125,343 research outputs found
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
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
Caratteristiche geomorfologiche e sedimentologiche del litorale fra Terracina e Sperlonga.
No full textPharmacological strategies for overcoming multidrug resistance
No full textMultidrug resistance (MDR) is a major obstacle to the effective treatment of cancer. One of the underlying mechanisms of MDR is cellular overproduction of P-glycoprotein (P-gp) which acts as an efflux pump for various anticancer drugs. P-gp is encoded by the MDR1 gene and its overexpression in cancer cells has become a therapeutic target for circumventing multidrug resistance. A potential strategy is to co-administer efflux pump inhibitors, although such reversal agents might actually increase the side effects of chemotherapy by blocking physiological anticancer drug efflux from normal cells. Although many efforts to overcome MDR have been made using fast and second generation reversal agents comprising drugs already in current clinical use for other indications (e.g. verapamil, cyclosporine A, quinidine) or analogues of the first-generation drugs (e.g. dexverapamil, valspodar, cinchonine), few significant advances have been made. Clinical trials with third generation modulators (e.g. biricodar, zosuquidar, and laniquidar) specifically developed for MDR reversal are ongoing. The results however are not encouraging and it may be that the perfect reverser does not exist. Other approaches to multidrug resistan cereversal have also been considered: encapsulation of anthracyclines in liposomes or other carriers which deliver these drugs selectively to tumor tissues, the use of P-gp targeted antibodies such as UIC2 or the use of antisense strategies targeting the MDR1 messenger RNA. More recently, the development of transcriptional regulators appears promising. Also anticancer drugs that belong structurally to classes of drugs extruded from cells by P-gp but that are not substrates of this drug transporter may act as potent inhibitors of MDR tumors (e.g. epothilones, second generation taxanes). Taking advantage of MDR has also been studied. Bone marrow suppression, one of the major side effects of cancer chemotherapy, can compromise the potential of curative and palliative chemotherapy. It is conceivable that drug resistance gene transfer into bone marrow stem cells may be able to reduce or abolish chemotherapy-induced myelosuppression and facilitate the use of high dose chemotherapy. Clinical trials of retroviral vectors containing drug resistance genes have established that the approach is safe and are now being designed to address the therapeutically relevant issues. © 2006 Bentham Science Publishers Ltd
Technology, property rights and organizational diversity in the software industry
No full textWhy do open- and closed-source productions co-exist? To address this question, the paper studies the viability of distinct systems for software development. The model shows that: (a) for low design costs of modularity, both open- and closed-source productions are viable systems; (b) closed-source production is more likely to be adopted the greater the expected rents on software; and (c) production efficiency is not a necessary condition for the stochastic stability of a system to obtain. These three results can shed light on the emergence of organizational diversity in the software industry. The paper adds to the literature in three ways: first, it considers property rights and technology as endogenous variables in the process of system design; second it argues that in producing software multiple equilibrium designs may exist; and third, it shows that, in because of high rents and low design costs of modularity, production inefficiency can be persistent. © 2012 Elsevier B.V
The evolution of control in the digital economy
No full textControl over digital transactions has steadily risen in recent years, to an extent that puts into question the Internet’s traditional openness. To investigate the origins and effects of such change, the paper formally models the historical evolution of digital control. In the model, the economy-wide features of the digital space emerge as a result of the endogenous adaptation (co-evolution) of users’ preferences (culture) and platform designs (technology). The model shows that: a) in the digital economy there exist two stable cultural-technological equilibria: one with intrinsically motivated users and low control; and the other with purely extrinsically motivated users and high control; b) before the opening of the Internet to commerce, the emergence of a low-control-intrinsic-motivation equilibrium was favored by the specific set of norms and values that formed the early culture of the networked environment; and c) the opening of the Internet to commerce can indeed cause a transition to a high-control-extrinsic-motivation equilibrium, even if the latter is Pareto inferior. Although it is too early to say whether such a transition is actually taking place, these results call for a great deal of attention in evaluating policy proposals on Internet regulation
Pragmatic Case Studies as a Source of Unity in Applied Psychology
No full textTo unify or not to unify applied psychology: that is the question. In this article we review pendulum swings in the historical efforts to answer this question—from a comprehensive, positivist, “top-down,” deductive yes between the 1930s and the early 60s, to a postmodern no since then. A rationale and proposal for a limited, “bottom-up,” inductive yes in applied psychology is then presented, employing a case-based paradigm that integrates both positivist and postmodern themes and components. This paradigm is labeled “pragmatic psychology” and, its specific use of case studies, the “Pragmatic Case Study Method” (“PCS Method”). We call for the creation of peer-reviewed journal-databases of pragmatic case studies as a foundational source of unifying applied knowledge in our discipline. As one example, the potential of the PCS Method for unifying different angles of theoretical regard is illustrated in an area of applied psychology, psychotherapy, via the case of Mrs. B. The article then turns to the broader historical and epistemological arguments for the unifying nature of the PCS Method in both applied and basic psychology.Peer reviewe
Caratteristiche morfosedimentologiche e tendenza evolutiva del Lago Lungo (Lazio meridionale)
No full textSono state analizzate le caratteristiche morfosedimentologiche del Lago Lungo (Lazio Meridionale) integrate da dati batimetri. Il lago risulta costituito da due bacini la cui soglia di separazione è un delta lacustre generato dagli apporti sedimentari da mare attraverso un canale emissario. Il confronto tra Modelli Digitali del Terreno costruiti attraverso le isobate riferite all’anno 2000 e quelle ricostruite prima dell’apertura del canale emissario, portano a stimare in poco meno di 26.000 mc il volume del deposito deltizio
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