31,019 research outputs found
"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.
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
A comprehensive review of monoamine oxidase-a inhibitors in their syntheses and potencies
No full textBackground: Monoamine oxidases (MAOs) play a crucial role during the development of various neurodegenerative disorders. There are two MAO isozymes, MAO-A and MAO-B. MAO-A is a flavoenzyme, which binds to the outer mitochondrial membrane and catalyzes the oxidative transformations of neurotransmitters like serotonin, norepinephrine, and dopamine. Materials and Methods: Focus on synthetic studies has culminated in the preparation of many MAO-A inhibitors, and advancements in combinatorial and parallel synthesis have accelerated the developments of synthetic schemes. Here, we provided an overview of the synthetic protocols employed to prepare different classes of MAO-A inhibitors. We classified these inhibitors according to their molecular scaffolds and the synthetic methods used. Results: Various synthetic and natural derivatives from a different class of MAO-A inhibitors were reported. Conclusion: The review provides a valuable tool for the development of a new class of various selective MAO-A inhibitors for the treatment of depression and other anxiety disorders
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
Avatar's 'Development' Predicament
No full textThe globally-acclaimed film looks back to the past from a futuristic standpoint to simulate an archetypal moral tale of developmental inequality. Is that a good thing
Aldoxime- and hydroxy-functionalized chalcones as highly potent and selective monoamine oxidase-B inhibitors
No full textA panel of 30 chalcone derivatives, including 19 aldoxime-chalcone ethers (ACE), and 11 hydroxyl‐chalcones (HC), previously synthesized using a Pd-catalyzed C–O cross-coupling method were evaluated for their inhibitory activities against monoamine oxidases (MAOs), cholinesterases (ChEs), and β-secretase (BACE-1). HC6 was the most potent inhibitor of MAO-B with an IC50 value of 0.0046 μM and a selectivity index (SI) of 1,113. HC3 also potently inhibited MAO-B (IC50 = 0.0067 μM) and had the highest SI (1,455). ACE7 and ACE15 were also potent MAO-B inhibitors (IC50 = 0.012 and 0.018 μM, respectively), with SIs of 260 and 1,161, respectively. HC3 and HC6 were reversible competitive inhibitors of MAO-B, with Ki values of 0.0036 and 0.0013 μM, respectively. A structure–activity relationship revealed that methyl and fluorine substituents contributed to increasing both inhibition and selectivity. ACE7 was the most effective inhibitor of MAO-A (IC50 = 1.49 μM), followed by ACE3 (IC50 = 3.75 μM). No compounds effectively inhibited AChE, BChE, or BACE-1. A docking simulation showed that the ligand efficiency and docking scores of HC3 and HC6 toward MAO-B were consistent with the experimental IC50 values. These results suggest that HC3 and HC6 can be considered promising candidates for the treatment of neurological disorders
Roughness-triggered turbulent boundary layers in Rayleigh-Bénard convection
No full textWe present measurements carried out inside the Barrel of Ilmenau as part of the European EuHIT transnational infrastructure access program. The Barrel of Ilmenau is the worldwide largest experiment to study highly turbulent convection in air. A rectangular cell, with proportions strictly identical to the water cell in Lyon [Salort, et al. PoF 26:015112 (2014)], but six times larger, has been inserted inside the Barrel. The top plate is smooth, and the bottom plate is rough. The roughness are also similar to the one in Lyon, but six times larger. We have obtained velocity fields using PIV near the obstacles, as well as the local heat-flux on the bottom plate. This has allowed us to test and improve our previous interpretation of the roughness-induced heat transfer enhancement mechanisms
A 2 h periodic variation in the low-mass X-ray binary Ser X-1
No full textSpectroscopy of the low-mass X-ray binary Ser X-1 using the Gran Telescopio Canarias have revealed a ?2 h periodic variability that is present in the three strongest emission lines. We tentatively interpret this variability as due to orbital motion, making it the first indication of the orbital period of Ser X-1. Together with the fact that the emission lines are remarkably narrow, but still resolved, we show that a main-sequence K dwarf together with a canonical 1.4 M? neutron star gives a good description of the system. In this scenario, the most likely place for the emission lines to arise is the accretion disc, instead of a localized region in the binary (such as the irradiated surface or the stream-impact point), and their narrowness is due instead to the low inclination (?10°) of Ser X-1
Joint scaling analysis of atmospheric velocity and wind power plant production
No full textIn a context of energy transition, wind energy is a source of clean energy with the potential of partially satisfying the growing demand. The main problem of this type of energy, and other types of renewable energy remains the discontinuity of the electric power produced in different scales, inducing large fluctuations also called intermittency. This intermittency of wind energy is inherent to the turbulent nature of wind. Here, we consider the relation between velocity and power output with two wind turbine databases. We focus on joint relations with Fourrier analysis, empirical mode decomposition (EMD), Time-dependent intrinsic correlation (TDIC). We also consider the causality using a new method of analysis of the causality between two time series
Parameterized Algorithms and Hardness for the Maximum Edge q-Coloring Problem
No full textAn edge q-coloring of a graph G is a coloring of its edges such that every vertex sees at most q colors on the edges incident on it. The size of an edge q-coloring is the total number of colors used in the coloring. Given a graph G and a positive integer t, the Maximum Edge q-Coloring problem is about whether G has an edge q-coloring of size t. Studies on this coloring problem were motivated by its application in the channel assignment problem in wireless networks.
Goyal, Kamat, and Misra (MFCS 2013) studied Maximum Edge 2-Coloring from the perspective of parameterized complexity. Given a graph on n vertices, they considered the standard parameter t, the number of colors in an optimal edge 2-coloring, and the dual parameter , where n- is the number of colors in an optimal edge 2-coloring. They designed FPT algorithms for Maximum Edge 2-Coloring parameterized by t and . In this paper, we revisit and study Maximum Edge 2-Coloring from the perspective of parameterized complexity and show the following results.
1) Let γ(G) denote the maximum matching size in a given graph G. It is easy to see that a maximum edge 2-coloring of G is of size at least γ(G). Goyal, Kamat, and Misra (MFCS 2013) had asked if there exists an FPT algorithm for Maximum Edge 2-Coloring parameterized by k, where k: = (size of a maximum edge 2-coloring of G) - γ(G). We show that Maximum Edge 2-Coloring parameterized by k is W[1] hard.
2) On the positive side, we show that there is an algorithm that, given a graph G on n vertices and a tree decomposition of width tw, runs in time 2^{O(qtw log {q tw})}n and outputs a maximum edge q-coloring of G
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