Aplicación de la técnica mapas mentales para desarrollar la compresión lectora en los estudiantes del primer ciclo de la Facultad de Ciencias Empresariales de la Universidad Técnica de Machala - Ecuador - 2013

Publicación a texto completo no autorizada por el autorAplica la técnica de mapas mentales para desarrollar la comprensión lectora en los estudiantes del primer ciclo de la Facultad De Ciencias Empresariales de la Universidad Técnica de Machala. El diseño empleado fue el cuasi experimental. El estudio se desarrolló durante el segundo semestre del año 201con una muestra de 144 estudiantes de ambos sexos pertenecientes a la Facultad de Ciencias empresariales de la Universidad Técnica de Machala. Los niveles de comprensión lectora fueron evaluados antes y después de la aplicación de la técnica de mapas mentales mediante la prueba de comprensión lectora. Se utilizó también el instrumento para evaluar mapas mentales, de Suárez y García. Los resultados permiten concluir que la aplicación de la técnica de mapas mentales ha producido un incremento significativo en los niveles de comprensión lectora de la población estudiada.Tesi

Economic Fluctuation and Japanese Monetary Policy : Two Empirical Studies with SVAR Approach

The paper investigates the effects of Japanese monetary policy with two structure VAR (SVAR) analyses. Firstly, it constructs SVAR model using seven economic variables of Japan and assumes a particular structure matrix to identify it. By estimating this model with monthly data from 1970:Ol to 2002:12, it shows the following main results, 1) interest rate shock and money supply shock have significant effects on economic variables; 2) the shock's effect of the credit from central bank is very small; 3) the effect of exchange rate shock is limited 4) the Bank of Japan implements monetary policy by both of interest rate and money supply. Secondly, following Huang and Guo (2006) and NG (2002), it introduces the world GDP to denote world economy growth and oil price to denote world price level, and estimates SVAR model containing them and Japanese interest rate and exchange rate. Empirical results show that the external demand shock has negative effect on exchange rate and positive effect on interest rate, and the external supply shock has positive effects on both exchange rate and interest rate

Metal cofactor modulated folding and target recognition of HIV-1 NCp7.

The HIV-1 nucleocapsid 7 (NCp7) plays crucial roles in multiple stages of HIV-1 life cycle, and its biological functions rely on the binding of zinc ions. Understanding the molecular mechanism of how the zinc ions modulate the conformational dynamics and functions of the NCp7 is essential for the drug development and HIV-1 treatment. In this work, using a structure-based coarse-grained model, we studied the effects of zinc cofactors on the folding and target RNA(SL3) recognition of the NCp7 by molecular dynamics simulations. After reproducing some key properties of the zinc binding and folding of the NCp7 observed in previous experiments, our simulations revealed several interesting features in the metal ion modulated folding and target recognition. Firstly, we showed that the zinc binding makes the folding transition states of the two zinc fingers less structured, which is in line with the Hammond effect observed typically in mutation, temperature or denaturant induced perturbations to protein structure and stability. Secondly, We showed that there exists mutual interplay between the zinc ion binding and NCp7-target recognition. Binding of zinc ions enhances the affinity between the NCp7 and the target RNA, whereas the formation of the NCp7-RNA complex reshapes the intrinsic energy landscape of the NCp7 and increases the stability and zinc affinity of the two zinc fingers. Thirdly, by characterizing the effects of salt concentrations on the target RNA recognition, we showed that the NCp7 achieves optimal balance between the affinity and binding kinetics near the physiologically relevant salt concentrations. In addition, the effects of zinc binding on the inter-domain conformational flexibility and folding cooperativity of the NCp7 were also discussed

Rapid synthesis and characterization of spinel manganese ferrite nanopowder by microwave-assisted hydrothermal method

Spinel manganese ferrite (MnFe2O4) nanopowder is widely used in many fields, such as the targeted drugs, magnetic fluid sealing technology, magnetic resonance imaging, sewage treatment and so on. The MnFe2O4 nanopowder was synthesized by a rapid microwave hydrothermal method. The phase composition, microstructure and particle size distribution of the as-synthesized nanopowder were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM), and laser particle size analysis, respectively. And their static magnetic properties were measured by vibrating sample magnetometry (VSM). It is found that the microwave hydrothermal reaction time, temperature and the pH of reaction system possess the great effects on the crystallinity, crystallite size and phase composition of the prepared MnFe2O4 nanopowder, and consequently its saturation magnetization (Ms). As the reaction temperature and reaction system pH increase, the average crystallite size of the samples increases gradually, their crystallinities are improved, and the Ms of the prepared nano-MnFe2O4 firstly increase, and then decrease. The MnFe2O4 powder with an average crystallite size of 17 nm and a specific saturation magnetization of 53.6 emu·g−1 was obtained by a microwave-assisted hydrothermal method at a reaction temperature of 130 °C, a reaction system pH of 12 and a reaction time of 10 min. This work provides a rapid and simple approach to prepare MnFe2O4 nanopowder with a high saturation magnetization

Strata Architectural Variability and Facies Distribution in Structural Transfer Zone: A Case Study of Fushan Sag, Northern South China Sea

