transfer (LET) for organs at risk. This second LET-based approach can also be used for ions, by changing the LET parameters. Results GUI screenshots are used to show the input and output parameters for different clinical situations used in worked examples. The results from the GUI are in agreement with manual calculations, but the results are now rapidly available without tedious and error-prone manual computations. The software outputs provide a maximum dose limit boundary, which should not be exceeded. Clinicians may also choose to further lower the number of treatment fractions, whilst using the same dose per fraction (or conversely a lower dose per fraction but with the same number of fractions) in order to achieve the intended clinical benefit as safely as possible. Conclusions The new GUI will allow scientific-based estimations of time related radiation tolerance changes in the spinal cord and similar central nervous tissues (optic chiasm, brainstem), which can be used to guide the choice of retreatment dose fractionation schedules, with either photons, protons or ions

    Modelling polarity-driven laminar patterns in bilayer tissues with mixed signalling mechanisms

    Get PDF
    Recent advances in high-resolution experimental methods have highlighted the significance of cell signal pathway crosstalk and localised signalling activity in the development and disease of numerous biological systems. The investigation of multiple signal pathways often introduces different methods of cell-cell communication, i.e. contact-based or diffusive signalling, which generates both a spatial and temporal dependence on cell behaviours. Motivated by cellular mechanisms that control cell-fate decisions in developing bilayer tissues, we use dynamical systems coupled with multilayer graphs to analyse the role of signalling polarity and pathway crosstalk in fine-grain pattern formation of protein activity. Specifically, we study how multilayer graph edge structures and weights influence the layer-wise (laminar) patterning of cells in bilayer structures, which are commonly found in glandular tissues. We present sufficient conditions for existence, uniqueness and instability of homogeneous cell states in the large-scale spatially discrete dynamical system. Using methods of pattern templating by graph partitioning to generate quotient systems, in combination with concepts from monotone dynamical systems, we exploit the extensive dimensionality reduction to provide existence conditions for the polarity required to induce fine-grain laminar patterns with multiple spatially dependent intracellular components. We then explore the spectral links between the quotient and large-scale dynamical systems to extend the laminar patterning criteria from existence to convergence for sufficiently large amounts of cellular polarity in the large-scale dynamical system, independent of spatial dimension and number of cells in the tissue

    The Role of Clinical Pharmacists in Modifying Cardiovascular Disease Risk Factors

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    Objective: Assess the effect of intensive clinical and educational interventions aimed at reducing risk factors for Cardiovascular Disease (CVD), implemented by clinical pharmacists, on modifying risk factors in targeted patients at high risk for CVD. Design: Patients with at least two risk factors for CHD were identified at two clinics by conducting a pre-intervention survey and were monitored over a period of 6 months with follow up conversations conducted every 4 weeks by phone and at subsequent physician visits. A post-intervention survey was conducted at the end of the study period to detect modified risk factors. Setting: The Jefferson County Public Health Department (JCHD) Participants: We followed a total of 47 patients over 6 months. The average age at baseline was 51 years old and 80% of the participants were female. The baseline average number of modifiable cardiovascular disease risk factors was 3.7. Measurements: We assessed total number of CVD risk factors, smoking behavior, blood pressure, LDL, A1C, weight, and level of physical activity (major modifiable risk factors by the American Heart Association). Results: Over a 6 month follow-up of 47 patients, statistically significant reductions occurred in total number of CVD risk factors, systolic and diastolic blood pressures, and A1C. Reductions also occurred in LDL level, weight, and changes in smoking behavior and physical activity were identified. Conclusions: Results showed that increased patient counseling on adherence and lifestyle changes along with increased disease state monitoring and medication adjustment led by a clinical pharmacist can decrease risk factors in patients with multiple risk factors for cardiovascular disease.   Type: Student Projec

    Baseline Knowledge and Education on Patient Safety in the Ambulatory Care Setting for 4th Year Pharmacy Students

