• 제목/요약/키워드: Luis

검색결과 299건 처리시간 0.024초

Hubble Space Telescope Survey of Host Galaxies of Hard X-ray-Selected AGNs

  • Hwang, Hyunmo;Kim, Minjin;Barth, Aaron J.;Ho, Luis C.
    • 천문학회보
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    • 제44권1호
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    • pp.74.1-74.1
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    • 2019
  • We present an ongoing imaging survey of the host galaxies of hard X-ray-selected active galactic nuclei (AGNs) observed with the Hubble Space Telescope (HST). The snapshot images are taken with the Advanced Camera for Surveys through an HST gap-filler program. The sample, selected from the 70-month Swift-BAT X-ray source catalog, represents an unbiased and uniform AGN population, which will enable us to test the AGN unification model and explore the physical connection between host galaxies and central supermassive black holes. We also plan to investigate the AGN triggering mechanism by examining merger signatures and searching for dual nuclei. We present the pipeline for imaging analysis and the current status of the survey.

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PARAMETER DEPENDENCE OF SMOOTH STABLE MANIFOLDS

  • Barreira, Luis;Valls, Claudia
    • 대한수학회지
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    • 제56권3호
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    • pp.825-855
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    • 2019
  • We establish the existence of $C^1$ stable invariant manifolds for differential equations $u^{\prime}=A(t)u+f(t,u,{\lambda})$ obtained from sufficiently small $C^1$ perturbations of a nonuniform exponential dichotomy. Since any linear equation with nonzero Lyapunov exponents has a nonuniform exponential dichotomy, this is a very general assumption. We also establish the $C^1$ dependence of the stable manifolds on the parameter ${\lambda}$. We emphasize that our results are optimal, in the sense that the invariant manifolds are as regular as the vector field. We use the fiber contraction principle to establish the smoothness of the invariant manifolds. In addition, we can also consider linear perturbations, and thus our results can be readily applied to the robustness problem of nonuniform exponential dichotomies.

Applications of Solid Viscoelastic Coupling Dampers (VCDs) in Wind and Earthquake Sensitive Tall Buildings

  • Montgomery, Michael;Ardila, Luis;Christopoulos, Constantin
    • 국제초고층학회논문집
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    • 제10권2호
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    • pp.123-135
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    • 2021
  • Solid Viscoelastic Coupling Dampers (VCDs) provide distributed damping that improves the dynamic performance of tall buildings for both wind-storms and earthquakes for all amplitudes of vibration. They are configured in place of typical structural members in tall buildings and therefore do not occupy any architectural space. This paper summarizes the research and development at the University of Toronto in collaboration with Nippon Steel Engineering, 3M and Kinetica over the past two decades. In addition, impact studies on buildings incorporating the VCDs are presented, consisting of a wind sensitive 66-story building in Toronto, a dual-wind and seismic performance-based design of a 4-tower development in Manila and finally a 630 meter Megatall building in Southeast Asia in a severe seismic environment. In all applications the VCDs are shown to provide significant benefits in the dynamic performance under both wind and earthquake loading in a cost-effective manner.

A simplified CAD/CAM extraoral surgical guide for therapeutic injections

  • Cameron, Andrew;Custodio, Antonio Luis Neto;Bakr, Mahmoud;Reher, Peter
    • Journal of Dental Anesthesia and Pain Medicine
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    • 제21권3호
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    • pp.253-260
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    • 2021
  • Therapeutic injections into the craniofacial region can be a complex procedure because of the nature of its anatomical structure. This technical note demonstrates a process for creating an extra-oral template to inject therapeutic substances into the temporomandibular joint and the lateral pterygoid muscle. The described process involves merging cone-beam computed tomography data and extra-oral facial scans obtained using a mobile device to establish a correlated data set for virtual planning. Virtual injection points were simulated using existing dental implant planning software to assist clinicians in precisely targeting specific anatomical structures. A template was designed and then 3D printed. The printed template showed adequate surface fit. This innovative process demonstrates a potential new clinical technique. However, further validation and in vivo trials are necessary to assess its full potential.

