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Primitive grain

Coralie Pasquier, Mario Vazdar, Jan Forsman, Pavel Jungwirth, Mikael Lund
The stability of aqueous protein solutions is strongly affected by multivalent ions, which induce ion-ion correlations beyond the scope of classical mean-field theory. Using all-atom molecular dynamics (MD) and coarse grained Monte Carlo (MC) simulations, we investigate the interaction between a pair of protein molecules in 3:1 electrolyte solution. In agreement with available experimental findings of "reentrant protein condensation", we observe an anomalous trend in the protein-protein potential of mean force with increasing electrolyte concentration in the order: (i) double-layer repulsion, (ii) ion-ion correlation attraction, (iii) overcharge repulsion, and in excess of 1:1 salt, (iv) non Coulombic attraction...
March 31, 2017: Journal of Physical Chemistry. B
Yinbin Miao, Jianfeng Ma, Ximeng Liu, Fushan Wei, Zhiquan Liu, Xu An Wang
Online personal health record (PHR) is more inclined to shift data storage and search operations to cloud server so as to enjoy the elastic resources and lessen computational burden in cloud storage. As multiple patients' data is always stored in the cloud server simultaneously, it is a challenge to guarantee the confidentiality of PHR data and allow data users to search encrypted data in an efficient and privacy-preserving way. To this end, we design a secure cryptographic primitive called as attribute-based multi-keyword search over encrypted personal health records in multi-owner setting to support both fine-grained access control and multi-keyword search via Ciphertext-Policy Attribute-Based Encryption...
November 2016: Journal of Medical Systems
A Bouvier, M Boyet
The early evolution of planetesimals and planets can be constrained using variations in the abundance of neodymium-142 ((142)Nd), which arise from the initial distribution of (142)Nd within the protoplanetary disk and the radioactive decay of the short-lived samarium-146 isotope ((146)Sm). The apparent offset in (142)Nd abundance found previously between chondritic meteorites and Earth has been interpreted either as a possible consequence of nucleosynthetic variations within the protoplanetary disk or as a function of the differentiation of Earth very early in its history...
September 15, 2016: Nature
Rogelio Daniel Acevedo
At the southernmost part of Tierra del Fuego a few outcrops and erratic boulders of alkali basaltic rocks with ultramafic enclaves have been studied. Alkali basalt plugs or pipes hitherto identified are scarce, and host rocks are constituted by slates that belong to Mesozoic deposition. The petrography, texture and composition of the basalt and xenoliths were investigated by petrographic microscope and electron microprobe analysis. Xenocrysts of amphibole and alkali feldspar, phenocrysts of nepheline, olivine, spinel, phlogopite and Fe-Ti minerals (10 %) and a diversity of xenoliths, mainly lherzolitic, pyroxenite and wehrlitic nodules (15 %), but also from metamorphic rocks provenance, are contained in the basalt groundmass (75 %)...
2016: SpringerPlus
Adoración Zafra, Juan D Rejón, Simon J Hiscock, Juan de Dios Alché
Accumulation of reactive oxygen species (ROS) in the stigma of several plant species has been investigated. Four developmental stages (unopened flower buds, recently opened flowers, dehiscent anthers, and flowers after fertilization) were analyzed by confocal laser scanning microscopy using the ROS-specific probe DCFH2-DA. In all plants scrutinized, the presence of ROS in the stigmas was detected at higher levels during those developmental phases considered "receptive" to pollen interaction. In addition, these molecules were also present at early (unopened flower) or later (post-fertilization) stages, by following differential patterns depending on the different species...
2016: Frontiers in Plant Science
Jasmine M Gardner, Markus Deserno, Cameron F Abrams
We use a combination of coarse-grained molecular dynamics simulations and theoretical modeling to examine three-junctions in mixed lipid bilayer membranes. These junctions are localized defect lines in which three bilayers merge in such a way that each bilayer shares one monolayer with one of the other two bilayers. The resulting local morphology is non-lamellar, resembling the threefold symmetric defect lines in inverse hexagonal phases, but it regularly occurs during membrane fission and fusion events. We realize a system of junctions by setting up a honeycomb lattice, which in its primitive cell contains two hexagons and four three-line junctions, permitting us to study their stability as well as their line tension...
August 21, 2016: Journal of Chemical Physics
Muhammad Ali Gulzar, Matteo Interlandi, Seunghyun Yoo, Sai Deep Tetali, Tyson Condie, Todd Millstein, Miryung Kim
Developers use cloud computing platforms to process a large quantity of data in parallel when developing big data analytics. Debugging the massive parallel computations that run in today's data-centers is time consuming and error-prone. To address this challenge, we design a set of interactive, real-time debugging primitives for big data processing in Apache Spark, the next generation data-intensive scalable cloud computing platform. This requires re-thinking the notion of step-through debugging in a traditional debugger such as gdb, because pausing the entire computation across distributed worker nodes causes significant delay and naively inspecting millions of records using a watchpoint is too time consuming for an end user...
