1,721,615 research outputs found
Optimal Surveillance and Indemnity Policy for Eradicating Exotic Livestock Diseases
No full textWe present a theoretical model that identifies the optimal resource allocation between surveillance and intervention for eradicating exotic livestock diseases. We apply a game theory approach to analyse the strategic interaction between the Animal Health
Authority (AHA) and the stockbreeders. The model elucidates how the breeders' pay-offs depend upon the AHA's choices and
vice versa. We first model the stockbreeder reporting decision (passive surveillance) under uncertainty. Then, we analyse how the AHA should efficiently allocate resources between active surveillance (inspections) and intervention, and determine how
this trade-off is influenced by various economic factors, such as the operation size and breeders' risk attitudes. By explicitly considering the relationship between passive and active surveillance, the model reconciles the literature investigating the nexus
between compensation payments and reporting with the literature on the relationship between surveillance and intervention.
We use the case study of a parasite of social bee colonies, the Small Hive Beetle, in Italy, which presents no moral hazard concerns, and hence limits the complexity of the analysis. However, the model can be adapted to other types of exotic diseases and
livestock. The model does not provide precise quantitative prescriptions of the optimal values to be assigned to indemnities and probability of monitoring. Rather, it contributes to the understanding of the economic factors that influence optimal surveillance
and intervention strategies
Functional 3-Arylisoxazoles and 3-Aryl-2-isoxazolines from reaction of aryl nitrile oxides and enolates: Synthesis and reactivity
No full textHeterocyclic compounds are crucial starting reagents and intermediates, or they are direct precursors of target chemicals and/or bio-pharmacological active compounds. Today, they are used in the total synthesis of natural products, in drugs or herbicides, and agrochemical preparation. Developing synthetic strategies targeting isoxazoles is a recurrent aim in preparative chemistry. In particular, five-membered heterocycles such as isoxazoles and isoxazolines are easily formed in a two steps or by a 'one-pot' procedure, by reacting aryl nitrile oxides with a variety of enolates of carbonyl compounds (i.e., aldehydes, ketones, carboxylic acids), followed by aromatization. Such a methodology was found to be selective and versatile allowing the preparation of pharmacologically active isoxazoles in high yields. 1 Introduction 2 Preparation, Synthetic Applications, and Reactivity of 3-Aryl-5-hydroxy-2- isoxazolines and 3-Arylisoxazoles 3 Synthesis of 5-Alkyl-3-aryl-5-hydroxy-2- isoxazolines and 5-Alkyl-3-arylisoxazoles 4 Synthesis and Reactivity of 3,4-Diaryl-5-hydroxy-2-isoxsazolines and 3,4-Diarylisoxazoles 5 Synthesis and Reactivity of 3-Aryl-5-hydroxy-5-vinyl-2-isoxazolines and 3-Aryl-5- vinylisoxazoles 6 Synthesis of 3-Aryl-4-phenylisoxazole-5-carboxylic Acid 7 Conclusions 8 Experimental Methodologies. © Georg Thieme Verlag Stuttgart
Four-dimensional noncommutative deformations of U(1) gauge theory and L∞ bootstrap
No full textWe construct a family of four-dimensional noncommutative deformations of U(1) gauge theory following a general scheme, recently proposed in JHEP 08 (2020) 041 for a class of coordinate-dependent noncommutative algebras. This class includes the su(2), the su(1, 1) and the angular (or λ-Minkowski) noncommutative structures. We find that the presence of a fourth, commutative coordinate x0 leads to substantial novelties in the expression for the deformed field strength with respect to the corresponding three-dimensional case. The constructed field theoretical models are Poisson gauge theories, which correspond to the semi-classical limit of fully noncommutative gauge theories. Our expressions for the deformed gauge transformations, the deformed field strength and the deformed classical action exhibit flat commutative limits and they are exact in the sense that all orders in the deformation parameter are present. We review the connection of the formalism with the L∞ bootstrap and with symplectic embeddings, and derive the L∞-algebra, which underlies our model
Selective inhibition of cyclooxygenase (COX) isoenzymes and neuroinflammation
No full textMicroglia, the immune cells of the brain, are one of the key mediators of neuroinflammation.
Microglial activation leads these cells to produce various proinflammatory
and neurotoxic substances.
Several in vitro and in vivo studies have demonstrated that a decrease in the
levels of pro-inflammatory mediators in microglia can attenuate the severity of
neuro-degenerative diseases, including AD, PD, ALS, MS and Huntingtons
disease. Thus, regulation of excessive microglial activation should be of
therapeutic value especially in neuro-degenerative disorders.
Cyclooxygenase(COX) is a key enzyme in the conversion of arachidonic acid
into prostaglandins and other lipid mediators. It is widely accepted that this
enzyme play a pivotal role in the neuro-inflammatory process exacerbation. Two
COX isoforms are known: COX-1, constitutively expressed in most tissues,
classically considered as the isoform primarily responsible for maintaining the
homeostasis by mediating physiological responses, and COX-2, which
represents the inducible form, mainly activated in response to inflammatory
stimuli. In this respect, recent studies have also indicated a previously
unrecognized pro-inflammatory role of COX-1 in the pathophysiology of acute
and chronic neurological disorders. Consequently, it was reconsidered the
potential beneficial effect of COX-1 inhibition in the treatment of neuroinflammation
[1].
These findings prompted us to investigate the behaviour of two selective COX-1
inhibitors such as P6 (COX-1 IC50= 0.5 mM and COX-2 IC50 >100 mM) and P10
(COX-1 IC50= 0.09 mM and COX-2 IC50 = 2.49 mM) [2] in an in vitro experimental
model of inflammation, represented by mouse N13 microglial cells activated by
lipopolysaccharide (LPS) [3]. LPS is a component of the outer cell wall of gramnegative
bacteria and is well known as an inducer of inflammatory responses.
New selective COX-1 inhibitors are here proposed also as useful tools in
pharmacological studies to investigate the role of COX-1 isoenzyme in neuroinflammation
or more in general in all the investigations in which only COX-1
needs to be selectively inhibited.
The results of this study as well as their rationale will be presented and
discussed.
References:
1. Perrone, M.G.; Scilimati, A.; Simone, L., Vitale, P. Curr. Med. Chem.2010,17, 3769-805.
2. Di Nunno. L., Vitale, P., Scilimati, A., Tacconelli, S.; Patignani, P. J. Med. Chem. 2004, 47, 4881-90.
3. Calvello, R.; Panaro, M.A.; Carbone, M.L.; Cianciulli, A.; Perrone, M.G.; Vitale, P.; Malerba, P.; Scilimati,
A. Biochem. Pharmacol.,2011, submitted for publication
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
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
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