The skew-t censored regression model: parameter estimation via an EM-type algorithm

  • Lachos, Victor H.;Bazan, Jorge L.;Castro, Luis M.;Park, Jiwon
    • Communications for Statistical Applications and Methods
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    • 제29권3호
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    • pp.333-351
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    • 2022
  • The skew-t distribution is an attractive family of asymmetrical heavy-tailed densities that includes the normal, skew-normal and Student's-t distributions as special cases. In this work, we propose an EM-type algorithm for computing the maximum likelihood estimates for skew-t linear regression models with censored response. In contrast with previous proposals, this algorithm uses analytical expressions at the E-step, as opposed to Monte Carlo simulations. These expressions rely on formulas for the mean and variance of a truncated skew-t distribution, and can be computed using the R library MomTrunc. The standard errors, the prediction of unobserved values of the response and the log-likelihood function are obtained as a by-product. The proposed methodology is illustrated through the analyses of simulated and a real data application on Letter-Name Fluency test in Peruvian students.

Pensar la Fraternidad en la Diferencia

  • Jurado, Jenniffer Londono
    • 이베로아메리카
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    • 제21권1호
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    • pp.107-125
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    • 2019
  • How to conceive fraternity in difference? I will hold two premises to answer this question. First: fraternity is an ineradicable element of the Political. Second: the recognition of fraternity in difference is a precondition for the consolidation of fraternal relations in Latin America in the context of coloniality. On the same path, I will show that fraternity must be thought of as difference in order to face the logic of neoliberal life imposed by capitalism in globalization. The articulation of both premises in the political praxis would contribute to the preservation of our life in common; in conditions of dignified existence. The fraters of precariousness and vulnerability are the ones who can re-establish being-with- and being-together.

HOXA9 is Underexpressed in Cervical Cancer Cells and its Restoration Decreases Proliferation, Migration and Expression of Epithelial-to-Mesenchymal Transition Genes

  • Alvarado-Ruiz, Liliana;Martinez-Silva, Maria Guadalupe;Torres-Reyes, Luis Alberto;Pina-Sanchez, Patricia;Ortiz-Lazareno, Pablo;Bravo-Cuellar, Alejandro;Aguilar-Lemarroy, Adriana;Jave-Suarez, Luis Felipe
    • Asian Pacific Journal of Cancer Prevention
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    • 제17권3호
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    • pp.1037-1047
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    • 2016
  • HOX transcription factors are evolutionarily conserved in many different species and are involved in important cellular processes such as morphogenesis, differentiation, and proliferation. They have also recently been implicated in carcinogenesis, but their precise role in cancer, especially in cervical cancer (CC), remains unclear. In this work, using microarray assays followed by the quantitative polymerase chain reaction (qPCR), we found that the expression of 25 HOX genes was downregulated in CC derived cell lines compared with non-tumorigenic keratinocytes. In particular, the expression of HOXA9 was observed as down-modulated in CC-derived cell lines. The expression of HOXA9 has not been previously reported in CC, or in normal keratinocytes of the cervix. We found that normal CC from women without cervical lesions express HOXA9; in contrast, CC cell lines and samples of biopsies from women with CC showed significantly diminished HOXA9 expression. Furthermore, we found that methylation at the first exon of HOXA9 could play an important role in modulating the expression of this gene. Exogenous restoration of HOXA9 expression in CC cell lines decreased cell proliferation and migration, and induced an epithelial-like phenotype. Interestingly, the silencing of human papilloma virus (HPV) E6 and E7 oncogenes induced expression of HOXA9. In conclusion, controlling HOXA9 expression appears to be a necessary step during CC development. Further studies are needed to delineate the role of HOXA9 during malignant progression and to afford more insights into the relationship between downmodulation of HOXA9 and viral HPV oncoprotein expression during cercical cancer development.

