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https://www.readbyqxmd.com/read/28340346/the-upsides-and-downsides-of-organelle-interconnectivity
#1
REVIEW
Daniel E Gottschling, Thomas Nyström
Interconnectivity and feedback control are hallmarks of biological systems. This includes communication between organelles, which allows them to function and adapt to changing cellular environments. While the specific mechanisms for all communications remain opaque, unraveling the wiring of organelle networks is critical to understand how biological systems are built and why they might collapse, as occurs in aging. A comprehensive understanding of all the routes involved in inter-organelle communication is still lacking, but important themes are beginning to emerge, primarily in budding yeast...
March 23, 2017: Cell
https://www.readbyqxmd.com/read/28339251/distinct-turbulence-saturation-regimes-in-stellarators
#2
G G Plunk, P Xanthopoulos, P Helander
In the complex 3D magnetic fields of stellarators, ion-temperature-gradient turbulence is shown to have two distinct saturation regimes, as revealed by petascale numerical simulations and explained by a simple turbulence theory. The first regime is marked by strong zonal flows and matches previous observations in tokamaks. The newly observed second regime, in contrast, exhibits small-scale quasi-two-dimensional turbulence, negligible zonal flows, and, surprisingly, a weaker heat flux scaling. Our findings suggest that key details of the magnetic geometry control turbulence in stellarators...
March 10, 2017: Physical Review Letters
https://www.readbyqxmd.com/read/28339200/accurate-electron-affinities-and-orbital-energies-of-anions-from-a-non-empirically-tuned-range-separated-dft-approach
#3
Lindsey N Anderson, Maria Belen Oviedo, Bryan M Wong
The treatment of atomic anions with Kohn-Sham density functional theory (DFT) has long been controversial since the highest occupied molecular orbital (HOMO) energy, EHOMO, is often calculated to be positive with most approximate density functionals. We assess the accuracy of orbital energies and electron affinities for all three rows of elements in the periodic table (H-Ar) using a variety of theoretical approaches and customized basis sets. Among all of the theoretical methods studied here, we find that a non-empirically tuned range-separated approach (constructed to satisfy DFT-Koopmans' theorem for the anionic electron system) provides the best accuracy for a variety of basis sets - even for small basis sets where most functionals typically fail...
March 24, 2017: Journal of Chemical Theory and Computation
https://www.readbyqxmd.com/read/28334991/frameworks-to-assess-health-systems-governance-a-systematic-review
#4
Thidar Pyone, Helen Smith, Nynke van den Broek
Governance of the health system is a relatively new concept and there are gaps in understanding what health system governance is and how it could be assessed. We conducted a systematic review of the literature to describe the concept of governance and the theories underpinning as applied to health systems; and to identify which frameworks are available and have been applied to assess health systems governance. Frameworks were reviewed to understand how the principles of governance might be operationalized at different levels of a health system...
March 3, 2017: Health Policy and Planning
https://www.readbyqxmd.com/read/28334943/effects-of-prefrontal-cortex-damage-on-emotion-understanding-eeg-and-behavioural-evidence
#5
Anat Perry, Samantha N Saunders, Jennifer Stiso, Callum Dewar, Jamie Lubell, Torstein R Meling, Anne-Kristin Solbakk, Tor Endestad, Robert T Knight
Humans are highly social beings that interact with each other on a daily basis. In these complex interactions, we get along by being able to identify others' actions and infer their intentions, thoughts and feelings. One of the major theories accounting for this critical ability assumes that the understanding of social signals is based on a primordial tendency to simulate observed actions by activating a mirror neuron system. If mirror neuron regions are important for action and emotion recognition, damage to regions in this network should lead to deficits in these domains...
February 22, 2017: Brain: a Journal of Neurology
https://www.readbyqxmd.com/read/28333126/cheetahs-have-a-stronger-constitutive-innate-immunity-than-leopards
#6
Sonja K Heinrich, Heribert Hofer, Alexandre Courtiol, Jörg Melzheimer, Martin Dehnhard, Gábor Á Czirják, Bettina Wachter
As a textbook case for the importance of genetics in conservation, absence of genetic variability at the major histocompatibility complex (MHC) is thought to endanger species viability, since it is considered crucial for pathogen resistance. An alternative view of the immune system inspired by life history theory posits that a strong response should evolve in other components of the immune system if there is little variation in the MHC. In contrast to the leopard (Panthera pardus), the cheetah (Acinonyx jubatus) has a relatively low genetic variability at the MHC, yet free-ranging cheetahs are healthy...
