Hypothesis: NDL proteins function in stress responses by regulating microtubule organization

OpenAIRE

Khatri, Nisha; Mudgil, Yashwanti

2015-01-01

N-MYC DOWNREGULATED-LIKE proteins (NDL), members of the alpha/beta hydrolase superfamily were recently rediscovered as interactors of G-protein signaling in Arabidopsis thaliana. Although the precise molecular function of NDL proteins is still elusive, in animals these proteins play protective role in hypoxia and expression is induced by hypoxia and nickel, indicating role in stress. Homology of NDL1 with animal counterpart N-MYC DOWNREGULATED GENE (NDRG) suggests similar functions in animals...

Connotation and category of functional-molecular imaging

International Nuclear Information System (INIS)

Li Tianran; Tian Jiahe

2007-01-01

Function and molecular lmaging represent medical imaging' s direction. The review article introduce function and molecular's concept and category and its characteristic. Comparing with traditionary classics radiology, function and molecular imaging have many features, such as micro-mount and specificity and quantitative. There are many technology about function and molecular imaging. Function and molecular imaging is important ingredient of modern medical and play a considerable role. (authors)

Neurobiology of Chronic Stress-Related Psychiatric Disorders: Evidence from Molecular Imaging Studies

Science.gov (United States)

Davis, Margaret T.; Holmes, Sophie E.; Pietrzak, Robert H.; Esterlis, Irina

2018-01-01

Chronic stress accounts for billions of dollars of economic loss annually in the United States alone, and is recognized as a major source of disability and mortality worldwide. Robust evidence suggests that chronic stress plays a significant role in the onset of severe and impairing psychiatric conditions, including major depressive disorder, bipolar disorder, and posttraumatic stress disorder. Application of molecular imaging techniques such as positron emission tomography and single photon emission computed tomography in recent years has begun to provide insight into the molecular mechanisms by which chronic stress confers risk for these disorders. The present paper provides a comprehensive review and synthesis of all positron emission tomography and single photon emission computed tomography imaging publications focused on the examination of molecular targets in individuals with major depressive disorder, posttraumatic stress disorder, or bipolar disorder to date. Critical discussion of discrepant findings and broad strengths and weaknesses of the current body of literature is provided. Recommended future directions for the field of molecular imaging to further elucidate the neurobiological substrates of chronic stress-related disorders are also discussed. This article is part of the inaugural issue for the journal focused on various aspects of chronic stress. PMID:29862379

Molecular and Genetic Basis of Stress

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Bakir Mehić

2012-05-01

Full Text Available A person’s reaction to trauma depends on the traumatic situation itself, personality characteristics of the person exposed to trauma, and posttraumatic social environment. Stressor must be extreme event that is extremely dangerous or fatal nature, and which is outside normal human experience [1].Studies investigating psychological consequences of military and civil trauma confirmed the correlation between the nature and intensity of trauma, previous traumatic experience, and psychological consequences. Stress causes the autonomic nervous system hyperactivity. If the stress is extreme or constant symptoms of hyperactivity, increased heart rate, increased respiration, sweating, muscle tension, insomnia and increased anxiety are becoming significant for the prolonging the symptoms of PTSD. Our cells are well adapted to exposure to a mild stress for a short time. In contrast there are potentially serious consequences of exposure to the prolonged stress[2].Various damages arising from the war in Bosnia (1992 - 1995 are almost undetectable, and the consequences for the mental health of the population of Bosnia and Herzegovina are long and painful. It is estimated that in Bosnia and Herzegovina there are 1.75 million people who have some stress-related mental disorders, of which 1 million in the Federation.PTSD may be represented by mutations that must be carried by many genes. There may even be epigenetic reasons for the disorder that have nothing to do with heritable mutations per se. Epigenetic means related to functional changes in the genome that can be regulated by external environmental events that do not involve alterations in the genetic code. One epigenetic mechanism is called “methylation,” a molecular process that affects the activity of a large percentage of genes. Epigenetic investigations say that methylation may be involved in the development of stress regulation in early life[3].A number of longitudinal studies have looked at

Illustrating the Molecular Origin of Mechanical Stress in Ductile Deformation of Polymer Glasses.

Science.gov (United States)

Li, Xiaoxiao; Liu, Jianning; Liu, Zhuonan; Tsige, Mesfin; Wang, Shi-Qing

2018-02-16

New experiments show that tensile stress vanishes shortly after preyield deformation of polymer glasses while tensile stress after postyield deformation stays high and relaxes on much longer time scales, thus hinting at a specific molecular origin of stress in ductile cold drawing: chain tension rather than intersegmental interactions. Molecular dynamics simulation based on a coarse-grained model for polystyrene confirms the conclusion that the chain network plays an essential role, causing the glassy state to yield and to respond with a high level of intrachain retractive stress. This identification sheds light on the future development regarding an improved theoretical account for molecular mechanics of polymer glasses and the molecular design of stronger polymeric materials to enhance their mechanical performance.

Illustrating the Molecular Origin of Mechanical Stress in Ductile Deformation of Polymer Glasses

Science.gov (United States)

Li, Xiaoxiao; Liu, Jianning; Liu, Zhuonan; Tsige, Mesfin; Wang, Shi-Qing

2018-02-01

New experiments show that tensile stress vanishes shortly after preyield deformation of polymer glasses while tensile stress after postyield deformation stays high and relaxes on much longer time scales, thus hinting at a specific molecular origin of stress in ductile cold drawing: chain tension rather than intersegmental interactions. Molecular dynamics simulation based on a coarse-grained model for polystyrene confirms the conclusion that the chain network plays an essential role, causing the glassy state to yield and to respond with a high level of intrachain retractive stress. This identification sheds light on the future development regarding an improved theoretical account for molecular mechanics of polymer glasses and the molecular design of stronger polymeric materials to enhance their mechanical performance.

Polyamines Function in Stress Tolerance: From Synthesis to Regulation

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Ji-Hong eLiu

2015-10-01

Full Text Available Plants are challenged by a variety of biotic or abiotic stresses, which can affect their growth and development, productivity and geographic distribution. In order to survive adverse environmental conditions, plants have evolved various adaptive strategies, among which is the accumulation of metabolites that play protective roles. A well-established example of the metabolites that are involved in stress responses, or stress tolerance, is the low-molecular-weight aliphatic polyamines, including putrescine,spermidine and spermine. The critical role of polyamines in stress tolerance is suggested by several lines of evidence: firstly, the transcript levels of polyamine biosynthetic genes, as well as the activities of the corresponding enzymes, are induced by stresses; secondly, elevation of endogenous polyamine levels by exogenous supply of polyamines, or overexpression of polyamine biosynthetic genes, results in enhanced stress tolerance; and thirdly, a reduction of endogenous polyamines is accompanied by compromised stress tolerance. A number of studies have demonstrated that polyamines function in stress tolerance largely by modulating the homeostasis of reactive oxygen species (ROS due to their direct, or indirect, roles in regulating antioxidant systems or suppressing ROS production. The transcriptional regulation of polyamine synthesis by transcription factors is also reviewed here. Meanwhile, future perspectives on polyamine research are also suggested.

Catecholaminergic systems in stress: structural and molecular genetic approaches.

Science.gov (United States)

Kvetnansky, Richard; Sabban, Esther L; Palkovits, Miklos

2009-04-01

Stressful stimuli evoke complex endocrine, autonomic, and behavioral responses that are extremely variable and specific depending on the type and nature of the stressors. We first provide a short overview of physiology, biochemistry, and molecular genetics of sympatho-adrenomedullary, sympatho-neural, and brain catecholaminergic systems. Important processes of catecholamine biosynthesis, storage, release, secretion, uptake, reuptake, degradation, and transporters in acutely or chronically stressed organisms are described. We emphasize the structural variability of catecholamine systems and the molecular genetics of enzymes involved in biosynthesis and degradation of catecholamines and transporters. Characterization of enzyme gene promoters, transcriptional and posttranscriptional mechanisms, transcription factors, gene expression and protein translation, as well as different phases of stress-activated transcription and quantitative determination of mRNA levels in stressed organisms are discussed. Data from catecholamine enzyme gene knockout mice are shown. Interaction of catecholaminergic systems with other neurotransmitter and hormonal systems are discussed. We describe the effects of homotypic and heterotypic stressors, adaptation and maladaptation of the organism, and the specificity of stressors (physical, emotional, metabolic, etc.) on activation of catecholaminergic systems at all levels from plasma catecholamines to gene expression of catecholamine enzymes. We also discuss cross-adaptation and the effect of novel heterotypic stressors on organisms adapted to long-term monotypic stressors. The extra-adrenal nonneuronal adrenergic system is described. Stress-related central neuronal regulatory circuits and central organization of responses to various stressors are presented with selected examples of regulatory molecular mechanisms. Data summarized here indicate that catecholaminergic systems are activated in different ways following exposure to distinct

What molecular mechanism is adapted by plants during salt stress ...

African Journals Online (AJOL)

What molecular mechanism is adapted by plants during salt stress tolerance? ... Salt stress harmfully shocks agricultural yield throughout the world affecting production whether it is for subsistence or economic outcomes. ... from 32 Countries:.

Hypothesis: NDL proteins function in stress responses by regulating microtubule organization.

Science.gov (United States)

Khatri, Nisha; Mudgil, Yashwanti

2015-01-01

N-MYC DOWNREGULATED-LIKE proteins (NDL), members of the alpha/beta hydrolase superfamily were recently rediscovered as interactors of G-protein signaling in Arabidopsis thaliana. Although the precise molecular function of NDL proteins is still elusive, in animals these proteins play protective role in hypoxia and expression is induced by hypoxia and nickel, indicating role in stress. Homology of NDL1 with animal counterpart N-MYC DOWNREGULATED GENE (NDRG) suggests similar functions in animals and plants. It is well established that stress responses leads to the microtubule depolymerization and reorganization which is crucial for stress tolerance. NDRG is a microtubule-associated protein which mediates the microtubule organization in animals by causing acetylation and increases the stability of α-tubulin. As NDL1 is highly homologous to NDRG, involvement of NDL1 in the microtubule organization during plant stress can also be expected. Discovery of interaction of NDL with protein kinesin light chain- related 1, enodomembrane family protein 70, syntaxin-23, tubulin alpha-2 chain, as a part of G protein interactome initiative encourages us to postulate microtubule stabilizing functions for NDL family in plants. Our search for NDL interactors in G protein interactome also predicts the role of NDL proteins in abiotic stress tolerance management. Based on published report in animals and predicted interacting partners for NDL in G protein interactome lead us to hypothesize involvement of NDL in the microtubule organization during abiotic stress management in plants.

Molecular correlates of impaired prefrontal plasticity in response to chronic stress

NARCIS (Netherlands)

Kuipers, SD; Trentani, A; Den Boer, JA; Ter Horst, GJ

Disturbed adaptations at the molecular and cellular levels following stress could represent compromised neural plasticity that contributes to the pathophysiology of stress-induced disorders. Evidence illustrates atrophy and cell death of stress-vulnerable neurones in the prefrontal cortex. Reduced

Endoplasmic reticulum stress induces different molecular structural alterations in human dilated and ischemic cardiomyopathy.

Directory of Open Access Journals (Sweden)

Ana Ortega

Full Text Available BACKGROUND: The endoplasmic reticulum (ER is a multifunctional organelle responsible for the synthesis and folding of proteins as well as for signalling and calcium storage, that has been linked to the contraction-relaxation process. Perturbations of its homeostasis activate a stress response in diseases such as heart failure (HF. To elucidate the alterations in ER molecular components, we analyze the levels of ER stress and structure proteins in human dilated (DCM and ischemic (ICM cardiomyopathies, and its relationship with patient's functional status. METHODS AND RESULTS: We examined 52 explanted human hearts from DCM (n = 21 and ICM (n = 21 subjects and 10 non-failing hearts as controls. Our results showed specific changes in stress (IRE1, p<0.05; p-IRE1, p<0.05 and structural (Reticulon 1, p<0.01 protein levels. The stress proteins GRP78, XBP1 and ATF6 as well as the structural proteins RRBP1, kinectin, and Nogo A and B, were upregulated in both DCM and ICM patients. Immunofluorescence results were concordant with quantified Western blot levels. Moreover, we show a novel relationship between stress and structural proteins. RRBP1, involved in procollagen synthesis and remodeling, was related with left ventricular function. CONCLUSIONS: In the present study, we report the existence of alterations in ER stress response and shaping proteins. We show a plausible effect of the ER stress on ER structure in a suitable sample of DCM and ICM subjects. Patients with higher values of RRBP1 had worse left ventricular function.

Oxidative stress induced inflammation initiates functional decline of tear production.

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Yuichi Uchino

Full Text Available Oxidative damage and inflammation are proposed to be involved in an age-related functional decline of exocrine glands. However, the molecular mechanism of how oxidative stress affects the secretory function of exocrine glands is unclear. We developed a novel mev-1 conditional transgenic mouse model (Tet-mev-1 using a modified tetracycline system (Tet-On/Off system. This mouse model demonstrated decreased tear production with morphological changes including leukocytic infiltration and fibrosis. We found that the mev-1 gene encodes Cyt-1, which is the cytochrome b(560 large subunit of succinate-ubiquinone oxidoreductase in complex II of mitochondria (homologous to succinate dehydrogenase C subunit (SDHC in humans. The mev-1 gene induced excessive oxidative stress associated with ocular surface epithelial damage and a decrease in protein and aqueous secretory function. This new model provides evidence that mitochondrial oxidative damage in the lacrimal gland induces lacrimal dysfunction resulting in dry eye disease. Tear volume in Tet-mev-1 mice was lower than in wild type mice and histopathological analyses showed the hallmarks of lacrimal gland inflammation by intense mononuclear leukocytic infiltration and fibrosis in the lacrimal gland of Tet-mev-1 mice. These findings strongly suggest that oxidative stress can be a causative factor for the development of dry eye disease.

QTAIM and Stress Tensor Characterization of Intramolecular Interactions Along Dynamics Trajectories of a Light-Driven Rotary Molecular Motor.

Science.gov (United States)

Wang, Lingling; Huan, Guo; Momen, Roya; Azizi, Alireza; Xu, Tianlv; Kirk, Steven R; Filatov, Michael; Jenkins, Samantha

2017-06-29

A quantum theory of atoms in molecules (QTAIM) and stress tensor analysis was applied to analyze intramolecular interactions influencing the photoisomerization dynamics of a light-driven rotary molecular motor. For selected nonadiabatic molecular dynamics trajectories characterized by markedly different S 1 state lifetimes, the electron densities were obtained using the ensemble density functional theory method. The analysis revealed that torsional motion of the molecular motor blades from the Franck-Condon point to the S 1 energy minimum and the S 1 /S 0 conical intersection is controlled by two factors: greater numbers of intramolecular bonds before the hop-time and unusually strongly coupled bonds between the atoms of the rotor and the stator blades. This results in the effective stalling of the progress along the torsional path for an extended period of time. This finding suggests a possibility of chemical tuning of the speed of photoisomerization of molecular motors and related molecular switches by reshaping their molecular backbones to decrease or increase the degree of coupling and numbers of intramolecular bond critical points as revealed by the QTAIM/stress tensor analysis of the electron density. Additionally, the stress tensor scalar and vector analysis was found to provide new methods to follow the trajectories, and from this, new insight was gained into the behavior of the S 1 state in the vicinity of the conical intersection.

Molecular calculations with B functions

International Nuclear Information System (INIS)

Steinborn, E.O.; Homeier, H.H.H.; Ema, I.; Lopez, R.; Ramirez, G.

2000-01-01

A program for molecular calculations with B functions is reported and its performance is analyzed. All the one- and two-center integrals and the three-center nuclear attraction integrals are computed by direct procedures, using previously developed algorithms. The three- and four-center electron repulsion integrals are computed by means of Gaussian expansions of the B functions. A new procedure for obtaining these expansions is also reported. Some results on full molecular calculations are included to show the capabilities of the program and the quality of the B functions to represent the electronic functions in molecules

Molecular characteristics of stress overshoot for polymer melts under start-up shear flow.

Science.gov (United States)

Jeong, Sohdam; Kim, Jun Mo; Baig, Chunggi

2017-12-21

Stress overshoot is one of the most important nonlinear rheological phenomena exhibited by polymeric liquids undergoing start-up shear at sufficient flow strengths. Despite considerable previous research, the fundamental molecular characteristics underlying stress overshoot remain unknown. Here, we analyze the intrinsic molecular mechanisms behind the overshoot phenomenon using atomistic nonequilibrium molecular dynamics simulations of entangled linear polyethylene melts under shear flow. Through a detailed analysis of the transient rotational chain dynamics, we identify an intermolecular collision angular regime in the vicinity of the chain orientation angle θ ≈ 20° with respect to the flow direction. The shear stress overshoot occurs via strong intermolecular collisions between chains in the collision regime at θ = 15°-25°, corresponding to a peak strain of 2-4, which is an experimentally well-known value. The normal stress overshoot appears at approximately θ = 10°, at a corresponding peak strain roughly equivalent to twice that for the shear stress. We provide plausible answers to several basic questions regarding the stress overshoot, which may further help understand other nonlinear phenomena of polymeric systems.

Inhomogeneous Relaxation of a Molecular Layer on an Insulator due to Compressive Stress

Science.gov (United States)

Bocquet, F.; Nony, L.; Mannsfeld, S. C. B.; Oison, V.; Pawlak, R.; Porte, L.; Loppacher, Ch.

