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State dependent model

Matilde M Vaghi, Petra E Vértes, Manfred G Kitzbichler, Annemieke M Apergis-Schoute, Febe E van der Flier, Naomi A Fineberg, Akeem Sule, Rashid Zaman, Valerie Voon, Prantik Kundu, Edward T Bullmore, Trevor W Robbins
BACKGROUND: A recent hypothesis has suggested that core deficits in goal-directed behavior in obsessive-compulsive disorder (OCD) are caused by impaired frontostriatal function. We tested this hypothesis in OCD patients and control subjects by relating measures of goal-directed planning and cognitive flexibility to underlying resting-state functional connectivity. METHODS: Multiecho resting-state acquisition, combined with micromovement correction by blood oxygen level-dependent sensitive independent component analysis, was used to obtain in vivo measures of functional connectivity in 44 OCD patients and 43 healthy comparison subjects...
August 11, 2016: Biological Psychiatry
María Asunción López-Bascón, Mónica Calderón-Santiago, Feliciano Priego-Capote
A novel class of endogenous mammalian lipids endowed with antidiabetic and anti-inflammatory properties has been recently discovered. These are fatty acid esters of hydroxy fatty acids (FAHFAs) formed by condensation between a hydroxy fatty acid and a fatty acid. FAHFAs are present in human serum and tissues at low nanomolar concentrations. Therefore, high sensitivity and selectivity profiling analysis of these compounds in clinical samples is demanded. An automated qualitative and quantitative method based on on-line coupling between solid phase extraction and liquid chromatography-tandem mass spectrometry has been here developed for determination of FAHFAs in serum with the required sensitivity and selectivity...
November 2, 2016: Analytica Chimica Acta
B L Altshuler, E Cuevas, L B Ioffe, V E Kravtsov
We combine numerical diagonalization with semianalytical calculations to prove the existence of the intermediate nonergodic but delocalized phase in the Anderson model on disordered hierarchical lattices. We suggest a new generalized population dynamics that is able to detect the violation of ergodicity of the delocalized states within the Abou-Chakra, Anderson, and Thouless recursive scheme. This result is supplemented by statistics of random wave functions extracted from exact diagonalization of the Anderson model on ensemble of disordered random regular graphs (RRG) of N sites with the connectivity K=2...
October 7, 2016: Physical Review Letters
Junki Yoshitake, Joji Nasu, Yukitoshi Motome
Experimental identification of quantum spin liquids remains a challenge, as the pristine nature is to be seen in asymptotically low temperatures. We here theoretically show that the precursor of quantum spin liquids appears in the spin dynamics in the paramagnetic state over a wide temperature range. Using the cluster dynamical mean-field theory and the continuous-time quantum Monte Carlo method, which are newly developed in the Majorana fermion representation, we calculate the dynamical spin structure factor, relaxation rate in nuclear magnetic resonance, and magnetic susceptibility for the honeycomb Kitaev model whose ground state is a canonical example of the quantum spin liquid...
October 7, 2016: Physical Review Letters
Pravas Deria, Diego A Gómez-Gualdrón, Idan Hod, Randall Q Snurr, Joseph T Hupp, Omar K Farha
Catalytic activity for acyl transfer from N-acetylimidazole (NAI) to different pyridylcarbinol (PC) regioisomers (2-PC, 3-PC, and 4-PC) is demonstrated for a set of topologically diverse, zirconium-based (porphinato)zinc metal-organic frameworks (MOFs). The MOFs studied are PCN-222, MOF-525, and NU-902, which are based on the csq, ftw, and scu topologies, respectively. The experimentally obtained reaction kinetics are discussed in light of molecular modeling results. The catalytic activity is shown to vary across the series of MOFs due to the different extent to which each topology facilitates reactant preconcentration and alignment of PC and NAI via coordination to framework porphyrin sites (orientation effects)...
October 21, 2016: Journal of the American Chemical Society
Shehrin Sayed, Seokmin Hong, Supriyo Datta
It is experimentally established that charge current flowing in a channel with spin-momentum locking such as topological insulator surface states or Rashba interfaces induces a spin voltage, which can be electrically measured with a ferromagnetic contact along the current path. Using this fact in conjunction with Onsager reciprocity arguments, we make the surprising prediction that the anti-parallel resistance of a spin valve can be either larger or smaller than the parallel resistance depending on the direction of spin flow relative to the direction of spin-momentum locking...