March 23, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28333096/molecularly-imprinted-polymers-for-selective-extraction-of-oblongifolin-c-from-garcinia-yunnanensis-hu
#7
Liping Wang, Wenwei Fu, Yunhui Shen, Hongsheng Tan, Hongxi Xu
Molecularly imprinted polymers (MIPs) were synthesized and applied for the selective extraction of oblongifolin C (OC) from fruit extracts of Garcinia yunnanensis Hu. A series of experiments and computational approaches were employed to improve the efficiency of screening for optimal MIP systems in the study. The molar ratio (1:4) was eventually chosen based on the comparison of the binding energy of the complexes between the template (OC) and the functional monomers using density functional theory (DFT) at the RI-PBE-D3-gCP/def2-TZVP level of theory...
March 23, 2017: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
https://www.readbyqxmd.com/read/28332401/ultrafast-excited-state-dynamics-of-cytosine-aza-derivative-and-analogues
#8
Zhongneng Zhou, Xueyao Zhou, Xueli Wang, Bin Jiang, Yongle Li, Jinquan Chen, Jianhua Xu
Excited state dynamics of 5-azacytosine (5-AC), 2,4-diamino-1,3,5-triazine (2,4-DT), and 2-amino-1,3,5-triazine (2-AT) were comprehensively investigated with steady state absorption, fluorescence and femtosecond transient absorption measurements. Time-dependent density functional theory (TDDFT) calculations were performed to help assign the absorption bands and understand the excited state decay mechanisms. The experimental results of excited singlet state dynamics for 5-AC, 2,4-DT and 2-AT with femtosecond time resolution were reported for the first time...
March 23, 2017: Journal of Physical Chemistry. A
https://www.readbyqxmd.com/read/28330990/on-the-growth-and-form-of-shoots
#9
Raghunath Chelakkot, L Mahadevan
Growing plant stems and shoots exhibit a variety of shapes that embody growth in response to various stimuli. Building on experimental observations, we provide a quantitative biophysical theory for these shapes by accounting for the inherent observed passive and active effects: (i) the active controllable growth response of the shoot in response to its orientation relative to gravity, (ii) proprioception, the shoot's growth response to its own observable current shape, and (iii) the passive elastic deflection of the shoot due to its own weight, which determines the current shape of the shoot...
March 2017: Journal of the Royal Society, Interface
https://www.readbyqxmd.com/read/28330486/relationships-between-structure-process-and-outcome-to-assess-quality-of-integrated-chronic-disease-management-in-a-rural-south-african-setting-applying-a-structural-equation-model
#10
Soter Ameh, Francesc Xavier Gómez-Olivé, Kathleen Kahn, Stephen M Tollman, Kerstin Klipstein-Grobusch
BACKGROUND: South Africa faces a complex dual burden of chronic communicable and non-communicable diseases (NCDs). In response, the Integrated Chronic Disease Management (ICDM) model was initiated in primary health care (PHC) facilities in 2011 to leverage the HIV/ART programme to scale-up services for NCDs, achieve optimal patient health outcomes and improve the quality of medical care. However, little is known about the quality of care in the ICDM model. The objectives of this study were to: i) assess patients' and operational managers' satisfaction with the dimensions of ICDM services; and ii) evaluate the quality of care in the ICDM model using Avedis Donabedian's theory of relationships between structure (resources), process (clinical activities) and outcome (desired result of healthcare) constructs as a measure of quality of care...
