1,721,004 research outputs found
Complex Heart Valve Disease: Functional Capacity and Natriuretic Peptides Predict Outcomes in mixed and Multiple Heart Valve Disease
No full textChronic mixed and multiple heart valve disease constitutes a complex group of cardiac pathologies that are prevalent world wide causing significant mortality and morbidity. The American Heart Association and the European Society of Cardiology concede in their guidelines that little data exists in the international literature on this important subject. Patients tend to adopt a sedentary lifestyle in order to cope with this illness and avoid symptoms causing a steady decline in functional capacity. A physically active lifestyle
is imperative for a good quality of life and cardiovascular wellness. Significant functional impairment through disease portends an adverse prognosis.
Functional capacity impairment can be objectively measured through formal cardiopulmonary exercise testing through determining the peak oxygen consumption (peakVO2). Exercise intolerance may suggest significant underlying symptoms especially in asymptomatic or mildly symptomatic states with severe heart valve lesions. The onset of symptoms is central to the decision to operate and surgical valve replacement. The peakVO2
measurement is the international gold standard of functional aerobic capacity and is widely used in heart failure and cardiac transplant to predict prognosis and outcome. The role of peakVO2 has not been evaluated in complex heart valve disease.Thesis (PhD Doctorate)Doctor of Philosophy (PhD)School of Medical ScienceGriffith HealthFull Tex
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Understanding individual engagement in outpatient cardiac rehabilitation programs based on the Model of Therapeutic Engagement
No full textFacilitating individual engagement in the rehabilitation process is vital if our investment in interventions is to achieve the desired outcomes. Studies of engagement in the cardiac rehabilitation (CR) context are limited, in that they lack a comprehensive and detailed basis for understanding and monitoring the whole process of engagement. The Model of Therapeutic Engagement (MTE) (Lequerica & Kortte, 2010) is the most comprehensive theoretical framework yet proposed to explain CR engagement, however, in the ten years since its first proposal, no research has investigated this multi-layered model empirically to determine its utility in the context of CR. The MTE defines the process of engagement by theorising a series of sub-models that focus on: 1) individual intention to engage in CR programs; 2) initiation of CR (i.e. actual attendance); and 3) maintenance of participation in CR programs over time (i.e. completion). Although the MTE is likely to be useful in understanding engagement in CR, it has been derived from a psychological orientation. Consequently, it gives little consideration to the role of socio-environmental factors which are considered vital in the fields of rehabilitation and health promotion. The overall aim of this empirical study was to evaluate the way in which the components of the MTE contribute to engagement outcomes and interact with each other, and also to examine the role of socio-environmental barriers in the MTE. This empirical study aims to evaluate the theory underlying the MTE by implementing it empirically, and thus develop a better understanding of the process of CR engagement. Through this approach, useful predictors that may act as management ‘levers’ can be identified, which if manipulated, can lead to better engagement. In turn, this could inform planning and design of future programs.
The research began with a synthesis of the existing evidence for each of the proposed relationships among variables at each of the three stages of the MTE within a CR setting (see Chapter Three). A model-centric systematic review was used to explicitly structure the evidence, according to each stage of the MTE. This review identified eight studies which focused on aspects of stage one of the MTE, four additional studies which were relevant to stage two of the MTE, and six studies which considered aspects of stage three of the MTE. The results showed that the propositions of the first stage of the MTE have been well supported in the literature. However, there has been limited research investigating the proposed relationships among the variables that define the second and third stages of the MTE. Importantly, the literature review revealed that research to date has failed to provide a holistic approach to the understanding of individual engagement in CR programs. Hence, this literature review provided a strong basis for designing a substantial empirical study that aimed, for the first time, to comprehensively consider all stages of the MTE. However, due to its complexity, the analysis of the whole MTE was broken into several components, as explained below.
Implementing a complex multi-component model such as the MTE, in an empirical study, raises significant analytical challenges. The MTE reflects the process that individuals follow during CR as this process unfolds over time. As would be expected, some individuals drop out. Changes in the sample during investigation of each stage of the MTE reflect the construct of interest (i.e., engagement) and, therefore, cannot be ignored by treating this as missing data or attrition. For example, not all those who are referred to CR will wish to attend; not all those who intend to engage in the CR program will initiate contact; attendance will fluctuate during CR; not all those who remain in the program will sustain their engagement.
These attrition issues make it difficult for empirical modelling to make use of a single model to reflect the whole process of CR. For that reason, a modular approach to analysis was chosen, where each module focuses on a different key stage of the MTE process: 1) individual intention to engage in CR programs; 2) initiation of CR (i.e. actual attendance); and 3) maintenance of participation in CR programs over time. Due to the emphasis on modelling relationship ‘pathways’ amongst variables, and the limited amount of data available, structural equation modelling (SEM) was determined to be suitable to provide an explanation of engagement, and therefore was applied to each of the three stages of the MTE.
