1,721,104 research outputs found
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
Preclinical and clinical investigations as an approach to rational phytotherapy in prostate diseases
Full text linkPhytotherapeuticals have gained widespread usage in the treatment of symptomatic
benign prostatic hyperplasia (BPH). Among these phytotherapeutics, the most
popular and extensively studied are extracts of the dried ripe fruit of Serenoa repens
(SRE). The commercially available hydroethanolic (96%) SRE, Me180, is already
used as a medical treatment of symptomatic BPH. However, this extract was so far
neither investigated in vitro nor in vivo. The other extracts tested herein, derived from
Vitex agnus-castus (VAC), are so far not described to be used for treatment of
prostatic diseases or tested on prostate cells.
In a first part of the present studies, an in vitro screening system was established,
representative for different prostate disease stages. BPH and prostate cancer (PCA)
are multifactorial disease processes. Both diseases are age-related proliferative
disorders of the human prostate and with disturbed homeostasis in both conditions by
upsetting the balance between prostate cell proliferation and apoptosis. Thus, the
inhibition of proliferation and the reversion of the imbalance of homoeostasis is a
desired therapeutic option in both diseases.
Three different cell lines (BPH-1, LNCaP, PC-3) were chosen, representing different
disease stages. To evaluate the potential effects of selected plant extracts in
proliferative prostate diseases, several methodological approaches were used:
Crystal violet staining and WST-8 (tetrazolium based assay) were conducted to
establish the effects on cell proliferation and viability. To further elucidate the
mechanisms of cell death, FACScan analysis was performed to detect effects on cell
cycle distribution and apoptosis. Apoptosis was further investigated by co-treatment
of the cells with a pan-caspase inhibitor Z-VAD-fmk and by DNA fragmentation
assays. In addition, cytotoxicity was determined by measurement of lactate
dehydrogenase (LDH) in cell supernatants.
Proliferation of BPH-1 and PC-3 cells was modestly inhibited by Serenoa repens
extract Me180 in a dose-dependent manner with IC50 values of 100μg/ml, whereas in
androgen-responsive LNCaP cells, lower IC50 values of 35μg/ml, indicated a
possible mechanism through androgen-receptors. Me180 exerted similar effects in
vitro as other SRE’s previously investigated. Additional SRE’s, which varied with
respect to ripeness conditions of the raw material and the choice of solvents (hexane or ethanol) displayed no crucial differences in potency of growth inhibitory activities.
Moreover, Me180 exhibited a dose-dependent apoptotic effect in LNCaP cells, with
additional low cytotoxic effects. A low apoptotic effect was found in BPH-1 cells
without a cytotoxic effect, whereas PC-3 cells were almost insensitive to the Me180
treatment.
In addition, using the same methodology, these preclinical investigations were the
first to examine the effects of VAC fruit and leaf extracts on prostate cell proliferation.
The two different VAC’s were found to be effective inhibitors in all three cell lines
(with IC50 values < 10μg/ml after exposure to fruit extract and < 20μg/ml for leaf
extract, respectively) inducing apoptosis, and a low cytotoxic effect. Our new results
suggest that extracts of VAC, by modulating the cell cycle and the apoptotic
machinery, may possess a potential for development as an agent for prevention
and/or therapy of benign and malign prostatic hyperplastic diseases. Additional
studies are however required to further clarify their mechanisms of action and to
investigate their effects in vivo.
The in vitro data indicate that the chosen screening model system is suitable for the
detection of growth inhibitory activities of plant extracts in human prostate cell lines
and may help to find new phytotherapeuticals for this field of indication.
The objective of the second part was a clinical pilot study to compare the
therapeutical effects, tolerability and safety of treatment with Serenoa repens extract
Me180 (SabCaps®) versus tamsulosin (Pradif®) in patients with obstructive BPH. Due
to stringent exclusion criteria and hence difficulties in patient recruitment, the planned
patient number of 70 could not be achieved within a reasonable time for the thesis.
Only 19 patients, aged 50-79 years, with obstructive BPH (mean Qmax < 10ml/s for a
voiding volume of 150ml or assessed by flow-pressure study) were therefore included
in the study. Patients were randomised with either 320mg Me180 or Tamsulosin
0.4mg, given over a scheduled treatment period of 26 weeks in a double-blind
manner. The primary outcome measures were the change in peak urinary flow rate
(Qmax) and International Prostate Symptom Score (IPSS) with quality-of-life score
during the treatment. The secondary outcome measures included average urinary
flow rate (Qave), post-void residual urine volume and prostate volume, assessed by
transabdominal ultrasound. In addition, the International Index of Erectile Function
(IIEF) score was determined and adverse events were recorded. No significant differences were found in baseline parameters between the two
treatment groups. The treatment over 26 weeks was completed by 18 patients. In the
tamsulosin group, one patient withdrew from the study because of continuous
dizziness. There was no significant difference between the two treatments over the
26 weeks of the study with respect to IPSS, Qmax, Qave, residual urine, prostate
volume, and IIEF. During this pilot study all participants had some improvements in
their symptoms of BPH, but there was no significant difference in the beneficial effect
of either medication over the 26-weeks treatment time. With respect to the overall
incidence of adverse effects, Me180 was found significantly superior to the
tamsulosin group (p = 0.013).
The present data describe for the first time clinical results obtained with Me180.
Based on this pilot study, future clinical trials with larger patient numbers and longer
periods of treatment will be needed to assert if Me180 is an efficacious alternative
medical therapy for men with obstructive BPH
Downsides of Robot-assisted Laparoscopic Radical Prostatectomy: Limitations and Complications
No full textContext: Robot-assisted laparoscopic radical prostatectomy (RALP) using the da Vinci Surgical System (Intuitive Surgical, Sunnyvale, CA, USA) is now in widespread use for the management of localised prostate cancer (PCa). Many reports of the safety and efficacy of this procedure have been published. However, there are few specific reports of the limitations and complications of RALP. Objective: The primary purpose of this review is to ascertain the downsides of RALP by focusing on complications and limitations of this approach. Evidence acquisition: A Medline search of the English-language literature was performed to identify all papers published since 2001 relating to RALP. Papers providing data on technical failures, complications, learning curve, or other downsides of RALP were considered. Of 412 papers identified, 68 were selected for review based on their relevance to the objective of this paper. Evidence synthesis: RALP has the following principal downsides: (1) device failure occurs in 0.2-0.4% of cases; (2) assessment of functional outcome is unsatisfactory because of nonstandardised assessment techniques; (3) overall complication rates of RALP are low, although higher rates are noted when complications are reported using a standardised system; (4) long-term oncologic data and data on high-risk PCa are limited; (5) a steep learning curve exists, and although acceptable operative times can be achieved in 80 cases before a plateau is achieved; (6) robotic assistance does not reduce the difficulty associated with obese patients and those with large prostates, middle lobes, or previous surgery, in whom outcomes are less satisfactory than in patients without such factors; (7) economic barriers prevent uniform dissemination of robotic technology. Conclusions: Many of the downsides of RALP identified in this paper can be addressed with longer-term data and more widespread adoption of standardised reporting measures. The significant learning curve should not be understated, and the expense of this technology continues to restrict access for many patients. (C) 2009 European Association of Urology. Published by Elsevier B. V. All rights reserved
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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
- …