2012-05-01

We discuss the inhomogeneous stress relaxation of a monolayer of hexahydroxytriphenylene (HHTP) which adopts the rare line-on-line (LOL) coincidence on KCl(001) and forms moiré patterns. The fact that the hexagonal HHTP layer is uniaxially compressed along the LOL makes this system an ideal candidate to discuss the influence of inhomogeneous stress relaxation. Our work is a combination of noncontact atomic force microscopy experiments, density functional theory and potential energy calculations, and a thorough interpretation by means of the Frenkel-Kontorova model. We show that the assumption of a homogeneous molecular layer is not valid for this organic-inorganic heteroepitaxial system since the best calculated energy configuration correlates with the experimental data only if inhomogeneous relaxations of the layer are taken into account.

Dissecting molecular stress networks: identifying nodes of divergence between life-history phenotypes.

Science.gov (United States)

Schwartz, Tonia S; Bronikowski, Anne M

2013-02-01

The complex molecular network that underlies physiological stress response is comprised of nodes (proteins, metabolites, mRNAs, etc.) whose connections span cells, tissues and organs. Variable nodes are points in the network upon which natural selection may act. Thus, identifying variable nodes will reveal how this molecular stress network may evolve among populations in different habitats and how it might impact life-history evolution. Here, we use physiological and genetic assays to test whether laboratory-born juveniles from natural populations of garter snakes (Thamnophis elegans), which have diverged in their life-history phenotypes, vary concomitantly at candidate nodes of the stress response network, (i) under unstressed conditions and (ii) in response to an induced stress. We found that two common measures of stress (plasma corticosterone and liver gene expression of heat shock proteins) increased under stress in both life-history phenotypes. In contrast, the phenotypes diverged at four nodes both under unstressed conditions and in response to stress: circulating levels of reactive oxygen species (superoxide, H(2)O(2)); liver gene expression of GPX1 and erythrocyte DNA damage. Additionally, allele frequencies for SOD2 diverge from neutral markers, suggesting diversifying selection on SOD2 alleles. This study supports the hypothesis that these life-history phenotypes have diverged at the molecular level in how they respond to stress, particularly in nodes regulating oxidative stress. Furthermore, the differences between the life-history phenotypes were more pronounced in females. We discuss the responses to stress in the context of the associated life-history phenotype and the evolutionary pressures thought to be responsible for divergence between the phenotypes. © 2012 Blackwell Publishing Ltd.

Recent Molecular Advances on Downstream Plant Responses to Abiotic Stress

Directory of Open Access Journals (Sweden)

Cláudia Regina Batista de Souza

2012-07-01

Full Text Available Abiotic stresses such as extremes of temperature and pH, high salinity and drought, comprise some of the major factors causing extensive losses to crop production worldwide. Understanding how plants respond and adapt at cellular and molecular levels to continuous environmental changes is a pre-requisite for the generation of resistant or tolerant plants to abiotic stresses. In this review we aimed to present the recent advances on mechanisms of downstream plant responses to abiotic stresses and the use of stress-related genes in the development of genetically engineered crops.

Fetal Programming of Body Composition, Obesity, and Metabolic Function: The Role of Intrauterine Stress and Stress Biology

Directory of Open Access Journals (Sweden)

Sonja Entringer

2012-01-01

Full Text Available Epidemiological, clinical, physiological, cellular, and molecular evidence suggests that the origins of obesity and metabolic dysfunction can be traced back to intrauterine life and supports an important role for maternal nutrition prior to and during gestation in fetal programming. The elucidation of underlying mechanisms is an area of interest and intense investigation. In this perspectives paper we propose that in addition to maternal nutrition-related processes it may be important to concurrently consider the potential role of intrauterine stress and stress biology. We frame our arguments in the larger context of an evolutionary-developmental perspective that supports roles for both nutrition and stress as key environmental conditions driving natural selection and developmental plasticity. We suggest that intrauterine stress exposure may interact with the nutritional milieu, and that stress biology may represent an underlying mechanism mediating the effects of diverse intrauterine perturbations, including but not limited to maternal nutritional insults (undernutrition and overnutrition, on brain and peripheral targets of programming of body composition, energy balance homeostasis, and metabolic function. We discuss putative maternal-placental-fetal endocrine and immune/inflammatory candidate mechanisms that may underlie the long-term effects of intrauterine stress. We conclude with a commentary of the implications for future research and clinical practice.

Molecular-Scale Electronics: From Concept to Function.

Science.gov (United States)

Xiang, Dong; Wang, Xiaolong; Jia, Chuancheng; Lee, Takhee; Guo, Xuefeng

2016-04-13

Creating functional electrical circuits using individual or ensemble molecules, often termed as "molecular-scale electronics", not only meets the increasing technical demands of the miniaturization of traditional Si-based electronic devices, but also provides an ideal window of exploring the intrinsic properties of materials at the molecular level. This Review covers the major advances with the most general applicability and emphasizes new insights into the development of efficient platform methodologies for building reliable molecular electronic devices with desired functionalities through the combination of programmed bottom-up self-assembly and sophisticated top-down device fabrication. First, we summarize a number of different approaches of forming molecular-scale junctions and discuss various experimental techniques for examining these nanoscale circuits in details. We then give a full introduction of characterization techniques and theoretical simulations for molecular electronics. Third, we highlight the major contributions and new concepts of integrating molecular functionalities into electrical circuits. Finally, we provide a critical discussion of limitations and main challenges that still exist for the development of molecular electronics. These analyses should be valuable for deeply understanding charge transport through molecular junctions, the device fabrication process, and the roadmap for future practical molecular electronics.

Stress field models from Maxwell stress functions: southern California

Science.gov (United States)

Bird, Peter

2017-08-01

The lithospheric stress field is formally divided into three components: a standard pressure which is a function of elevation (only), a topographic stress anomaly (3-D tensor field) and a tectonic stress anomaly (3-D tensor field). The boundary between topographic and tectonic stress anomalies is somewhat arbitrary, and here is based on the modeling tools available. The topographic stress anomaly is computed by numerical convolution of density anomalies with three tensor Green's functions provided by Boussinesq, Cerruti and Mindlin. By assuming either a seismically estimated or isostatic Moho depth, and by using Poisson ratio of either 0.25 or 0.5, I obtain four alternative topographic stress models. The tectonic stress field, which satisfies the homogeneous quasi-static momentum equation, is obtained from particular second derivatives of Maxwell vector potential fields which are weighted sums of basis functions representing constant tectonic stress components, linearly varying tectonic stress components and tectonic stress components that vary harmonically in one, two and three dimensions. Boundary conditions include zero traction due to tectonic stress anomaly at sea level, and zero traction due to the total stress anomaly on model boundaries at depths within the asthenosphere. The total stress anomaly is fit by least squares to both World Stress Map data and to a previous faulted-lithosphere, realistic-rheology dynamic model of the region computed with finite-element program Shells. No conflict is seen between the two target data sets, and the best-fitting model (using an isostatic Moho and Poisson ratio 0.5) gives minimum directional misfits relative to both targets. Constraints of computer memory, execution time and ill-conditioning of the linear system (which requires damping) limit harmonically varying tectonic stress to no more than six cycles along each axis of the model. The primary limitation on close fitting is that the Shells model predicts very sharp

Architectonics: Design of Molecular Architecture for Functional Applications.

Science.gov (United States)

Avinash, M B; Govindaraju, Thimmaiah

2018-02-20

The term architectonics has its roots in the architectural and philosophical (as early as 1600s) literature that refers to "the theory of structure" and "the structure of theory", respectively. The concept of architectonics has been adapted to advance the field of molecular self-assembly and termed as molecular architectonics. In essence, the methodology of organizing molecular units in the required and controlled configurations to develop advanced functional systems for materials and biological applications comprises the field of molecular architectonics. This concept of designing noncovalent systems enables to focus on different functional aspects of designer molecules for biological and nonbiological applications and also strengthens our efforts toward the mastery over the art of controlled molecular self-assemblies. Programming complex molecular interactions and assemblies for specific functions has been one of the most challenging tasks in the modern era. Meticulously ordered molecular assemblies can impart remarkable developments in several areas spanning energy, health, and environment. For example, the well-defined nano-, micro-, and macroarchitectures of functional molecules with specific molecular ordering possess potential applications in flexible electronics, photovoltaics, photonic crystals, microreactors, sensors, drug delivery, biomedicine, and superhydrophobic coatings, among others. The functional molecular architectures having unparalleled properties are widely evident in various designs of Nature. By drawing inspirations from Nature, intended molecular architectures can be designed and developed to harvest various functions, as there is an inexhaustible resource and scope. In this Account, we present exquisite designer molecules developed by our group and others with an objective to master the art of molecular recognition and self-assembly for functional applications. We demonstrate the tailor-ability of molecular self-assemblies by employing

Probabilistic molecular dynamics evaluation of the stress-strain behavior of polyethylene

International Nuclear Information System (INIS)

Stowe, J.Q.; Predecki, P.K.; Laz, P.J.; Burks, B.M.; Kumosa, M.

2009-01-01

The primary goal of this study was to utilize molecular dynamics to predict the mechanical behavior of polyethylene. In particular, stress-strain relationships, the Young's modulus and Poisson ratio were predicted for low-density polyethylene at several molecular weights and polymer configurations with the number of united CH 2 atoms ranging between 500 and 5000. Probabilistic Monte Carlo methods were also used to identify the extent of uncertainty in mechanical property predictions. In general, asymptotic behavior was observed for stress and the Young's modulus as the molecular weight of the models increased. At the same time, significant variability, of the order of 1000% of the mean, in the stress-strain relationships and the Young's modulus predictions was observed, especially for low molecular weight models. The variability in the Young's modulus predictions ranged from 17.9 to 3.2 GPa for the models ranging from 100 to 5000 CH 2 atom models. However, it was also found that the mean value of the Young's modulus approached a physically possible value of 194 MPa for the 5000 atom model. Poisson ratio predictions also resulted in significant variability, from 200% to 425% of the mean, and ranged from 0.75 to 1.30. The mean value of the Poisson ratios calculated in this study ranged from 0.32 to 0.44 for the 100 to 5000 atom models, respectively.

Measurement of residual stresses using fracture mechanics weight functions

International Nuclear Information System (INIS)

Fan, Y.

2000-01-01

A residual stress measurement method has been developed to quantify through-the-thickness residual stresses. Accurate measurement of residual stresses is crucial for many engineering structures. Fabrication processes such as welding and machining generate residual stresses that are difficult to predict. Residual stresses affect the integrity of structures through promoting failures due to brittle fracture, fatigue, stress corrosion cracking, and wear. In this work, the weight function theory of fracture mechanics is used to measure residual stresses. The weight function theory is an important development in computational fracture mechanics. Stress intensity factors for arbitrary stress distribution on the crack faces can be accurately and efficiently computed for predicting crack growth. This paper demonstrates that the weight functions are equally useful in measuring residual stresses. In this method, an artificial crack is created by a thin cut in a structure containing residual stresses. The cut relieves the residual stresses normal to the crack-face and allows the relieved residual stresses to deform the structure. Strain gages placed adjacent to the cut measure the relieved strains corresponding to incrementally increasing depths of the cut. The weight functions of the cracked body relate the measured strains to the residual stresses normal to the cut within the structure. The procedure details, such as numerical integration of the singular functions in applying the weight function method, will be discussed

Measurement of residual stresses using fracture mechanics weight functions

International Nuclear Information System (INIS)

Fan, Y.

2001-01-01

A residual stress measurement method has been developed to quantify through-the-thickness residual stresses. Accurate measurement of residual stresses is crucial for many engineering structures. Fabrication processes such as welding and machining generate residual stresses that are difficult to predict. Residual stresses affect the integrity of structures through promoting failures due to brittle fracture, fatigue, stress corrosion cracking, and wear. In this work, the weight function theory of fracture mechanics is used to measure residual stresses. The weight function theory is an important development in computational fracture mechanics. Stress intensity factors for arbitrary stress distribution on the crack faces can be accurately and efficiently computed for predicting crack growth. This paper demonstrates that the weight functions are equally useful in measuring residual stresses. In this method, an artificial crack is created by a thin cut in a structure containing residual stresses. The cut relieves the residual stresses normal to the crack-face and allows the relieved residual stresses to deform the structure. Strain gages placed adjacent to the cut measure the relieved strains corresponding to incrementally increasing depths of the cut. The weight functions of the cracked body relate the measured strains to the residual stresses normal to the cut within the structure. The procedure details, such as numerical integration of the singular functions in applying the weight function method, will be discussed. (author)

Racism-Related Stress, General Life Stress, and Psychological Functioning among Black American Women

Science.gov (United States)

Pieterse, Alex L.; Carter, Robert T.; Ray, Kilynda V.

2013-01-01

The relationship between general life stress, perceived racism, and psychological functioning was explored in a sample of 118 Black American women. Findings indicate that racism-related stress was not a significant predictor of psychological functioning when controlling for general life stress. Perceived racism was positively associated with…

Evidence-based efficacy of adaptogens in fatigue, and molecular mechanisms related to their stress-protective activity.

Science.gov (United States)

Panossian, Alexander; Wikman, Georg

2009-09-01

The aim of this review article is to assess the level of scientific evidence presented by clinical trials of adaptogens in fatigue, and to provide a rationale at the molecular level for verified effects. Strong scientific evidence is available for Rhodiola rosea SHR-5 extract, which improved attention, cognitive function and mental performance in fatigue and in chronic fatigue syndrome. Good scientific evidence has been documented in trails in which Schisandra chinensis and Eleutherococcus senticosus increased endurance and mental performance in patients with mild fatigue and weakness. Based on their efficacy in clinical studies, adaptogens can be defined as a pharmacological group of herbal preparations that increase tolerance to mental exhaustion and enhance attention and mental endurance in situations of decreased performance. The beneficial stress-protective effect of adaptogens is related to regulation of homeostasis via several mechanisms of action associated with the hypothalamic-pituitary-adrenal axis and the control of key mediators of stress response such as molecular chaperons (e.g. Hsp70), stress-activated c-Jun N-terminal protein kinase (JNK1), Forkhead Box O transcription factor DAF-16, cortisol and nitric oxide (NO). The key point of action of phytoadaptogens appears to be their up-regulating and stress-mimetic effects on the "stress-sensor" protein Hsp70, which plays an important role in cell survival and apoptosis. Hsp70 inhibits the expression of NO synthase II gene and interacts with glucocorticoid receptors directly and via the JNK pathway, thus affecting the levels of circulating cortisol and NO. Prevention of stress-induced increase in NO, and the associated decrease in ATP production, results in increased performance and endurance. Adaptogen-induced up-regulation of Hsp70 triggers stress-induced JNK-1 and DAF-16-mediated pathways regulating the resistance to stress and resulting in enhanced mental and physical performance and, possibly

Perceived stress and cognitive function in older adults: which aspect of perceived stress is important?

Science.gov (United States)

Korten, Nicole C M; Comijs, Hannie C; Penninx, Brenda W J H; Deeg, Dorly J H

2017-04-01

Few studies examined the association between perceived stress and cognitive function in older adults. This study will examine which aspects of perceived stress especially impact cognitive function. Cross-sectional data of 1099 older adults between 64 and 100 years from the Longitudinal Aging Study Amsterdam were used. Perceived stress and its subscales perceived helplessness and perceived self-efficacy were measured with the Perceived Stress Scale. Cognitive function was assessed regarding memory, processing speed and executive function. Univariate and multivariate linear regression analyses were performed between the stress measures and the domains of cognitive function. Perceived stress was associated with worse processing speed, direct and delayed recall, semantic fluency and digit span backwards (range β = -0.10; -0.11; p cognitive function, also after adjustment for depressive symptoms or sense of mastery (range β = 0.10; 0.18; p cognitive functions. Perceived self-efficacy might be an important factor in reducing stress and the prevention of cognitive decline. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Molecular evolution and the role of oxidative stress in the expansion and functional diversification of cytosolic glutathione transferases

Directory of Open Access Journals (Sweden)

Vasconcelos Vítor

2010-09-01

Full Text Available Abstract Background Cytosolic glutathione transferases (cGST are a large group of ubiquitous enzymes involved in detoxification and are well known for their undesired side effects during chemotherapy. In this work we have performed thorough phylogenetic analyses to understand the various aspects of the evolution and functional diversification of cGSTs. Furthermore, we assessed plausible correlations between gene duplication and substrate specificity of gene paralogs in humans and selected species, notably in mammalian enzymes and their natural substrates. Results We present a molecular phylogeny of cytosolic GSTs that shows that several classes of cGSTs are more ubiquitous and thus have an older ancestry than previously thought. Furthermore, we found that positive selection is implicated in the diversification of cGSTs. The number of duplicate genes per class is generally higher for groups of enzymes that metabolize products of oxidative damage. Conclusions 1 Protection against oxidative stress seems to be the major driver of positive selection in mammalian cGSTs, explaining the overall expansion pattern of this subfamily; 2 Given the functional redundancy of GSTs that metabolize xenobiotic chemicals, we would expect the loss of gene duplicates, but by contrast we observed a gene expansion of this family, which likely has been favored by: i the diversification of endogenous substrates; ii differential tissue expression; and iii increased specificity for a particular molecule; 3 The increased availability of sequence data from diversified taxa is likely to continue to improve our understanding of the early origin of the different cGST classes.

