Slow dynamics and precursors of the glass transition in granular fluids

We use event driven simulations to analyze glassy dynamics as a function of density and energy dissipation in a two-dimensional bidisperse granular fluid under stationary conditions. Clear signatures of a glass transition are identified, such as an increase of relaxation times over several orders of magnitude. As the inelasticity is increased, the glass transition is shifted to higher densities and the precursors of the transition become less and less pronounced -- in agreement with a recent mode-coupling theory. We analyze the long-time tails of the velocity autocorrelation and discuss its consequences for the nonexistence of the diffusion constant in two dimensions.Comment: 10 pages, 16 figure

Metaphors in Arabic and English Texts: A Case Study of Translation of Metaphors in the English Versions of Al-Sahifah Al-Sajjadiyyah

The aim of the present research is the study of translation of metaphor as one of the literary devices of Al-Sahifah Al-Sajjadiyah from Arabic into English. Al-Sahifah Al-Sajjadiyah contains 54 valuable supplications regarding political, social, military, family, religious, etc, issues. The secret of its permanency among Moslems and Shi'ites, in particular, has been its elegance and fluency. It is replete with literary devices such as proverbs, parables, metaphors, etc. It contains beautiful metaphors throughout. This study is an attempt to examine the translation of this literary device from Arabic into English based on Roman Jakobson’s (1956) framework. Therefore, a group of 65 metaphors of that book was selected from the entire book. The translation of selected metaphors by two English translators, namely William C. Chittick (2008) and Sayyid Ahmad Muhani (1984) were compared with the original ones according to the Roman Jakobson’ s (1956) syntagmatic and paradigmatic axes.On the syntagmatic axis, the axis of combination, words are linked, or chained, together according to grammatical rules, but we make choices about which words to link together on the paradigmatic axis, the axis of selection. The study finally comes up with the conclusion that Chittick has tried to render the metaphors as literally and of course faithfully as possible. He has observed two axes in his translation more than second translator, Muhani and for this reason approaches the original text’s literary style. Muhani mostly has converted the metaphors to their senses. He has more attention to meaning and content rather than linguistic form and in some cases ignoring the form to present the meaning. Keywords: Al-Sahifah Al-Sajjadiyah, Metaphor, Jakobson, Syntagmatic axis, Paradigmatic axis

Improved Stack-Slide Searches for Gravitational-Wave Pulsars

We formulate and optimize a computational search strategy for detecting gravitational waves from isolated, previously-unknown neutron stars (that is, neutron stars with unknown sky positions, spin frequencies, and spin-down parameters). It is well known that fully coherent searches over the relevant parameter-space volumes are not computationally feasible, and so more computationally efficient methods are called for. The first step in this direction was taken by Brady & Creighton (2000), who proposed and optimized a two-stage, stack-slide search algorithm. We generalize and otherwise improve upon the Brady-Creighton scheme in several ways. Like Brady & Creighton, we consider a stack-slide scheme, but here with an arbitrary number of semi-coherent stages and with a coherent follow-up stage at the end. We find that searches with three semi-coherent stages are significantly more efficient than two-stage searches (requiring about 2-5 times less computational power for the same sensitivity) and are only slightly less efficient than searches with four or more stages. We calculate the signal-to-noise ratio required for detection, as a function of computing power and neutron star spin-down-age, using our optimized searches.Comment: 19 pages, 7 figures, RevTeX

Melatonin Protects Mouse Type A Spermatogonial Stem Cells against Oxidative Stress via The Mitochondrial Thioredoxin System

Objective: Mitochondrial oxidative stress is an important factor in infertility. The mitochondrial thioredoxin systemplays an important role in this condition. N-acetyl-5-methoxy tryptamine (melatonin) plays a role in reducing oxidativestress and apoptosis in spermatogonial stem cells (SSCs). In this study, we explore the probable protective effects ofmelatonin on the mitochondrial thioredoxin system [thioredoxin 2 (Trx2)/Txnip] in SSCs under oxidative stress.Materials and Methods: In this experimental study, SSCs were co-cultured two-dimensionally (2D) with Sertoli cellsin DMEM culture medium that contained 10% fetal bovine serum (FBS), 1% antibiotics, and 10 ng/ml glial cell-derivedneurotrophic factor (GDNF) for 30 days. The cultured cells were subsequently divided into four groups: control; melatonin(250 μM, 24 hours); melatonin (250 μM, 24 hours)+hydrogen peroxide (H2O2, 50 μM, 24 hours); and H2O2 (50 μM, 24hours). Intracellular reactive oxygen species (ROS) production was determined by flow cytometry. Malondialdehyde(MDA) levels were measured by Fluorometry. The expressions of apoptotic and antioxidant genes and nuclear factorerythroid 2-related factor 2 (Nrf2), Trx2, and nicotinamide nucleotide transhydrogenase (NNT) proteins were determinedby quantitative real-time polymerase chain reaction (qRT-PCR) and Western blot. Adenosine triphosphate (ATP) levelswere measured by fluorometry.Results: Melatonin reduced H2O2-induced ROS levels and apoptosis in the SSCs. Melatonin also increased mRNAexpression of Nrf2, Trx2, NNT, Sirtuin 3 (Sirt3), and decreased mRNA expression of Txnip, and increased proteinexpressions of Nrf2, Trx2, NNT thereby increasing activity of the mitochondrial thioredoxin system. In addition, melatoninincreased ATP levels.Conclusion: Melatonin increased Trx2 expression through the Nrf2 pathway. This study suggests that melatonin mayprotect SSCs from oxidative stress in diseases related to infertility

In Silico Analysis of Six Known Leishmania major Antigens and In Vitro Evaluation of Specific Epitopes Eliciting HLA-A2 Restricted CD8 T Cell Response

Leishmaniasis is currently a serious health as well as economic problem in underdeveloped and developing countries in Africa, Asia, the Near and Middle East, Central and South America and the Mediterranean region. Cutaneous leishmaniasis is highly endemic in Iran, remarkably in Isfahan, Fars, Khorasan, Khozestan and Kerman provinces. Since effective prevention is not available and current curative therapy is expensive, often poorly tolerated and not always effective, alternative therapies including vaccination against leishmaniasis are of priority to overcome the problem. Although Th1 dominant response is so far considered as a pre-requisite for the immune system to overcome the infection, CD8+ T cell response could also be considered as a potent arm of immune system fighting against intracellular Leishmania. Polytope vaccine strategy may open up a new way in vaccine design against leishmaniasis, since they act as a potent tool to stimulate multi-CD8 T cell responses. Clearly there is a substantial need to evaluate the promising epitopes from different proteins of Leishmania parasite species. Some new immunoinformatic tools are now available to speed up this process, and we have shown here that in silico prediction can effectively evaluate HLA class I-restricted epitopes out of Leishmania proteins

Parasitic Helminths in Wild Boars (Sus scrofa) in Mazandaran Province, Northern Iran

Background: Wild boars (Sus scrofa) are distributed worldwide and found in many parts of Iran. Although S. scrofa is reservoirs for many parasites, there is little data on helminthic prevalence in them. We aimed to survey the status of helminthic infections in S. scrofa in the Mazandaran Province of northern Iran. Methods: Twenty-one wild boars were captured and examined for helminth infection during Dec 2012-Mar 2014. Adult worms such as Macracanthorhynchus hirudinaceus were identified by helminth size and shape, and the arrangement of the proboscis hooks. The sedimentation and flotation techniques were used to detect parasite eggs and larvae in faecal samples. Muscle samples were also surveyed for Trichinella larvae by artificial digestion method. Results: Of the 21 samples, 13 (61.9%) were infected with one or more helminth species. Seven helminth types were identified in the alimentary track, comprising 5 nematodes, 1 trematode, and 1 acanthocephalan, with prevalence rates of Macracanthorhynchus hirudinaceus (57.14%), Globocephalus spp. (33.33%), Trichuris suis (19.04), Gongylonema pulchrum (14.28%), Fasciola hepatica (14.28%), Dioctophyma renale (4.76%), and Ascaris suum (4.76%). Conclusion: Wild boars might be involved in transmitting zoonotic parasites to humans. The abundance of these animals near human habitation creates favorable conditions for infection. So the risk of parasitic helminth diseases increases in other animals and humans

Search for gravitational wave bursts in LIGO's third science run

We report on a search for gravitational wave bursts in data from the three LIGO interferometric detectors during their third science run. The search targets subsecond bursts in the frequency range 100-1100 Hz for which no waveform model is assumed, and has a sensitivity in terms of the root-sum-square (rss) strain amplitude of hrss ~ 10^{-20} / sqrt(Hz). No gravitational wave signals were detected in the 8 days of analyzed data.Comment: 12 pages, 6 figures. Amaldi-6 conference proceedings to be published in Classical and Quantum Gravit

Searching for a Stochastic Background of Gravitational Waves with LIGO

The Laser Interferometer Gravitational-wave Observatory (LIGO) has performed the fourth science run, S4, with significantly improved interferometer sensitivities with respect to previous runs. Using data acquired during this science run, we place a limit on the amplitude of a stochastic background of gravitational waves. For a frequency independent spectrum, the new limit is $\Omega_{\rm GW} < 6.5 \times 10^{-5}$. This is currently the most sensitive result in the frequency range 51-150 Hz, with a factor of 13 improvement over the previous LIGO result. We discuss complementarity of the new result with other constraints on a stochastic background of gravitational waves, and we investigate implications of the new result for different models of this background.Comment: 37 pages, 16 figure

Quantum state preparation and macroscopic entanglement in gravitational-wave detectors

Long-baseline laser-interferometer gravitational-wave detectors are operating at a factor of 10 (in amplitude) above the standard quantum limit (SQL) within a broad frequency band. Such a low classical noise budget has already allowed the creation of a controlled 2.7 kg macroscopic oscillator with an effective eigenfrequency of 150 Hz and an occupation number of 200. This result, along with the prospect for further improvements, heralds the new possibility of experimentally probing macroscopic quantum mechanics (MQM) - quantum mechanical behavior of objects in the realm of everyday experience - using gravitational-wave detectors. In this paper, we provide the mathematical foundation for the first step of a MQM experiment: the preparation of a macroscopic test mass into a nearly minimum-Heisenberg-limited Gaussian quantum state, which is possible if the interferometer's classical noise beats the SQL in a broad frequency band. Our formalism, based on Wiener filtering, allows a straightforward conversion from the classical noise budget of a laser interferometer, in terms of noise spectra, into the strategy for quantum state preparation, and the quality of the prepared state. Using this formalism, we consider how Gaussian entanglement can be built among two macroscopic test masses, and the performance of the planned Advanced LIGO interferometers in quantum-state preparation