March 23, 2017: BMC Health Services Research
https://www.readbyqxmd.com/read/28330413/molecular-dynamic-simulation-and-dft-study-on-the-drug-dna-interaction-crocetin-as-an-anticancer-and-dna-nanostructure-model
#11
Ebrahim Azarhazin, Mohammad Izadyar, Mohammad Reza Housaindokht
In this research, the interaction of Crocetin as an anticancer drug and a Dickerson DNA has been investigated. 25 ns molecular dynamic simulations of Crocetin and DNA composed of twelve base pairs and a sequence of d(CGCGAATTCGCG)2 were done in water. Three definite parts of the B-DNA were considered in analyzing the best interactive site from the thermodynamic point of view. Binding energy analysis showed that van der Waals interaction is the most important part related to the reciprocal O and H atoms of the Crocetin and DNA...
March 22, 2017: Journal of Biomolecular Structure & Dynamics
https://www.readbyqxmd.com/read/28330369/energy-transfer-in-multi-collision-environments-an-experimental-test-of-theory-lih-10-2-in-h2-0-0
#12
Xiaoyan Shen, Shuyin Wang, Kang Dai, Yifan Shen, Anthony J McCaffery
We report separate experimental and theoretical studies of the equilibration of highly excited LiH (v = 10; J = 2) in H2 at 680 K. Experiments that follow the time evolution of state-to-state population transfer in multi-collision conditions with μs resolution were carried out by Shen and co-workers at Xinjiang University and East China Institute of Science and Technology. At the same time, theoretical computations on the relaxation of this gas mixture were undertaken by McCaffery and co-workers at Sussex University...
March 21, 2017: Journal of Chemical Physics
https://www.readbyqxmd.com/read/28329782/theories-of-memory-and-aging-a-look-at-the-past-and-a-glimpse-of-the-future
#13
Denise C Park, Sara B Festini
The present article reviews theories of memory and aging over the past 50 years. Particularly notable is a progression from early single-mechanism perspectives to complex multifactorial models proposed to account for commonly observed age deficits in memory function. The seminal mechanistic theories of processing speed, limited resources, and inhibitory deficits are discussed and viewed as especially important theories for understanding age-related memory decline. Additionally, advances in multivariate techniques including structural equation modeling provided new tools that led to the development of more complex multifactorial theories than existed earlier...
June 2, 2016: Journals of Gerontology. Series B, Psychological Sciences and Social Sciences
https://www.readbyqxmd.com/read/28328213/reversible-coordination-of-boron-aluminum-zinc-magnesium-and-calcium-hydrogen-bonds-to-bent-cul2-fragments-heavy-%C3%AF-complexes-of-the-lightest-coinage-metal
#14
Alexandra Hicken, Andrew J P White, Mark R Crimmin
A series of copper(I) complexes bearing electron-deficient β-diketiminate ligands have been prepared. The study includes [{{ArNC(CR3)}2CH}Cu(η(2)-toluene)n] (Ar = Mes, R = F, n = 0.5, [12·tol]; Ar = C6F5, R = Me, n = 1, [2·tol]; Ar = 2,6-Cl2C6H3, R = H, n = 0.5, [32·tol]). Reactions of [1-3n·tol] with boranes, alanes, a zinc hydride, a magnesium hydride, and a calcium hydride generate the corresponding σ complexes ([1-3·B], [3·B'], [3·Al], [3·Al'], [1-3·Zn], [1·Mg], and [1·Ca]). These species all form reversibly, being in equilibrium with the arene solvates in solution...
March 22, 2017: Inorganic Chemistry
https://www.readbyqxmd.com/read/28328203/a-physical-molecular-mechanics-method-for-damped-dispersion
#15
Pragya Verma, Bo Wang, Laura E Fernandez, Donald G Truhlar
Damped dispersion can be a significant component of the interaction energy in many physical and chemical processes, for example, physisorption and noncovalent complexation. For physically interpreting and modeling such processes, it is convenient to have an analytic method to calculate damped dispersion that is readily applicable across the entire periodic table. Of the available methods to calculate damped dispersion energy for interacting systems with overlapping charge distributions, we select symmetry-adapted perturbation theory (SAPT) as providing a reasonable definition, and of the possible analytic forms, we choose the D3(BJ) method...