Molecular mechanism of catalase activity change under sodium dodecyl sulfate-induced oxidative stress in the mouse primary hepatocytes.

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Wang, Jing; Wang, Jiaxi; Xu, Chi; Liu, Rutao; Chen, Yadong

2016-04-15

Sodium dodecyl sulfate (SDS) contributes to adverse effects of organisms probably because of its ability to induce oxidative stress via changing the activity of antioxidant enzyme catalase (CAT). But the underlying molecular mechanisms still remain unclear. This study characterized the harmful effects of SDS-induced oxidative stress on the mouse primary hepatocytes as well as the structure and function of CAT molecule and investigated the underlying molecular mechanism. After 12h SDS (0.1μM to 0.2mM) exposure, no significant change was observed in CAT activity of the hepatocytes. After 0.5 and 0.8mM SDS exposure, the state of oxidative stress stimulated CAT production in the hepatocytes. The inhibition of CAT activity induced by directly interacting with SDS was unable to catch the synthesis of CAT and therefore resulted in the increased activity and elevated ROS level. Further molecular experiments showed that SDS prefers to bind to the interface with no direct effect on the active site and the structure of heme groups of CAT molecule. When the sites in the interface is saturated, SDS interacts with VAL 73, HIS 74, ASN 147 and PHE 152, the key residues of the enzyme activity, and leads to the decrease of CAT activity. Copyright © 2015 Elsevier B.V. All rights reserved.

Antidepressant-like activity of venlafaxine and clonidine in mice exposed to single prolonged stress - A model of post-traumatic stress disorder. Pharmacodynamic and molecular docking studies.

Science.gov (United States)

Malikowska, Natalia; Fijałkowski, Łukasz; Nowaczyk, Alicja; Popik, Piotr; Sałat, Kinga

2017-10-15

Post-traumatic stress disorder (PTSD) is a growing issue worldwide characterized by stress and anxiety in response to re-experiencing traumatic events which strongly impair patient's quality of life and social functions. Available antidepressant and anxiolytic drugs are not efficacious in the majority of treated individuals. This necessitates a significant medical demand to develop novel therapeutic strategies for PTSD. Animal model of PTSD was induced using a mouse single prolonged stress protocol (mSPS). To assess the activity of venlafaxine and clonidine, the forced swim test (FST) was used repeatedly 24h, 3days, 8days, 15days and 25days after mSPS. To get insight into a possible mechanism of anti-PTSD action, molecular docking procedure was utilized for the most active drug. This in silico part comprised molecular docking of enantiomers of venlafaxine to human transporters for serotonin (hSERT), norepinephrine (hNET) and dopamine (hDAT). In mSPS-subjected mice FST revealed the effectiveness of venlafaxine, however in non SPS-subjected mice both venlafaxine and clonidine were active. Molecular docking studies indicated that the affinity of venlafaxine to monoamine transporters is growing in the following rank order: hDATPTSD. Its mechanism of action, i.e., SERT, NET and DAT inhibition indicates potential drug targets for PTSD treatment. We expect that these results will contribute to a broader application of VLX in PTSD patients. Copyright © 2017 Elsevier B.V. All rights reserved.

Molecular Adaptations to Social Defeat Stress and Induced Depression in Mice.

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Bondar, Natalya; Bryzgalov, Leonid; Ershov, Nikita; Gusev, Fedor; Reshetnikov, Vasiliy; Avgustinovich, Damira; Tenditnik, Mikhail; Rogaev, Evgeny; Merkulova, Tatiana

2018-04-01

Chronic stress is a risk factor for major depression. Social defeat stress is a well-validated murine model of depression. However, little is known about the gene activity dynamics during the development of a depression-like state. We analyzed the effects of social defeat stress of varying duration (10 and 30 days) on the behavioral patterns and prefrontal-cortex transcriptome of C57BL/6 mice. The 10-day exposure to social defeat stress resulted in a high level of social avoidance with no signs of depression-associated behavior. Most animals exposed to 30 days of social defeat stress demonstrated clear hallmarks of depression, including a higher level of social avoidance, increased immobility in the forced swimming test, and anhedonic behavior. The monitoring of transcriptome changes revealed widespread alterations in gene expression on the 10th day. Surprisingly, the expression of only a few genes were affected by the 30th day of stress, apparently due to a reversal of the majority of the early stress-induced changes to the original basal state. Moreover, we have found that glucocorticoid-sensitive genes are clearly stimulated targets on the 10th day of stress, but these genes stop responding to the elevated corticosterone level by the 30th day of stress. The majority of genes altered by the 30-day stress were downregulated, with the most relevant ones participating in chromatin modifications and neuroplasticity (e.g., guanine nucleotide exchange factors of the Rho-family of GTPases). Very different molecular responses occur during short-term and long-term social stress in mice. The early-stress response is associated with social avoidance and with upregulation and downregulation of many genes, including those related to signal transduction and cell adhesion pathways. Downregulation of a few genes, in particular, genes for histone-modifying methyltransferases, is a signature response to prolonged stress that induces symptoms of depression. Altogether, our data

Endoplasmic Reticulum Stress in Reproductive Function

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Kang-sheng LIU

2016-09-01

Full Text Available Normal folding requires that unique conditions should be maintained within the endoplasmic reticulum (ER lumen, and nascent proteins are initially bound to Ca2+dependent chaperone proteins. Proteins synthesized in the ER are properly folded with the assistance of ER chaperones. misfolded proteins are disposed by ER-associated protein degradation. Accumulation of misfolded proteins in the ER triggers an adaptive ER stress response, which leads to activation of the unfolded protein response (UPR, a conserved pathway that transmits signals to restore homeostasis or eliminate the irreparably damaged cells. It has been shown that ER stress involves in pathophysiological development of many diseases, including neurological diseases. However, nowadays, a few studies have begun to focus on the possibility that the accumulation of misfolded proteins can also contribute to reproductive diseases. In this article, we mainly introduced the involvement of ER stress response in preimplantation embryos, placental development, intrauterine growth restriction (IUGR and testicular germ cells so as to provide important insights for the molecular mechanisms of ER stress-induced apoptosis in reproductive diseases.

Sirtuins: Molecular Traffic Lights in the Crossroad of Oxidative Stress, Chromatin Remodeling, and Transcription

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Ramkumar Rajendran

2011-01-01

Full Text Available Transcription is regulated by acetylation/deacetylation reactions of histone and nonhistone proteins mediated by enzymes called KATs and HDACs, respectively. As a major mechanism of transcriptional regulation, protein acetylation is a key controller of physiological processes such as cell cycle, DNA damage response, metabolism, apoptosis, and autophagy. The deacetylase activity of class III histone deacetylases or sirtuins depends on the presence of NAD+ (nicotinamide adenine dinucleotide, and therefore, their function is closely linked to cellular energy consumption. This activity of sirtuins connects the modulation of chromatin dynamics and transcriptional regulation under oxidative stress to cellular lifespan, glucose homeostasis, inflammation, and multiple aging-related diseases including cancer. Here we provide an overview of the recent developments in relation to the diverse biological activities associated with sirtuin enzymes and stress responsive transcription factors, DNA damage, and oxidative stress and relate the involvement of sirtuins in the regulation of these processes to oncogenesis. Since the majority of the molecular mechanisms implicated in these pathways have been described for Sirt1, this sirtuin family member is more extensively presented in this paper.

Unraveling the Root Proteome Changes and Its Relationship to Molecular Mechanism Underlying Salt Stress Response in Radish (Raphanus sativus L.

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Xiaochuan Sun

2017-07-01

Full Text Available To understand the molecular mechanism underlying salt stress response in radish, iTRAQ-based proteomic analysis was conducted to investigate the differences in protein species abundance under different salt treatments. In total, 851, 706, and 685 differential abundance protein species (DAPS were identified between CK vs. Na100, CK vs. Na200, and Na100 vs. Na200, respectively. Functional annotation analysis revealed that salt stress elicited complex proteomic alterations in radish roots involved in carbohydrate and energy metabolism, protein metabolism, signal transduction, transcription regulation, stress and defense and transport. Additionally, the expression levels of nine genes encoding DAPS were further verified using RT-qPCR. The integrative analysis of transcriptomic and proteomic data in conjunction with miRNAs was further performed to strengthen the understanding of radish response to salinity. The genes responsible for signal transduction, ROS scavenging and transport activities as well as several key miRNAs including miR171, miR395, and miR398 played crucial roles in salt stress response in radish. Based on these findings, a schematic genetic regulatory network of salt stress response was proposed. This study provided valuable insights into the molecular mechanism underlying salt stress response in radish roots and would facilitate developing effective strategies toward genetically engineered salt-tolerant radish and other root vegetable crops.

Executive function in cancer patients with posttraumatic stress disorder.

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Yang, Juan; Guo, Juncheng; Jiang, Xiangling

2017-03-01

Background Cancer patients with posttraumatic stress disorder can lead to their noncompliant behaviors. However, less is known about the neurocognitive functioning of posttraumatic stress disorder in general cancer types or patient populations. The current study attempted to examine the prevalence of posttraumatic stress disorder and their relationships with executive function in individuals with cancer. Methods A total of 285 cancer patients with posttraumatic stress disorder and 150 healthy individuals were recruited for the present study. The Clinician Administered PTSD Scale, Tower of Hanoi, Wisconsin Card Sorting Test, and Wechsler Adult Intelligence Scale-Revised Chinese revision were administered to all participants. Results Significant differences in the score of Tower of Hanoi, Wisconsin Card Sorting Test, and Wechsler Adult Intelligence Scale-Revised Chinese revision were observed between the posttraumatic stress disorder group and the healthy control group ( p posttraumatic stress disorder symptoms and executive function. Conclusions These findings suggest that individuals with cancer-related posttraumatic stress disorder exhibit more severe impairment in executive function than healthy controls do.

DAE-BRNS life sciences symposium on molecular biology of stress response and its applications

International Nuclear Information System (INIS)

2005-01-01

The world of living organisms is full of challenges from their surroundings and these organisms learn to adapt themselves to the changes - some transient and some permanent - in these surroundings. The demands on adaptability to stress are very strong for extremophiles that live in harsh conditions such as cold or hot temperatures, salinity and hyperbaric habitats. The stress could be biotic (e.g. infection or parasitism) or abiotic (e.g. temperature, light, salinity, heavy metals etc.) Evolutionarily living organisms have developed different shapes, coloration, habits etc. to survive in their habitats. The molecular mechanisms of these biological adaptations have become clearer only in recent years from the studies on the biological responses of an organism to stresses during its life time. Such responses are characterized by activation of certain genes and synthesis of proteins and metabolites, which facilitate amelioration of the stress. The molecular biology (biochemistry and genetics) of stress response is being constantly unravelled thanks to the availability of highly sensitive and high throughput techniques and a plethora of extremophilic experimental systems such as archaebacteria, radio resistant bacteria and midges, plants surviving in cold etc. An interesting outcome of this voluminous research has been the knowledge that responses to a group of stresses share common mechanisms, at least in part. This reflects the biologically conservationist trend among otherwise diverse organisms and stresses. In this symposium several papers and posters in the area of molecular biology of stress are presented in addition to some very interesting and promising-to-be informative and stimulating plenary lectures and invited talks from highly reputed scientists. The papers relevant to INIS are indexed separately

Individual vs. combinatorial effect of elevated CO2 conditions and salinity stress on Arabidopsis thaliana liquid cultures: Comparing the early molecular response using time-series transcriptomic and metabolomic analyses

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Dutta Bhaskar

2010-12-01

Full Text Available Abstract Background In this study, we investigated the individual and combinatorial effect of elevated CO2 conditions and salinity stress on the dynamics of both the transcriptional and metabolic physiology of Arabidopsis thaliana liquid hydroponic cultures over the first 30 hours of continuous treatment. Both perturbations are of particular interest in plant and agro-biotechnological applications. Moreover, within the timeframe of this experiment, they are expected to affect plant growth to opposite directions. Thus, a major objective was to investigate whether this expected "divergence" was valid for the individual perturbations and to study how it is manifested under the combined stress at two molecular levels of cellular function, using high-throughput analyses. Results We observed that a high salinity has stronger effect than elevated CO2 at both the transcriptional and metabolic levels, b the transcriptional responses to the salinity and combined stresses exhibit strong similarity, implying a robust transcriptional machinery acting to the salinity stress independent of the co-occurrence of elevated CO2, c the combinatorial effect of the two perturbations on the metabolic physiology is milder than of the salinity stress alone. Metabolomic analysis suggested that the beneficial role of elevated CO2 on salt-stressed plants within the timeframe of this study should be attributed to the provided additional resources; these allow the plants to respond to high salinity without having to forfeit other major metabolic functions, and d 9 h-12 h and 24 h of treatment coincide with significant changes in the metabolic physiology under any of the investigated stresses. Significant differences between the acute and longer term responses were observed at both molecular levels. Conclusions This study contributes large-scale dynamic omic data from two levels of cellular function for a plant system under various stresses. It provides an additional example

Identifying Molecular Targets For PTSD Treatment Using Single Prolonged Stress

Science.gov (United States)

2014-10-01

Post - traumatic stress disorder ( PTSD ) is a chronic, debilitating psychiatric disorder that can...SPS animals. Post - traumatic stress disorder ( PTSD ) is associated with neurocognitive impairments that have been attributed to functional deficits...and resilience. 2. KEYWORDS Post - traumatic stress disorder , Single Prolonged Stress , Neurobiological Mechanisms 5 3. ACCOMPLISHMENTS

Early-life stress impacts the developing hippocampus and primes seizure occurrence: cellular, molecular, and epigenetic mechanisms

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Huang, Li-Tung

2014-01-01

Early-life stress includes prenatal, postnatal, and adolescence stress. Early-life stress can affect the development of the hypothalamic-pituitary-adrenal (HPA) axis, and cause cellular and molecular changes in the developing hippocampus that can result in neurobehavioral changes later in life. Epidemiological data implicate stress as a cause of seizures in both children and adults. Emerging evidence indicates that both prenatal and postnatal stress can prime the developing brain for seizures and an increase in epileptogenesis. This article reviews the cellular and molecular changes encountered during prenatal and postnatal stress, and assesses the possible link between these changes and increases in seizure occurrence and epileptogenesis in the developing hippocampus. In addititon, the priming effect of prenatal and postnatal stress for seizures and epileptogenesis is discussed. Finally, the roles of epigenetic modifications in hippocampus and HPA axis programming, early-life stress, and epilepsy are discussed. PMID:24574961

The effects of stress hormones on immune function may be vital for the adaptive reconfiguration of the immune system during fight-or-flight behavior.

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Adamo, Shelley A

2014-09-01

Intense, short-term stress (i.e., robust activation of the fight-or-flight response) typically produces a transient decline in resistance to disease in animals across phyla. Chemical mediators of the stress response (e.g., stress hormones) help induce this decline, suggesting that this transient immunosuppression is an evolved response. However, determining the function of stress hormones on immune function is difficult because of their complexity. Nevertheless, evidence suggests that stress hormones help maintain maximal resistance to disease during the physiological changes needed to optimize the body for intense physical activity. Work on insects demonstrates that stress hormones both shunt resources away from the immune system during fight-or-flight responses as well as reconfigure the immune system. Reconfiguring the immune system minimizes the impact of the loss of these resources and reduces the increased costs of some immune functions due to the physiological changes demanded by the fight-or-flight response. For example, during the stress response of the cricket Gryllus texensis, some molecular resources are shunted away from the immune system and toward lipid transport, resulting in a reduction in resistance to disease. However, insects' immune cells (hemocytes) have receptors for octopamine (the insect stress neurohormone). Octopamine increases many hemocyte functions, such as phagocytosis, and these changes would tend to mitigate the decline in immunity due to the loss of molecular resources. Moreover, because the stress response generates oxidative stress, some immune responses are probably more costly when activated during a stress response (e.g., those that produce reactive molecules). Some of these immune responses are depressed during stress in crickets, while others, whose costs are probably not increased during a stress response, are enhanced. Some effects of stress hormones on immune systems may be better understood as examples of reconfiguration

Discontinuous approximate molecular electronic wave-functions

International Nuclear Information System (INIS)

Stuebing, E.W.; Weare, J.H.; Parr, R.G.

1977-01-01

Following Kohn, Schlosser and Marcus and Weare and Parr an energy functional is defined for a molecular problem which is stationary in the neighborhood of the exact solution and permits the use of trial functions that are discontinuous. The functional differs from the functional of the standard Rayleigh--Ritz method in the replacement of the usual kinetic energy operators circumflex T(μ) with operators circumflex T'(μ) = circumflex T(μ) + circumflex I(μ) generates contributions from surfaces of nonsmooth behavior. If one uses the nabla PSI . nabla PSI way of writing the usual kinetic energy contributions, one must add surface integrals of the product of the average of nabla PSI and the change of PSI across surfaces of discontinuity. Various calculations are carried out for the hydrogen molecule-ion and the hydrogen molecule. It is shown that ab initio calculations on molecules can be carried out quite generally with a basis of atomic orbitals exactly obeying the zero-differential overlap (ZDO) condition, and a firm basis is thereby provided for theories of molecular electronic structure invoking the ZDO aoproximation. It is demonstrated that a valence bond theory employing orbitals exactly obeying ZDO can provide an adequate account of chemical bonding, and several suggestions are made regarding molecular orbital methods

Molecular Responses of Groundnut (Arachis hypogea L. to Zinc Stress

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A. John De Britto

2013-08-01

Full Text Available Heavy metals are important environmental pollutants and their toxicity is a problem of increasing significance for ecological, evolutionary and environmental reasons. The interference of germination related proteins by heavy metals has not been well documented at the proteomic and genomic level. In the current study, molecular responses of germinating groundnut seeds were investigated under Zinc stress. The SDS-PAGE showed the preliminary changes in the polypeptides patterns under Zinc stress. Restriction digestion banding pattern of EcoRI and Hind III enzymes showed distinct banding pattern in the treated plants.

