1,721,076 research outputs found

    Going Beyond Counting First Authors in Author Co-citation Analysis

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    The 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

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    “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

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    We 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

    Reducing weight in an internal medicine outpatient clinic using a lifestyle medicine approach : a proof of concept

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    Background Chronic non-communicable diseases represent the major drivers of disease burden, being responsible for the majority of health care cost and deaths. Almost half of premature deaths is due to behaviors amenable to change. Accordingly, addressing behavior might represent a strategic change in the health delivery system. Improving lifestyle requires a specific strategy embedding the active collaboration of individuals with a multilevel team-oriented medical practice. With the present study we sought to assess whether the implementation of cognitive-behavioral strategies, following the principles of lifestyle medicine in an outpatient clinic provides better results in weight reduction as compared to simpler strategies as presently executed in General Practitioners' offices. Methods This is an observational study on 173 subjects (age 53.1 ± 11.5), comparing three different groups of preventive practice: a personalized lifestyle medicine, combining cognitive behavioral strategies with patient tailored prescription of exercise and nutrition (Group A); a semi-structured approach with generic counseling (Group B); and an unstructured advice (Group C). Results At the end of the intervention period (17-20 months), group A showed an average weight loss of 5.4 ± 5.1 kg, which was significantly (p < 0.001)more than observed in group B (2.8 ± 5.1 kg) and group C (1.2 ± 4.8 kg). Likewise BMI and waist were progressively more reduced from A to C. Conclusions It is possible to implement preventive cognitive-behavioral lifestyle strategies in outpatient internal medicine clinics. This methodology appears more efficacious in inducing weight reduction after more than a year as compared to usual family medicine approaches

    A composite autonomic index as unitary metric for heart rate variability: a proof of concept

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    Background: This study addresses whether a unitary cardiac autonomic nervous system index (ANSI), obtained combining multiple metrics from heart rate variability (HRV) into a radar plot could provide an easy appreciation of autonomic performance in a clinical setting. Materials and Methods: Data are standardized using percentile ranking of autonomic proxies from a relatively large reference population (n = 1593, age 39 ± 13 years). Autonomic indices are obtained from autoregressive spectral analysis of (ECG derived) HRV at rest and during standing up. A reduced ANSI (using RR, RR variance and rest–stand difference of LFnu) is then constructed as a radar plot, quantified according to its combined area and tested against different risk subgroups. Results: With growing risk profile, there is a marked reduction of the rank value of ANSI, quantified individually by the radar plot area. The practical usefulness of the approach was tested in small groups of additional subjects putatively characterized by elevated or poor autonomic performance. Data show that elite endurance athletes are characterized by elevated values of ANSI (80·6 ± 14·9, P < 0·001) while subjects with either Type 1 or Type 2 diabetes show lower values (DM1 = 37·0 ± 18·9 and DM2 = 26·8 ± 23·3, P = 0·002), and patients with coronary artery disease (CAD) represent a nadir (17 ± 20, P < 0·001). Conclusions: This observational study shows the feasibility of testing simpler metrics of cardiac autonomic regulation based on a multivariate unitary index in a preventive setting. This simple approach might foster a wider application of HRV in the clinical arena, and permit an easier appreciation of autonomic performance

    Evidence of increased cardiac parasympathetic drive in subjects meeting current physical activity recommendations

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    Introduction: Aerobic fitness seems to provide extra protection to the cardiovascular system beyond changing the traditional risk factors, a phenomenon referred to as the risk factor gap model. Aerobic fitness may possibly lead to improved autonomic regulation. The Task Force of the American Heart Association supports a national campaign to reach specific cardiovascular health goals considering various metrics, including recommended physical activity (PA) volumes. It may be clinically relevant to assess whether autonomic remodeling occurs in those who adhere to the PA recommendations. Methods: We studied 39 healthy subjects (22 males and 17 females), subdivided into two groups, according to whether they were meeting or not meeting PA recommendations (150 min/week of moderate aerobic activity, or 75 min/week of vigorous aerobic activity, or a combination of both). For each group, we evaluated aerobic capacity (VO2 Peak), body composition (Fat Mass) and autonomic nervous system profile, by way of mono and bivariate spectral analysis of cardiovascular beat by beat variability. Results: Subjects following PA recommendations show higher RR period, higher RR variance, greater absolute power of the respiratory component of RR variability (HFRR) and higher index alpha (a measure of spontaneous baroreflex). Moreover, as expected, the group that was meeting or exceeding current PA recommendations had higher VO2 peak, less fat mass and greater weekly energy expenditure. Conclusion: Data show that subjects meeting current PA recommendations present a phenotype suggestive of enhanced parasympathetic drive to the SA node. This finding is compatible with the hypothesis that a more favorable autonomic profile is part of the mechanisms of the risk factor gap

    Complementary medicine for the management of chronic stress : superiority of active versus passive techniques

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    BACKGROUND: Recent epidemiological data indicate that chronic stress is an important component of cardiovascular risk, implicitly suggesting that stress management might offer a useful complement to orthodox medical treatment and prevention of hypertension. In this context, information on mechanisms, such as subclinical increases in arterial pressure and sympathetic drive, is well documented. Conversely, evidence on methodologies and comparative efficacy needs to be improved. Accordingly, this study was planned to test the autonomic and subjective effects of two popular modalities of stress management. METHODS: We studied 70 patients complaining of stress-related symptoms, avoiding any potential autonomic confounder, such as established hypertension or drug treatment. Patients were divided in three groups: group I (n ≤ 30) followed a breathing-guided relaxation training (active); group II (n ≤ 15) an oriental massage, shiatsu (passive); and group III (n ≤ 25) followed a sham intervention. Subjective effects of stress were assessed by validated questionnaires and autonomic nervous system regulation by spectral analysis of RR interval variability. Factor analysis was used to extract information simultaneously embedded in subjective and functional data. RESULTS: Although the problem of a greater quantity of treatment procedure in the active group than in the passive group existed, results showed that active relaxation, further to slightly reducing arterial pressure, might be more effective in relieving symptoms of stress and inducing an improved profile of autonomic cardiovascular regulation, as compared with passive massage or sham intervention. CONCLUSION: This active technique seems capable of beneficially addressing simultaneously the individual psychological and physiopathological dimensions of stress in clinical settings, with potentially beneficial effects on cardiovascular risk profile

    Dispelling the Myths Behind First-author Citation Counts

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    We 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

    Author Index

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