Two binary Darboux transformations for the KdV hierarchy with self-consistent sources

Two binary (integral type) Darboux transformations for the KdV hierarchy with self-consistent sources are proposed. In contrast with the Darboux transformation for the KdV hierarchy, one of the two binary Darboux transformations provides non auto-B\"{a}cklund transformation between two n-th KdV equations with self-consistent sources with different degrees. The formula for the m-times repeated binary Darboux transformations are presented. This enables us to construct the N-soliton solution for the KdV hierarchy with self-consistent sources.Comment: 19 pages, LaTeX, no figures, to be published in Journal of Mathematical Physic

MERCADOTECNIA

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On the Equivalence Between Type I Liouville Dynamical Systems in the Plane and the Sphere

Producción CientíficaSeparable Hamiltonian systems either in sphero-conical coordinates on an S2 sphere or in elliptic coordinates on a R2 plane are described in a unified way. A back and forth route connecting these Liouville Type I separable systems is unveiled. It is shown how the gnomonic projection and its inverse map allow us to pass from a Liouville Type I separable system with a spherical configuration space to its Liouville Type I partners where the configuration space is a plane and back. Several selected spherical separable systems and their planar cousins are discussed in a classical context

JOB BURNOUT AND PERFORMANCE OF STAFF NURSES IN SELECTED HOSPITALS IN METRO MANILA

This study was conducted to determine the job burnout and performance of staff nurses in selected tertiary hospitals in Manila using the Oldenburg Burnout Inventory. Results showed that there’s: a high degree of agreement in relation to burnout of the staff-nurses in terms of exhaustion and disengagement; an average level of performance of the staff nurses in terms of task performance, contextual performance, and counter-productive behavior; significant differences between the degrees of agreement in relation to job burnout of the staff-nurses (disengagement and exhaustion) when they are grouped according to nurse-patient ratio and census per area; significant relationships between the degree of agreement in relation to job burnout (disengagement) and overall level of performance of the staff nurses. Researchers pursued this study because some of their colleagues have lost the enjoyment of their job; that they feel that their efforts were being unnoticed; and feel overworked. Through this study, the degree of agreement in relation to job burnout of the staff nurses and their level of performance was determined. This paved a way for the development of new plans and programs to help staff nurses overcome their feelings of burnout, making them more energetic and enthusiastic in performing their job

Observations and Interpretation of a Low Coronal Shock Wave Observed in the EUV by the SDO/AIA

Taking advantage of both the high temporal and spatial resolution of the Atmospheric Imaging Assembly (AIA) on board the Solar Dynamics Observatory (SDO), we studied a limb coronal shock wave and its associated extreme ultraviolet (EUV) wave that occurred on 2010 June 13. Our main findings are (1) the shock wave appeared clearly only in the channels centered at 193 \AA and 211 \AA as a dome-like enhancement propagating ahead of its associated semi-spherical CME bubble; (2) the density compression of the shock is 1.56 according to radio data and the temperature of the shockis around 2.8 MK; (3) the shock wave first appeared at 05:38 UT, 2 minutes after the associated flare has started and 1 minute after its associated CME bubble appeared;(4) the top of the dome-like shock wave set out from about 1.23 R\odot and the thickness of the shocked layer is ~ 2\times10^4 km; (5) the speed of the shock wave is consistent with a slight decrease from about 600 km/s to 550 km/s; (6) the lateral expansion of the shock wave suggests a constant speed around 400 km/s, which varies at different heights and directions. Our findings support the view that the coronal shock wave is driven by the CME bubble, and the on-limb EUV wave is consistent with a fast wave or at least includes the fast wave component.Comment: 24 pages,8 Figures and 6 movies. It is scheduled for publication on the Astrophysical Journal on the August 1, 2011, Issue 736 -

Understanding the Behavior of Filipino Twitter Users during Disaster

The Philippines is a country that frequentlyexperiences disasters, such as typhoons. During these events,many citizens spread information and communicate with eachother through social media like Twitter. This study aims to takeadvantage of that fact by analyzing the data from social media toget some insights on the situation. Specifically, this paper studiesthe behavior of Filipinos on Twitter during a disaster, and tries tosee the differences between participants, or the direct victims ofthe disaster, and observers. The study used Latent DirichletAllocation and Principal Component Analysis to extract thedifferent topics discussed during a disaster, and found out whichtopics participants are more likely to talk about. Results also showwhich topics are more likely to be retweeted, which languageparticipants in disaster use more often, and what emotions arepresent in the disaster-time tweets of Filipinos

Blue Light Induces A Neuroprotective Open Access Gene Expression Program in Drosophila Photoreceptors

Background: Light exposure induces oxidative stress, which contributes to ocular diseases of aging. Blue light provides a model for light‑induced oxidative stress, lipid peroxidation and retinal degeneration in Drosophila melanogaster. In contrast to mature adults, which undergo retinal degeneration when exposed to prolonged blue light, newly‑eclosed fies are resistant to blue light‑induced retinal degeneration. Here, we sought to characterize the gene expression programs induced by blue light in fies of diferent ages to identify neuroprotective pathways utilized by photoreceptors to cope with light‑induced oxidative stress. Results: To identify gene expression changes induced by blue light exposure, we profled the nuclear transcriptome of Drosophila photoreceptors from one‑ and six‑day‑old fies exposed to blue light and compared these with dark controls. Flies were exposed to 3 h blue light, which increases levels of reactive oxygen species but does not cause retinal degeneration. We identifed substantial gene expression changes in response to blue light only in six‑day‑old fies. In six‑day‑old fies, blue light induced a neuroprotective gene expression program that included upregulation of stress response pathways and downregulation of genes involved in light response, calcium infux and ion transport. An intact phototransduction pathway and calcium infux were required for upregulation, but not downregulation, of genes in response to blue light, suggesting that distinct pathways mediate the blue light‑associated transcriptional response. Conclusion: Our data demonstrate that under phototoxic conditions, Drosophila photoreceptors upregulate stress response pathways and simultaneously, downregulate expression of phototransduction components, ion transporters, and calcium channels. Together, this gene expression program both counteracts the calcium infux resulting from prolonged light exposure, and ameliorates the oxidative stress resulting from this calcium infux. Thus, six‑day‑old fies can withstand up to 3 h blue light exposure without undergoing retinal degeneration. Developmental transitions during the frst week of adult Drosophila life lead to an altered gene expression program in photoreceptors that includes reduced expression of genes that maintain redox and calcium homeostasis, reducing the capacity of six‑day‑old fies to cope with longer periods (8 h) of light exposure. Together, these data provide insight into the neuroprotective gene regulatory mechanisms that enable photoreceptors to withstand light‑induced oxidative stress

5-Dimensional Kaluza-Klein Theory with a Source

A free test particle in 5-dimensional Kaluza-Klein spacetime will show its electricity in the reduced 4-dimensional spacetime when it moves along the fifth dimension. In the light of this observation, we study the coupling of a 5-dimensional dust field with the Kaluza-Klein gravity. It turns out that the dust field can curve the 5-dimensional spacetime in such a way that it provides exactly the source of the electromagnetic field in the 4-dimensional spacetime after the dimensional reduction.Comment: 8 pages, three references adde