Hal2p functions in Bdf1p-involved salt stress response in Saccharomyces cerevisiae.

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Lei Chen

Full Text Available The Saccharomyces cerevisiae Bdf1p associates with the basal transcription complexes TFIID and acts as a transcriptional regulator. Lack of Bdf1p is salt sensitive and displays abnormal mitochondrial function. The nucleotidase Hal2p detoxifies the toxic compound 3' -phosphoadenosine-5'-phosphate (pAp, which blocks the biosynthesis of methionine. Hal2p is also a target of high concentration of Na(+. Here, we reported that HAL2 overexpression recovered the salt stress sensitivity of bdf1Δ. Further evidence demonstrated that HAL2 expression was regulated indirectly by Bdf1p. The salt stress response mechanisms mediated by Bdf1p and Hal2p were different. Unlike hal2Δ, high Na(+ or Li(+ stress did not cause pAp accumulation in bdf1Δ and methionine supplementation did not recover its salt sensitivity. HAL2 overexpression in bdf1Δ reduced ROS level and improved mitochondrial function, but not respiration. Further analyses suggested that autophagy was apparently defective in bdf1Δ, and autophagy stimulated by Hal2p may play an important role in recovering mitochondrial functions and Na(+ sensitivity of bdf1Δ. Our findings shed new light towards our understanding about the molecular mechanism of Bdf1p-involved salt stress response in budding yeast.

Functional characterization of novel genotypes and cellular oxidative stress studies in propionic acidemia.

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Gallego-Villar, Lorena; Pérez-Cerdá, Celia; Pérez, Belén; Abia, David; Ugarte, Magdalena; Richard, Eva; Desviat, Lourdes R

2013-09-01

Propionic acidemia (PA), caused by a deficiency of the mitochondrial biotin dependent enzyme propionyl-CoA carboxylase (PCC) is one of the most frequent organic acidurias in humans. PA is caused by mutations in either the PCCA or PCCB genes encoding the α- and β-subunits of the PCC enzyme which are assembled as an α6β6 dodecamer. In this study we have investigated the molecular basis of the defect in ten fibroblast samples from PA patients. Using homology modeling with the recently solved crystal structure of the PCC holoenzyme and a eukaryotic expression system we have analyzed the structural and functional effect of novel point mutations, also revealing a novel splice defect by minigene analysis. In addition, we have investigated the contribution of oxidative stress to cellular damage measuring reactive oxygen species (ROS) levels and apoptosis parameters in patient fibroblasts, as recent studies point to a secondary mitochondrial dysfunction as pathophysiological mechanism in this disorder. The results show an increase in intracellular ROS content compared to controls, correlating with the activation of the JNK and p38 signaling pathways. Highest ROS levels were present in cells harboring functionally null mutations, including one severe missense mutation. This work provides molecular insight into the pathogenicity of PA variants and indicates that oxidative stress may be a major contributing factor to the cellular damage, supporting the proposal of antioxidant strategies as novel supplementary therapy in this rare disease.

Better executive function under stress mitigates the effects of recent life stress exposure on health in young adults.

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Shields, Grant S; Moons, Wesley G; Slavich, George M

2017-01-01

Executive function is a neuropsychological construct that enables controlled cognitive processing, which has been hypothesized to enhance individuals' resilience to stress. However, little empirical work has directly examined how executive function under different conditions mitigates the negative effects of stress exposure on health. To address this issue, we recruited 110 healthy young adults and assessed their recent life stress exposure, executive function in either a stressful or non-stressful context, and current health complaints. Based on existing research, we hypothesized that individuals exhibiting better executive function following a laboratory-based stressor (but not a control task) would demonstrate weaker associations between recent stress exposure and health because they perceived recent life stressors as being less severe. Consistent with this hypothesis, better executive function during acute stress, but not in the absence of stress, was associated with an attenuated link between participants' recent life stress exposure and their current health complaints. Moreover, this attenuating effect was mediated by lesser perceptions of stressor severity. Based on these data, we conclude that better executive function under stress is associated with fewer health complaints and that these effects may occur by reducing individuals' perceptions of stressor severity. The data thus suggest the possibility of reducing stress-related health problems by enhancing executive function.

Molecular and genetic substrates linking stress and addiction.

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Briand, Lisa A; Blendy, Julie A

2010-02-16

Drug addiction is one of the top three health concerns in the United States in terms of economic and health care costs. Despite this, there are very few effective treatment options available. Therefore, understanding the causes and molecular mechanisms underlying the transition from casual drug use to compulsive drug addiction could aid in the development of treatment options. Studies in humans and animal models indicate that stress can lead to both vulnerability to develop addiction, and increased drug taking and relapse in addicted individuals. Exposure to stress or drugs of abuse results in long-term adaptations in the brain that are likely to involve persistent alterations in gene expression or activation of transcription factors, such as the cAMP Response Element Binding (CREB) protein. The signaling pathways controlled by CREB have been strongly implicated in drug addiction and stress. Many potential CREB target genes have been identified based on the presence of a CRE element in promoter DNA sequences. These include, but are not limited to CRF, BDNF, and dynorphin. These genes have been associated with initiation or reinstatement of drug reward and are altered in one direction or the other following stress. While many reviews have examined the interactions between stress and addiction, the goal of this review was to focus on specific molecules that play key roles in both stress and addiction and are therefore posed to mediate the interaction between the two. Focus on these molecules could provide us with new targets for pharmacological treatments for addiction. Copyright 2009 Elsevier B.V. All rights reserved.

Liquid ammonia: Molecular correlation functions from x-ray diffraction

International Nuclear Information System (INIS)

Narten, A.H.

1977-01-01

For nearly spherical molecules the x-ray scattering from liquids yields structure and correlation functions for molecular centers. The distribution of electron density in an ammonia molecular is very nearly spherical, and orientational correlation between molecules in the liquid is not ''seen'' by x rays. Structure and correlation functions for molecular centers (nitrogen atoms) are derived from x-ray data on liquid NH 3 at 4 degreeC and tabulated. They provide a sensitive test for future work on a molecular theory of liquid ammonia

Thymic function in the regulation of T cells, and molecular mechanisms underlying the modulation of cytokines and stress signaling (Review).

Science.gov (United States)

Yan, Fenggen; Mo, Xiumei; Liu, Junfeng; Ye, Siqi; Zeng, Xing; Chen, Dacan

2017-11-01

The thymus is critical in establishing and maintaining the appropriate microenvironment for promoting the development and selection of T cells. The function and structure of the thymus gland has been extensively studied, particularly as the thymus serves an important physiological role in the lymphatic system. Numerous studies have investigated the morphological features of thymic involution. Recently, research attention has increasingly been focused on thymic proteins as targets for drug intervention. Omics approaches have yielded novel insights into the thymus and possible drug targets. The present review addresses the signaling and transcriptional functions of the thymus, including the molecular mechanisms underlying the regulatory functions of T cells and their role in the immune system. In addition, the levels of cytokines secreted in the thymus have a significant effect on thymic functions, including thymocyte migration and development, thymic atrophy and thymic recovery. Furthermore, the regulation and molecular mechanisms of stress‑mediated thymic atrophy and involution were investigated, with particular emphasis on thymic function as a potential target for drug development and discovery using proteomics.

Abiotic stressors and stress responses

DEFF Research Database (Denmark)

Sulmon, Cecile; Van Baaren, Joan; Cabello-Hurtado, Francisco

2015-01-01

Abstract Organisms are regularly subjected to abiotic stressors related to increasing anthropogenic activities, including chemicals and climatic changes that induce major stresses. Based on various key taxa involved in ecosystem functioning (photosynthetic microorganisms, plants, invertebrates), we...... review how organisms respond and adapt to chemical- and temperature-induced stresses from molecular to population level. Using field-realistic studies, our integrative analysis aims to compare i) how molecular and physiological mechanisms related to protection, repair and energy allocation can impact...... life history traits of stressed organisms, and ii) to what extent trait responses influence individual and population responses. Common response mechanisms are evident at molecular and cellular scales but become rather difficult to define at higher levels due to evolutionary distance and environmental...

Microstructural stress relaxation mechanics in functionally different tendons.

Science.gov (United States)

Screen, H R C; Toorani, S; Shelton, J C

2013-01-01

Tendons experience widely varying loading conditions in vivo. They may be categorised by their function as either positional tendons, which are used for intricate movements and experience lower stress, or as energy storage tendons which act as highly stressed springs during locomotion. Structural and compositional differences between tendons are thought to enable an optimisation of their properties to suit their functional environment. However, little is known about structure-function relationships in tendon. This study adopts porcine flexor and extensor tendon fascicles as examples of high stress and low stress tendons, comparing their mechanical behaviour at the micro-level in order to understand their stress relaxation response. Stress-relaxation was shown to occur predominantly through sliding between collagen fibres. However, in the more highly stressed flexor tendon fascicles, more fibre reorganisation was evident when the tissue was exposed to low strains. By contrast, the low load extensor tendon fascicles appears to have less capacity for fibre reorganisation or shearing than the energy storage tendon, relying more heavily on fibril level relaxation. The extensor fascicles were also unable to sustain loads without rapid and complete stress relaxation. These findings highlight the need to optimise tendon repair solutions for specific tendons, and match tendon properties when using grafts in tendon repairs. Copyright © 2012 IPEM. Published by Elsevier Ltd. All rights reserved.

Revisiting the Role of Plant Transcription Factors in the Battle against Abiotic Stress.

Science.gov (United States)

Khan, Sardar-Ali; Li, Meng-Zhan; Wang, Suo-Min; Yin, Hong-Ju

2018-05-31

Owing to diverse abiotic stresses and global climate deterioration, the agricultural production worldwide is suffering serious losses. Breeding stress-resilient crops with higher quality and yield against multiple environmental stresses via application of transgenic technologies is currently the most promising approach. Deciphering molecular principles and mining stress-associate genes that govern plant responses against abiotic stresses is one of the prerequisites to develop stress-resistant crop varieties. As molecular switches in controlling stress-responsive genes expression, transcription factors (TFs) play crucial roles in regulating various abiotic stress responses. Hence, functional analysis of TFs and their interaction partners during abiotic stresses is crucial to perceive their role in diverse signaling cascades that many researchers have continued to undertake. Here, we review current developments in understanding TFs, with particular emphasis on their functions in orchestrating plant abiotic stress responses. Further, we discuss novel molecular mechanisms of their action under abiotic stress conditions. This will provide valuable information for understanding regulatory mechanisms to engineer stress-tolerant crops.

Molecular and Functional Neuroscience in Immunity.

Science.gov (United States)

Pavlov, Valentin A; Chavan, Sangeeta S; Tracey, Kevin J

2018-04-26

The nervous system regulates immunity and inflammation. The molecular detection of pathogen fragments, cytokines, and other immune molecules by sensory neurons generates immunoregulatory responses through efferent autonomic neuron signaling. The functional organization of this neural control is based on principles of reflex regulation. Reflexes involving the vagus nerve and other nerves have been therapeutically explored in models of inflammatory and autoimmune conditions, and recently in clinical settings. The brain integrates neuro-immune communication, and brain function is altered in diseases characterized by peripheral immune dysregulation and inflammation. Here we review the anatomical and molecular basis of the neural interface with immunity, focusing on peripheral neural control of immune functions and the role of the brain in the model of the immunological homunculus. Clinical advances stemming from this knowledge within the framework of bioelectronic medicine are also briefly outlined.

Molecular doping for control of gate bias stress in organic thin film transistors

Energy Technology Data Exchange (ETDEWEB)

Hein, Moritz P., E-mail: hein@iapp.de; Lüssem, Björn; Jankowski, Jens; Tietze, Max L.; Riede, Moritz K. [Institut für Angewandte Photophysik, Technische Universität Dresden, George-Bähr-Straße 1, 01069 Dresden (Germany); Zakhidov, Alexander A. [Fraunhofer COMEDD, Maria-Reiche-Str. 2, 01109 Dresden (Germany); Leo, Karl [Institut für Angewandte Photophysik, Technische Universität Dresden, George-Bähr-Straße 1, 01069 Dresden (Germany); Fraunhofer COMEDD, Maria-Reiche-Str. 2, 01109 Dresden (Germany)

2014-01-06

The key active devices of future organic electronic circuits are organic thin film transistors (OTFTs). Reliability of OTFTs remains one of the most challenging obstacles to be overcome for broad commercial applications. In particular, bias stress was identified as the key instability under operation for numerous OTFT devices and interfaces. Despite a multitude of experimental observations, a comprehensive mechanism describing this behavior is still missing. Furthermore, controlled methods to overcome these instabilities are so far lacking. Here, we present the approach to control and significantly alleviate the bias stress effect by using molecular doping at low concentrations. For pentacene and silicon oxide as gate oxide, we are able to reduce the time constant of degradation by three orders of magnitude. The effect of molecular doping on the bias stress behavior is explained in terms of the shift of Fermi Level and, thus, exponentially reduced proton generation at the pentacene/oxide interface.

Molecular doping for control of gate bias stress in organic thin film transistors

International Nuclear Information System (INIS)

Hein, Moritz P.; Lüssem, Björn; Jankowski, Jens; Tietze, Max L.; Riede, Moritz K.; Zakhidov, Alexander A.; Leo, Karl

2014-01-01

The key active devices of future organic electronic circuits are organic thin film transistors (OTFTs). Reliability of OTFTs remains one of the most challenging obstacles to be overcome for broad commercial applications. In particular, bias stress was identified as the key instability under operation for numerous OTFT devices and interfaces. Despite a multitude of experimental observations, a comprehensive mechanism describing this behavior is still missing. Furthermore, controlled methods to overcome these instabilities are so far lacking. Here, we present the approach to control and significantly alleviate the bias stress effect by using molecular doping at low concentrations. For pentacene and silicon oxide as gate oxide, we are able to reduce the time constant of degradation by three orders of magnitude. The effect of molecular doping on the bias stress behavior is explained in terms of the shift of Fermi Level and, thus, exponentially reduced proton generation at the pentacene/oxide interface

Transcriptome analysis of Crossostephium chinensis provides insight into the molecular basis of salinity stress responses.

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Haiyan Yang

Full Text Available Soil salinization is becoming a limitation to the utilization of ornamental plants worldwide. Crossostephium chinensis (Linnaeus Makino is often cultivated along the southeast coast of China for its desirable ornamental qualities and high salt tolerance. However, little is known about the genomic background of the salt tolerance mechanism in C. chinensis. In the present study, we used Illumina paired-end sequencing to systematically investigate leaf transcriptomes derived from C. chinensis seedlings grown under normal conditions and under salt stress. A total of 105,473,004 bp of reads were assembled into 163,046 unigenes, of which 65,839 (40.38% of the total and 54,342 (33.32% of the total were aligned in Swiss-Prot and Nr protein, respectively. A total of 11,331 (6.95% differentially expressed genes (DEGs were identified among three comparisons, including 2,239 in 'ST3 vs ST0', 5,880 in 'ST9 vs ST3' and 9,718 in 'ST9 vs ST0', and they were generally classified into 26 Gene Ontology terms and 58 Kyoto Encyclopedia of Genes and Genomes (KEGG pathway terms. Many genes encoding important transcription factors (e.g., WRKY, MYB, and AP2/EREBP and proteins involved in starch and sucrose metabolism, arginine and proline metabolism, plant hormone signal transduction, amino acid biosynthesis, plant-pathogen interactions and carbohydrate metabolism, among others, were substantially up-regulated under salt stress. These genes represent important candidates for studying the salt-response mechanism and molecular biology of C. chinensis and its relatives. Our findings provide a genomic sequence resource for functional genetic assignments in C. chinensis. These transcriptome datasets will help elucidate the molecular mechanisms responsible for salt-stress tolerance in C. chinensis and facilitate the breeding of new stress-tolerant cultivars for high-saline areas using this valuable genetic resource.

