117,577 research outputs found
Raw and preprocessed data: Talluri, Kang et al. 2022
No full textExample raw data, preprocessed data to reproduce analyses in Talluri, Kang et al. 2022 bioRxiv. doi: 10.1101/2022.09.08.507006. (now in press at Nature Neuroscience).The code to reproduce the analysis is in https://github.com/NienborgLab/TalluriKang_et_al_2022.Raw and preprocessed data files are in .mat format.If you use the data or the code, please cite: Talluri, B. C., Kang I., Lazere, A., Quinn, K. R., Kaliss, N., Yates, J.L., Butts, D.A., Nienborg, H. (2022). Activity in primate visual cortex is minimally driven by spontaneous movements. bioRxiv. 2022.09.08.507006. doi: https://doi.org/10.1101/2022.09.08.507006</p
Life cycle assessment of geothermal power plants: A comparison with other energy conversion technologies
No full textGeothermal is a very promising renewable energy, which differently from variable renewable energies is independent of external/climate conditions and can cover both power and heat demands. Nonetheless, albeit these advantageous characteristics, traditional geothermal power plants may have not negligible environmental impacts: these range from emissions of pollutants or greenhouse gases to relevant use of chemicals, power, and other resources during plant development (wells), operation, and construction.It is therefore of paramount importance to provide a reliable methodology to assess the environmental performance of geothermal systems, which should also allow a comparison of the effects with other renewable energies and with traditional fossil fuels used in the power and heat sector.For this reason, Life Cycle Assessment (LCA) was selected as the proper tool to conduct the comparison. An updated analysis of several representative geothermal power plant reference cases of different types and sizes was performed using the Product Environmental Footprint EF 2.0 assessment method. This represents also an update concerning the current practice documented in the technical literature, which often applies different methods (e.g. RECIPE, ILCD, CML, or Eco-Indicator) which are being superseded.In this research, the final single score of each power plant was also calculated and compared among different plants, as well as with other renewables and national energy mixes. The single score results indicate that geothermal plants' environmental impacts are in line with other renewable technologies and that they are in general lower than the corresponding national energy mixes
CAGL, A SPECIALIZED HELICOBACTER PYLORI ADHESIN, AS A POTENTIAL PHARMACOLOGICAL TARGET AND CANDIDATE FOR DEVELOPING NEW VACCINE
No full textCagL is recognized as a specialized adhesin localized on the pilus surface of H. pyloriType IV secretion system (T4SS). CagL binds to α5β1 integrin on gastric epithelial cells by the RGD motif. This interaction contributes in triggering the virulence factor CagA delivery into target cells. Chronic gastritis, peptic ulcers and even cancer may represent the final effect after infection. However, the CagL-integrin interaction is not essential for the CagA translocation suggesting the existence of an alternative mechanism of action of CagL in H. pylori infection. Sequence analyses of CagL showed the presence of three motifs that resemble conserved motifs in ADP-ribosylating toxins. These motifs are involved in ADP-ribosylation activity which is one of the main mechanisms of cell intoxication employed by bacteria. A comparison between the aminoacidic sequences ofH. pylori strains available in databases showed that only Shi470 possesses an R in the first domain that could confer the expected ADP-ribosylation activity to the protein. R, in this region, is reported to be important for the nicotinamide adenine dinucleotide (NAD) binding. R is substituted by either N or S in other H. pylori strains. Thus, the attention has been focused on the pathogenic H. pylori Shi470 strain. Here, we cloned and purified recombinant CagL lacking the leader sequence, with the aim of investigating its biochemical properties. Preliminary results showed an auto-ADP ribosylation activity of CagL utilizing biotinylated NAD as substrate and chemiluminescence for activity detection. Moreover, CagL resulted sensitive to novobiocin, a potent ADP-ribosylation inhibitor, in a concentration dependent manner. Heat inactivation also inhibited the activity, thus confirming the absence of unspecific binding of substrate. We also demonstrated the protective efficacy in the murine model of infection of recombinant CagL which can be taken into consideration as antigen in therapeutic or preventive vaccines
Additive Manufacturing for Spare Parts Management: Is Decentralized Production Always Environmentally Preferable?
