131,636 research outputs found
Oxygen: Modulator of Physiological and Pathophysiological Processes in the Liver
No full textOxygen has important functions as substrate for biochemical reactions and as modulator of gene expression. In the liver, the physiologically occurring oxygen gradient is a major effector of metabolic zonation. In addition, cross-talks between the O-2 signaling and nutrient signaling chains initiate a dynamic zonation pattern. Under pathological situations, hypoxia appears to be a major determinant for liver diseases and cancer. Thereby transcription factors of the HIF family are activated whereas USF proteins have the potential to counteract HIFs. In addition, feedback mechanisms between hypoxia, HIF and the IGF axes appear to exist. Thus, the knowledge of these mechanisms may help to initiate new therapies in diseases with disturbed O-2 availability
MeSH term explosion and author rank improve expert recommendations
No full textInformation overload is an often-cited phenomenon that reduces the productivity, efficiency and efficacy of scientists. One challenge for scientists is to find appropriate collaborators in their research. The literature describes various solutions to the problem of expertise location, but most current approaches do not appear to be very suitable for expert recommendations in biomedical research. In this study, we present the development and initial evaluation of a vector space model-based algorithm to calculate researcher similarity using four inputs: 1) MeSH terms of publications; 2) MeSH terms and author rank; 3) exploded MeSH terms; and 4) exploded MeSH terms and author rank. We developed and evaluated the algorithm using a data set of 17,525 authors and their 22,542 papers. On average, our algorithms correctly predicted 2.5 of the top 5/10 coauthors of individual scientists. Exploded MeSH and author rank outperformed all other algorithms in accuracy, followed closely by MeSH and author rank. Our results show that the accuracy of MeSH term-based matching can be enhanced with other metadata such as author rank
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe 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
The Impact on Structural Reforms on Employment Growth and Labour Productivity: Evidence from Bulgaria and Romania
No full textUsing firm-level data from Bulgaria and Romania, this paper addresses a lacuna in the transition literature, namely, the link of firm-level employment turnover with firm-level growth in labour productivity. The results suggest that while net job creation at the firm level was affected by privatization in Bulgaria, privatization in Romania did not have any effect on firm-level employment growth. Further, Olley-Pakes (1996) decomposition indicates that in Bulgaria, over time, resources moved from less productive firms to more productive firms in almost all industries, but that in Romania such a phenomenon was observed in less than half of the industries. At the same time, the Grilliches-Regev (1995) decomposition indicates that in both these countries mobility of labour across firms, i.e., the process of job creation and job destruction at the firm level, contributed more to productivity changes than did other firm-level characteristics and industry-level factors affecting productivity. Finally, we find that the rate of employment changes in Bulgarian firms has a significant impact on the country’s firm-level productivity changes. Regressions using Romania data, however, do not provide any support for this observation.job flows, employment growth, labour productivity, Bulgaria, Romania
"Closing the R&D Gap, Evaluating the Sources of R&D Spending"
No full textBoth spending and tax policies have been implemented in the United States with the goal of stimulating private sector research and development (R&D). Karier questions whether current R&D policy, especially the research and experimentation tax credit, can contribute to closing the gap between nondefense expenditures on R&D in the United States and such expenditures in other countries, such as Japan and Germany. He also explores possible changes to our current R&D policy to make it more effective.
Psychologische und genetische Risikofaktoren und Konsequenzen postoperativer Schmerzen
No full textKumulative Dissertation, Otto-Friedrich-Universität Bamberg, 2016Zusammenfassung
Die vorliegende publikationsbasierte Dissertation umfasst eine Literaturübersicht und zwei klinische Studien, die in drei unabhängigen Publikationen veröffentlicht wurden. Die Publikationen werden zu Beginn des jeweiligen Kapitels zitiert, der die Inhalte der entsprechenden Publikation darstellt. Die vorliegende Dissertation befasst sich mit den wechselseitigen Beziehungen zwischen psychologischen und geneti-schen Risikofaktoren und dem postoperativen Schmerz. Das Ziel dieser Arbeit ist die Ermittlung klinisch relevanter Aussagen zur Verbesserung der Identifikation von Patienten mit erhöhtem Risiko für die Entwicklung chronischer Schmerzen infolge eines chirurgischen Eingriffs. Als Modell für postoperative Schmerzen wurde in den klinischen Studien die kosmetische Korrektur einer angeborenen Deformität des Brustkorbs, bekannt als Trichterbrust, verwendet. Diese Patienten sind jung und weisen präoperativ keine schwerwiegende Schmerzerfahrung auf. Aus diesem Grund bot dieses Operationsmodell herausragende Bedingungen für die Untersuchung des Übergangs zum chronischen Schmerz.