October 21, 2016: Scientific Reports
Judy P Hines, Aaron T Smith, Jose P Jacob, Gudrun S Lukat-Rodgers, Ian Barr, Kenton R Rodgers, Feng Guo, Judith N Burstyn
The RNA-binding heme protein DiGeorge critical region 8 (DGCR8) and its ribonuclease partner Drosha cleave primary transcripts of microRNA (pri-miRNA) as part of the canonical microRNA (miRNA) processing pathway. Previous studies show that bis-cysteine thiolate-coordinated Fe(III) DGCR8 supports pri-miRNA processing activity, while Fe(II) DGCR8 does not. In this study, we further characterized Fe(II) DGCR8 and tested whether CO or NO might bind and restore pri-miRNA processing activity to the reduced protein...
October 20, 2016: Journal of Biological Inorganic Chemistry: JBIC
Christoph Funk, Adrian Roth
Drug-induced liver injury (DILI) is a major concern for drug developers, regulators and clinicians. It is triggered by drug and xenobiotic insults leading to liver impairment or damage, in the worst-case liver failure. In contrast to acute "intrinsic" hepatotoxicity, DILI typically manifests in a very small subset of the population under treatment with no clear dose relationship and inconsistent temporal patterns and is therefore termed an idiosyncratic event. Involved are multifactorial, compound-dependent mechanisms and host-specific factors, making the prediction in preclinical test systems very challenging...
October 20, 2016: Archives of Toxicology
A G Dimitrov
The membrane transporters (pumps and co-transporters) are the main players in maintaining the cell homeostasis. Models of various types, each with their own drawbacks, describe transporter behavior. The aim of this study is to find the link between the biophysically based and empirical models to face and solve their specific problems. Instead of decreasing the number of states and using few complex rate constants as is usually done, we use the number of states as great as possible. Then, each transition in the cycle can represent an elementary process and we can apply the mass action law, according to which if rate constants depend on concentrations the dependence is linear...
October 17, 2016: Journal of Theoretical Biology
Tina M Mitre, Anmar Khadra, Massimo Pietropaolo
The expression level of tissue-restricted autoantigens (TSA) in the thymus is crucial for the negative selection of autoreactive T cells during central tolerance. The autoimmune regulator factor (AIRE) plays an important role in the positive regulation of these TSA in medullary thymic epithelial cells and, consequently, in the negative selection of high-avidity autoreactive T cells. Recent studies, however, revealed that thymic islet cell autoantigen (ICA69) expression level in non-obese diabetic (NOD) mice, prone to developing type 1 diabetes (T1D), is reduced due to an increase in the binding affinity of AIRE to the Ica1-promoter region, which regulates ICA69 protein synthesis...
October 17, 2016: Mathematical Biosciences
Benjamin Bohman, Finn Rasmussen, Ata Ghaderi
BACKGROUND: Parental self-efficacy (PSE) refers to beliefs of parents to effectively engage in behaviors that result in desired outcomes for their children. There are several instruments of PSE for promoting healthy dietary or physical activity (PA) behaviors in children. These measures typically assess PSE in relation to some quantity or frequency of behavior, for example, number of servings or times per week. However, measuring PSE in relation to contextual circumstances, for example, psychological states and situational demands, may be a more informative approach...
October 20, 2016: International Journal of Behavioral Nutrition and Physical Activity
Alejandro Agostini, Enric Celaya
Function approximation in online, incremental, reinforcement learning needs to deal with two fundamental problems: biased sampling and nonstationarity. In kinds of tasks, biased sampling occurs because samples are obtained from specific trajectories dictated by the dynamics of the environment and are usually concentrated in particular convergence regions, which in the long term tend to dominate the approximation in the less sampled regions. The nonstationarity comes from the recursive nature of the estimations typical of temporal difference methods...
October 20, 2016: Neural Computation
Matthieu Barbier, James R Watson
Predators of all kinds, be they lions hunting in the Serengeti or fishermen searching for their catch, display various collective strategies. A common strategy is to share information about the location of prey. However, depending on the spatial characteristics and mobility of predators and prey, information sharing can either improve or hinder individual success. Here, our goal is to investigate the interacting effects of space and information sharing on predation efficiency, represented by the expected rate at which prey are found and consumed...
October 2016: PLoS Computational Biology
Woon Yong Sohn, Valérie Brenner, Eric Gloaguen, Michel Mons
Conformer-selective IR gas phase spectroscopy and high level quantum chemistry methods have been used to characterise the diversity of local NH-π interactions between the π ring of a phenylalanine aromatic residue and the nearby main chain amide groups. The study of model systems shows how the amide NH stretch vibrational features, in the 3410-3460 cm(-1) frequency range, can be used to monitor the strength of these local π H-bonds, which is found to depend on both the backbone conformation and the aromatic side chain orientation...