International audienceStructural transfer zones in a half‐graben rift basin play a significant role in controlling the sandy sediments and provided a target to the hydrocarbon exploration. Previous studies have classified the transfer zone in lacustrine environments into two different patterns: synthetic approaching transfer zones and synthetic overlapping transfer zones. However, the depositional pattern evolution and control factors of the above transfer zones are still unclear. In the Fushan Sag, the northern South China Sea, an overlapping transfer zone developed in the early Eocene Epoch, while a synthetic approaching transfer zone developed in the late Eocene due to tectonic uplift. This evolution process provided an opportunity to study the stack pattern of strata architectural variability and facies distribution in the structural transfer zone of the Eocene lacustrine basin. In this study, as the oriented sedimentary structures in core samples and heavy mineral assemblages of 18 wells indicating, we rebuilt the paleo‐hydrodynamic distribution evolution during the early and late Eocene. Then, we divide the sequence‐stratigraphy and calculate the sand body parameters according to the seismic data and well log interpretation. During the early Eocene, the lake level was in the low stand, and the faults broken displacement in the East block was over 50 m. We point out that the prograding delta and turbidities are oriented perpendicular to the structural transfer zone. According to the quantitative analysis of the flow rate and the depositional parameters, we speculate that its gravity transported the sediment and the sediment‐supply is dominated factors during this period. Up to the late Eocene, the rising lake level and the decreased faults displacement lead the flow diverted to a NE‐direction, resulting in it being parallel to the axis of the transfer zone. Thus, we speculated that the accommodation space is domination in this period. In comparison, the above two periods, a braid river delta with an isolated sand body and turbidities developed in the deep area is prominent in the overlapping transfer zone, while a meandering river delta characterized in the synthetic approaching transfer zone

Zero Watermarking Algorithm for Vector Geographic Data Based on the Number of Neighboring Features

Zero watermarking is an important part of copyright protection of vector geographic data. However, how to improve the robustness of zero watermarking is still a critical challenge, especially in resisting attacks with significant distortion. We proposed a zero watermarking method for vector geographic data based on the number of neighboring features. The method makes full use of spatial characteristics of vector geographic data, including topological characteristics and statistical characteristics. First, the number of first-order neighboring features (NFNF) and the number of second-order neighboring features (NSNF) of every feature in vector geographic data are counted. Then, the watermark bit is determined by the NFNF value, and the watermark index is determined by the NSNF value. Finally, combine the watermark bits and the watermark indices to construct a watermark. Experiments verify the theoretical achievements and good robustness of this method. Simulation results also demonstrate that the normalized coefficient of the method is always kept at 1.00 under the attacks that distort data significantly, which has the superior performance in comparison to other methods

Zero Watermarking Algorithm for Vector Geographic Data Based on the Number of Neighboring Features

Zero watermarking is an important part of copyright protection of vector geographic data. However, how to improve the robustness of zero watermarking is still a critical challenge, especially in resisting attacks with significant distortion. We proposed a zero watermarking method for vector geographic data based on the number of neighboring features. The method makes full use of spatial characteristics of vector geographic data, including topological characteristics and statistical characteristics. First, the number of first-order neighboring features (NFNF) and the number of second-order neighboring features (NSNF) of every feature in vector geographic data are counted. Then, the watermark bit is determined by the NFNF value, and the watermark index is determined by the NSNF value. Finally, combine the watermark bits and the watermark indices to construct a watermark. Experiments verify the theoretical achievements and good robustness of this method. Simulation results also demonstrate that the normalized coefficient of the method is always kept at 1.00 under the attacks that distort data significantly, which has the superior performance in comparison to other methods

Metal cofactor modulated folding and target recognition of HIV-1 NCp7 - Fig 4

<p>(<b>A</b>) Free energy surface of NCp7 projected on <i>Q</i>_<i>ZF</i>1 and <i>Q</i>_<i>ZF</i>2 at intermediate concentration of Zn²⁺. (<b>B</b>) One-dimensional free energy profiles projected onto the <i>Q</i> value of the ZF2 with the ZF1 well-folded (red) and unstructured (blue), respectively at intermediate zinc concentration. For comparison, the corresponding free energy profiles from the simulations. ‘U’ and ‘F’ denote the unfold and fold states of the ZF1, respectively. with the inter-domain interactions removed are also shown (dots).</p

Joint Image Encryption and Screen-Cam Robust Two Watermarking Scheme

This paper proposes a joint encryption and screen-cam robust watermarking scheme. This method combines the advantages of smartphone, encryption and watermarking technologies, thereby achieving watermark extraction with a smartphone, partial decryption and tracking leakage from sneak shots. We design a dual watermarking algorithm to achieve watermark detection from both encrypted and decrypted images. First, a watermark is embedded in the discrete Fourier transform (DFT) domain to enable leakage tracking. Then, a second watermark is generated based on QR (Quick response) code encoding and inverse DFT to achieve high watermark capacity and error correction ability, where the secret key for decryption is included in the watermark message. By hiding this message carrying the watermark for the encrypted image in the changes caused by embedding the first watermark, we can improve imperceptibility and will not affect the effectiveness of the proposed scheme. Finally, to enhance the robustness of watermark after encryption, a chaotic mapping-based segment encryption algorithm is proposed. In the process of watermark detection, to cope with perspective correction, a frame locating based algorithm is employed to achieve watermark synchronization from a recaptured picture of the encrypted image. Considering the severe quality degradation, we use a noise component and local statistic feature-based method to extract the message bits. The experimental results show that the proposed scheme is secure, and highly robust, to screen-cam the process for both before and after decryption. Additionally, after decryption, the proposed scheme also has high robustness against common image processing attacks