899 research outputs found
Герменевтика іконографічної програми ранньобарокових священних євлогіїв у контексті євхаристійної еклезіології (на прикладі «могилянської» євхаристійної чаші)
We report a numerical study on the phase behaviour of a ‘patch–anti-patch’ model for particles with tetrahedrally arranged attractive spots. In particular, we compute the phase equilibria between the fluid and a low density diamond cubic (DC) crystal for different realizations of the patch–anti-patch interaction. By increasing the ‘specificity’ of the patches, i.e. lowering the number of corresponding attractive ‘anti-patches’ to a given patch, we find that the metastability gap between the DC freezing boundary and the liquid–gas critical point widens considerably. We argue that this effect of interaction specificity is relevant for the description of protein phase diagrams, as patch–anti-patch interactions can stabilise relatively open, ordered structures
Интеграционные процессы в условиях международной глобализации экономики
We present a double-charge model for the interaction between parallel polarizable hard spherocylinders subject to an external electric field. Using Monte Carlo simulations and free-energy calculations, we predict the phase behaviour for this model as a function of the density and electric field strength, at a fixed length-to-diameter ratio L/D = 5. The resulting phase diagram contains, in addition to the well-known nematic, smectic A, ABC crystal, and columnar phases, a smectic C phase, and a low temperature crystal X phase. We also find a string fluid at low densities and field strengths, resembling results found for dipolar spheres
Orbital and spin physics in LiNiO2 and NaNiO2
We derive a spin-orbital Hamiltonian for a triangular lattice of e_g orbital
degenerate (Ni^{3+}) transition metal ions interacting via 90 degree
superexchange involving (O^{2-}) anions, taking into account the on-site
Coulomb interactions on both the anions and the transition metal ions. The
derived interactions in the spin-orbital model are strongly frustrated, with
the strongest orbital interactions selecting different orbitals for pairs of Ni
ions along the three different lattice directions. In the orbital ordered
phase, favoured in mean field theory, the spin-orbital interaction can play an
important role by breaking the U(1) symmetry generated by the much stronger
orbital interaction and restoring the threefold symmetry of the lattice. As a
result the effective magnetic exchange is non-uniform and includes both
ferromagnetic and antiferromagnetic spin interactions. Since ferromagnetic
interactions still dominate, this offers yet insufficient explanation for the
absence of magnetic order and the low-temperature behaviour of the magnetic
susceptibility of stoichiometric LiNiO_2. The scenario proposed to explain the
observed difference in the physical properties of LiNiO_2 and NaNiO_2 includes
small covalency of Ni-O-Li-O-Ni bonds inducing weaker interplane superexchange
in LiNiO_2, insufficient to stabilize orbital long-range order in the presence
of stronger intraplane competition between superexchange and Jahn-Teller
coupling.Comment: 33 pages, 12 postscript figures, uses iopams.sty . This article
features in New Journal of Physics as part of a Focus Issue on Orbital
Physics - all contributions may be freely accessed at
(http://stacks.iop.org/1367-2630/6/i=1/a=E05). The published version of this
article may be found at http://stacks.iop.org/1367-2630/7/12
Marine epibiosis. II. Reduced fouling on Polysyncraton lacazei (Didemnidae, Tunicata) and proposal of an antifouling potential index
Polysyncraton lacazei is a colonial tunicate (family didemnidae) living in the NW-mediterranean rocky sublitoral. A thorough scanning of numerous colonies revealed that in spite of an apparently heavy local fouling pressure only one fouling species — a kamptozoan — is encountered with some regularity on Polysyncraton. We try to define the epibiotic situation of sessile marine organisms as composed of four epibiotic parameters: longevity or exposure time (A), epibiont load (E), colonizer pool (CP) and fouling-period (FP). Subsequently, these factors are combined to propose an “Antifouling Potential” index: AFP=(1−E/CP)×A/(FP+A). This index is intended to permit evaluating the relative antifouling defense potency to be expected in a given organism in a given epibiotic situation and to compare different cases of epibiosis and fouling
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Purpose in life predicts better emotional recovery from negative stimuli
Purpose in life predicts both health and longevity suggesting that the ability to find meaning from life’s experiences, especially when confronting life’s challenges, may be a mechanism underlying resilience. Having purpose in life may motivate reframing stressful situations to deal with them more productively, thereby facilitating recovery from stress and trauma. In turn, enhanced ability to recover from negative events may allow a person to achieve or maintain a feeling of greater purpose in life over time. In a large sample of adults (aged 36-84 years) from the MIDUS study (Midlife in the U.S., http://www.midus.wisc.edu/), we tested whether purpose in life was associated with better emotional recovery following exposure to negative picture stimuli indexed by the magnitude of the eyeblink startle reflex (EBR), a measure sensitive to emotional state. We differentiated between initial emotional reactivity (during stimulus presentation) and emotional recovery (occurring after stimulus offset). Greater purpose in life, assessed over two years prior, predicted better recovery from negative stimuli indexed by a smaller eyeblink after negative pictures offset, even after controlling for initial reactivity to the stimuli during the picture presentation, gender, age, trait affect, and other well-being dimensions. These data suggest a proximal mechanism by which purpose in life may afford protection from negative events and confer resilience is through enhanced automatic emotion regulation after negative emotional provocation
Cell-type-specific profiling of protein-DNA interactions without cell isolation using targeted DamID with next-generation sequencing.