Functional Genomic Screening Reveals Core Modulators of Echinocandin Stress Responses in Candida albicans

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Tavia Caplan

2018-05-01

Full Text Available Summary: Candida albicans is a leading cause of death due to fungal infection. Treatment of systemic candidiasis often relies on echinocandins, which disrupt cell wall synthesis. Resistance is readily acquired via mutations in the drug target gene, FKS1. Both basal tolerance and resistance to echinocandins require cellular stress responses. We performed a systematic analysis of 3,030 C. albicans mutants to define circuitry governing cellular responses to echinocandins. We identified 16 genes for which deletion or transcriptional repression enhanced echinocandin susceptibility, including components of the Pkc1-MAPK signaling cascade. We discovered that the molecular chaperone Hsp90 is required for the stability of Pkc1 and Bck1, establishing key mechanisms through which Hsp90 mediates echinocandin resistance. We also discovered that perturbation of the CCT chaperonin complex causes enhanced echinocandin sensitivity, altered cell wall architecture, and aberrant septin localization. Thus, we provide insights into the mechanisms by which cellular chaperones enable crucial responses to echinocandin-induced stress. : Caplan et al. screen 3,030 Candida albicans mutants to define circuitry governing cellular responses to echinocandins, the first-line therapy for systemic candidiasis. They reveal that the molecular chaperone Hsp90 is required for stability of Pkc1 and Bck1 and that the CCT chaperonin complex is a key modulator of echinocandin susceptibility. Keywords: fungal pathogen, Candida albicans, echinocandins, Hsp90, Pkc1, CCT complex, client protein, stress response, functional genomic screen, drug resistance

Angle-dependent strong-field molecular ionization rates with tuned range-separated time-dependent density functional theory

Energy Technology Data Exchange (ETDEWEB)

Sissay, Adonay [Department of Chemistry, Louisiana State University, Baton Rouge, Louisiana 70803 (United States); Abanador, Paul; Mauger, François; Gaarde, Mette; Schafer, Kenneth J. [Department of Physics and Astronomy, Louisiana State University, Baton Rouge, Louisiana 70803 (United States); Lopata, Kenneth, E-mail: klopata@lsu.edu [Department of Chemistry, Louisiana State University, Baton Rouge, Louisiana 70803 (United States); Center for Computation and Technology, Louisiana State University, Baton Rouge, Louisiana 70803 (United States)

2016-09-07

Strong-field ionization and the resulting electronic dynamics are important for a range of processes such as high harmonic generation, photodamage, charge resonance enhanced ionization, and ionization-triggered charge migration. Modeling ionization dynamics in molecular systems from first-principles can be challenging due to the large spatial extent of the wavefunction which stresses the accuracy of basis sets, and the intense fields which require non-perturbative time-dependent electronic structure methods. In this paper, we develop a time-dependent density functional theory approach which uses a Gaussian-type orbital (GTO) basis set to capture strong-field ionization rates and dynamics in atoms and small molecules. This involves propagating the electronic density matrix in time with a time-dependent laser potential and a spatial non-Hermitian complex absorbing potential which is projected onto an atom-centered basis set to remove ionized charge from the simulation. For the density functional theory (DFT) functional we use a tuned range-separated functional LC-PBE*, which has the correct asymptotic 1/r form of the potential and a reduced delocalization error compared to traditional DFT functionals. Ionization rates are computed for hydrogen, molecular nitrogen, and iodoacetylene under various field frequencies, intensities, and polarizations (angle-dependent ionization), and the results are shown to quantitatively agree with time-dependent Schrödinger equation and strong-field approximation calculations. This tuned DFT with GTO method opens the door to predictive all-electron time-dependent density functional theory simulations of ionization and ionization-triggered dynamics in molecular systems using tuned range-separated hybrid functionals.

Angle-dependent strong-field molecular ionization rates with tuned range-separated time-dependent density functional theory

International Nuclear Information System (INIS)

Sissay, Adonay; Abanador, Paul; Mauger, François; Gaarde, Mette; Schafer, Kenneth J.; Lopata, Kenneth

2016-01-01

Strong-field ionization and the resulting electronic dynamics are important for a range of processes such as high harmonic generation, photodamage, charge resonance enhanced ionization, and ionization-triggered charge migration. Modeling ionization dynamics in molecular systems from first-principles can be challenging due to the large spatial extent of the wavefunction which stresses the accuracy of basis sets, and the intense fields which require non-perturbative time-dependent electronic structure methods. In this paper, we develop a time-dependent density functional theory approach which uses a Gaussian-type orbital (GTO) basis set to capture strong-field ionization rates and dynamics in atoms and small molecules. This involves propagating the electronic density matrix in time with a time-dependent laser potential and a spatial non-Hermitian complex absorbing potential which is projected onto an atom-centered basis set to remove ionized charge from the simulation. For the density functional theory (DFT) functional we use a tuned range-separated functional LC-PBE*, which has the correct asymptotic 1/r form of the potential and a reduced delocalization error compared to traditional DFT functionals. Ionization rates are computed for hydrogen, molecular nitrogen, and iodoacetylene under various field frequencies, intensities, and polarizations (angle-dependent ionization), and the results are shown to quantitatively agree with time-dependent Schrödinger equation and strong-field approximation calculations. This tuned DFT with GTO method opens the door to predictive all-electron time-dependent density functional theory simulations of ionization and ionization-triggered dynamics in molecular systems using tuned range-separated hybrid functionals.

Functional Molecular Junctions Derived from Double Self-Assembled Monolayers.

Science.gov (United States)

Seo, Sohyeon; Hwang, Eunhee; Cho, Yunhee; Lee, Junghyun; Lee, Hyoyoung

2017-09-25

Information processing using molecular junctions is becoming more important as devices are miniaturized to the nanoscale. Herein, we report functional molecular junctions derived from double self-assembled monolayers (SAMs) intercalated between soft graphene electrodes. Newly assembled molecular junctions are fabricated by placing a molecular SAM/(top) electrode on another molecular SAM/(bottom) electrode by using a contact-assembly technique. Double SAMs can provide tunneling conjugation across the van der Waals gap between the terminals of each monolayer and exhibit new electrical functions. Robust contact-assembled molecular junctions can act as platforms for the development of equivalent contact molecular junctions between top and bottom electrodes, which can be applied independently to different kinds of molecules to enhance either the structural complexity or the assembly properties of molecules. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Molecular and Functional Characterization of Broccoli EMBRYONIC FLOWER 2 Genes

Science.gov (United States)

Chen, Long-Fang O.; Lin, Chun-Hung; Lai, Ying-Mi; Huang, Jia-Yuan; Sung, Zinmay Renee

2012-01-01

Polycomb group (PcG) proteins regulate major developmental processes in Arabidopsis. EMBRYONIC FLOWER 2 (EMF2), the VEFS domain-containing PcG gene, regulates diverse genetic pathways and is required for vegetative development and plant survival. Despite widespread EMF2-like sequences in plants, little is known about their function other than in Arabidopsis and rice. To study the role of EMF2 in broccoli (Brassica oleracea var. italica cv. Elegance) development, we identified two broccoli EMF2 (BoEMF2) genes with sequence homology to and a similar gene expression pattern to that in Arabidopsis (AtEMF2). Reducing their expression in broccoli resulted in aberrant phenotypes and gene expression patterns. BoEMF2 regulates genes involved in diverse developmental and stress programs similar to AtEMF2 in Arabidopsis. However, BoEMF2 differs from AtEMF2 in the regulation of flower organ identity, cell proliferation and elongation, and death-related genes, which may explain the distinct phenotypes. The expression of BoEMF2.1 in the Arabidopsis emf2 mutant (Rescued emf2) partially rescued the mutant phenotype and restored the gene expression pattern to that of the wild type. Many EMF2-mediated molecular and developmental functions are conserved in broccoli and Arabidopsis. Furthermore, the restored gene expression pattern in Rescued emf2 provides insights into the molecular basis of PcG-mediated growth and development. PMID:22537758

Emerging Importance of Helicases in Plant Stress Tolerance: Characterization of Oryza sativa Repair Helicase XPB2 Promoter and Its Functional Validation in Tobacco under Multiple Stresses.

Science.gov (United States)

Raikwar, Shailendra; Srivastava, Vineet K; Gill, Sarvajeet S; Tuteja, Renu; Tuteja, Narendra

2015-01-01

Genetic material always remains at the risk of spontaneous or induced damage which challenges the normal functioning of DNA molecule, thus, DNA repair is vital to protect the organisms against genetic damage. Helicases, the unique molecular motors, are emerged as prospective molecules to engineer stress tolerance in plants and are involved in nucleic acid metabolism including DNA repair. The repair helicase, XPB is an evolutionary conserved protein present in different organisms, including plants. Availability of few efficient promoters for gene expression in plants provoked us to study the promoter of XPB for better understanding of gene regulation under stress conditions. Here, we report the in silico analysis of novel stress inducible promoter of Oryza sativa XPB2 (OsXPB2). The in vivo validation of functionality/activity of OsXPB2 promoter under abiotic and hormonal stress conditions was performed by Agrobacterium-mediated transient assay in tobacco leaves using OsXPB2::GUS chimeric construct. The present research revealed that OsXPB2 promoter contains cis-elements accounting for various abiotic stresses (salt, dehydration, or cold) and hormone (Auxin, ABA, or MeJA) induced GUS expression/activity in the promoter-reporter assay. The promoter region of OsXPB2 contains CACG, GTAACG, CACGTG, CGTCA CCGCCGCGCT cis acting-elements which are reported to be salt, dehydration, cold, MeJA, or ABA responsive, respectively. Functional analysis was done by Agrobacterium-mediated transient assay using agroinfiltration in tobacco leaves, followed by GUS staining and fluorescence quantitative analyses. The results revealed high induction of GUS activity under multiple abiotic stresses as compared to mock treated control. The present findings suggest that OsXPB2 promoter is a multi-stress inducible promoter and has potential applications in sustainable crop production under abiotic stresses by regulating desirable pattern of gene expression.

Utilization of the molecular dynamic to study the effect of hydrogen in the stress corrosion

International Nuclear Information System (INIS)

Arnoux, P.

2007-01-01

Many microscopic and theoretical models of stress corrosion have been proposed, in particularly to explain the grain boundary cracking of stainless steels and nickel base. In this work calculus of molecular dynamic have been used to propose a mechanism of stress corrosion at the atomic scale. The author aims to reproduce, by molecular dynamic, the mechanism of an open crack in irradiated stainless steel in PWR reactor and show that the growth of the oxide at the crack back produce hydrogen. (A.L.B.)

Hormonal and molecular effects of restraint stress on formalin-induced pain-like behavior in male and female mice.

Science.gov (United States)

Long, Caela C; Sadler, Katelyn E; Kolber, Benedict J

2016-10-15

The evolutionary advantages to the suppression of pain during a stressful event (stress-induced analgesia (SIA)) are obvious, yet the reasoning behind sex-differences in the expression of this pain reduction are not. The different ways in which males and females integrate physiological stress responses and descending pain inhibition are unclear. A potential supraspinal modulator of stress-induced analgesia is the central nucleus of the amygdala (CeA). This limbic brain region is involved in both the processing of stress and pain; the CeA is anatomically and molecularly linked to regions of the hypothalamic pituitary adrenal (HPA) axis and descending pain network. The CeA exhibits sex-based differences in response to stress and pain that may differentially induce SIA in males and females. Here, sex-based differences in behavioral and molecular indices of SIA were examined following noxious stimulation. Acute restraint stress in male and female mice was performed prior to intraplantar injections of formalin, a noxious inflammatory agent. Spontaneous pain-like behaviors were measured for 60min following formalin injection and mechanical hypersensitivity was evaluated 120 and 180min post-injection. Restraint stress altered formalin-induced spontaneous behaviors in male and female mice and formalin-induced mechanical hypersensitivity in male mice. To assess molecular indices of SIA, tissue samples from the CeA and blood samples were collected at the 180min time point. Restraint stress prevented formalin-induced increases in extracellular signal regulated kinase 2 (ERK2) phosphorylation in the male CeA, but no changes associated with pERK2 were seen with formalin or restraint in females. Sex differences were also seen in plasma corticosterone concentrations 180min post injection. These results demonstrate sex-based differences in behavioral, molecular, and hormonal indices of acute stress in mice that extend for 180min after stress and noxious stimulation. Copyright �

Molecular mechanisms of NCAM function

DEFF Research Database (Denmark)

Hinsby, Anders M; Berezin, Vladimir; Bock, Elisabeth

2004-01-01

receptor that responds to both homophilic and heterophilic cues, as well as a mediator of cell-cell adhesion. This review describes NCAM function at the molecular level. We discuss recent models for extracellular ligand-interactions of NCAM, and the intracellular signaling cascade that follows to define...

Prenatal stress alters amygdala functional connectivity in preterm neonates.

Science.gov (United States)

Scheinost, Dustin; Kwon, Soo Hyun; Lacadie, Cheryl; Sze, Gordon; Sinha, Rajita; Constable, R Todd; Ment, Laura R

2016-01-01

Exposure to prenatal and early-life stress results in alterations in neural connectivity and an increased risk for neuropsychiatric disorders. In particular, alterations in amygdala connectivity have emerged as a common effect across several recent studies. However, the impact of prenatal stress exposure on the functional organization of the amygdala has yet to be explored in the prematurely-born, a population at high risk for neuropsychiatric disorders. We test the hypothesis that preterm birth and prenatal exposure to maternal stress alter functional connectivity of the amygdala using two independent cohorts. The first cohort is used to establish the effects of preterm birth and consists of 12 very preterm neonates and 25 term controls, all without prenatal stress exposure. The second is analyzed to establish the effects of prenatal stress exposure and consists of 16 extremely preterm neonates with prenatal stress exposure and 10 extremely preterm neonates with no known prenatal stress exposure. Standard resting-state functional magnetic resonance imaging and seed connectivity methods are used. When compared to term controls, very preterm neonates show significantly reduced connectivity between the amygdala and the thalamus, the hypothalamus, the brainstem, and the insula (p amygdala and the thalamus, the hypothalamus, and the peristriate cortex (p amygdala connectivity associated with preterm birth. Functional connectivity from the amygdala to other subcortical regions is decreased in preterm neonates compared to term controls. In addition, these data, for the first time, suggest that prenatal stress exposure amplifies these decreases.

Oxidative stress markers, cognitive functions, and psychosocial functioning in bipolar disorder: an empirical cross-sectional study.

Science.gov (United States)

Aydemir, Ömer; Çubukçuoğlu, Zeynep; Erdin, Soner; Taş, Cumhur; Onur, Ece; Berk, Michael

2014-01-01

This study aimed to evaluate the relationship between oxidative stress markers and cognitive functions and domains of psychosocial functioning in bipolar disorder. Oxidative stress markers, cognitive functions, and domains of psychosocial functioning were evaluated in 51 patients with bipolar disorder who were in remission. Correlation analyses between these parameters were calculated with data controlled for duration of illness and number of episodes. There was no statistically significant correlation between oxidative stress markers and cognitive functions. In terms of psychosocial functioning, significant correlations were found between malondialdehyde and sense of stigmatization (r = -0.502); household activities and superoxide dismutase (r = 0.501); participation in social activities and nitric oxide (r = 0.414); hobbies and leisure time activities and total glutathione (r = -0.567), superoxide dismutase (r = 0.667), and neurotrophin 4 (r = 0.450); and taking initiative and self-sufficiency and superoxide dismutase (r = 0.597). There was no correlation between other domains of psychosocial functioning and oxidative stress markers. These results imply that oxidative stress markers do not appear to correlate clearly with cognitive impairment and reduced psychosocial functioning. However, there were some associations between selected oxidative markers and activity-oriented functional markers. This may represent a true negative association, or may be an artifact of oxidative stress being a state rather than a trait marker.

Oxidative stress markers, cognitive functions, and psychosocial functioning in bipolar disorder: an empirical cross-sectional study

Directory of Open Access Journals (Sweden)

Ömer Aydemir

2014-12-01

Full Text Available Objective: This study aimed to evaluate the relationship between oxidative stress markers and cognitive functions and domains of psychosocial functioning in bipolar disorder. Methods: Oxidative stress markers, cognitive functions, and domains of psychosocial functioning were evaluated in 51 patients with bipolar disorder who were in remission. Correlation analyses between these parameters were calculated with data controlled for duration of illness and number of episodes. Results: There was no statistically significant correlation between oxidative stress markers and cognitive functions. In terms of psychosocial functioning, significant correlations were found between malondialdehyde and sense of stigmatization (r = -0.502; household activities and superoxide dismutase (r = 0.501; participation in social activities and nitric oxide (r = 0.414; hobbies and leisure time activities and total glutathione (r = -0.567, superoxide dismutase (r = 0.667, and neurotrophin 4 (r = 0.450; and taking initiative and self-sufficiency and superoxide dismutase (r = 0.597. There was no correlation between other domains of psychosocial functioning and oxidative stress markers. Conclusion: These results imply that oxidative stress markers do not appear to correlate clearly with cognitive impairment and reduced psychosocial functioning. However, there were some associations between selected oxidative markers and activity-oriented functional markers. This may represent a true negative association, or may be an artifact of oxidative stress being a state rather than a trait marker.

Emerging Importance of Helicases in Plant Stress Tolerance: Characterization of Oryza sativa Repair Helicase XPB2 Promoter and Its Functional Validation in Tobacco under Multiple Stresses

OpenAIRE

Raikwar, Shailendra; Srivastava, Vineet K.; Gill, Sarvajeet S.; Tuteja, Renu; Tuteja, Narendra

2015-01-01

Genetic material always remains at the risk of spontaneous or induced damage which challenges the normal functioning of DNA molecule, thus, DNA repair is vital to protect the organisms against genetic damage. Helicases, the unique molecular motors, are emerged as prospective molecules to engineer stress tolerance in plants and are involved in nucleic acid metabolism including DNA repair. The repair helicase, XPB is an evolutionary conserved protein present in different organisms, including pl...

Molecular designing of nanoparticles and functional materials

Directory of Open Access Journals (Sweden)

Ignjatović Nenad L.

