Modulational instability of ion-acoustic wave packets in quantum pair-ion plasmas

Amplitude modulation of quantum ion-acoustic waves (QIAWs) in a quantum electron-pair-ion plasma is studied. It is shown that the quantum coupling parameter $H$ (being the ratio of the plasmonic energy density to the Fermi energy) is ultimate responsible for the modulational stability of QIAW packets, without which the wave becomes modulational unstable. New regimes for the modulational stability (MS) and instability (MI) are obtained in terms of $H$ and the positive to negative ion density ratio $\beta$. The growth rate of MI is obtained, the maximum value of which increases with $\beta$ and decreases with $H$. The results could be important for understanding the origin of modulated QIAW packets in the environments of dense astrophysical objects, laboratory negative ion plasmas as well as for the next generation laser solid density plasma experiments.Comment: 4 pages, 2 figures (to appear in Astrophysics and Space Science

Pharmacological Or Genetic Targeting Of Transient Receptor Potential (TRP) Channels Can Disrupt The Planarian Escape Response

In response to noxious stimuli, planarians cease their typical ciliary gliding and exhibit an oscillatory type of locomotion called scrunching. We have previously characterized the biomechanics of scrunching and shown that it is induced by specific stimuli, such as amputation, noxious heat, and extreme pH. Because these specific inducers are known to activate Transient Receptor Potential (TRP) channels in other systems, we hypothesized that TRP channels control scrunching. We found that chemicals known to activate TRPA1 (allyl isothiocyanate (AITC) and hydrogen peroxide) and TRPV (capsaicin and anandamide) in other systems induce scrunching in the planarian species Dugesia japonica and, except for anandamide, in Schmidtea mediterranea. To confirm that these responses were specific to either TRPA1 or TRPV, respectively, we tried to block scrunching using selective TRPA1 or TRPV antagonists and RNA interference (RNAi) mediated knockdown. Unexpectedly, co-treatment with a mammalian TRPA1 antagonist, HC-030031, enhanced AITC-induced scrunching by decreasing the latency time, suggesting an agonistic relationship in planarians. We further confirmed that TRPA1 in both planarian species is necessary for AITC-induced scrunching using RNAi. Conversely, while co-treatment of a mammalian TRPV antagonist, SB-366791, also enhanced capsaicin-induced reactions in D. japonica, combined knockdown of two previously identified D. japonica TRPV genes (DjTRPVa and DjTRPVb) did not inhibit capsaicin-induced scrunching. RNAi of DjTRPVa/DjTRPVb attenuated scrunching induced by the endocannabinoid and TRPV agonist, anandamide. Overall, our results show that although scrunching induction can involve different initial pathways for sensing stimuli, this behavior’s signature dynamical features are independent of the inducer, implying that scrunching is a stereotypical planarian escape behavior in response to various noxious stimuli that converge on a single downstream pathway. Understanding which aspects of nociception are conserved or not across different organisms can provide insight into the underlying regulatory mechanisms to better understand pain sensation

Nonlinear structures: explosive, soliton and shock in a quantum electron-positron-ion magnetoplasma

Theoretical and numerical studies are performed for the nonlinear structures (explosive, solitons and shock) in quantum electron-positron-ion magnetoplasmas. For this purpose, the reductive perturbation method is employed to the quantum hydrodynamical equations and the Poisson equation, obtaining extended quantum Zakharov-Kuznetsov equation. The latter has been solved using the generalized expansion method to obtain a set of analytical solutions, which reflect the possibility of the propagation of various nonlinear structures. The relevance of the present investigation to the white dwarfs is highlighted.Comment: 7 figure

Obtenção de híbridos de melão adaptados as condições da região Nordeste.

bitstream/CNPAT-2010/11937/1/Pa-042.pd

Melhoramento populacional do meloeiro para cultivo na Região Nordeste.

Este trabalho objetiva desenvolver e melhorar geneticamente populacoes de melao para os tipos de frutos rendilhado e amarelo, e adapta-las ao cultivo nas condicoes do Nordeste.bitstream/CNPAT-2010/5408/1/Pa-043.pd

Spin and Rotations in Galois Field Quantum Mechanics

We discuss the properties of Galois Field Quantum Mechanics constructed on a vector space over the finite Galois field GF(q). In particular, we look at 2-level systems analogous to spin, and discuss how SO(3) rotations could be embodied in such a system. We also consider two-particle `spin' correlations and show that the Clauser-Horne-Shimony-Holt (CHSH) inequality is nonetheless not violated in this model.Comment: 21 pages, 11 pdf figures, LaTeX. Uses iopart.cls. Revised introduction. Additional reference

The Second Terrace Lodge. Reconnecting with Nature and Vernacular.

The project stems from the landscape, which is the most important and exciting socio-cultural and natural element that characterizes the Ifugao Community. The Banaue Rice Terraces are the main inspiration for designing a contemporary architectural lodge project, which should be integrated with the existing nature and vernacular activities of the community without being disruptive and alienating. The terraces testify to a long synergy between the community and the steep slopes of the mountains, and they are generated thanks to a clever and respectful use of natural resources such as water and the earth. THE TERRACE Lodge is in continuity with this wise vernacular legacy, becoming part of the historical terraced landscape and, at the same time, propelling a brand-new contemporary connection experience between nature and people. Inspired by the Bahay Kubo materiality, the project is made by three volumes with two floors hosting 7 apartments (6 single and 1 for family) which are connected by a main retaining wall in continuity with the wall of the terrace above. The existing path, which dissects the entire terraced hill, connects the project on the ground floor and the first floor, allowing the new project to integrate with the present paths and habits. Water is one of the main elements considered for reconnecting with nature. The new terrace frames an internal courtyard, where water flows from the terrace above and continues to spill into the terrace below without altering the site's existing ecosystem. The water court is a relaxing space for meditation and social interaction, filled with local plants and crops, reiterating the human-natural connection with the site. While preserving the inner courtyard for cultivating the regional Oryza Sativa Rice, we’re using the rest of the terrace for other local crops, such as: sweet potato, taro, corn and coffee; to enhance contextual sensitivity. The roof of the main building is filled with water as well, and it is integrated with the existing agricultural activities of the rice field above. Finally, blending contemporary architecture with the vernacular-landscape elements will be a new challenge for our future practice. The SECOND TERRACE Lodge cleverly achieves a respectful avant-garde for a correct synergy with natural presences and local communities