In the initial empirical study, the first stage of the MTE was evaluated in a sample of 217 participants at one hospital in metropolitan Australia who were referred to CR following a cardiac event that required hospitalisation. The results (Chapter Seven) revealed that perceived self-efficacy and perceived need for rehabilitation positively impacted on intention to engage in CR, with moderate to large effect sizes. Perceived need and outcome expectancies were also strongly and significantly associated with each other. Contrary to the MTE, there were no significant relationships detected between outcome expectancies and intention to engage in the CR program, and between perceived self-efficacy and outcome expectancies. However, more detailed inspection (by supplementing SEM with bootstrap resampling) revealed that willingness to consider treatment acted as a mediator of the relationship between perceived self-efficacy and intention to engage in the CR program, through a small indirect effect that was significant and negative. The inclusion of this mediator doubled the variance explained by the relationship pathways.
A prospective study was then conducted to test the entire MTE in the subset of 101 participants who enrolled in, and commenced, the CR program. The subsequent findings (Chapter Eight) mirrored the effects found in the initial cross-sectional study (Chapter Seven). The effects remained the same in both direction and size in most cases. The main exception was the small significant negative relationship between perceived self-efficacy and outcome expectancies, which was much smaller and non-significant in the total sample. Another exception was the effect of perceived need on intention to engage which was found to be positive and significant in both studies, but larger in the cross-sectional analysis (Chapter Seven) compared to the prospective analysis (Chapter Eight). In this prospective study, the findings were consistent with all relationships proposed within the second and third stages of the MTE.
Finally, in Chapter Nine, the SEM was expanded to a multi-group analysis in order to examine the role of socio-environmental barriers. Despite being omitted from the original MTE, these barriers were found to be important in this first exploratory empirical analysis. The findings indicated that experiencing high-level socio-environmental barriers appeared to have a substantial moderating impact on the majority of the relationships proposed at the second and third stages of the MTE, with barriers tending to reduce engagement as would be expected. Significant differences were found between participants with high-level barriers and those with low-level barriers when comparing the effects, as shown by the beta estimate of the statistical model. Several relationships in the model were significantly weakened for participants with high levels of barriers compared to participants with low levels of barriers. Specifically, the strength of the relationship between intention to engage and actual involvement in preparation for the program was five times lower as was the relationship between their analysis of the CR experience and engagement. The strength of the relationship between CR initiation and engagement in the CR program was ten times lower and the relationship between CR maintenance and engagement was three times lower. These findings suggest that people with high levels of barriers are less likely to translate their intention to engage into actual engagement or involvement in preparing for CR. Even for those who initiated CR, or maintained CR over time, this was less likely to translate into deep levels of engagement. Importantly, their engagement over time was less likely to be influenced by their experience of rehabilitation, presumably reflecting the greater influence of barriers on their engagement. Thus, overall, a high level of socio-environmental barriers substantially diluted the relationships between variables in subsequent phases of CR, with the relationships being three to ten times stronger for individuals who had a low level of barriers.
In summary, this study showed that perceived self-efficacy and perceived need for rehabilitation positively impacted on intention to engage in CR in the total population of eligible participants. Willingness to consider treatment was a strong mediator that doubled the likelihood of self-efficacy influencing intention to engage in CR. Perceived need was associated with outcome expectancies, however, these expectancies did not directly impact on intention to engage in CR program. Perceived need reduced in importance for people who did engage in CR, as might be expected. For those who did engage in CR, sustained engagement was associated with individual analysis of experience. Barriers in the social and physical environment reduced the strength of the MTE relationships, so must be included in future articulations of the model. Addressing barriers would significantly enhance engagement in CR.
This study has indicated that the MTE can improve our understanding of the process of engagement in CR programs. Further, a deeper acknowledgment and understanding of socio-environmental barriers can improve the utility of the MTE. Based on this more holistic view of CR, as provided by the extended MTE, it is now possible to identify potential management levers that could be manipulated in order to enhance engagement. In particular, these results highlight that more attention is needed for raising the perceived need for CR and supporting the involvement of participants in preparation for their rehabilitation. These changes could significantly increase intention to engage in CR and actual initiation. Most importantly, the current study has confirmed the need to carefully review socio-environmental barriers that affect sustained engagement in CR. Prospective studies with larger samples than used in this first exploratory study, are required to determine whether these findings can be replicated, and are generally applicable to different populations of CR patients. Such a quantitative analysis could perhaps be supplemented by a qualitative study, to allow a deeper examination of the mechanisms underlying the apparent relationships among these variables. In addition, future studies must focus directly on exploring the role of other elements of engagement in order to provide a more comprehensive understanding of the engagement process. Specifically, greater consideration needs to be provided to CR barriers and facilitators, such as health professional-related factors (e.g. clinicians’ communicative and relational skills); factors associated with family caregivers of individuals; and mental distress factors to expand the MTE.Thesis (PhD Doctorate)Doctor of Philosophy (PhD)School of Human Serv & Soc WrkGriffith HealthFull Tex
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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