May 2016: Proceedings of International Conference on Software Engineering. International Conference on Software Engineering
Noriyoshi Arai, Yuki Yoshimoto, Kenji Yasuoka, Toshikazu Ebisuzaki
Researchers have studied the origin of life and the process of evolution on early Earth for decades. However, we lack a comprehensive understanding of biogenesis, because there are many stages in the formation and growth of the first cell. We investigate the self-replication processes of coacervate protocells using computer simulations of single-chain lipid and phospholipid aqueous mixtures. Based on a morphological phase diagram, we develop a model of prebiotic self-replication driven by only environmental factors (i...
July 28, 2016: Physical Chemistry Chemical Physics: PCCP
Tobias Göppel, Vladimir V Palyulin, Ulrich Gerland
An out-of-equilibrium physical environment can drive chemical reactions into thermodynamically unfavorable regimes. Under prebiotic conditions such a coupling between physical and chemical non-equilibria may have enabled the spontaneous emergence of primitive evolutionary processes. Here, we study the coupling efficiency within a theoretical model that is inspired by recent laboratory experiments, but focuses on generic effects arising whenever reactant and product molecules have different transport coefficients in a flow-through system...
July 27, 2016: Physical Chemistry Chemical Physics: PCCP
Hatice Bilgic, Erdogan E Hakki, Anamika Pandey, Mohd Kamran Khan, Mahinur S Akkaya
Human history was transformed with the advent of agriculture in the Fertile Crescent with wheat as one of the founding crops. Although the Fertile Crescent is renowned as the center of wheat domestication, archaeological studies have shown the crucial involvement of Çatalhöyük in this process. This site first gained attention during the 1961-65 excavations due to the recovery of primitive hexaploid wheat. However, despite the seeds being well preserved, a detailed archaeobotanical description of the samples is missing...
2016: PloS One
Carolina Cragnell, Dominique Durand, Bernard Cabane, Marie Skepö
Monte Carlo simulations and coarse-grained modeling have been used to analyze Histatin 5, an unstructured short cationic salivary peptide known to have anticandidical properties. The calculated scattering functions have been compared with intensity curves and the distance distribution function P(r) obtained from small angle X-ray scattering (SAXS), at both high and low salt concentrations. The aim was to achieve a molecular understanding and a physico-chemical insight of the obtained SAXS results and to gain information of the conformational changes of Histatin 5 due to altering salt content, charge distribution, and net charge...
June 2016: Proteins
Yunlong Zhou, Ryan L Marson, Greg van Anders, Jian Zhu, Guanxiang Ma, Peter Ercius, Kai Sun, Bongjun Yeom, Sharon C Glotzer, Nicholas A Kotov
Chiroptical materials found in butterflies, beetles, stomatopod crustaceans, and other creatures are attributed to biocomposites with helical motifs and multiscale hierarchical organization. These structurally sophisticated materials self-assemble from primitive nanoscale building blocks, a process that is simpler and more energy efficient than many top-down methods currently used to produce similarly sized three-dimensional materials. Here, we report that molecular-scale chirality of a CdTe nanoparticle surface can be translated to nanoscale helical assemblies, leading to chiroptical activity in the visible electromagnetic range...
March 22, 2016: ACS Nano
Nicolas Biver, Dominique Bockelée-Morvan, Raphaël Moreno, Jacques Crovisier, Pierre Colom, Dariusz C Lis, Aage Sandqvist, Jérémie Boissier, Didier Despois, Stefanie N Milam
The presence of numerous complex organic molecules (COMs; defined as those containing six or more atoms) around protostars shows that star formation is accompanied by an increase of molecular complexity. These COMs may be part of the material from which planetesimals and, ultimately, planets formed. Comets represent some of the oldest and most primitive material in the solar system, including ices, and are thus our best window into the volatile composition of the solar protoplanetary disk. Molecules identified to be present in cometary ices include water, simple hydrocarbons, oxygen, sulfur, and nitrogen-bearing species, as well as a few COMs, such as ethylene glycol and glycine...
October 2015: Science Advances
Abrar Hussain, Hans Larsson, Ramune Kuktaite, Marie E Olsson, Eva Johansson
In this study, 33 spring and winter wheat genotypes were analyzed for carotenoid content and composition. Investigated genotypes were divided into four genotype groups i.e., spelt, landraces, old cultivars and primitive wheat. The results showed a high level of variation among the genotypes in amount of carotenoids in the grain with high values (around 4 mg/Kg) especially in one of the genotypes-Öland 8. Lutein was the most common carotenoid in all the investigated genotypes, contributing 70%-90% of the carotenoids in the grain...
