2,393 research outputs found

    Undergraduate Textbook Representations of Meiosis Neglect Essential Elements

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    The process of meiosis is an essential topic that secondary and postsecondary students struggle with. The important meiosis-related concepts of homology, ploidy, and segregation can be described using the DNA Triangle framework, which connects them to the multidimensional nature of DNA (chromosomal, molecular, and informational levels). We have previously established that undergraduate biology students typically fail to describe and/or link appropriate levels to their explanations of meiosis. We hypothesize that students\u27 understanding mirrors the resources they are given – in other words, textbook figures often lack many of the important connections that experts include when talking about meiosis. Prior work showed that text in meiosis chapters typically fails to include many concepts that experts consider important, so we examined how textbook figures present meiosis concepts. We found that almost all textbook representations include the chromosomal level of DNA, but few include the other levels, even to illustrate concepts that are rooted in informational and/or molecular levels. In particular, the molecular level of DNA was absent from nearly all introductory textbook figures examined, and the informational level was seldom depicted in mid/upper-level textbook figures. The previously established deficits in text portions of textbooks are clearly not compensated by their accompanying illustrations

    Trajectory Mapping and Applications to Data from the Upper Atmosphere Research Satellite

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    The problem of creating synoptic maps from asynoptically gathered trace gas data has prompted the development of a number of schemes. Most notable among these schemes are the Kalman filter, the Salby-Fourier technique, and constituent reconstruction. This paper explores a new technique called trajectory mapping. Trajectory mapping creates synoptic maps from asynoptically gathered data by advecting measurements backward or forward in time using analyzed wind fields. A significant portion of this work is devoted to an analysis of errors in synoptic trajectory maps associated with the calculation of individual parcel trajectories. In particular, we have considered (1) calculational errors; (2) uncertainties in the values and locations of constituent measurements, (3) errors incurred by neglecting diabatic effects, and (4) sensitivity to differences in wind field analyses. These studies reveal that the global fields derived from the advection of large numbers of measurements are relatively insensitive to the errors in the individual trajectories. The trajectory mapping technique has been successfully applied to a variety of problems. In this paper, the following two applications demonstrate the usefulness of the technique: an analysis of dynamical wave-breaking events and an examination of Upper Atmosphere Research Satellite data accuracy

    Personalized behavior change program for glaucoma patients with poor adherence: a pilot interventional cohort study with a pre-post design

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    Abstract Background About half of people with glaucoma do not adhere to their recommended medications. Interventions for other chronic conditions have successfully utilized reminder systems and motivational interviewing (MI)-based counseling. This study was designed to pilot a personalized intervention that leverages these strategies to assess their impact on medication adherence in glaucoma patients. Methods Glaucoma patients taking ≥ 1 medication will be pre-screened by telephone survey for adherence to their medication(s). Those who self-report poor adherence will be enrolled in a 3-month monitoring period to measure medication adherence using electronic medication monitors. Participants who are non-adherent (take </=80% of their medication doses) over the 3-month run in phase will be eligible for the study. We plan to enroll 57 participants who are non-adherent to their medications. Participants’ adherence will then be continuously measured with electronic medication monitors, by self-report, and via pharmacy refill data over 2 years, during which two successively more resource-intensive components of an intervention aimed to improve medication adherence will be administered. The first component is a 3-month period of reminders (audio and/or visual) and text message or automated phone call if a dose of medication is not taken within a pre-specified time frame. The second component is a 6-month MI-based counseling program with a trained glaucoma counselor. This component uses the eyeGuide, a computer-based personalized behavior change program that enables para-professional staff to provide personalized education and counseling for glaucoma. The primary outcome is change in medication adherence. The secondary outcomes include changes in clinical outcomes (intraocular pressure, IOP, and IOP fluctuation) and psychosocial mediators of adherence (e.g., competence, energy for change and satisfaction). Participants will undergo semi-structured interviews at 12 months to give feedback about the counseling program in order to improve it. Discussion This pilot study will provide insight into ways to deliver more personalized health care to non-adherent glaucoma patients in order to better support them in managing their chronic disease. Trial registration Retrospectively registered with ClinicalTrials.gov ( NCT03159247 ).https://deepblue.lib.umich.edu/bitstream/2027.42/145182/1/40814_2018_Article_320.pd

    Evolution of Cooperation and Coordination in a Dynamically Networked Society

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    Situations of conflict giving rise to social dilemmas are widespread in society and game theory is one major way in which they can be investigated. Starting from the observation that individuals in society interact through networks of acquaintances, we model the co-evolution of the agents' strategies and of the social network itself using two prototypical games, the Prisoner's Dilemma and the Stag Hunt. Allowing agents to dismiss ties and establish new ones, we find that cooperation and coordination can be achieved through the self-organization of the social network, a result that is non-trivial, especially in the Prisoner's Dilemma case. The evolution and stability of cooperation implies the condensation of agents exploiting particular game strategies into strong and stable clusters which are more densely connected, even in the more difficult case of the Prisoner's Dilemma.Comment: 18 pages, 14 figures. to appea

