Particle production and transplanckian problem on the non-commutative plane

We consider the coherent state approach to non-commutativity, and we derive from it an effective quantum scalar field theory. We show how the non-commutativity can be taken in account by a suitable modification of the Klein-Gordon product, and of the equal-time commutation relations. We prove that, in curved space, the Bogolubov coefficients are unchanged, hence the number density of the produced particle is the same as for the commutative case. What changes though is the associated energy density, and this offers a simple solution to the transplanckian problem.Comment: Minor typos corrected, references added. Accepted for publication by Modern Physics Letter

Resiliensi Pada Masyarakat Kota Padang Ditinjau Dari Jenis Kelamin

Sebagai salah satu negara yang berada dalam rangkaian gunung berapi aktif di dunia dan berada di atas tumbukan banyak lempeng bumi, Indonesia berpotensi mengalami banyak gempa bumi. Kota Padang adalah salah satu daerah yang rawan bencana gempa bumi karena berada pada jalur subduksi lempeng Australia dan Eurasia. Bencana alam tentunya membawa kerugian dan penderitaan bagi masyarakat yang tertimpa bencana. Tujuan dari penelitian ini adalah untuk mengukur perbedaan resiliensi pada masyarakat kota Padang ditinjau dari jenis kelamin. Partisipan dalam penelitian ini adalah 167 orang masyarakat kota Padang yang berada dalam daerah kuning (5-10 mdpl) dan merah (0-5 mdpl). Instrumen penelitian adalah kuesioner yang dikembangkan dari Connor-Davidson Resilience Scale (CD-RISC). Data dianalisis menggunakan uji perbandingan dari metode statistik. Hasil penelitian memperlihatkan bahwa ada perbedaan resiliensi antara pria dan wanita. Pria memiliki skor resiliensi lebih tinggi dibandingkan wanita

Dual-use Molecules from Yeast

This year the OPCW, the implementing body for the Chemical Weapons Convention, celebrates the 20th anniversary of entry into forces. In 2014, this organization examined the impact of new technologies in the field of chemical and biological weapons, in particular the “Convergence” of Chemistry and Biology. An OPCW report of the Scientific Advisory Group highlighted the importance of monitoring developments in science and technology: “New production processes, combined with developments in drug discovery and delivery, could be exploited in the development of new toxic chemicals that could be used as weapons.” 1 Indeed, since 2008, Synthetic Biology is monitored also by other international organizations, such as the Nonproliferation Export Control Regimes Australia Group

Evaluation of Aglianico grape skin and seed polyphenols astringency by SDS-PAGE electrophoresis of salivary proteins after the binding reaction

SDS–PAGE electrophoresis and densitometry analysis were carried out to evaluate the reactivity of Aglianico red grape skin and seed polyphenols with human salivary proteins in order to find a method able to assess their astringency. Analysis of the supernatant obtained after a tannin/human salivary protein binding assay and sensorial analysis showed that four proteins, lactoferrin, PRPbg1, PRPbg2 and a-amylase, were the proteins best able to distinguish tannin solutions characterised by different levels of astringency. A correlation between densitometric data and tannin concentration was plotted in order to give an indirect measure of astringency. The two sources of Aglianico grape polyphenols differed from each other in astringency power; the seed extract solution was about two-fold more tannic than the skin one. The difference in astringency was also perceived by sensorial analysis. The results from this study show that SDS–PAGE electrophoresis of human salivary proteins after the binding reaction with grape polyphenol extracts, coupled with densitometric analysis and the use of a calibration curve, looks extremely promising as a new approach to evaluate polyphenol astringency

Cheating and the evolutionary stability of mutualisms

Interspecific mutualisms have been playing a central role in the functioning of all ecosystems since the early history of life. Yet the theory of coevolution of mutualists is virtually nonexistent, by contrast with well-developed coevolutionary theories of competition, predator–prey and host–parasite interactions. This has prevented resolution of a basic puzzle posed by mutualisms: their persistence in spite of apparent evolutionary instability. The selective advantage of 'cheating', that is, reaping mutualistic benefits while providing fewer commodities to the partner species, is commonly believed to erode a mutualistic interaction, leading to its dissolution or reciprocal extinction. However, recent empirical findings indicate that stable associations of mutualists and cheaters have existed over long evolutionary periods. Here, we show that asymmetrical competition within species for the commodities offered by mutualistic partners provides a simple and testable ecological mechanism that can account for the long-term persistence of mutualisms. Cheating, in effect, establishes a background against which better mutualists can display any competitive superiority. This can lead to the coexistence and divergence of mutualist and cheater phenotypes, as well as to the coexistence of ecologically similar, but unrelated mutualists and cheaters

Valence band spectroscopy in V-grooved quantum wires

We present a combined theoretical and experimental study of the anisotropy in the optical absorption of V-shaped quantum wires. By means of realistic band structure calculations for these structures, we show that detailed information on the heavy- and light-hole states can be singled out from the anisotropy spectra {\em independently of the electron confinement}, thus allowing accurate valence band spectroscopy.Comment: To be published in Appl. Phys. Lett. (8 pages in REVTeX, two postscipt figures

Enumerating five families of pattern-avoiding inversion sequences; and introducing the powered Catalan numbers

The first problem addressed by this article is the enumeration of some families of pattern-avoiding inversion sequences. We solve some enumerative conjectures left open by the foundational work on the topics by Corteel et al., some of these being also solved independently by Lin, and Kim and Lin. The strength of our approach is its robustness: we enumerate four families $F_1 \subset F_2 \subset F_3 \subset F_4$ of pattern-avoiding inversion sequences ordered by inclusion using the same approach. More precisely, we provide a generating tree (with associated succession rule) for each family $F_i$ which generalizes the one for the family $F_{i-1}$. The second topic of the paper is the enumeration of a fifth family $F_5$ of pattern-avoiding inversion sequences (containing $F_4$). This enumeration is also solved \emph{via} a succession rule, which however does not generalize the one for $F_4$. The associated enumeration sequence, which we call the \emph{powered Catalan numbers}, is quite intriguing, and further investigated. We provide two different succession rules for it, denoted $\Omega_{pCat}$ and $\Omega_{steady}$, and show that they define two types of families enumerated by powered Catalan numbers. Among such families, we introduce the \emph{steady paths}, which are naturally associated with $\Omega_{steady}$. They allow us to bridge the gap between the two types of families enumerated by powered Catalan numbers: indeed, we provide a size-preserving bijection between steady paths and valley-marked Dyck paths (which are naturally associated with $\Omega_{pCat}$). Along the way, we provide several nice connections to families of permutations defined by the avoidance of vincular patterns, and some enumerative conjectures.Comment: V2 includes modifications suggested by referees (in particular, a much shorter Section 3, to account for arXiv:1706.07213

Motivasi India Menjalin Kerjasama Ekonomi dengan Negara-negara Afrika

Africa is the poorest continent with economic growth is relatively slow compared to other countries. This is because since the beginning of its independence from western colonialism, Africa was hit by the prolonged conflict. Due to poverty and security, Western nations are reluctant to invest and provide economic assistance to African countries. Western countries saw Africa as a field of conflict and human rights violations. In contrast to Western countries, India actually investing heavily in Africa. Indian direct investment in Africa is growing as cooperation occurs.This study analyzed the motivation of India to cooperate with African countries, why India is interested to cooperate, while on the other side of the western countries are reluctant to cooperate with African countries. This study uses the theory of international cooperation by KJ.Holsti, which explains the factors that encourage a state of international cooperation.Keywords: State, international cooperation, motivation, national interes