1,795 research outputs found

    Estimation of discontinuous coefficients and boundary parameters for hyperbolic systems

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    The problem of estimating discontinuous coefficients, including locations of discontinuities, that occur in second order hyperbolic systems typical of those arising in I-D surface seismic problems is discussed. In addition, the problem of identifying unknown parameters that appear in boundary conditions for the system is treated. A spline-based approximation theory is presented, together with related convergence findings and representative numerical examples

    Combined State and Parameter Estimation for a Static Model of the Maypole (Hoop-Column) Antenna Suface

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    Parameter and state estimation techniques are discussed for an elliptic system arising in a developmental model for the antenna surface of the Maypole Hoop/Column antenna. A computational algorithm based on spline approximations for the state and elastic parameters is given and numerical results obtained using this algorithm are summarized

    Associating Importance with Behavior: Providing Direction for Water Conservation Communication

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    This study identified differences in characteristics of High Water Users (HWUs) based on their perceived importance of plentiful water and their engagement in water conservation behaviors. Differences in the characteristics of high water users based on the level of importance they associated with plentiful water and their engagement in water conservation behaviors were identified. Communication needs and interests of HWUs were also identified. The Situational Theory of Publics (STP) was applied to explore why HWUs might perceive plentiful water to be important but may not feel personally responsible and may perceive barriers to changing their behaviors. Significant differences were found in terms of gender and race between the four primary groups of respondents identified (High Importance/High Engagement, Low Importance/High Engagement, Low Importance/Low Engagement and High Importance/Low Engagement). The High Importance/Low Engagement group was identified as an important and potentially high impact public for communicators

    Beyond the medical model:Thinking differently about medical education and medical education research

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    Issue: In medical education, teaching is currently viewed as an intervention that causes learning. The task of medical education research is seen as establishing which educational interventions produce the desired learning outcomes. This ‘medical model’ of education does not do justice to the dynamics of education as an open, semiotic, recursive system rather than a closed, causal system. Evidence: Empirical ‘evidence’ of ‘what works’–that is, what is supposed to affect ‘learning’–has become the norm for medical educational improvements, where generalized summary outcomes of research are often presented as must-follow guidelines for myriad future educational situations. Such investigations of educational processes tend to lack an explicit engagement with the purposes of medical education, which we suggest to understand in terms of qualification (the acquisition of knowledge, skills, and understanding), socialization (becoming a member of the professional group) and subjectification (becoming a thoughtful, independent, responsible professional). In addition, investigations of educational processes tend to rely on causal assumptions that are inadequate for capturing the dynamics of educational communication and interaction. Although we see an increasing acknowledgement of the context-dependency of teaching practices toward educational aims, the currently prevailing view in medical education and educational research limits understanding of what is actually going on when educators teach and students participate in medical education–a situation which seriously hinders advancements in the field. Implications: In this paper, we hope to inform discussion about the practice of medical education by proposing to view medical education in terms of three domains of purpose (professional qualification, professional socialization, and professional subjectification) and with full acknowledgement of the dynamics of educational interaction and communication. Such a view implies that curriculum design, pedagogy, assessment, and evaluation should be reoriented to include and integrate all three purposes in educational practice. It also means that medical education research findings cannot be applied in just any teaching context without carefully considering the value of the suggested courses of actions toward the particular educational aims and teaching setting. In addition, medical educational research would need to investigate all three purposes and recognize the openness, semiotic nature, and recursivity of education in offering implic