Potential influence of κ-casein and β-lactoglobulin genes in genetic association studies of milk quality traits

  • Zepeda-Batista, Jose Luis;Saavedra-Jimenez, Luis Antonio;Ruiz-Flores, Agustin;Nunez-Dominguez, Rafael;Ramirez-Valverde, Rodolfo
    • Asian-Australasian Journal of Animal Sciences
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    • 제30권12호
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    • pp.1684-1688
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    • 2017
  • Objective: From a review of published information on genetic association studies, a meta-analysis was conducted to determine the influence of the genes ${\kappa}-casein$ (CSN3) and ${\beta}-lactoglobulin$ (LGB) on milk yield traits in Holstein, Jersey, Brown Swiss, and Fleckvieh. Methods: The GLIMMIX procedure was used to analyze milk production and percentage of protein and fat in milk. Models included the main effects and all their possible two-way interactions; not estimable effects and non-significant (p>0.05) two-way interactions were dropped from the models. The three traits analyzed used Poisson distribution and a log link function and were determined with the Interactive Data Analysis of SAS software. Least square means and multiple mean comparisons were obtained and performed for significant main effects and their interactions (p<0.0255). Results: Interaction of breed by gene showed that Holstein and Fleckvieh were the breeds on which CSN3 ($6.01%{\pm}0.19%$ and $5.98%{\pm}0.22%$), and LGB ($6.02%{\pm}0.19%$ and $5.70%{\pm}0.22%$) have the greatest influence. Interaction of breed by genotype nested in the analyzed gene indicated that Holstein and Jersey showed greater influence of the CSN3 AA genotype, $6.04%{\pm}0.22%$ and $5.59%{\pm}0.31%$ than the other genotypes, while LGB AA genotype had the largest influence on the traits analyzed, $6.05%{\pm}0.20%$ and $5.60%{\pm}0.19%$, respectively. Furthermore, interaction of type of statistical model by genotype nested in the analyzed gene indicated that CSN3 and LGB genes had similar behavior, maintaining a difference of more than 7% across analyzed genotypes. These results could indicate that both Holstein and Jersey have had lower substitution allele effect in selection programs that include CSN3 and LGB genes than Brown Swiss and Fleckvieh. Conclusion: Breed determined which genotypes had the greatest association with analyzed traits. The mixed model based in Bayesian or Ridge Regression was the best alternative to analyze CSN3 and LGB gene effects on milk yield and protein and fat percentages.

Backgrounding steers on temperate grasses mixed with vetch and/or using energy supplementation

  • de Oliveira Lazzarotto, Eduardo Felipe Colerauz;de Menezes, Luis Fernando Glasenapp;Paris, Wagner;Molinete, Marcos Luis;Schmitz, Gean Rodrigo;Baraviera, Jose Henrique Ignacio;Farenzena, Roberta;de Paula, Adalberto Luiz
    • Asian-Australasian Journal of Animal Sciences
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    • 제32권6호
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    • pp.800-807
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    • 2019
  • Objective: The aim was to evaluate backgrounding beef steers on oat + ryegrass pastures mixed with vetch and/or using energy supplementation. Methods: A randomized block design with three treatments and three replications was used. The treatments were: grass + supplement (oat + ryegrass + supplementation), legume + supplement (oat + ryegrass + vetch + supplementation) and grass + legume (oat + ryegrass + vetch). A continuous grazing system with a variable stocking rate was used. Twenty-seven intact crossbred steers (1/4 Marchigiana, 1/4 Aberdeen Angus and 2/4 Nellore) aged 7 months old and average weight of 190 kg were used. Steers were supplemented at 1% of the body weight of ground corn. The experiment lasted 84 days, between May and August 2014. Behavioral assessments were performed two times per experimental period, for 24 hours. Results: The forage mass was different between treatments, being greater for steers fed without legume. The accumulation rate, forage allowance, and stocking rate did not differ between treatments due to the adequate adjustment of forage allowance. The final weight of animals, as well as the dry matter intake (kg/d), did not differ between treatments. However, forage intake was higher for non-supplemented animals in relation to supplemented steers. Supplement intake did not alter the total digestible nutrient intake due to pasture quality. Animals fed grass + supplement had higher live weight gain per area than those fed grass + legume. Animals without supplementation spent more time in grazing. Conclusion: Feeding behavior was not altered by mixing with vetch or supplementation. Non-supplemented animals started the grazing peak earlier and spent more time in grazing than those supplemented; however, the average daily gain was similar between treatments. The live weight gain per hectare was 47% higher in pastures in which the animals received supplementation compared with those mixed with vetch, a consequence of the substitutive effect.