No full textAdditive manufacturing (AM) has emerged as a promising solution for spare parts management. Given the possibility of producing spare parts close to the point of use, the literature generally asserts that decentralized AM production is more environmentally friendly than centralized AM production. However, when asserting this, the literature overlooks AM's high energy intensity and variable CO2,eq emissions from electricity generation in different countries. The current study addresses this problem by analyzing when centralized AM production is environmentally preferable to decentralized AM production, taking a lifecycle perspective. A mathematical model quantifies CO2,eq emissions for both strategies and determines which is environmentally preferable, and a decision tree analysis is used to develop a decision tree that suggests when centralized AM production is environmentally preferable. Interestingly, our results contradict the current literature, showing how centralized AM production can be a more environmentally friendly strategy than decentralized AM production, especially in countries with low CO2,eq emissions. Adopting centralized AM production when preferable would result in significant reductions of CO2,eq emissions that, considering the current carbon reduction schemes recently introduced, would lead to substantial economic savings (even up to 3000 USD/year per spare part). Moreover, considering future trends in sustainable energy sources and AM technology advancements, this study explores how the preferable AM production strategy might evolve, showing that this does not greatly affect the convenience of centralized AM production. Finally, a practical application of the decision tree in two case studies demonstrates its utility for two companies and the potential savings achievable
On bounds for network revenue management
No full textThe Network Revenue Management problem can be formulated as a stochastic dynamic programming problem (DP or the\optimal" solution V *) whose exact solution is computationally intractable. Consequently, a number of heuristics have been proposed in the literature, the most popular of which are the deterministic linear programming (DLP) model, and a simulation based method, the randomized linear programming (RLP) model. Both methods give upper bounds on the optimal solution value (DLP and PHLP respectively). These bounds are used to provide control values that can be used in practice to make accept/deny decisions for booking requests. Recently Adelman [1] and Topaloglu [18] have proposed alternate upper bounds, the affine relaxation (AR) bound and the Lagrangian relaxation (LR) bound respectively, and showed that their bounds are tighter than the DLP bound. Tight bounds are of great interest as it appears from empirical studies and practical experience that models that give tighter bounds also lead to better controls (better in the sense that they lead to more revenue). In this paper we give tightened versions of three bounds, calling themsAR (strong Affine Relaxation), sLR (strong Lagrangian Relaxation) and sPHLP (strong Perfect Hindsight LP), and show relations between them. Speciffically, we show that the sPHLP bound is tighter than sLR bound and sAR bound is tighter than the LR bound. The techniques for deriving the sLR and sPHLP bounds can potentially be applied to other instances of weakly-coupled dynamic programming.revenue management, bid-prices, relaxations, bounds
A randomized concave programming method for choice network revenue management
No full textModels incorporating more realistic models of customer behavior, as customers choosing from an offer set, have recently become popular in assortment optimization and revenue management. The dynamic program for these models is intractable and approximated by a deterministic linear program called the CDLP which has an exponential number of columns. However, when the segment consideration sets overlap, the CDLP is difficult to solve. Column generation has been proposed but finding an entering column has been shown to be NP-hard. In this paper we propose a new approach called SDCP to solving CDLP based on segments and their consideration sets. SDCP is a relaxation of CDLP and hence forms a looser upper bound on the dynamic program but coincides with CDLP for the case of non-overlapping segments. If the number of elements in a consideration set for a segment is not very large (SDCP) can be applied to any discrete-choice model of consumer behavior. We tighten the SDCP bound by (i) simulations, called the randomized concave programming (RCP) method, and (ii) by adding cuts to a recent compact formulation of the problem for a latent multinomial-choice model of demand (SBLP+). This latter approach turns out to be very effective, essentially obtaining CDLP value, and excellent revenue performance in simulations, even for overlapping segments. By formulating the problem as a separation problem, we give insight into why CDLP is easy for the MNL with non-overlapping considerations sets and why generalizations of MNL pose difficulties. We perform numerical simulations to determine the revenue performance of all the methods on reference data sets in the literature.assortment optimization, randomized algorithms, network revenue management.
Neonatal hyperbilirubinemia. Evidence for a role of the erythrocyte enzyme activities involved in the detoxification of oxygen radicals
No full textDeterminations of erythrocyte enzyme scavengers of oxygen radicals (glutathione-peroxidase, superoxide-dismutase and catalase) and determinations of erythrocytes age-dependent glycolytic activities (glucose-6-phosphatedehydrogenase, pyruvate-kinase and glucose-phosphate-isomerase) were carried out in cord blood and in the blood taken on the 4th day of life in 152 newborn infants with different peak bilirubin levels. The enzyme activities scavenging oxygen radicals, glutathione-peroxidase and superoxide-dismutase were significantly lower in infants with peak bilirubinemia higher than 214 μmol/l, compared to less-jaundiced neonates, both at birht and on the 4th day of life; their values correlated negatively with peak bilirubinemia at birth and on the 4th day of life. Glycolytic age-dependent enzyme activities were significantly higher in more jaundiced newborn infants only on the 4th day of life, when their values correlated positively with peak bilirubinemia. The results of this investigation suggest that a deficiency of factors protecting from oxygen toxicity, may play a role in the development of neonatal hemolysis and jaundice
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
Square Dancing with the Stars to Enhance Dynamic Hirschman Linkages?
No full textIn this Presidential Address, the author takes the reader on a reconnaissance of his life and time as a regional scientist. He points out scenery he found scintillating along the way, hoping that some may pick up the banner and chew on a few of the ideas for a while. He suggests a revisit to Albert O. Hirschman’s notion of key sectors and more empirical analysis related to Marcus Berliant’s and Masahisa Fujita’s notion of knowledge creation and transfer.Presidential Address, San Antonio, Texas, March 29, 2014 (53rd Meetings of the Southern Regional Science Association
Appropriate Similarity Measures for Author Cocitation Analysis
No full textWe 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
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