October 20, 2016: Physical Chemistry Chemical Physics: PCCP
Hidekazu Nishikii, Byung-Su Kim, Yasuhisa Yokoyama, Yan Chen, Jeanette Baker, Antonio Pierini, Maite Alvarez, Melissa Mavers, Kristina Maas-Bauer, Yuqiong Pan, Shigeru Chiba, Robert S Negrin
CD4(+)Foxp3(+) regulatory T cells (Treg) are a subpopulation of T cells, which regulate the immune system and enhance immune tolerance after transplantation. Donor-derived Treg prevent the development of lethal acute graft versus host disease (GVHD) in murine models of allogeneic hematopoietic stem cell transplantation (HCT). We recently demonstrated that a single treatment of the agonistic antibody to DR3 (Death receptor 3, αDR3) to donor mice resulted in the expansion of donor derived Treg and prevented acute GVHD, although the precise role of DR3 signaling in GVHD has not been elucidated...
October 19, 2016: Blood
A McKEE, K Shea, M J Ferrari
Measles was eliminated in the Americas in 2002 by a combination of routine immunizations and supplementary immunization activities. Recent outbreaks underscore the importance of reconsidering vaccine policy in order to maintain elimination. We constructed an age-structured dynamical model for the distribution of immunity in a population with routine immunization and without disease, and analysed the steady state for an idealized age structure and for real age structures of countries in the Americas. We compared the level of immunity maintained by current policy in these countries to the level maintainable by an optimal policy...
October 20, 2016: Epidemiology and Infection
Jessica M Wilson, Jeremy W Prokop, Ellen Lorimer, Elizabeth Ntantie, Carol L Williams
Two isoforms of the small GTPase Rap1, Rap1A and Rap1B, participate in cell adhesion; Rap1A promotes steady state adhesion, while Rap1B regulates dynamic changes in cell adhesion. These events depend on the prenylation of Rap1, which promotes its membrane localization. Here, we identify previously unsuspected differences in the regulation of prenylation of Rap1A versus Rap1B, due in part to their different phosphorylation-dependent interactions with the chaperone protein SmgGDS-607. Previous studies indicate that activation of Gαs protein-coupled receptors (GPCRs) phosphorylates S-179 and S-180 in the polybasic region (PBR) of Rap1B, which inhibits Rap1B binding to SmgGDS-607 and diminishes Rap1B prenylation and membrane localization...
October 16, 2016: Journal of Molecular Biology
Aude Giard, Jean-Sébastien Filhol, Franck Jolibois, Florine Cavelier, Dorothée Berthomieu
The determination of pKa values for molecules containing multiple acidic groups in solution is challenging both experimentally and theoretically. We propose a general method to obtain these values by combining a graphical analysis based on a predominance diagram, for amino acids and nicotianamine polyacid with first principle DFT calculations. Implicit and semi-explicit water solvent models were included to account for solvation. This strategy enables the investigation of the protonation states of compounds containing acidic moities in solution depending on the pH domain...
October 19, 2016: Journal of Chemical Theory and Computation
Deepak Kotiya, Bharti Jaiswal, Sampa Ghose, Rachna Kaul, Kasturi Datta, Rakesh K Tyagi
The role of nuclear receptor PXR in detoxification and clearance of xenobiotics and endobiotics is well-established. However, its projected role in hepatic cancer is rather illusive where its expression is reported altered in different cancers depending on the tissue-type and microenvironment. The expression of PXR, its target genes and their biological or clinical significance have not been examined in hepatic cancer. In the present study, by generating DEN-induced hepatic cancer in mice, we report that the expression of PXR and its target genes CYP3A11 and GSTa2 are down-regulated implying impairment of hepatic detoxification capacity...
2016: PloS One
Stephan Ingmar Brückner, Sergii Donets, Arezoo Dianat, Manfred Bobeth, Rafael Gutierrez, Gianaurelio Cuniberti, Eike Brunner
Understanding the molecular interactions between inorganic phases such as silica and organic material is fundamental for chromatographic applications, for tailoring silica-enzyme interactions, and for elucidating the mechanisms of biomineralization. The formation, structure, and properties of the organic/inorganic interface is crucial in this context. Here, we investigate the interaction of selectively (13)C-labeled choline with (29)Si-labeled monosilicic acid/silica at the molecular level. Silica/choline nanocomposites were analyzed by solid-state NMR spectroscopy in combination with extended molecular dynamics (MD) simulations to understand the silica/organic interface...
October 19, 2016: Langmuir: the ACS Journal of Surfaces and Colloids
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