This protocol is an extension to: Nat. Protoc. 2, 1467-1478 (2007); doi:10.1038/nprot.2007.148; published online 7 June 2007The ability to profile transcription and chromatin binding in a cell-type-specific manner is a powerful aid to understanding cell-fate specification and cellular function in multicellular organisms. We recently developed targeted DamID (TaDa) to enable genome-wide, cell-type-specific profiling of DNA- and chromatin-binding proteins in vivo without cell isolation. As a protocol extension, this article describes substantial modifications to an existing protocol, and it offers additional applications. TaDa builds upon DamID, a technique for detecting genome-wide DNA-binding profiles of proteins, by coupling it with the GAL4 system in Drosophila to enable both temporal and spatial resolution. TaDa ensures that Dam-fusion proteins are expressed at very low levels, thus avoiding toxicity and potential artifacts from overexpression. The modifications to the core DamID technique presented here also increase the speed of sample processing and throughput, and adapt the method to next-generation sequencing technology. TaDa is robust, reproducible and highly sensitive. Compared with other methods for cell-type-specific profiling, the technique requires no cell-sorting, cross-linking or antisera, and binding profiles can be generated from as few as 10,000 total induced cells. By profiling the genome-wide binding of RNA polymerase II (Pol II), TaDa can also identify transcribed genes in a cell-type-specific manner. Here we describe a detailed protocol for carrying out TaDa experiments and preparing the material for next-generation sequencing. Although we developed TaDa in Drosophila, it should be easily adapted to other organisms with an inducible expression system. Once transgenic animals are obtained, the entire experimental procedure-from collecting tissue samples to generating sequencing libraries-can be accomplished within 5 d.This work was funded by a Wellcome Trust Senior Investigator Award (103792), Wellcome Trust Programme Grant (092545) and BBSRC Project Grant (BB/L00786X/1) to A.H.B. A.H.B acknowledges core funding to the Gurdon Institute from the Wellcome Trust (092096) and CRUK (C6946/A14492).This is the author accepted manuscript. The final version is available from Nature Publishing Group via http://dx.doi.org/10.1038/nprot.2016.08
Guidelines for pre-operative cardiac risk assessment and perioperative cardiac management in non-cardiac surgery : the Task Force for Preoperative Cardiac Risk Assessment and Perioperative Cardiac Management in Non-cardiac Surgery of the European Society of Cardiology (ESC) and endorsed by the European Society of Anaesthesiology (ESA)
Non-cardiac surgery; Pre-operative cardiac risk assessment; Pre-operative cardiac testing; Pre-operative coronary artery revascularization; Perioperative cardiac management; Renal disease; Pulmonary disease; Neurological disease; Anaesthesiology; Post-operative cardiac surveillanc
Dual phase-shift Bragg grating silicon photonic modulator operating up to 60 Gb/s
We demonstrate PAM-4 and OOK operation of a novel silicon photonic modulator. The modulator design is based on two phase-shifts in a Bragg Grating structure driven in a push pull configuration. Back-to-back PAM-4 modulation is demonstrated below the FEC threshold at up to 60 Gb/s. OOK modulation is also shown up to 55 Gb/s with MMSE equalization and up to 50 Gb/s without equalization. Eye diagrams and BER curves at different bit rates are provided for both PAM-4 and OOK modulations. To our knowledge, this structure is the fastest silicon photonic modulator based on Bragg gratings, reaching modulation speed comparable to the fastest Mach-Zehnder modulators and micro-ring modulators
A Cis-Regulatory Map of the Drosophila Genome
Systematic annotation of gene regulatory elements is a major challenge in genome science. Direct mapping of chromatin modification marks and transcriptional factor binding sites genome-wide1, 2 has successfully identified specific subtypes of regulatory elements3. In Drosophila several pioneering studies have provided genome-wide identification of Polycomb response elements4, chromatin states5, transcription factor binding sites6, 7, 8, 9, RNA polymerase II regulation8 and insulator elements10; however, comprehensive annotation of the regulatory genome remains a significant challenge. Here we describe results from the modENCODE cis-regulatory annotation project. We produced a map of the Drosophila melanogaster regulatory genome on the basis of more than 300 chromatin immunoprecipitation data sets for eight chromatin features, five histone deacetylases and thirty-eight site-specific transcription factors at different stages of development. Using these data we inferred more than 20,000 candidate regulatory elements and validated a subset of predictions for promoters, enhancers and insulators in vivo. We identified also nearly 2,000 genomic regions of dense transcription factor binding associated with chromatin activity and accessibility. We discovered hundreds of new transcription factor co-binding relationships and defined a transcription factor network with over 800 potential regulatory relationships
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