    Targeting determinants of dosage compensation in Drosophila

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    The dosage compensation complex (DCC) in Drosophila melanogaster is responsible for up-regulating transcription from the single male X chromosome to equal the transcription from the two X chromosomes in females. Visualization of the DCC, a large ribonucleoprotein complex, on male larval polytene chromosomes reveals that the complex binds selectively to many interbands on the X chromosome. The targeting of the DCC is thought to be in part determined by DNA sequences that are enriched on the X. So far, lack of knowledge about DCC binding sites has prevented the identification of sequence determinants. Only three binding sites have been identified to date, but analysis of their DNA sequence did not allow the prediction of further binding sites. We have used chromatin immunoprecipitation to identify a number of new DCC binding fragments and characterized them in vivo by visualizing DCC binding to autosomal insertions of these fragments, and we have demonstrated that they possess a wide range of potential to recruit the DCC. By varying the in vivo concentration of the DCC, we provide evidence that this range of recruitment potential is due to differences in affinity of the complex to these sites. We were also able to establish that DCC binding to ectopic high-affinity sites can allow nearby low-affinity sites to recruit the complex. Using the sequences of the newly identified and previously characterized binding fragments, we have uncovered a number of short sequence motifs, which in combination may contribute to DCC recruitment. Our findings suggest that the DCC is recruited to the X via a number of binding sites of decreasing affinities, and that the presence of high-and moderate-affinity sites on the X may ensure that lower-affinity sites are occupied in a context-dependent manner. Our bioinformatics analysis suggests that DCC binding sites may be composed of variable combinations of degenerate motifs

    Using Cognitive Dissonance to Communicate with Hypocrites About Water Conservation and Climate Change

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    The effects of climate change can be mitigated by altering human behavior related to water conservation; however, many who are aware of climate change are not aligning their behavior to curb the impact. This research sought to explore the relationship between citizens’ beliefs, attitudes and behaviors regarding water conservation and their knowledge and beliefs regarding climate change to guide the development of effective communication campaigns focused on water conservation. Using cognitive dissonance theory and an adapted environmental attitudes and behavior quartet, this research focused on individuals who demonstrated high levels of climate change knowledge but did not engage in positive water conservation behaviors; referred to as Hypocrites. The findings revealed Hypocrites held different perspectives on climate change than the general public. They believed climate change was real and caused by humans but are doing little to curb their personal water use and are not taking personal action to mitigate the effects of climate change. The best communication sources to use in reaching these individuals was examined and discussed with recommendations offered for how to best engage the hypocritical group who should be most likely to change their water conservation behaviors

    Water use in Florida: Examining Perceptions of Water use Based on Visual Images

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    Residents and decision makers often perceive information regarding water use differently. This is an issue in Florida where water quantity is a concern, and the distribution of accurate knowledge will be necessary to assist in effective conservation efforts. This study used two online surveys to gain insight into Florida residents’ and decision makers’ (county commissioners, county clerks and county managers) perceptions of water use based on visual images. Using non-probability opt-in sampling methods a total of 525 Florida residents’ responses were collected, and in a second survey 169 decision makers’ responses were collected. Respondents were asked to associate a specific water user, based on a visual, with high, moderate, or low water usage. A series of chi-square tests were used to compare and test for differences between Florida residents’ and decision makers’ perceptions, revealing that significant differences in perception did exist. The identification of these differences was used to develop recommendations for enhancing education and communication regarding water use

    Varied Signature Splitting Phenomena in Odd Proton Nuclei

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    Varied signature splitting phenomena in odd proton rare earth nuclei are investigated. Signature splitting as functions of KK and jj in the angular momentum projection theory is explicitly shown and compared with those of the particle rotor model. The observed deviations from these rules are due to the band mixings. The recently measured 169^{169}Ta high spin data are taken as a typical example where fruitful information about signature effects can be extracted. Six bands, two of which have not yet been observed, were calculated and discussed in detail in this paper. The experimentally unknown band head energies are given

    Anomalous Crossing Frequency in Odd Proton Nuclei

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    A generic explanation for the recently observed anomalous crossing frequencies in odd proton rare earth nuclei is given. As an example, the proton 12[541]{1\over 2} [541] band in 175^{175}Ta is discussed in detail by using the angular momentum projection theory. It is shown that the quadrupole pairing interaction is decisive in delaying the crossing point and the changes in crossing frequency along the isotope chain are due to the different neutron shell fillings
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