725 research outputs found

    Manual actuator

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    An actuator for an exercising machine employable by a crewman aboard a manned spacecraft is presented. The actuator is characterized by a force delivery arm projected from a rotary imput shaft of an exercising machine and having a force input handle extended orthogonally from its distal end. The handle includes a hand-grip configured to be received within the palm of the crewman's hand and a grid pivotally supported for angular displacement between a first position, wherein the grid is disposed in an overlying juxtaposition with the hand-grip, and a second position, angularly displaced from the first position, for affording access to the hand-grip, and a latching mechanism fixed to the sole of a shoe worn by the crewman for latching the shoe to the grid when the grid is in the first position

    Ergometer

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    An ergometer is described that has a pedal driven direct current motor as a load and includes a frame for supporting the body of a person in either a sitting or a prone position. The pedals may be operated by either the feet or the hands. The electrical circuitry of the ergometer includes means for limiting the load applied to the pedals as a function of work being performed, heart rate, and increases in heart rate

    Conductive elastomeric extensometer

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    Bridge circuit, in which conductive elastomeric material is the variable leg, precisely measures surface area changes in the human body. Circuits are used singularly, or in quantity by adding elements and amplifier circuits. Elastomeric strips can be located in a form-fitting garment

    Multimode ergometer system

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    System overcomes previous ergometer design and calibration problems including inaccurate measurements, large weight, size, and input power requirements, poor heat dissipation, high flammability, and inaccurate calibration. Device consists of lightweight, accurately controlled ergometer, restraint system, and calibration system

    PSA Screening in Lewiston Maine

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    PSA Screening Patient Information for 2017 guidelineshttps://scholarworks.uvm.edu/fmclerk/1379/thumbnail.jp

    Emergence of diversity in a model ecosystem

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    The biological requirements for an ecosystem to develop and maintain species diversity are in general unknown. Here we consider a model ecosystem of sessile and mutually excluding organisms competing for space [Mathiesen et al. Phys. Rev. Lett. 107, 188101 (2011)]. The competition is controlled by an interaction network with fixed links chosen by a Bernoulli process. New species are introduced in the system at a predefined rate. In the limit of small introduction rates, the system becomes bistable and can undergo a phase transition from a state of low diversity to high diversity. We suggest that patches of isolated meta-populations formed by the collapse of cyclic relations are essential for the transition to the state of high diversity.Comment: 7 pages, 6 figures. Accepted for publication in PRE. Typos corrected, Fig.3A and Fig.6 update

    Ecosystems with mutually exclusive interactions self-organize to a state of high diversity

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    Ecological systems comprise an astonishing diversity of species that cooperate or compete with each other forming complex mutual dependencies. The minimum requirements to maintain a large species diversity on long time scales are in general unknown. Using lichen communities as an example, we propose a model for the evolution of mutually excluding organisms that compete for space. We suggest that chain-like or cyclic invasions involving three or more species open for creation of spatially separated sub-populations that subsequently can lead to increased diversity. In contrast to its non-spatial counterpart, our model predicts robust co-existence of a large number of species, in accordance with observations on lichen growth. It is demonstrated that large species diversity can be obtained on evolutionary timescales, provided that interactions between species have spatial constraints. In particular, a phase transition to a sustainable state of high diversity is identified.Comment: 4 pages, 4 figure

    Nutrition Education in Vermont Public Schools

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    Introduction. Despite positive changes, childhood obesity and food insecurity remain prevalent across the country. Vermont is not immune to these issues. We set out to: research the level of nutrition education Vermont elementary schools provide their students, understand teacher perceptions of these programs, and recommend ways to fill identified gaps. Methods. Our study is a cross-sectional survey of Vermont educators around nutrition education. The survey consisted of 17 questions, used LimeSurvey, and included demographic and nutrition education questions. The survey was distributed statewide through newsletters and list-servers. Results. 64 responses met inclusion criteria. Vermont elementary school (K-6) teachers report a mean satisfaction score of 2.51 out of 5.0 for their schools\u27 current nutrition education programs. School nurses reported a score of 2.5 out of 5.0. Highest satisfaction scores included school administrators and health and wellness coordinators (3.3 out of 5.0). When comparing teachers to non-classroom educators (administrators and nutrition educators) data showed a significant difference between high satisfaction (3-5) and low satisfaction (1-2); (Fischer p = 0.009). Overall, Vermont elementary school teachers report a high level of knowledge about nutrition, (4.1/5.0), but a lower level of understanding in their students (2.5/5.0). Conclusions. Given teacher perceptions regarding current school nutrition education programs, development and implementation of a state-wide nutrition education curriculum with dedicated teaching time may be warranted. Programs recommended by the CDC include Eat Well & Get Moving and Planet Health, designed by the Harvard School of Public Health. These could be adapted as a framework for Vermont.https://scholarworks.uvm.edu/comphp_gallery/1244/thumbnail.jp

    Coexistence and critical behaviour in a lattice model of competing species

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    In the present paper we study a lattice model of two species competing for the same resources. Monte Carlo simulations for d=1, 2, and 3 show that when resources are easily available both species coexist. However, when the supply of resources is on an intermediate level, the species with slower metabolism becomes extinct. On the other hand, when resources are scarce it is the species with faster metabolism that becomes extinct. The range of coexistence of the two species increases with dimension. We suggest that our model might describe some aspects of the competition between normal and tumor cells. With such an interpretation, examples of tumor remission, recurrence and of different morphologies are presented. In the d=1 and d=2 models, we analyse the nature of phase transitions: they are either discontinuous or belong to the directed-percolation universality class, and in some cases they have an active subcritical phase. In the d=2 case, one of the transitions seems to be characterized by critical exponents different than directed-percolation ones, but this transition could be also weakly discontinuous. In the d=3 version, Monte Carlo simulations are in a good agreement with the solution of the mean-field approximation. This approximation predicts that oscillatory behaviour occurs in the present model, but only for d>2. For d>=2, a steady state depends on the initial configuration in some cases.Comment: 11 pages, 14 figure

    The impact of the Arab Spring on democracy and development in the MENA region

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    © 2019 John Wiley & Sons Ltd. In evaluating the consequences of the Arab Spring 8 years later, this paper not only focuses on the short-term consequences of the uprisings that swept through a number of countries in the Middle East and North African region but also analyzes the long-term prospects for democratization and development in the MENA region. The impact of the Arab Spring, despite its promises and the expectations of the rest of the world, has been dismal. While only Tunisia made a successful transition to a democratic polity with a constitution guaranteeing the basic rights of the people, the rest of the Arab Spring countries remain in the grip of the authoritarian rule, and countries such as Syria, Libya, and Yemen have been degenerated into bloody civil wars with dwindling hope of peace and freedom. On economic front, the growth has been tardy, showing little difference with countries that were unaffected by the Arab Spring. Yet, the paper concludes, echoing historian Eric Hobsbawm\u27s view, that revolutionary outcomes need not be judged as failure too quickly as they are likely to be partial success in the long term. The impact may be observed in the area of social opening, newer class alliances, and the emergence of a less rapacious, reformed, hybrid authoritarianism
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