November 2015: International Journal of Environmental Research and Public Health
Boris Laurent, Mathieu Roskosz, Laurent Remusat, François Robert, Hugues Leroux, Hervé Vezin, Christophe Depecker, Nicolas Nuns, Jean-Marc Lefebvre
Primitive carbonaceous chondrites contain a large array of organic compounds dominated by insoluble organic matter (IOM). A striking feature of this IOM is the systematic enrichment in deuterium compared with the solar hydrogen reservoir. This enrichment has been taken as a sign of low-temperature ion-molecule or gas-grain reactions. However, the extent to which Solar System processes, especially ionizing radiation, can affect D/H ratios is largely unknown. Here, we report the effects of electron irradiation on the hydrogen isotopic composition of organic precursors containing different functional groups...
2015: Nature Communications
Hua Guo, Jeff Huang, David H Laidlaw
When visualizing data with uncertainty, a common approach is to treat uncertainty as an additional dimension and encode it using a visual variable. The effectiveness of this approach depends on how the visual variables chosen for representing uncertainty and other attributes interact to influence the user's perception of each variable. We report a user study on the perception of graph edge attributes when uncertainty associated with each edge and the main edge attribute are visualized simultaneously using two separate visual variables...
October 2015: IEEE Transactions on Visualization and Computer Graphics
Amy E Skerry, Rebecca Saxe
Research on emotion attribution has tended to focus on the perception of overt expressions of at most five or six basic emotions. However, our ability to identify others' emotional states is not limited to perception of these canonical expressions. Instead, we make fine-grained inferences about what others feel based on the situations they encounter, relying on knowledge of the eliciting conditions for different emotions. In the present research, we provide convergent behavioral and neural evidence concerning the representations underlying these concepts...
August 3, 2015: Current Biology: CB
Tao Zhang, Shifeng Jin, Yuanxin Gu, Yao He, Ming Li, Yang Li, Haifu Fan
Serial femtosecond crystallography (SFX) is capable of collecting three-dimensional single-crystal diffraction data using polycrystalline samples. This may dramatically enhance the power of X-ray powder diffraction. In this paper a test has been performed using simulated diffraction patterns. The test sample is a mixture of two zeolites with crystal grain sizes from 100 to 300 nm. X-ray diffraction snapshots by SFX were simulated and processed using the program suite CrystFEL. Identification according to the primitive unit-cell volume determined from individual snapshots was able to separate the whole set of snapshots into two subsets, which correspond to the two zeolites in the sample...
May 1, 2015: IUCrJ
Neusa Steiner, Francine L Farias-Soares, Éder C Schmidt, Maria L T Pereira, Bruna Scheid, Gladys D Rogge-Renner, Zenilda L Bouzon, Daniela Schmidt, Sara Maldonado, Miguel P Guerra
Somatic embryogenesis is a morphogenetic route useful for the study of embryonic development, as well as the large-scale propagation of endangered species, such as the Brazilian pine (Araucaria angustifolia). In the present study, we investigated the morphological and ultrastructural organization of A. angustifolia somatic embryo development by means of optical and electron microscopy. The proembryogenic stage was characterized by the proliferation of proembryogenic masses (PEMs), which are cellular aggregates composed of embryogenic cells (ECs) attached to suspensor-like cells (SCs)...
March 2016: Protoplasma
M Rubin, K Altwegg, H Balsiger, A Bar-Nun, J-J Berthelier, A Bieler, P Bochsler, C Briois, U Calmonte, M Combi, J De Keyser, F Dhooghe, P Eberhardt, B Fiethe, S A Fuselier, S Gasc, T I Gombosi, K C Hansen, M Hässig, A Jäckel, E Kopp, A Korth, L Le Roy, U Mall, B Marty, O Mousis, T Owen, H Rème, T Sémon, C-Y Tzou, J H Waite, P Wurz
Molecular nitrogen (N2) is thought to have been the most abundant form of nitrogen in the protosolar nebula. It is the main N-bearing molecule in the atmospheres of Pluto and Triton and probably the main nitrogen reservoir from which the giant planets formed. Yet in comets, often considered the most primitive bodies in the solar system, N2 has not been detected. Here we report the direct in situ measurement of N2 in the Jupiter family comet 67P/Churyumov-Gerasimenko, made by the Rosetta Orbiter Spectrometer for Ion and Neutral Analysis mass spectrometer aboard the Rosetta spacecraft...
April 10, 2015: Science
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