126,727 research outputs found
Forecasting and Stress Testing Credit Card Default with Dynamic Models
No full textTypically models of credit card default are built on static data, often collected at timeof application. We consider alternative models that also include behavioural dataabout credit card holders and macroeconomic conditions across the credit cardlifetime, using a discrete survival analysis framework. We find that dynamic modelsthat include these behavioural and macroeconomic variables give statisticallysignificant improvements in model fit which translates into better forecasts of defaultat both account and portfolio level when applied to an out-of-sample dataset. Additionally, by simulating extreme economic conditions, we show how thesemodels can be used to stress test credit card portfolios
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
Deferoxamine B: A Natural, Excellent and Versatile Metal Chelator
No full textDeferoxamine B is an outstanding molecule which has been widely studied in the past decade for its ability to bind iron and many other metal ions. The versatility of this metal chelator makes it suitable for a number of medicinal and analytical applications, from the well-known iron chelation therapy to the most recent use in sensor devices. The three bidentate hydroxamic functional groups of deferoxamine B are the centerpiece of its metal binding ability, which allows the formation of stable complexes with many transition, lanthanoid and actinoid metal ions. In addition to the ferric ion, in fact, more than 20 different metal complexes of deferoxamine b have been characterized in terms of their chemical speciation in solution. In addition, the availability of a terminal amino group, most often not involved in complexation, opens the way to deferoxamine B modification and functionalization. This review aims to collect and summarize the available data concerning the complex-formation equilibria in solutions of deferoxamine B with different metal ions. A general overview of the progress of its applications over the past decade is also discussed, including the treatment of iron overload-associated diseases, its clinical use against cancer and neurodegenerative disorders and its role as a diagnostic tool
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
Support Vector Machines for Credit Scoring and discovery of significant features
No full textThe assessment of risk of default on credit is important for financial institutions. Logistic regression and discriminant analysis are techniques traditionally used in credit scoring for determining likelihood to default based on consumer application and credit reference agency data. We test support vector machines against these traditional methods on a large credit card database. We find that they are competitive and can be used as the basis of a feature selection method to discover those features that are most significant in determining risk of default
Managerial determinants of industrial research and development performance.
No full textIncludes bibliographical references (p. 28).Supported by the M.I.T. International Center for Research on the Management of Technology (ICRMOT).Edward B. Roberts, Paulo Bellotti
Gobius ater Bellotti 1888
No full text<p> <b>10.</b></p> <p> Ostroumoff (1896) on page 75 is clearly stated <i>Gobius ater</i> Bellotti, 1888 in the list of caught 3 teleost fishes by dredge (sampling) records, as study no 31. It was not understood what kind of output was made without reading the relevant article.</p>Published as part of <i>Artüz, M. Levent & Fricke, Ronald, 2020, Response to the comments regarding " The marine teleost fishes of the Sea of Marmara; an updated and annotated checklist " by Artüz & Fricke (2019), pp. 395-400 in Zootaxa 4802 (2)</i> on page 397, DOI: 10.11646/zootaxa.4802.2.13, <a href="http://zenodo.org/record/3991001">http://zenodo.org/record/3991001</a>
Managerial determinants of industrial research and development performance.
No full textIncludes bibliographical references (p. 28).Sponsored by the M.I.T. Industrial Liaison Program, PA Consulting Group and the M.I.T. International Center for Research on the Management of Technology (ICRMOT).by Edward B. Roberts & Paulo Roberto Bellotti
Understanding the mechanism of ZinT-mediated metal acquisition: a thermodynamic study
No full textZinT is a periplasmic protein found in Gram-negative bacteria. It is involved in cellular metal trafficking and may function as zinc-chaperone for the ZnuABC transporter. There is a general consensus that the three highly conserved histidine residues (His167, His176 and His178) facing the centre of ZinT calycin like-domain and the amino-terminal fragment between residues 24 and 29 (-HXHHXH-) should be effective zinc binding sites [1, 2]. The Zn2+-ZinT complex from S. enterica can interact with ZnuA forming a ternary complex where both proteins expose their binding pocket to the Zn2+ ion and where the His-rich loop of ZnuA functions as a hypothetical metal transfer intermediary between the two proteins [3, 4]. The main aim of this work is therefore to provide insight into the correlation between the metal-binding ability of ZinT and its biological role. The chosen unstructured fragments, which serve as models to simulate the coordination and transport of metal ions in ZinT protein (see Figure 1) from Escherichia coli and Salmonella enterica, correspond to the 24–29 and 166–178 amino acid sequences and are protected at the amino- and carboxyl-termini: Ac-24HGHHSH29-Am and Ac-166DHIIAPRKSSHFH178-Am (E. coli), Ac-24HGHHAH29-Am and Ac-166DHIIAPRKSAHFH178-Am (S. enterica). Interestingly, both the metal-binding sites of ZinT from S. enterica undergo a Ser-to-Ala substitution (position 28 and 175). A deep investigation of the complex-formation equilibria and coordination chemistry of the formed species has been performed through different experimental techniques, including potentiometry, mass spectrometry and various spectroscopies.
The obtained results highlight novel insight into the mechanism of ZinT-mediated metal acquisition and allow a comparison with other biologically relevant metal-binding systems, such as the antimicrobial peptide calcitermin which can, in principle, participate in human nutritional immunity, competing with ZinT for the metal ion acquisition.
Financial support of the National Science Centre (UMO-2017/26/A/ST5/00364 and UMO-2020/37/N/ST4/03165) is gratefully acknowledged. This paper is based upon work from COST Action CA18202, NECTAR – Network for Equilibria and Chemical Thermodynamics Advanced Research, supported by COST (European Cooperation in Science and Technology).
References:
[1] J. Chen, L. Wang, F. Shang, Y. Dong, N.-C. Ha, K. H. Nam, C. Quan, Y. Xu, Biochem. Biophys. Res. Commun. 2018, 500(2), 139-144.
[2] H. G. Colaço, P. E. Santo, P. M. Matias, T. M. Bandeiras, J. B. Vicente, Metallomics 2016, 8(3), 327-336.
[3] A. Ilari, F. Alaleona, G. Tria, P. Petrarca, A. Battistoni, C. Zamparelli, D. Verzili, M. Falconi, E. Chiancone, Biochim. Biophys. Acta 2014, 1840(1), 535-544.
[4] D. Bellotti, M. Rowińska-Żyrek, M. Remelli, Dalton Trans. 2020, 49(27), 9393-9403
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
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