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    Objectives: To assess the baseline knowledge of fourth year student pharmacists on their ability to properly identify and categorize medication related problems (MRP) during their Advanced Pharmacy Practice Experience (APPE) in the ambulatory care setting, and to assess the efficacy of a written resource designed to educate and train users on identification and documentation of MRP’s and used for this purpose with participating students on their ambulatory care APPE. Methods: A pretest consisting of ten multiple-choice questions was administered electronically to fourth year student pharmacists (N=18) at the start of their ambulatory care APPE. The test was designed to assess both the students’ baseline knowledge regarding MRP’s, and their ability to identify a wide variety of medication-related problems. Students then received a written copy of The Medication Therapy Intervention & Safety Documentation Program training manual and were asked to read it in its entirety in the first week of their APPE. Finally, students were given a posttest survey (identical to the pretest) to complete to assess if their knowledge had increased from baseline. Results: The average score for the 18 students taking the baseline knowledge pre-test was 63.33%, indicating limited baseline knowledge regarding the identification and classification of MRP’s. In assessing the effectiveness of the written training document, the overall posttest results compared to pretest results did not indicate improvement in students’ knowledge or ability to properly identify and classify medication related problems (MRP) after reviewing the training manual. The average scores declined from 63.33% on the pretest to 62.78% on the posttest, although this was not found to be statistically significant (p = 0.884). However, a statistically significant decline in students’ knowledge occurred on one specific question, which tested their ability to classify MRP’s (p = 0.029). Conclusions: Based on the results of the pre-test, students at our institution enter their APPE year with limited baseline knowledge of medication safety within the ambulatory care setting. Results from the posttest indicate potential ineffectiveness of a written document in providing effective education on MRP’s to students in the experiential setting. Education may be made more effective with a hands-on, active learning approach that overcomes the limitations of other passive forms of learning

    A general computational framework for COVID-19 modelling with applications to testing varied interventions in education environments

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    We construct a spatially-compartmental, individual-based model of the spread of SARS-CoV-2 in indoor spaces. The model can be used to predict the infection rates in a variety of locations when various non-pharmaceutical interventions (NPIs) are introduced. Tasked by the Welsh Government, we apply the model to secondary schools and to Further and Higher Education environments. Specifically, we consider student populations mixing in a classroom and in halls of residence. We focus on assessing the potential efficacy of Lateral Flow Devices (LFDs) when used in broad-based screens for asymptomatic infection or in ‘test-to-release’ scenarios in which individuals who have been exposed to infection are released from isolation after a negative LFD result. LFDs are also compared to other NPIs; we find that, although LFD testing can be used to mitigate the spread of SARS-CoV-2, it is more effective to invest in personal protective equipment, e.g., masks, and in increasing ventilation quality. In addition, we provide an open-access and user-friendly online applet that simulates the model, complete with user tutorials to encourage the use of the model to aid educational policy decisions as input infection data becomes available

    Taking a more nuanced look at behavior change for demand reduction in the illegal wildlife trade

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    The illegal wildlife trade threatens the future of many species, and undermines economies and livelihoods. Conservationists have largely responded with supply‐side interventions, such as antipoaching patrols, but these often fail to stem the tide of wildlife trafficking. There is now increasing interest in demand‐side interventions, which seek to lower poaching pressure on sought‐after species by reducing consumer's desire for, and purchase of, specific wildlife products. Individual behavior change approaches, from environmental education to social marketing, have been widely advocated by academics, practitioners, and policy makers. However, this is an emerging field and we lack the breadth of evidence needed to understand and predict the potential outcomes of demand reduction interventions. To help us gain broader insights, we examine the literature from public health and international development on the effectiveness of behavior change interventions, and critique the current conceptualization of strategies for reducing consumer demand in the illegal wildlife trade. We show that behavior change is difficult to achieve and interventions may have unintended and undesirable consequences because of unaddressed systemic, cultural and environmental drivers, and limited resourcing. We conclude that some sections of the conservation community are advocating a shift from one reductionist approach based on limiting supply, to another based on limiting demand, and argue that conservationists should learn from the public health and international development projects that have integrated systems thinking. By accounting for the multiple interactions and synergies between different factors in the wildlife trade, we can develop more strategic approaches to protecting endangered species
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