2017-01-01

Full Text Available The interdisciplinary research team implemented the program titled “Molecular designing of nanoparticles with controlled morphological and physicochemical characteristics and functional materials based on them” (MODENAFUNA, between 2011 and 2016, gaining new knowledge significant to the further improvement of nanomaterials and nanotechnologies. It gathered under its umbrella six main interrelated topics pertaining to the design and control of morphological and physicochemical properties of nanoparticles and functional material based on them using new methods of synthesis and processing: 1 inorganic nanoparticles, 2 cathode materials for lithium-ion batteries, 3 functional ceramics with improved electrical and optical properties, 4 full density nanostructured calcium phosphate and functionally-graded materials, 5 nano-calcium phosphate in bone tissue engineering and 6 biodegradable micro- and nano-particles for the controlled delivery of medicaments. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. III45004: Molecular designing of nanoparticles with controlled morphological and physicochemical characteristics and functional materials based on them

Effects of work stress and home stress on autonomic nervous function in Japanese male workers.

Science.gov (United States)

Maeda, Eri; Iwata, Toyoto; Murata, Katsuyuki

2015-01-01

Autonomic imbalance is one of the important pathways through which psychological stress contributes to cardiovascular diseases/sudden death. Although previous studies have focused mainly on stress at work (work stress), the association between autonomic function and stress at home (home stress) is still poorly understood. The purpose was to clarify the effect of work/home stress on autonomic function in 1,809 Japanese male workers. We measured corrected QT (QTc) interval and QT index on the electrocardiogram along with blood pressure and heart rate. Participants provided self-reported information about the presence/absence of work/home stress and the possible confounders affecting QT indicators. Home stress was related positively to QT index (p=0.040) after adjusting for the possible confounders, though work stress did not show a significant relation to QTc interval or QT index. The odds ratio of home stress to elevated QT index (≥105) was 2.677 (95% CI, 1.050 to 6.822). Work/home stress showed no significant relation to blood pressure or heart rate. These findings suggest that autonomic imbalance, readily assessed by QT indicators, can be induced by home stress in Japanese workers. Additional research is needed to identify different types of home stress that are strongly associated with autonomic imbalance.

Weight functions for the determination of stress intensity factor and T-stress for edge-cracked plates with built-in ends

International Nuclear Information System (INIS)

Li, J.; Wang, X.; Tan, C.L.

2004-01-01

This paper presents the weight functions for the determination of the stress intensity factor and T-stress solutions for edge-cracked plates with built-in ends under complex stress distributions. First, a compliance analysis approach is used to calculate stress intensity factor and T-stress for edge cracks in finite width plates with built-in ends with uniform or linear stress distributions acting on the crack face. The results serve as the reference solutions for the next step in which the approaches of deriving weight functions from reference stress intensity factor and T-stress solutions developed for stress boundary conditions are extended to obtain the corresponding weight functions for edge-cracked plates with built-in ends. Finite element analysis is conducted to validate the derived solutions. The weight functions derived are suitable for obtaining stress intensity factors and T-stress solutions under any complex stress field

NAC Transcription Factors in Senescence: From Molecular Structure to Function in Crops

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Dagmara Podzimska-Sroka

2015-07-01

Full Text Available Within the last decade, NAC transcription factors have been shown to play essential roles in senescence, which is the focus of this review. Transcriptome analyses associate approximately one third of Arabidopsis NAC genes and many crop NAC genes with senescence, thereby implicating NAC genes as important regulators of the senescence process. The consensus DNA binding site of the NAC domain is used to predict NAC target genes, and protein interaction sites can be predicted for the intrinsically disordered transcription regulatory domains of NAC proteins. The molecular characteristics of these domains determine the interactions in gene regulatory networks. Emerging local NAC-centered gene regulatory networks reveal complex molecular mechanisms of stress- and hormone-regulated senescence and basic physiological steps of the senescence process. For example, through molecular interactions involving the hormone abscisic acid, Arabidopsis NAP promotes chlorophyll degradation, a hallmark of senescence. Furthermore, studies of the functional rice ortholog, OsNAP, suggest that NAC genes can be targeted to obtain specific changes in lifespan control and nutrient remobilization in crop plants. This is also exemplified by the wheat NAM1 genes which promote senescence and increase grain zinc, iron, and protein content. Thus, NAC genes are promising targets for fine-tuning senescence for increased yield and quality.

Influence of Stress Shape Function on Analysis of Contact Problem Using Hybrid Photoelasticity

International Nuclear Information System (INIS)

Shin, Dongchul; Hawong, Jaisug

2013-01-01

In this research, a study on stress shape functions was conducted to analyze the contact stress problem by using a hybrid photoelasticity. Because the contact stress problem is generally solved as a half-plane problem, the relationship between two analytical stress functions, which are compositions of the Airy stress function, was similar to one of the crack problem. However, this relationship in itself could not be used to solve the contact stress problem (especially one with singular points). Therefore, to analyze the contact stress problem more correctly, stress shape functions based on the condition of two contact end points had to be considered in the form of these two analytical stress functions. The four types of stress shape functions were related to the stress singularities at the two contact end points. Among them, the primary two types used for the analysis of an O-ring were selected, and their validities were verified in this work

Emerging importance of helicases in plant stress tolerance: characterization of Oryza sativa repair helicase XPB2 promoter and its functional validation in tobacco under multiple stresses

Directory of Open Access Journals (Sweden)

Shailendra eRaikwar

2015-12-01

Full Text Available Genetic material always remains at the risk of spontaneous or induced damage which challenges the normal functioning of DNA molecule, thus, DNA repair is vital to protect the organisms against genetic damage. DNA hHelicases, the unique molecular motors, are emerged as potentialprospective molecules to engineer stress tolerance in plants and are involved in a variety of DNA nucleic acid metabolismc processes including DNA repair. The DNA repair helicase, OsXPB2 is an evolutionary conserved protein present in different organisms, including plants. Availability of few efficient promoters for gene expression in plants provoked us to study the promoter of XPB for better understanding of gene regulation under stress The analysis of promoter sequence from plant genome is important in understanding the gene regulation. Hereconditions. Here, we report the in silico analysis of novel stress inducible promoter of rice Oryza sativa OsXPB2 (OsXPB2. gene is reported. The in vivo validation of functionality/activity of novel stress inducible promoter of rice OsXPB2 gene promoter under abiotic and hormonal stress conditions was performed by Agrobacterium-mediated transient assay in tobacco leaves using OsXPB2::GUS chimeric construct. Our resultsThe present research revealed that OsXPB2 promoter contains cis-elements accounting for various abiotic stresses (salt, dehydration or cold and hormone (Auxin, ABA or MeJA induced GUS expression/activity in the promoter-reporter assay. The promoter region of OsXPB2 contains CACG, GTAACG, CACGTG, CGTCA CCGCCGCGCT cis acting-elements which are reported to be salt, dehydration, cold, MeJA or ABA responsive, respectively. Functional analysis was done by Agrobacterium-transient assays using agroinfiltration in tobacco leaves, followed by GUS staining and fluorescence quantitative analyses. The results revealed high induction of GUS activity under multiple abiotic stresses as compared to mock treated control. The present

Emerging importance of helicases in plant stress tolerance: characterization of Oryza sativa repair helicase XPB2 promoter and its functional validation in tobacco under multiple stresses

OpenAIRE

Shailendra eRaikwar; Vineet Kumar Shrivastava; Sarvajeet Singh Gill; Renu eTuteja; Narendra eTuteja; Narendra eTuteja

2015-01-01

Genetic material always remains at the risk of spontaneous or induced damage which challenges the normal functioning of DNA molecule, thus, DNA repair is vital to protect the organisms against genetic damage. DNA hHelicases, the unique molecular motors, are emerged as potentialprospective molecules to engineer stress tolerance in plants and are involved in a variety of DNA nucleic acid metabolismc processes including DNA repair. The DNA repair helicase, OsXPB2 is an evolutionary conserved pr...

RESEARCH ARTICLE Molecular cloning and functional ...

Indian Academy of Sciences (India)

Navya

2016-11-25

Nov 25, 2016 ... Molecular cloning and functional characterization of two novel ... Currently, many variants of HMW-GSs have been cloned from bread wheat .... SDS sedimentation tests were conducted using the methods described by Gao et ...

Molecular Mechanisms of Liver Injury and Hepatocarcinogenesis: Focusing on the Role of Stress-Activated MAPK

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Hayato Nakagawa

2012-01-01

Full Text Available Hepatocellular carcinoma (HCC is the third most common cause of cancer mortality. Short-term prognosis of patients with HCC has improved recently due to advances in early diagnosis and treatment, but long-term prognosis is still unsatisfactory. Therefore, obtaining a further understanding of the molecular carcinogenic mechanisms and the unique pathogenic biology of HCC is important. The most characteristic process in hepatocarcinogenesis is underlying chronic liver injury, which leads to repeated cycles of hepatocyte death, inflammation, and compensatory proliferation and subsequently provides a mitogenic and mutagenic environment leading to the development of HCC. Recent in vivo studies have shown that the stress-activated mitogen-activated protein kinase (MAPK cascade converging on c-Jun NH2-terminal kinase (JNK and p38 plays a central role in these processes, and it has attracted considerable attention as a therapeutic target. However, JNK and p38 have complex functions and a wide range of cellular effects. In addition, crosstalk with each other and the nuclear factor-kappaB pathway further complicate these functions. A full understanding is essential to bring these observations into clinical settings. In this paper, we discuss the latest findings regarding the mechanisms of liver injury and hepatocarcinogenesis focusing on the role of the stress-activated MAPK pathway.

Correlation between electron-irradiation defects and applied stress in graphene: A molecular dynamics study

Energy Technology Data Exchange (ETDEWEB)

Kida, Shogo; Yamamoto, Masaya; Kawata, Hiroaki; Hirai, Yoshihiko; Yasuda, Masaaki, E-mail: yasuda@pe.osakafu-u.ac.jp [Department of Physics and Electronics, Osaka Prefecture University, Sakai, Osaka 599-8531 (Japan); Tada, Kazuhiro [Department of Electrical and Control Systems Engineering, National Institute of Technology, Toyama College, Toyama 939-8630 (Japan)

2015-09-15

Molecular dynamics (MD) simulations are performed to study the correlation between electron irradiation defects and applied stress in graphene. The electron irradiation effect is introduced by the binary collision model in the MD simulation. By applying a tensile stress to graphene, the number of adatom-vacancy (AV) and Stone–Wales (SW) defects increase under electron irradiation, while the number of single-vacancy defects is not noticeably affected by the applied stress. Both the activation and formation energies of an AV defect and the activation energy of an SW defect decrease when a tensile stress is applied to graphene. Applying tensile stress also relaxes the compression stress associated with SW defect formation. These effects induced by the applied stress cause the increase in AV and SW defect formation under electron irradiation.

Structure-based inference of molecular functions of proteins of unknown function from Berkeley Structural Genomics Center

Energy Technology Data Exchange (ETDEWEB)

Kim, Sung-Hou; Shin, Dong Hae; Hou, Jingtong; Chandonia, John-Marc; Das, Debanu; Choi, In-Geol; Kim, Rosalind; Kim, Sung-Hou

2007-09-02

Advances in sequence genomics have resulted in an accumulation of a huge number of protein sequences derived from genome sequences. However, the functions of a large portion of them cannot be inferred based on the current methods of sequence homology detection to proteins of known functions. Three-dimensional structure can have an important impact in providing inference of molecular function (physical and chemical function) of a protein of unknown function. Structural genomics centers worldwide have been determining many 3-D structures of the proteins of unknown functions, and possible molecular functions of them have been inferred based on their structures. Combined with bioinformatics and enzymatic assay tools, the successful acceleration of the process of protein structure determination through high throughput pipelines enables the rapid functional annotation of a large fraction of hypothetical proteins. We present a brief summary of the process we used at the Berkeley Structural Genomics Center to infer molecular functions of proteins of unknown function.

Molecular level computational studies of polyethylene and polyacrylonitrile composites containing single walled carbon nanotubes: effect of carboxylic acid functionalization on nanotube-polymer interfacial properties

Directory of Open Access Journals (Sweden)

Shayesteh eHaghighatpanah

2014-09-01

Full Text Available Molecular dynamics and molecular mechanics methods have been used to investigate additive-polymer interfacial properties in single walled carbon nanotube – polyethylene and single walled carbon nanotube – polyacrylonitrile composites. Properties such as the interfacial shear stress and bonding energy are similar for the two composites. In contrast, functionalizing the single walled carbon nanotubes with carboxylic acid groups leads to an increase in these properties, with a larger increase for the polar polyacrylonitrile composite. Increasing the percentage of carbon atoms that were functionalized from 1% to 5% also leads to an increase in the interfacial properties. In addition, the interfacial properties depend on the location of the functional groups on the single walled carbon nanotube wall.

Importance of Force Decomposition for Local Stress Calculations in Biomembrane Molecular Simulations.

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Vanegas, Juan M; Torres-Sánchez, Alejandro; Arroyo, Marino

2014-02-11

Local stress fields are routinely computed from molecular dynamics trajectories to understand the structure and mechanical properties of lipid bilayers. These calculations can be systematically understood with the Irving-Kirkwood-Noll theory. In identifying the stress tensor, a crucial step is the decomposition of the forces on the particles into pairwise contributions. However, such a decomposition is not unique in general, leading to an ambiguity in the definition of the stress tensor, particularly for multibody potentials. Furthermore, a theoretical treatment of constraints in local stress calculations has been lacking. Here, we present a new implementation of local stress calculations that systematically treats constraints and considers a privileged decomposition, the central force decomposition, that leads to a symmetric stress tensor by construction. We focus on biomembranes, although the methodology presented here is widely applicable. Our results show that some unphysical behavior obtained with previous implementations (e.g. nonconstant normal stress profiles along an isotropic bilayer in equilibrium) is a consequence of an improper treatment of constraints. Furthermore, other valid force decompositions produce significantly different stress profiles, particularly in the presence of dihedral potentials. Our methodology reveals the striking effect of unsaturations on the bilayer mechanics, missed by previous stress calculation implementations.

Thermal and mechanical stresses in a functionally graded thick sphere

International Nuclear Information System (INIS)

Eslami, M.R.; Babaei, M.H.; Poultangari, R.

2005-01-01

In this paper, a general solution for the one-dimensional steady-state thermal and mechanical stresses in a hollow thick sphere made of functionally graded material is presented. The temperature distribution is assumed to be a function of radius, with general thermal and mechanical boundary conditions on the inside and outside surfaces of the sphere. The material properties, except Poisson's ratio, are assumed to vary along the radius r according to a power law function. The analytical solution of the heat conduction equation and the Navier equation lead to the temperature profile, radial displacement, radial stress, and hoop stress as a function of radial direction

Impact of prenatal environmental stress on cortical development

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Seiji eIshii

2015-05-01

Full Text Available Prenatal exposure of the developing brain to various types of environmental stress increases susceptibility to neuropsychiatric disorders such as autism, attention deficit hyperactivity disorder and schizophrenia. Given that even subtle perturbations by prenatal environmental stress in the cerebral cortex impair the cognitive and memory functions, this review focuses on underlying molecular mechanisms of pathological cortical development. We especially highlight recent works that utilized animal exposure models, human specimens or/and induced Pluripotent Stem (iPS cells to demonstrate: 1. molecular mechanisms shared by various types of environmental stressors, 2. the mechanisms by which the affected extracortical tissues indirectly impact the cortical development and function, and 3. interaction between prenatal environmental stress and the genetic predisposition of neuropsychiatric disorders. Finally, we discuss current challenges for achieving a comprehensive understanding of the role of environmentally disturbed molecular expressions in cortical maldevelopment, knowledge of which may eventually facilitate discovery of interventions for prenatal environment-linked neuropsychiatric disorders.

Molecular stress response pathways as the basis of hormesis

DEFF Research Database (Denmark)

Demirovic, Dino; de Toda, Irene Martinez; Rattan, Suresh

2014-01-01

There is now a large amount of data available for human beings showing positive hormetic effects of mild stresses from physical, chemical, nutritional and mental sources. However, these data are dispersed in the literature and not always interpreted as hormetic effects, thus restricting their full...... apprehension and application. A comprehensive discussion of the research, this book is composed of four sections: (1) History and terminology; (2) Evidence for hormesis in humans; (3) Molecular mechanisms of hormesis; and (4) Ethical and legal aspects, and risk assessment....

Effect of Heat Stress on Reproduction in Dairy Cows: Insights into the Cellular and Molecular Responses of the Oocyte.

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Roth, Zvi

2017-02-08

Among the components of the female reproductive tract, the ovarian pool of follicles and their enclosed oocytes are highly sensitive to hyperthermia. Heat-induced alterations in small antral follicles can be expressed later as compromised maturation and developmental capacity of the ovulating oocyte. This review summarizes the most up-to-date information on the effects of heat stress on the oocyte with an emphasis on unclear points and open questions, some of which might involve new research directions, for instance, whether preantral follicles are heat resistant. The review focuses on the follicle-enclosed oocytes, provides new insights into the cellular and molecular responses of the oocyte to elevated temperature, points out the role of the follicle microenvironment, and discusses some mechanisms that might underlie oocyte impairment. Mechanisms include nuclear and cytoplasmic maturation, mitochondrial function, apoptotic pathways, and oxidative stress. Understanding the mechanism by which heat stress compromises fertility might enable development of new strategies to mitigate its effects.

Molecular response to water stress in two contrasting Mediterranean pines (Pinus pinaster and Pinus pinea).

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Perdiguero, Pedro; Barbero, María Del Carmen; Cervera, María Teresa; Collada, Carmen; Soto, Alvaro

2013-06-01

Adaptation to water stress has determined the evolution and diversification of vascular plants. Water stress is forecasted to increase drastically in the next decades in certain regions, such as in the Mediterranean basin. Consequently, a proper knowledge of the response and adaptations to drought stress is essential for the correct management of plant genetic resources. However, most of the advances in the understanding of the molecular response to water stress have been attained in angiosperms, and are not always applicable to gymnosperms. In this work we analyse the transcriptional response of two emblematic Mediterranean pines, Pinus pinaster and Pinus pinea, which show noticeable differences in their performance under water stress. Using microarray analysis, up to 113 genes have been detected as significantly induced by drought in both species. Reliability of expression patterns has been confirmed by RT-PCR. While induced genes with similar profiles in both species can be considered as general candidate genes for the study of drought response in conifers, genes with diverging expression patterns can underpin the differences displayed by these species under water stress. Most promising candidate genes for drought stress response include genes related to carbohydrate metabolism, such as glycosyltransferases or galactosidases, sugar transporters, dehydrins and transcription factors. Additionally, differences in the molecular response to drought and polyethylene-glycol-induced water stress are also discussed. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

Chronic stress and neural function: accounting for sex and age.

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Luine, V N; Beck, K D; Bowman, R E; Frankfurt, M; Maclusky, N J

2007-10-01

Cognitive responses to stress follow the temporally dependent pattern originally established by Selye (1) wherein short-term stressors elicit adaptive responses whereas continued stress (chronic) results in maladaptive changes--deleterious effects on physiological systems and impaired cognition. However, this pattern for cognitive effects appears to apply to only half the population (males) and, more specifically, to young, adult males. Females show different cognitive responses to stress. In contrast to impaired cognition in males after chronic stress, female rodents show enhanced performance on the same memory tasks after the same stress. Not only cognition, but anxiety, shows sex-dependent changes following chronic stress--stress is anxiolytic in males and anxiogenic in females. Moreover, behavioral responses to chronic stress are different in developing as well as aging subjects (both sexes) as compared to adults. In aged rats, chronic stress enhances recognition memory in both sexes, does not alter spatial memory, and anxiety effects are opposite to young adults. When pregnant dams are exposed to chronic stress, at adulthood the offspring display yet different consequences of stress on anxiety and cognition, and, in contrast to adulthood when the behavioral effects of stress are reversible, prenatal stress effects appear enduring. Changing levels of estradiol in the sexes over the lifespan appear to contribute to the differences in response to stress. Thus, theories of stress dependent modulations in CNS function--developed solely in male models, focused on peripheral physiological processes and tested in adults--may require revision when applied to a more diverse population (age- and sex-wise) at least in relation to the neural functions of cognition and anxiety. Moreover, these results suggest that other stressors and neural functions should be investigated to determine whether age, sex and gonadal hormones also have an impact.

Molecular and physiological responses to abiotic stress in forest trees and their relevance to tree improvement.

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Harfouche, Antoine; Meilan, Richard; Altman, Arie

2014-11-01

Abiotic stresses, such as drought, salinity and cold, are the major environmental stresses that adversely affect tree growth and, thus, forest productivity, and play a major role in determining the geographic distribution of tree species. Tree responses and tolerance to abiotic stress are complex biological processes that are best analyzed at a systems level using genetic, genomic, metabolomic and phenomic approaches. This will expedite the dissection of stress-sensing and signaling networks to further support efficient genetic improvement programs. Enormous genetic diversity for stress tolerance exists within some forest-tree species, and due to advances in sequencing technologies the molecular genetic basis for this diversity has been rapidly unfolding in recent years. In addition, the use of emerging phenotyping technologies extends the suite of traits that can be measured and will provide us with a better understanding of stress tolerance. The elucidation of abiotic stress-tolerance mechanisms will allow for effective pyramiding of multiple tolerances in a single tree through genetic engineering. Here we review recent progress in the dissection of the molecular basis of abiotic stress tolerance in forest trees, with special emphasis on Populus, Pinus, Picea, Eucalyptus and Quercus spp. We also outline practices that will enable the deployment of trees engineered for abiotic stress tolerance to land owners. Finally, recommendations for future work are discussed. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Protective effect of low dose caffeine on psychological stress and cognitive function.

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Çakır, Özgür Kasımay; Ellek, Nurfitnat; Salehin, Nabila; Hamamcı, Rabia; Keleş, Hülya; Kayalı, Damla Gökçeoğlu; Akakın, Dilek; Yüksel, Meral; Özbeyli, Dilek

2017-01-01

Caffeine is an adrenergic antagonist that enhances neuronal activity. Psychological stress depresses cognitive function. To investigate the effects of acute and chronic low dose caffeine on anxiety-like behavior and cognitive functions of acute or chronic psychological stressed rats. Acute or chronic caffeine (3mg/kg) was administered to male Sprague Dawley rats (200-250g, n=42) before acute (cat odor) and chronic variable psychological stress (restraint overcrowding stress, elevated plus maze, cat odor, forced swimming) induction. Anxiety and cognitive functions were evaluated by hole-board and object recognition tests. The brain glutathione and malondialdehyde assays, myeloperoxidase, nitric oxide (NO), superoxide dismutase (SOD), luminol and lucigenin activity and histological examination were done. ANOVA and Student's t-test were used for statistical analysis. The depressed cognitive function with chronic stress exposure and the increased anxiety-like behavior with both stress inductions were improved via both caffeine applications (pcaffeine pretreatments in chronic stressed rats, and chronic caffeine in acute stressed ones reduced the elevated myeloperoxidase activities (pcaffeine (pcaffeine (pcaffeine decreased SOD activity (pcaffeine. The increased anxiety-like behavior and depleted cognitive functions under stress conditions were improved with both acute and predominantly chronic caffeine pretreatments by decreasing oxidative damage parameters. Copyright © 2016 Elsevier Inc. All rights reserved.

POLYANA-A tool for the calculation of molecular radial distribution functions based on Molecular Dynamics trajectories

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Dimitroulis, Christos; Raptis, Theophanes; Raptis, Vasilios

2015-12-01

We present an application for the calculation of radial distribution functions for molecular centres of mass, based on trajectories generated by molecular simulation methods (Molecular Dynamics, Monte Carlo). When designing this application, the emphasis was placed on ease of use as well as ease of further development. In its current version, the program can read trajectories generated by the well-known DL_POLY package, but it can be easily extended to handle other formats. It is also very easy to 'hack' the program so it can compute intermolecular radial distribution functions for groups of interaction sites rather than whole molecules.

Stressful Life Events in Children With Functional Defecation Disorders.

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Philips, Elise M; Peeters, Babette; Teeuw, Arianne H; Leenders, Arnold G E; Boluyt, Nicole; Brilleslijper-Kater, Sonja N; Benninga, Marc A

2015-10-01

The aim of the study was to determine the prevalence of stressful life events including (sexual) abuse in children with functional defecation disorders by performing a systematic review. We searched MEDLINE, EMBASE, and PsycINFO for cohort, case-control and cross-sectional studies investigating the prevalence of stressful life events, including (sexual) abuse in children with functional defecation disorders. The search yielded 946 articles, of which 8 were included with data from 654 children with functional constipation and 1931 children with (constipation-associated) fecal incontinence (FI). Overall, children with functional defecation disorders had been significantly more exposed to stressful life events than healthy children, with prevalence rates ranging from 1.6% to 90.9%. Being bullied, being a relational victim, interruption of toilet training, punishment by parents during toilet training, and hospitalization were significantly related to FI, whereas separation from the best friend, failure in an examination, severe illness in a close family member, loss of job by a parent, frequent punishment, and living in a war-affected area were significantly related to constipation. Only 1 study measured the prevalence of child abuse, which reported a significantly higher prevalence of child (sexual) abuse in children with FI compared with controls. The prevalence of stressful life events, including (sexual) abuse is significantly higher in children with functional defecation disorders compared with healthy children. To gain more insight into the true prevalence of child (sexual) abuse in children with functional defecation disorders, more studies are clearly needed.

Global plant-responding mechanisms to salt stress: physiological and molecular levels and implications in biotechnology.

Science.gov (United States)

Tang, Xiaoli; Mu, Xingmin; Shao, Hongbo; Wang, Hongyan; Brestic, Marian

2015-01-01

The increasing seriousness of salinization aggravates the food, population and environmental issues. Ameliorating the salt-resistance of plants especially the crops is the most effective measure to solve the worldwide problem. The salinity can cause damage to plants mainly from two aspects: hyperosmotic and hyperionic stresses leading to the restrain of growth and photosynthesis. To the adverse effects, the plants derive corresponding strategies including: ion regulation and compartmentalization, biosynthesis of compatible solutes, induction of antioxidant enzymes and plant hormones. With the development of molecular biology, our understanding of the molecular and physiology knowledge is becoming clearness. The complex signal transduction underlying the salt resistance is being illuminated brighter and clearer. The SOS pathway is the central of the cell signaling in salt stress. The accumulation of the compatible solutes and the activation of the antioxidant system are the effective measures for plants to enhance the salt resistance. How to make full use of our understanding to improve the output of crops is a huge challenge for us, yet the application of the genetic engineering makes this possible. In this review, we will discuss the influence of the salt stress and the response of the plants in detail expecting to provide a particular account for the plant resistance in molecular, physiological and transgenic fields.

Bio-functions and molecular carbohydrate structure association study in forage with different source origins revealed using non-destructive vibrational molecular spectroscopy techniques.

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Ji, Cuiying; Zhang, Xuewei; Yan, Xiaogang; Mostafizar Rahman, M; Prates, Luciana L; Yu, Peiqiang

2017-08-05

The objectives of this study were to: 1) investigate forage carbohydrate molecular structure profiles; 2) bio-functions in terms of CHO rumen degradation characteristics and hourly effective degradation ratio of N to OM (HED N/OM ), and 3) quantify interactive association between molecular structures, bio-functions and nutrient availability. The vibrational molecular spectroscopy was applied to investigate the structure feature on a molecular basis. Two sourced-origin alfalfa forages were used as modeled forages. The results showed that the carbohydrate molecular structure profiles were highly linked to the bio-functions in terms of rumen degradation characteristics and hourly effective degradation ratio. The molecular spectroscopic technique can be used to detect forage carbohydrate structure features on a molecular basis and can be used to study interactive association between forage molecular structure and bio-functions. Copyright © 2017 Elsevier B.V. All rights reserved.

Plant-parasitic nematodes: towards understanding molecular players in stress responses.

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Gillet, François-Xavier; Bournaud, Caroline; Antonino de Souza Júnior, Jose Dijair; Grossi-de-Sa, Maria Fatima

2017-03-01

Plant-parasitic nematode interactions occur within a vast molecular plant immunity network. Following initial contact with the host plant roots, plant-parasitic nematodes (PPNs) activate basal immune responses. Defence priming involves the release in the apoplast of toxic molecules derived from reactive species or secondary metabolism. In turn, PPNs must overcome the poisonous and stressful environment at the plant-nematode interface. The ability of PPNs to escape this first line of plant immunity is crucial and will determine its virulence. Nematodes trigger crucial regulatory cytoprotective mechanisms, including antioxidant and detoxification pathways. Knowledge of the upstream regulatory components that contribute to both of these pathways in PPNs remains elusive. In this review, we discuss how PPNs probably orchestrate cytoprotection to resist plant immune responses, postulating that it may be derived from ancient molecular mechanisms. The review focuses on two transcription factors, DAF-16 and SKN-1 , which are conserved in the animal kingdom and are central regulators of cell homeostasis and immune function. Both regulate the unfolding protein response and the antioxidant and detoxification pathways. DAF-16 and SKN-1 target a broad spectrum of Caenorhabditis elegans genes coding for numerous protein families present in the secretome of PPNs. Moreover, some regulatory elements of DAF-16 and SKN-1 from C. elegans have already been identified as important genes for PPN infection. DAF-16 and SKN-1 genes may play a pivotal role in PPNs during parasitism. In the context of their hub status and mode of regulation, we suggest alternative strategies for control of PPNs through RNAi approaches. © The Author 2017. Published by Oxford University Press on behalf of the Annals of Botany Company.

Functional evolution of leptin of Ochotona curzoniae in adaptive thermogenesis driven by cold environmental stress.

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Jie Yang

Full Text Available BACKGROUND: Environmental stress can accelerate the directional selection and evolutionary rate of specific stress-response proteins to bring about new or altered functions, enhancing an organism's fitness to challenging environments. Plateau pika (Ochotona curzoniae, an endemic and keystone species on Qinghai-Tibetan Plateau, is a high hypoxia and low temperature tolerant mammal with high resting metabolic rate and non-shivering thermogenesis to cope in this harsh plateau environment. Leptin is a key hormone related to how these animals regulate energy homeostasis. Previous molecular evolutionary analysis helped to generate the hypothesis that adaptive evolution of plateau pika leptin may be driven by cold stress. METHODOLOGY/PRINCIPAL FINDINGS: To test the hypothesis, recombinant pika leptin was first purified. The thermogenic characteristics of C57BL/6J mice injected with pika leptin under warm (23±1°C and cold (5±1°C acclimation is investigated. Expression levels of genes regulating adaptive thermogenesis in brown adipose tissue and the hypothalamus are compared between pika leptin and human leptin treatment, suggesting that pika leptin has adaptively and functionally evolved. Our results show that pika leptin regulates energy homeostasis via reduced food intake and increased energy expenditure under both warm and cold conditions. Compared with human leptin, pika leptin demonstrates a superior induced capacity for adaptive thermogenesis, which is reflected in a more enhanced β-oxidation, mitochondrial biogenesis and heat production. Moreover, leptin treatment combined with cold stimulation has a significant synergistic effect on adaptive thermogenesis, more so than is observed with a single cold exposure or single leptin treatment. CONCLUSIONS/SIGNIFICANCE: These findings support the hypothesis that cold stress has driven the functional evolution of plateau pika leptin as an ecological adaptation to the Qinghai-Tibetan Plateau.

Molecular and physiological responses of trees to waterlogging stress.

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Kreuzwieser, Jürgen; Rennenberg, Heinz

2014-10-01

One major effect of global climate change will be altered precipitation patterns in many regions of the world. This will cause a higher probability of long-term waterlogging in winter/spring and flash floods in summer because of extreme rainfall events. Particularly, trees not adapted at their natural site to such waterlogging stress can be impaired. Despite the enormous economic, ecological and social importance of forest ecosystems, the effect of waterlogging on trees is far less understood than the effect on many crops or the model plant Arabidopsis. There is only a handful of studies available investigating the transcriptome and metabolome of waterlogged trees. Main physiological responses of trees to waterlogging include the stimulation of fermentative pathways and an accelerated glycolytic flux. Many energy-consuming, anabolic processes are slowed down to overcome the energy crisis mediated by waterlogging. A crucial feature of waterlogging tolerance is the steady supply of glycolysis with carbohydrates, particularly in the roots; stress-sensitive trees fail to maintain sufficient carbohydrate availability resulting in the dieback of the stressed tissues. The present review summarizes physiological and molecular features of waterlogging tolerance of trees; the focus is on carbon metabolism in both, leaves and roots of trees. © 2014 John Wiley & Sons Ltd.

The interplay of early-life stress, nutrition, and immune activation programs adult hippocampal structure and function

Science.gov (United States)

Hoeijmakers, Lianne; Lucassen, Paul J.; Korosi, Aniko

2015-01-01

Early-life adversity increases the vulnerability to develop psychopathologies and cognitive decline later in life. This association is supported by clinical and preclinical studies. Remarkably, experiences of stress during this sensitive period, in the form of abuse or neglect but also early malnutrition or an early immune challenge elicit very similar long-term effects on brain structure and function. During early-life, both exogenous factors like nutrition and maternal care, as well as endogenous modulators, including stress hormones and mediator of immunological activity affect brain development. The interplay of these key elements and their underlying molecular mechanisms are not fully understood. We discuss here the hypothesis that exposure to early-life adversity (specifically stress, under/malnutrition and infection) leads to life-long alterations in hippocampal-related cognitive functions, at least partly via changes in hippocampal neurogenesis. We further discuss how these different key elements of the early-life environment interact and affect one another and suggest that it is a synergistic action of these elements that shapes cognition throughout life. Finally, we consider different intervention studies aiming to prevent these early-life adversity induced consequences. The emerging evidence for the intriguing interplay of stress, nutrition, and immune activity in the early-life programming calls for a more in depth understanding of the interaction of these elements and the underlying mechanisms. This knowledge will help to develop intervention strategies that will converge on a more complete set of changes induced by early-life adversity. PMID:25620909

Genetic, functional and molecular features of glucocorticoid receptor binding.