    Capture the fracture: a best practice framework and global campaign to break the fragility fracture cycle

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    Summary The International Osteoporosis Foundation (IOF) Capture the Fracture Campaign aims to support implementation of Fracture Liaison Services (FLS) throughout the world. Introduction FLS have been shown to close the ubiquitous secondary fracture prevention care gap, ensuring that fragility fracture sufferers receive appropriate assessment and intervention to reduce future fracture risk. Methods Capture the Fracture has developed internationally endorsed standards for best practice, will facilitate change at the national level to drive adoption of FLS and increase awareness of the challenges and opportunities presented by secondary fracture prevention to key stakeholders. The Best Practice Framework (BPF) sets an international benchmark for FLS, which defines essential and aspirational elements of service delivery. Results The BPF has been reviewed by leading experts from many countries and subject to beta-testing to ensure that it is internationally relevant and fit-for-purpose. The BPF will also serve as a measurement tool for IOF to award ‘Capture the Fracture Best Practice Recognition’ to celebrate successful FLS worldwide and drive service development in areas of unmet need. The Capture the Fracture website will provide a suite of resources related to FLS and secondary fracture prevention, which will be updated as new materials become available. A mentoring programme will enable those in the early stages of development of FLS to learn from colleagues elsewhere that have achieved Best Practice Recognition. A grant programme is in development to aid clinical systems which require financial assistance to establish FLS in their localities. Conclusion Nearly half a billion people will reach retirement age during the next 20 years. IOF has developed Capture the Fracture because this is the single most important thing that can be done to directly improve patient care, of both women and men, and reduce the spiralling fracture-related care costs worldwide.</p

    Association of Accelerometry-Measured Physical Activity and Cardiovascular Events in Mobility-Limited Older Adults: The LIFE (Lifestyle Interventions and Independence for Elders) Study.

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    BACKGROUND:Data are sparse regarding the value of physical activity (PA) surveillance among older adults-particularly among those with mobility limitations. The objective of this study was to examine longitudinal associations between objectively measured daily PA and the incidence of cardiovascular events among older adults in the LIFE (Lifestyle Interventions and Independence for Elders) study. METHODS AND RESULTS:Cardiovascular events were adjudicated based on medical records review, and cardiovascular risk factors were controlled for in the analysis. Home-based activity data were collected by hip-worn accelerometers at baseline and at 6, 12, and 24&nbsp;months postrandomization to either a physical activity or health education intervention. LIFE study participants (n=1590; age 78.9±5.2 [SD] years; 67.2% women) at baseline had an 11% lower incidence of experiencing a subsequent cardiovascular event per 500&nbsp;steps taken per day based on activity data (hazard ratio, 0.89; 95% confidence interval, 0.84-0.96; P=0.001). At baseline, every 30&nbsp;minutes spent performing activities ≥500&nbsp;counts per minute (hazard ratio, 0.75; confidence interval, 0.65-0.89 [P=0.001]) were also associated with a lower incidence of cardiovascular events. Throughout follow-up (6, 12, and 24&nbsp;months), both the number of steps per day (per 500&nbsp;steps; hazard ratio, 0.90, confidence interval, 0.85-0.96 [P=0.001]) and duration of activity ≥500&nbsp;counts per minute (per 30&nbsp;minutes; hazard ratio, 0.76; confidence interval, 0.63-0.90 [P=0.002]) were significantly associated with lower cardiovascular event rates. CONCLUSIONS:Objective measurements of physical activity via accelerometry were associated with cardiovascular events among older adults with limited mobility (summary score &gt;10 on the Short Physical Performance Battery) both using baseline and longitudinal data. CLINICAL TRIAL REGISTRATION:URL: http://www.clinicaltrials.gov. Unique identifier: NCT01072500

    Search for the standard model Higgs boson in the H to ZZ to 2l 2nu channel in pp collisions at sqrt(s) = 7 TeV

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    A search for the standard model Higgs boson in the H to ZZ to 2l 2nu decay channel, where l = e or mu, in pp collisions at a center-of-mass energy of 7 TeV is presented. The data were collected at the LHC, with the CMS detector, and correspond to an integrated luminosity of 4.6 inverse femtobarns. No significant excess is observed above the background expectation, and upper limits are set on the Higgs boson production cross section. The presence of the standard model Higgs boson with a mass in the 270-440 GeV range is excluded at 95% confidence level.Comment: Submitted to JHE
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