Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 6 de 6
Filtrar
Mais filtros








Base de dados
Intervalo de ano de publicação
1.
PLoS One ; 18(8): e0290229, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37616259

RESUMO

We propose a model and algorithm to measure the amount of influence a shareholder has over the flow of corporate control held by the ultimate owners. Existing models of corporate ownership and control either focus on the ultimate owners' influence or inadequately evaluate the influence possessed by intermediate shareholders in a ownership network. As it extends Network Power Index (NPI) that describes the the power of corporate control possessed by the ultimate owners, our new model, Network Power Flow (NPF), delineates the distribution of ownership influence among shareholders across the network and identifies the channels through which the ultimate owners' corporate control travel through the global shareholding network. Our analysis of NPI and NPF values for 7 million ultimate owners and 16 million shareholders reveals a new landscape of ownership and control in the global shareholding network that remained opaque before.


Assuntos
Algoritmos , Propriedade , Organizações , Viagem
2.
J Agric Food Chem ; 69(33): 9551-9556, 2021 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-34374535

RESUMO

A novel insecticide flupyrimin (FLP) with a trifluoroacetyl pharmacophore acts as an antagonist at the insect nicotinic acetylcholine receptor (nAChR). This investigation examines a hypothesis that the FLP C(O)CF3 moiety is primarily recognized by the ß subunit-face in the ligand-binding pocket (interface between α and ß subunits) of the insect nAChR. Accordingly, we evaluate the atomic interaction between a fluorine atom of FLP and the partnering amino acid side chain on the ß subunit employing a recombinant hybrid nAChR consisting of aphid Mpα2 and rat Rß2 subunits (with a mutation at T77 on the Rß2). The H-donating T77R, T77K, T77N, or T77Q nAChR enhances the FLP binding potency relative to that of the wild-type receptor, whereas the affinity of neonicotinoid imidaclprid (IMI) with a nitroguanidine pharmacophore remains unchanged. These results facilitate the establishment of the unique FLP molecular recognition at the Mpα2/Mpß1 interface structural model, thereby underscoring a distinction in its binding mechanism from IMI.


Assuntos
Afídeos , Inseticidas , Receptores Nicotínicos , Animais , Insetos , Neonicotinoides , Nitrocompostos , Ratos , Receptores Nicotínicos/genética
3.
PLoS One ; 16(8): e0256160, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34383856

RESUMO

We analyze the connectivity of equity investments to the firms in the global ownership network that are reported as non-compliant with Environment, Social, and Government (ESG) benchmarks. We find that a large number of shareholders have ownership linkages to non-ESG firms, most commonly with three or four degrees of separation. Analyzing the betweenness centrality for shareholders connecting the ultimate owners and non-ESG firms, we find that the investment management companies play important roles in channeling the investment money into non-ESG firms, where largest American asset managers commonly have one to two degrees of separation on their ownership linkages to those problematic firms. Since asset managers collect capital from investors by running the equity funds, we analyze the ownership stakes and the associated voting rights attributable to the equity funds investors. We estimate the distribution of the power of corporate control over non-ESG firms among specific asset managers (such as BlackRock and Fidelity) and among different types of the equity funds (such as mutual funds and exchanged-traded funds), and explores how investing in the equity funds rather than ownership investing may have shifted the distribution of the power to control those non-ESG firms.


Assuntos
Algoritmos , Administração Financeira/economia , Investimentos em Saúde/economia , Investimentos em Saúde/organização & administração , Organizações/economia , Propriedade/economia , Responsabilidade Social , Humanos , Estados Unidos
4.
J Comput Soc Sci ; 4(1): 187-205, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-32838050

RESUMO

Timely estimation of the distribution of socioeconomic attributes and their movement is crucial for academic as well as administrative and marketing purposes. In this study, assuming personal attributes affect human behavior and movement, we predict these attributes from location information. First, we predict the socioeconomic characteristics of individuals by supervised learning methods, i.e., logistic Lasso regression, Gaussian Naive Bayes, random forest, XGBoost, LightGBM, and support vector machine, using survey data we collected of personal attributes and frequency of visits to specific facilities, to test our conjecture. We find that gender, a crucial attribute, is as highly predictable from locations as from other sources such as social networking services, as done by existing studies. Second, we apply the model trained with the survey data to actual GPS log data to check the performance of our approach in a real-world setting. Though our approach does not perform as well as for the survey data, the results suggest that we can infer gender from a GPS log.

5.
PLoS One ; 15(8): e0237862, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32853210

RESUMO

As passive investment through index funds and Exchange Traded Funds (ETFs) has become pervasive, the structure of corporate control in the global capital market is more complex than before. We propose a new model and calculation algorithm to measure a shareholder's power to control corporations in the global economy. Our method takes into account how fragmented voting rights attached to dispersed ownership may be consolidated to generate corporate control. Analyzing the ownership holdings in 49 million companies worldwide by 69 million shareholders in 2016, we find that the landscape of global corporate control appears differently if we adequately evaluate indirect influence via dispersed ownership. In particular, a larger portion of corporate control appears to be concentrated in the hands of sovereign governments than has been recognized before. Yet, such governmental capacities are "hidden" if we use the conventional method. Moreover, financial institutions appear to not be as powerful as emphasized before. These results point to important financial and political risks both for scholars and policymakers.


Assuntos
Organizações/economia , Propriedade/economia , Algoritmos , Análise Numérica Assistida por Computador
6.
Appl Environ Microbiol ; 81(21): 7625-32, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26319877

RESUMO

The plasmid pGKE75-catA138T, which comprises pUC18 and the catA138T gene encoding thermostable chloramphenicol acetyltransferase with an A138T amino acid replacement (CATA138T), serves as an Escherichia coli-Geobacillus kaustophilus shuttle plasmid that confers moderate chloramphenicol resistance on G. kaustophilus HTA426. The present study examined the thermoadaptation-directed mutagenesis of pGKE75-catA138T in an error-prone thermophile, generating the mutant plasmid pGKE75(αß)-catA138T responsible for substantial chloramphenicol resistance at 65°C. pGKE75(αß)-catA138T contained no mutation in the catA138T gene but had two mutations in the pUC replicon, even though the replicon has no apparent role in G. kaustophilus. Biochemical characterization suggested that the efficient chloramphenicol resistance conferred by pGKE75(αß)-catA138T is attributable to increases in intracellular CATA138T and acetyl-coenzyme A following a decrease in incomplete forms of pGKE75(αß)-catA138T. The decrease in incomplete plasmids may be due to optimization of plasmid replication by RNA species transcribed from the mutant pUC replicon, which were actually produced in G. kaustophilus. It is noteworthy that G. kaustophilus was transformed with pGKE75(αß)-catA138T using chloramphenicol selection at 60°C. In addition, a pUC18 derivative with the two mutations propagated in E. coli at a high copy number independently of the culture temperature and high plasmid stability. Since these properties have not been observed in known plasmids, the outcomes extend the genetic toolboxes for G. kaustophilus and E. coli.


Assuntos
Resistência ao Cloranfenicol , Escherichia coli/genética , Vetores Genéticos , Geobacillus/genética , Mutagênese , Mutação , Plasmídeos , Acetilcoenzima A/metabolismo , Cloranfenicol O-Acetiltransferase/biossíntese , Temperatura Alta
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA