ALBERT

Description: Author(s): S. Azzawi, A. Ganguly, M. Tokaç, R. M. Rowan-Robinson, J. Sinha, A. T. Hindmarch, A. Barman, and D. Atkinson The evolution of damping in Co/Pt, Co/Au, and Ni 81 Fe 19 /Pt bilayers was studied with increasing nonmagnetic (NM) heavy-metal layer thicknesses in the range 0.2 nm ≤ t NM ≤ 10 nm , where t NM is the NM layer thickness. Magnetization precession was measured in the time domain using time-resolved magneto-optical… [Phys. Rev. B 93, 054402] Published Mon Feb 01, 2016

Description: Plants grow in dynamic environments where they can be exposed to a multitude of stressful factors, all of which affect their development, yield, and, ultimately, reproductive success. Plants are adept at rapidly acclimating to stressful conditions and are able to further fortify their defenses by retaining memories of stress to enable stronger or more rapid responses should an environmental perturbation recur. Indeed, one mechanism that is often evoked regarding environmental memories is epigenetics. Yet, there are relatively few examples of such memories; neither is there a clear understanding of their duration, considering the plethora of stresses in nature. We propose that this field would benefit from investigations into the processes and mechanisms enabling recovery from stress. An understanding of stress recovery could provide fresh insights into when, how, and why environmental memories are created and regulated. Stress memories may be maladaptive, hindering recovery and affecting development and potential yield. In some circumstances, it may be advantageous for plants to learn to forget. Accordingly, the recovery process entails a balancing act between resetting and memory formation. During recovery, RNA metabolism, posttranscriptional gene silencing, and RNA-directed DNA methylation have the potential to play key roles in resetting the epigenome and transcriptome and in altering memory. Exploration of this emerging area of research is becoming ever more tractable with advances in genomics, phenomics, and high-throughput sequencing methodology that will enable unprecedented profiling of high-resolution stress recovery time series experiments and sampling of large natural populations.

Description: We consider one-dimensional stationary position-dependent effective mass quantum model and derive a generalized Korteweg-de Vries (KdV) equation in (1+1) dimension through Lax pair formulation, one being the effective mass Schrödinger operator and the other being the time-evolution of wave functions. We obtain an infinite number of conserved quantities for the generated nonlinear equation and explicitly show that the new generalized KdV equation is an integrable system. Inverse scattering transform method is applied to obtain general solution of the nonlinear equation, and then N-soliton solution is derived for reflectionless potentials. Finally, a special choice has been made for the variable mass function to get mass-deformed soliton solution. The influence of position and time-dependence of mass and also of the different representations of kinetic energy operator on the nature of such solitons is investigated in detail. The remarkable features of such solitons are demonstrated in several interesting figures and are contrasted with the conventional KdV-soliton associated with constant-mass quantum model.

Description: The effect of spin torque from the spin Hall effect in Pt/Ni 81 Fe 19 rectangular bilayer film was investigated using time-resolved magneto-optical Kerr microscopy. Current flow through the stack resulted in a linear variation of effective damping up to ±7%, attributed to spin current injection from the Pt into the Ni 81 Fe 19 . The spin Hall angle of Pt was estimated as 0.11 ± 0.03. The modulation of the damping depended on the angle between the current and the bias magnetic field. These results demonstrate the importance of optical detection of precessional magnetization dynamics for studying spin transfer torque due to spin Hall effect.

Description: Fast radio bursts are bright, unresolved, non-repeating, broadband, millisecond flashes, found primarily at high Galactic latitudes, with dispersion measures much larger than expected for a Galactic source. The inferred all-sky burst rate is comparable to the core-collapse supernova rate out to redshift 0.5. If the observed dispersion measures are assumed to be dominated by the intergalactic medium, the sources are at cosmological distances with redshifts of 0.2 to 1 (refs 10 and 11). These parameters are consistent with a wide range of source models. One fast burst revealed circular polarization of the radio emission, but no linear polarization was detected, and hence no Faraday rotation measure could be determined. Here we report the examination of archival data revealing Faraday rotation in the fast radio burst FRB 110523. Its radio flux and dispersion measure are consistent with values from previously reported bursts and, accounting for a Galactic contribution to the dispersion and using a model of intergalactic electron density, we place the source at a maximum redshift of 0.5. The burst has a much higher rotation measure than expected for this line of sight through the Milky Way and the intergalactic medium, indicating magnetization in the vicinity of the source itself or within a host galaxy. The pulse was scattered by two distinct plasma screens during propagation, which requires either a dense nebula associated with the source or a location within the central region of its host galaxy. The detection in this instance of magnetization and scattering that are both local to the source favours models involving young stellar populations such as magnetars over models involving the mergers of older neutron stars, which are more likely to be located in low-density regions of the host galaxy.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Masui, Kiyoshi -- Lin, Hsiu-Hsien -- Sievers, Jonathan -- Anderson, Christopher J -- Chang, Tzu-Ching -- Chen, Xuelei -- Ganguly, Apratim -- Jarvis, Miranda -- Kuo, Cheng-Yu -- Li, Yi-Chao -- Liao, Yu-Wei -- McLaughlin, Maura -- Pen, Ue-Li -- Peterson, Jeffrey B -- Roman, Alexander -- Timbie, Peter T -- Voytek, Tabitha -- Yadav, Jaswant K -- England -- Nature. 2015 Dec 24;528(7583):523-5. doi: 10.1038/nature15769. Epub 2015 Dec 2.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Physics and Astronomy, University of British Columbia, 6224 Agricultural Road, Vancouver, British Columbia V6T 1Z1, Canada. ; Canadian Institute for Advanced Research, CIFAR Program in Cosmology and Gravity, Toronto, Ontario M5G 1Z8, Canada. ; McWilliams Center for Cosmology, Carnegie Mellon University, Department of Physics, 5000 Forbes Avenue, Pittsburgh, Pennsylvania 15213, USA. ; Astrophysics and Cosmology Research Unit, School of Chemistry and Physics, University of KwaZulu-Natal, Durban 4001, South Africa. ; National Institute for Theoretical Physics (NITheP), KZN node, Durban 4001, South Africa. ; Department of Physics, University of Wisconsin, Madison, Wisconsin 53706-1390, USA. ; Academia Sinica Institute of Astronomy and Astrophysics, 11F Astro-Math Building, AS/NTU 1, Section 4, Roosevelt Road, Taipei 10617, Taiwan. ; National Astronomical Observatories, Chinese Academy of Science, 20A Datun Road, Beijing 100012, China. ; Center of High Energy Physics, Peking University, Beijing 100871, China. ; Astrophysics and Cosmology Research Unit, School of Mathematics, Statistics, and Computer Science, University of KwaZulu-Natal, Durban 4001, South Africa. ; Department of Astronomy and Astrophysics, University of Toronto, 50 St George Street, Toronto, Ontario M5S 3H4, Canada. ; Department of Physics, National Sun Yat-Sen University No. 70, Lianhai Road, Gushan District, Kaohsiung City 804, Taiwan. ; Department of Physics and Astronomy, West Virginia University, Morgantown, West Virginia 26506, USA. ; Canadian Institute for Theoretical Astrophysics, 60 St George Street, Toronto, Ontario M5S 3H8, Canada. ; Perimeter Institute, 31 Caroline Street, Waterloo N2L 2Y5, Canada. ; Indian Institute of Science Education and Research Mohali, Knowledge City, Sector 81, SAS Nagar, Manauli, PO 140306, India.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/26633633" target="_blank"〉PubMed〈/a〉

Description: In this paper, a conceptual design of a parabolic trough collector supported multi–commodity cold storage based on LiBr–water absorption system has been proposed to reduce wastage of food grains. The cold storage has been designed to store three high value perishable commodities namely: potato, olive and grapefruit for different months of a calendar year. A thermal model has been developed to predict the performance of the proposed cold storage on an hourly basis. A parabolic trough collector based heating system has also been designed to meet the heat load of the generator during the sunshine hours. To make the system operational in rural areas where grid electricity may not be available, an outline for the power system based on a combination of solar PV and thermal system has been proposed. To provide power backup, an integrated solar hydrogen system has been introduced in the scheme. Finally, the performance of the proposed cold storage has been analysed for representative da...

Description: In this paper, a novel scheme of a solar-biomass integrated Fluidized Bed Drying (FBD) system has been proposed for drying of agricultural food-grains. During the hours of sunshine, ambient air passes through a solar air-heater and gets heated to the required drying temperature. When solar heating becomes inadequate or unavailable such as during cloudy days or at night, a biomass furnace assisted backup heat exchanger is used for heating the incoming air. This ensures continuous operation of the drying system all through the day and night (24h). Surplus heat from the biomass furnace after meeting the in-house requirements is utilized in an Organic Rankine Cycle (ORC) to generate electricity. A thermal model has been developed for the proposed system for drying of paddy grains. The performance of the system has been analyzed for representative days of January, May and September for the city Kolkata (22°34’N 88°22’E), located in the plains of India. The study reinforces the viabil...

Description: Chromosome stability models are usually qualitative models derived from molecular-genetic mechanisms for DNA repair, DNA synthesis, and cell division. While qualitative models are informative, they are also challenging to reformulate as precise quantitative models. In this report we explore how (A) laboratory experiments, (B) quantitative simulation, and (C) seriation algorithms can inform models of chromosome stability. Laboratory experiments were used to identify 19 genes that when over-expressed cause chromosome instability in the yeast Saccharomyces cerevisiae . To better understand the molecular mechanisms by which these genes act, we explored their genetic interactions with 18 deletion mutations known to cause chromosome instability. Quantitative simulations based on a mathematical model of the cell cycle were used to predict the consequences of several genetic interactions. These simulations lead us to suspect that the chromosome instability genes cause cell-cycle perturbations. Cell-cycle involvement was confirmed using a seriation algorithm, which was used to analyze the genetic interaction matrix to reveal an underlying cyclical pattern. The seriation algorithm searched over 10 14 possible arrangements of rows and columns to find one optimal arrangement, which correctly reflects events during cell cycle phases. To conclude, we illustrate how the molecular mechanisms behind these cell cycle events are consistent with established molecular interaction maps.

Description: Industrialization has elevated our energy demand during the last century by many a folds, to deal with the rapid social growth. Non-renewable energy sources, like petroleum being the main source of energy, have become scarce due to their overuse and limited available reserve. Water hyacinth can be considered as a good source of lignocellulosic biomass. Cellulose and hemi-cellulose derived from water hyacinth via effective bioprocess can be converted to bioethanol. Production of liquid fuel from biomass can only be made economically viable and sustainable only if the de-polymerization of the recalcitrant hemi-cellulosic fraction of the biomass can be optimally utilized. The study aims to obtain an in-depth mechanistic understanding of the catalytic reaction involved in dilute sulphuric acid pre-treatment of water hyacinth biomass. Acid catalysed hemi-cellulose hydrolysis reaction kinetics in water hyacinth was studied based on a bi-phasic model. Arrhenius equation was used to study the kinetic modelling in a greater depth. A distinct relationship of soaking time of the biomass in the acid before hydrolysis on the activation energy and frequency factor was observed. A maximum xylose yield of 76.96% was predicted by the genetic algorithm based model for the optimum operating conditions; operating temperature (135.8 °C), concentration of sulphuric acid (5.6%), treatment time (17.45 min), and soaking time (3.99 h).