Aus der Literaturübersicht erwies sich das Auftreten chronischer Schmerzen nach Operationen als ein häufiges Phänomen mit einer Abhängigkeit der Epidemiologie von der Art des chirurgischen Eingriffs. Depressivität, sowie schmerzspezifische psychologische Faktoren zeigten eine starke Aussagekraft als Risikofaktoren. Die selbstberichtete Hypervigilanz im Sinne eines Monitoring des Schmerzes schien ein Risikofaktor für die langfristige schmerzassoziierte Beeinträchtigung darzustellen [Dimova, V. & Lautenbacher, S. (2010). Chronische Schmerzen nach Operationen. Epidemiologie unter besonderer Berücksichtigung psychologischer Risikofaktoren. AINS 45, 488-494]. In Studie 1 lieferten ausgewählte schmerz-assoziierte genetische Polymorphismen einen schwachen Beitrag für die Erklärung des Verlaufs postopera-tiven Outcomes bis zu 1 Jahr nach der Trichterbrustoperation. Im Vergleich konnte die selbstberichtete Vigilanz für Schmerz die längerfristig verbleibende Beeinträchti-gung durch den postoperativen Schmerz erklären [Dimova, V., Lötsch, J., Hühne, K., Winterpacht, A., Heesen, M., Parthum, A., Weber, P. G., Carbon, R., Griessinger, N., Sittl, R. & Lautenbacher, S. (2015). Associations of genetic and psychological factors with persistent pain after cosmetic thoracic surgery, Journal of Pain Research, 8, 829-844]. In Studie 2 trug der akute postoperative Schmerz als Konsequenz zur einen unmittelbaren kurzfristigen psychologischen Sensibilisierung in der Patientenpopulation bei. Dieser Befund weist auf die generelle Implikation hin, dass ein ein-maliges intensives Schmerzereignis zur Veränderung kognitiv-emotionaler Prozesse führen kann [Dimova, V., Horn, C., Parthum, A., Kunz, M., Schöfer, D., Carbon, R., Griessinger, N., Sittl, R. & Lautenbacher, S. (2013). Does severe acute pain provoke lasting changes in attentional and emotional mechanisms of pain-related processing? A longitudinal study. PAIN, 154 (12), 2737-2744].
Zusammenfassend hebt die vorliegenden Dissertation folgende drei wissenschaftli-che Befunde hervor: Schmerzspezifische psychologische Risikofaktoren stellen potente Prädiktoren für postoperative Schmerzen dar. Ihr Erklärungswert kann den schmerzassoziierter genetischer Marker übersteigen, wie es für die selbstberichtete Schmerzvigilanz gezeigt wurde. Eine einmalige intensive Schmerzepisode beeinflusst negativ die kognitiv-emotionale Schmerzverarbeitung.Abstract
In the present dissertation, the results of a literature survey and two clinical studies published as three separate scientific publications are reported. The publication corresponding to the respective study is cited at the beginning of the particular chapter describing this study. The aim of the studies was to investigate the relationships between psychological as well as genetic factors and postoperative pain with the purpose to identify patients at risk of developing chronic pain conditions after surgery, in the particular example of thoracic surgery for funnel chest correction. The cosmetic correction of congenital chest malformation known as funnel chest was used as a model for postoperative pain because the patients are usually young and without severe pain experience prior to surgery. These conditions allowed for investigating the relationships between postoperative pain and its risk factors without confounding effects of preoperatively existing pain.
The review of available studies suggested that an alarmingly high proportion of patients undergoing surgery develop chronic pain. The rates depend on the type of surgical manipulation. Mood as well as pain-related cognitive-emotional mechanisms seem to be potential risk factors for the development of chronic pain [Dimova, V. & Lautenbacher, S. (2010). Chronische Schmerzen nach Operationen. Epidemiologie unter besonderer Berücksichtigung psychologischer Risikofaktoren. AINS, 45, 488-494]. In study 1, genetic variants functionally related to pain showed no meaningful impact on the time course of pain intensity and disability up to one year after surgery. They exerted also only small effects on final postoperative outcome. In contrast, a higher level of self-reported pain vigilance was a risk factor for long-lasting pain disability [Dimova, V., Lötsch, J., Hühne, K., Winterpacht, A., Heesen, M., Parthum, A., Weber, P. G., Carbon, R., Griessinger, N., Sittl, R. & Lautenbacher, S. (2015). Associations of genetic and psychological factors with persistent pain after cosmetic thoracic surgery, Journal of Pain Research, 8, 829-844]. In study 2, the acute postoperative pain, representing in this clinical sample a singular major pain episode, provoked in turn changes in cognitive and emotional mechanisms of pain processing that could not outlast the acute postoperative phase. Even if such changes were short-lived, they may act as risk factors that adversely affect the patient’s postoperative recovery [Dimova, V., Horn, C., Parthum, A., Kunz, M., Schöfer, D., Carbon, R., Griessinger, N., Sittl, R. & Lautenbacher, S. (2013). Does severe acute pain provoke lasting changes in attentional and emotional mechanisms of pain-related processing? A longitudinal study. PAIN, 154 (12), 2737-2744].
Summarized, the present dissertation highlights the following aspects: Pain-related psychological risk factors seem to be powerful predictors of postoperative outcome. Their effects on long-term postoperative outcome may even exceed the effects of pain-related genetic markers as shown for the pain vigilance. An intense pain episode such as postoperative pain acts negatively on cognitive-emotional processing
Dispelling the Myths Behind First-author Citation Counts
No full textWe 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
Scholarly Communication and Publishing Lunch and Learn Talk #11: The ULS Open Access Author Fee Fund
No full textAt the May 2014 talk, you will learn about the ULS Open Access Author Fee Fund--what it is, why we do it, how it works, and how the program is going so far
- …