March 22, 2017: Journal of Physical Chemistry. A
https://www.readbyqxmd.com/read/28328011/when-emotional-pain-becomes-physical-adverse-childhood-experiences-pain-and-the-role-of-mood-and-anxiety-disorders
#16
Natalie J Sachs-Ericsson, Julia L Sheffler, Ian H Stanley, Jennifer R Piazza, Kristopher J Preacher
OBJECTIVE: We examined the association between retrospective reports of adverse childhood experiences (ACEs) and painful medical conditions. We also examined the mediating and moderating roles of mood and anxiety disorders in the ACEs-painful medical conditions relationship. METHOD: Ten-year longitudinal data were obtained from the National Comorbidity Surveys (NCS-1, NCS-2; N = 5001). The NCS-1 obtained reports of ACEs, current health conditions, current pain severity, and mood and anxiety disorders...
March 22, 2017: Journal of Clinical Psychology
https://www.readbyqxmd.com/read/28327740/molecular-dynamics-simulations-elucidate-conformational-selection-and-induced-fit-mechanisms-in-the-binding-of-pd-1-and-pd-l1
#17
Wenping Liu, Bing Huang, Yashu Kuang, Guangjian Liu
Blockage of the interactions between immunologic checkpoint protein PD-1 and its ligand PD-L1 showed efficacy for cancer treatment. X-ray structures have captured static conformational snapshots of PD-1 and revealed that the CC' loop adopts an open conformation in the apo-protein but turns into a closed form and interacts with PD-L1 in the complex. This structural heterogeneity brings difficulties for structure-based drug discovery targeting PD-1. To gain insights into the role of the CC' loop in molecular recognition, we have undertaken a comparative study between the open and closed conformations in apo-PD-1 and the PD-1/PD-L1 complex using molecular dynamics simulations...
March 22, 2017: Molecular BioSystems
https://www.readbyqxmd.com/read/28327381/the-enhancing-effect-of-a-cation-%C3%AF-interaction-on-the-cooperativity-of-halogen-bonds-a-computational-study
#18
Mehdi D Esrafili, Soheila Asadollahi
In this work, we investigate the effect of a cation-π interaction on the cooperativity of X⋯N halogen bonds in PhX⋯NCX⋯NH3 complexes, where Ph=phenyl and X=Cl, Br, I. Molecular geometries and interaction energies of the resulting complexes are studied at the MP2/aug-cc-pVDZ(-PP) computational level. The mechanism of the cooperativity between halogen bonds is analyzed using parameters derived from the noncovalent index, quantum theory of atoms in molecules and natural bond orbital methodologies. It is found that the divalent cations (Be(2+), Mg(2+)) have a larger influence on the cooperativity of halogen bonds than monovalent ones (Li(+), Na(+))...
March 2, 2017: Journal of Molecular Graphics & Modelling
https://www.readbyqxmd.com/read/28327212/more-stereotypes-please-the-limits-of-theory-of-mind-and-the-need-for-further-studies-on-the-complexity-of-real-world-social-interactions
#19
Kristin Andrews
I suggest that the Stereotype Rationality Hypothesis (Jussim 2012) is only partially right. I agree it is rational to rely on stereotypes, but in the complexity of real world social interactions, most of our individuating information invokes additional stereotypes. Despite assumptions to the contrary, there is reason to think theory of mind is not accurate, and social psychology's denial of stereotype accuracy led us toward mindreading/theory of mind - a less accurate account of how we understand other people...
January 2017: Behavioral and Brain Sciences
https://www.readbyqxmd.com/read/28326782/synthesis-and-properties-of-triarylhalostibonium-cations
#20
Mengxi Yang, François P Gabbaï
As part of our fundamental interest in the chemistry of main-group Lewis acids, we have decided to target stibonium cations whose Lewis acidity is enhanced by the presence of a halogen substituent directly bound to antimony. Starting from Ph3Sb(OTf)2 (1) and Mes3Sb(OTf)2 (2), we successfully prepared the triflate derivatives Ph3SbF(OTf) (3) and Mes3SbF(OTf) (4). We also synthesized the hexachloroantimonate salt of [Mes3SbCl](+) (6), an analogue of the known [Ph3SbCl][SbCl6] (5). The structures of these complexes have been investigated experimentally as well as computationally using density functional theory methods...
March 22, 2017: Inorganic Chemistry
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