Directory of Open Access Journals (Sweden)

Francesca Luca

Full Text Available Glucocorticoids (GCs are key mediators of stress response and are widely used as pharmacological agents to treat immune diseases, such as asthma and inflammatory bowel disease, and certain types of cancer. GCs act mainly by activating the GC receptor (GR, which interacts with other transcription factors to regulate gene expression. Here, we combined different functional genomics approaches to gain molecular insights into the mechanisms of action of GC. By profiling the transcriptional response to GC over time in 4 Yoruba (YRI and 4 Tuscans (TSI lymphoblastoid cell lines (LCLs, we suggest that the transcriptional response to GC is variable not only in time, but also in direction (positive or negative depending on the presence of specific interacting transcription factors. Accordingly, when we performed ChIP-seq for GR and NF-κB in two YRI LCLs treated with GC or with vehicle control, we observed that features of GR binding sites differ for up- and down-regulated genes. Finally, we show that eQTLs that affect expression patterns only in the presence of GC are 1.9-fold more likely to occur in GR binding sites, compared to eQTLs that affect expression only in its absence. Our results indicate that genetic variation at GR and interacting transcription factors binding sites influences variability in gene expression, and attest to the power of combining different functional genomic approaches.

COPRED: prediction of fold, GO molecular function and functional residues at the domain level.

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López, Daniel; Pazos, Florencio

2013-07-15

Only recently the first resources devoted to the functional annotation of proteins at the domain level started to appear. The next step is to develop specific methodologies for predicting function at the domain level based on these resources, and to implement them in web servers to be used by the community. In this work, we present COPRED, a web server for the concomitant prediction of fold, molecular function and functional sites at the domain level, based on a methodology for domain molecular function prediction and a resource of domain functional annotations previously developed and benchmarked. COPRED can be freely accessed at http://csbg.cnb.csic.es/copred. The interface works in all standard web browsers. WebGL (natively supported by most browsers) is required for the in-line preview and manipulation of protein 3D structures. The website includes a detailed help section and usage examples. pazos@cnb.csic.es.

Efficient molecular density functional theory using generalized spherical harmonics expansions.

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Ding, Lu; Levesque, Maximilien; Borgis, Daniel; Belloni, Luc

2017-09-07

We show that generalized spherical harmonics are well suited for representing the space and orientation molecular density in the resolution of the molecular density functional theory. We consider the common system made of a rigid solute of arbitrary complexity immersed in a molecular solvent, both represented by molecules with interacting atomic sites and classical force fields. The molecular solvent density ρ(r,Ω) around the solute is a function of the position r≡(x,y,z) and of the three Euler angles Ω≡(θ,ϕ,ψ) describing the solvent orientation. The standard density functional, equivalent to the hypernetted-chain closure for the solute-solvent correlations in the liquid theory, is minimized with respect to ρ(r,Ω). The up-to-now very expensive angular convolution products are advantageously replaced by simple products between projections onto generalized spherical harmonics. The dramatic gain in speed of resolution enables to explore in a systematic way molecular solutes of up to nanometric sizes in arbitrary solvents and to calculate their solvation free energy and associated microscopic solvent structure in at most a few minutes. We finally illustrate the formalism by tackling the solvation of molecules of various complexities in water.

A novel hybrid stress-function finite element method immune to severe mesh distortion

International Nuclear Information System (INIS)

Cen Song; Zhou Mingjue; Fu Xiangrong

2010-01-01

This paper introduces a hybrid stress-function finite element method proposed recently for developing 2D finite element models immune to element shapes. Deferent from the first version of the hybrid-stress element constructed by Pian, the stress function φ of 2D elastic or fracture problem is regarded as the functional variable of the complementary energy functional. Then, the basic analytical solutions of φ are taken as the trial functions for finite element models, and meanwhile, the corresponding unknown stress-function constants are introduced. By using the principle of minimum complementary energy, these unknown stress-function constants can be expressed in terms of the displacements along element edges. Finally, the complementary energy functional can be rewritten in terms of element nodal displacement vector, and thus, the element stiffness matrix of such hybrid-function element can be obtained. As examples, two (8- and 12-node) quadrilateral plane elements and an arbitrary polygonal crack element are constructed by employing different basic analytical solutions of different stress functions. Numerical results show that, the 8- and 12-node plane models can produce the exact solutions for pure bending and linear bending problems, respectively, even the element shape degenerates into triangle and concave quadrangle; and the crack element can also predict accurate results with very low computational cost in analysis of stress-singularity problems.

Psychological stress-relieving effects of chewing - Relationship between masticatory function-related factors and stress-relieving effects.

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Tasaka, Akinori; Kikuchi, Manaki; Nakanishi, Kousuke; Ueda, Takayuki; Yamashita, Shuichiro; Sakurai, Kaoru

2018-01-01

The objective of the present study was to investigate the relationship between masticatory function-related factors (masticatory performance, occlusal contact area, maximum bite force, number of chewing strokes, and muscle activity) and the stress-relieving effects of chewing. A total of 28 healthy male subjects were instructed to rest or chew for 10min after 30min of stress loading with arithmetic calculations. Their stress state was assessed by measuring salivary cortisol levels. Saliva was collected at three time points: before stress loading, immediately after stress loading, and 10min after stress loading. Compared to resting, chewing produced a significantly greater reduction in the rate of change in salivary cortisol levels 10min after stress loading. A negative correlation was observed between the rate of decrease in salivary cortisol levels and the number of chewing strokes. No significant correlation was observed between the rate of decrease in salivary cortisol levels and other measurement items. In healthy dentulous people, the number of chewing strokes has been shown to be a masticatory function-related factor that affects stress relief from chewing, suggesting the possibility that more appropriate chewing would produce a greater effect psychological stress relief. Copyright © 2017 Japan Prosthodontic Society. Published by Elsevier Ltd. All rights reserved.

Molecular Motions in Functional Self-Assembled Nanostructures

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Jean-Marc Saiter

2013-01-01

Full Text Available The construction of “smart” materials able to perform specific functions at the molecular scale through the application of various stimuli is highly attractive but still challenging. The most recent applications indicate that the outstanding flexibility of self-assembled architectures can be employed as a powerful tool for the development of innovative molecular devices, functional surfaces and smart nanomaterials. Structural flexibility of these materials is known to be conferred by weak intermolecular forces involved in self-assembly strategies. However, some fundamental mechanisms responsible for conformational lability remain unexplored. Furthermore, the role played by stronger bonds, such as coordination, ionic and covalent bonding, is sometimes neglected while they can be employed readily to produce mechanically robust but also chemically reversible structures. In this review, recent applications of structural flexibility and molecular motions in self-assembled nanostructures are discussed. Special focus is given to advanced materials exhibiting significant performance changes after an external stimulus is applied, such as light exposure, pH variation, heat treatment or electromagnetic field. The crucial role played by strong intra- and weak intermolecular interactions on structural lability and responsiveness is highlighted.

Transient Stress Intensity Factors of Functionally Graded Hollow Cylinders with Internal Circumferential Cracks

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Iman Eshraghi

Full Text Available Abstract In this paper, transient thermomechanical stress intensity factors for functionally graded cylinders with complete internal circumferential cracks are obtained using the weight function method. The finite difference method is used to calculate the time dependent temperature distribution and thermal stresses along the cylinder thickness. Furthermore, finite element analysis is performed to determine the weight function coefficients and to investigate the accuracy of the predicted stress intensity factors from the weight functions. Variation of the stress intensity factors with time and effects of the material gradation on the results are investigated, as well. It is shown that the proposed technique can be used to accurately predict transient thermomechanical stress intensity factors for functionally graded cylinders with arbitrary material gradation.

Visualizing functional motions of membrane transporters with molecular dynamics simulations.

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Shaikh, Saher A; Li, Jing; Enkavi, Giray; Wen, Po-Chao; Huang, Zhijian; Tajkhorshid, Emad

2013-01-29

Computational modeling and molecular simulation techniques have become an integral part of modern molecular research. Various areas of molecular sciences continue to benefit from, indeed rely on, the unparalleled spatial and temporal resolutions offered by these technologies, to provide a more complete picture of the molecular problems at hand. Because of the continuous development of more efficient algorithms harvesting ever-expanding computational resources, and the emergence of more advanced and novel theories and methodologies, the scope of computational studies has expanded significantly over the past decade, now including much larger molecular systems and far more complex molecular phenomena. Among the various computer modeling techniques, the application of molecular dynamics (MD) simulation and related techniques has particularly drawn attention in biomolecular research, because of the ability of the method to describe the dynamical nature of the molecular systems and thereby to provide a more realistic representation, which is often needed for understanding fundamental molecular properties. The method has proven to be remarkably successful in capturing molecular events and structural transitions highly relevant to the function and/or physicochemical properties of biomolecular systems. Herein, after a brief introduction to the method of MD, we use a number of membrane transport proteins studied in our laboratory as examples to showcase the scope and applicability of the method and its power in characterizing molecular motions of various magnitudes and time scales that are involved in the function of this important class of membrane proteins.

A discrete stress-strength interference model based on universal generating function

International Nuclear Information System (INIS)

An Zongwen; Huang Hongzhong; Liu Yu

2008-01-01

Continuous stress-strength interference (SSI) model regards stress and strength as continuous random variables with known probability density function. This, to some extent, results in a limitation of its application. In this paper, stress and strength are treated as discrete random variables, and a discrete SSI model is presented by using the universal generating function (UGF) method. Finally, case studies demonstrate the validity of the discrete model in a variety of circumstances, in which stress and strength can be represented by continuous random variables, discrete random variables, or two groups of experimental data

Mitochondrial oxidative stress in aortic stiffening with age: the role of smooth muscle cell function.

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OBJECTIVE: Age-related aortic stiffness is an independent risk factor for cardiovascular diseases. Although oxidative stress is implicated in aortic stiffness, the underlying molecular mechanisms remain unelucidated. Here, we examined the source of oxidative stress in aging and i...

Autobiographical memory functions and posttraumatic stress symptoms across adulthood

DEFF Research Database (Denmark)

del Palacio Gonzalez, Adriana; Watson, Lynn Ann; Berntsen, Dorthe

2018-01-01

. In this study, we examined the unique relationship between autobiographical memory functions and posttraumatic stress symptoms (PTSS) and whether such relationships varied with age across adulthood. A representative sample of 1040 adult Danes (20–70 years old) reported the frequency with which they recall......Previous research has documented robust individual differences in the functions served by autobiographical memories, and shown that different autobiographical memory functions are related to both positive and negative indicators of psychological well-being, and that their frequency varies with age...... autobiographical memories for different purposes as well as their level of posttraumatic stress disorder (PTSD) symptoms. Higher reflective and ruminative functions, as well as lower social function, predicted higher levels of PTSS. There were no moderating effects of age. The results suggest that although...

The Role of Stress Exposure and Family Functioning in Internalizing Outcomes of Urban Families.

Science.gov (United States)

Sheidow, Ashli J; Henry, David B; Tolan, Patrick H; Strachan, Martha K

2014-11-01

Although research suggests that stress exposure and family functioning are associated with internalizing problems in adolescents and caregivers, surprisingly few studies have investigated the mechanisms that underlie this association. To determine whether family functioning buffers the development of internalizing problems in stress-exposed families, we assessed the relation between stress exposure, family functioning, and internalizing symptoms among a large sample of inner-city male youth and their caregivers living in poverty across five waves of data collection. We hypothesized that stress exposure and family functioning would predict development of subsequent youth and caregiver internalizing problems and that family functioning would moderate this relation, with higher functioning families demonstrating greater resiliency to stress exposure. We used a longitudinal, prospective design to evaluate whether family functioning (assessed at waves one through four) activated or buffered the effects of stress exposure (assessed at wave one) on subsequent internalizing symptoms (assessed at waves four and five). Stress from Developmental Transitions and family functioning were significant predictors of depressive symptoms and anxiety in youth; however, family functioning did not moderate the relation. Family functioning mediated the relation between stress from Daily Hassles and internalizing outcomes suggesting that poor parenting practices, low structure, and low emotional cohesion activate depression and anxiety in youth exposed to chronic and frequent everyday stressors. Surprisingly, only family functioning predicted depressive symptoms in caregivers. Results validate the use of a comprehensive, multi-informant assessment of stress when investigating internalizing outcomes in youth and support using family-based interventions in the treatment and prevention of internalizing.

Possible Contribution of Zerumbone-Induced Proteo-Stress to Its Anti-Inflammatory Functions via the Activation of Heat Shock Factor 1.

Directory of Open Access Journals (Sweden)

Yoko Igarashi

Full Text Available Zerumbone is a sesquiterpene present in Zinger zerumbet. Many studies have demonstrated its marked anti-inflammatory and anti-carcinogenesis activities. Recently, we showed that zerumbone binds to numerous proteins with scant selectivity and induces the expression of heat shock proteins (HSPs in hepatocytes. To dampen proteo-toxic stress, organisms have a stress-responsive molecular machinery, known as heat shock response. Heat shock factor 1 (HSF1 plays a key role in this protein quality control system by promoting activation of HSPs. In this study, we investigated whether zerumbone-induced HSF1 activation contributes to its anti-inflammatory functions in stimulated macrophages. Our findings showed that zerumbone increased cellular protein aggregates and promoted nuclear translocation of HSF1 for HSP expression. Interestingly, HSF1 down-regulation attenuated the suppressive effects of zerumbone on mRNA and protein expressions of pro-inflammatory genes, including inducible nitric oxide synthase and interlukin-1β. These results suggest that proteo-stress induced by zerumbone activates HSF1 for exhibiting its anti-inflammatory functions.

Abiotic stressors and stress responses: What commonalities appear between species across biological organization levels?

International Nuclear Information System (INIS)

Sulmon, Cécile; Baaren, Joan van; Cabello-Hurtado, Francisco; Gouesbet, Gwenola; Hennion, Françoise; Mony, Cendrine; Renault, David; Bormans, Myriam; El Amrani, Abdelhak; Wiegand, Claudia; Gérard, Claudia

2015-01-01

Organisms are regularly subjected to abiotic stressors related to increasing anthropogenic activities, including chemicals and climatic changes that induce major stresses. Based on various key taxa involved in ecosystem functioning (photosynthetic microorganisms, plants, invertebrates), we review how organisms respond and adapt to chemical- and temperature-induced stresses from molecular to population level. Using field-realistic studies, our integrative analysis aims to compare i) how molecular and physiological mechanisms related to protection, repair and energy allocation can impact life history traits of stressed organisms, and ii) to what extent trait responses influence individual and population responses. Common response mechanisms are evident at molecular and cellular scales but become rather difficult to define at higher levels due to evolutionary distance and environmental complexity. We provide new insights into the understanding of the impact of molecular and cellular responses on individual and population dynamics and assess the potential related effects on communities and ecosystem functioning. - Highlights: • Responses to chemical and thermal stressors are reviewed across organization levels. • Common responses between taxa are evident at the molecular and cellular scales. • At individual level, energy allocation connects species-specific stress responses. • Commonality decreases at higher levels due to increasing environmental complexity. - The commonality of stress responses to chemical and thermal stressors among taxa is evident at the molecular and cellular scales but remains unclear at higher levels of organization

The stress-buffering effects of functional social support on ambulatory blood pressure.

Science.gov (United States)

Bowen, Kimberly S; Uchino, Bert N; Birmingham, Wendy; Carlisle, McKenzie; Smith, Timothy W; Light, Kathleen C

2014-11-01

Social support is a reliable predictor of cardiovascular health. According to the buffering hypothesis, stress is 1 mechanism by which support is able to affect physiological processes. However, most of the experimental evidence for the hypothesis comes from laboratory studies. Ambulatory blood pressure (ABP) protocols examine participants in their natural environment, where they are more likely to encounter personally relevant real-world stressors. Furthermore, prior work shows that examining support by its specific functional components reveals additional independent links to health. The current study aimed to examine the stress-buffering effects of functional social support on ABP. One hundred eighty-eight participants completed a 1-day ABP assessment along with measures of functional social support and both global perceived stress and momentary stress at time of reading. RESULTS indicated main effects for both stress measures. Global support, emotional, tangible, and informational support only moderated the effects of momentary stress, but not global stress, in predicting ABP. Informational support was the most consistent stress-buffering predictor of ABP, predicting both ambulatory systolic and diastolic blood pressure. The predicted values in ABP for informational support achieved health-relevant differences, emphasizing the value of examining functional support beyond global support alone. PsycINFO Database Record (c) 2014 APA, all rights reserved.

The influence of viscosity on the functioning of molecular motors

NARCIS (Netherlands)

Klok, Martin; Janssen, Leon P.B.M.; Browne, Wesley R.; Feringa, Ben L.

2009-01-01

Light driven molecular motors based on sterically overcrowded alkenes achieve repetitive unidirectional rotation through a sequential series of photochemical and thermal steps. The influence of highly viscous environments on the functioning of unidirectional light driven molecular motors is

Plant Responses to Nanoparticle Stress

Directory of Open Access Journals (Sweden)

Zahed Hossain

2015-11-01

Full Text Available With the rapid advancement in nanotechnology, release of nanoscale materials into the environment is inevitable. Such contamination may negatively influence the functioning of the ecosystems. Many manufactured nanoparticles (NPs contain heavy metals, which can cause soil and water contamination. Proteomic techniques have contributed substantially in understanding the molecular mechanisms of plant responses against various stresses by providing a link between gene expression and cell metabolism. As the coding regions of genome are responsible for plant adaptation to adverse conditions, protein signatures provide insights into the phytotoxicity of NPs at proteome level. This review summarizes the recent contributions of plant proteomic research to elaborate the complex molecular pathways of plant response to NPs stress.

Identifying the molecular functions of electron transport proteins using radial basis function networks and biochemical properties.

Science.gov (United States)

Le, Nguyen-Quoc-Khanh; Nguyen, Trinh-Trung-Duong; Ou, Yu-Yen

2017-05-01

The electron transport proteins have an important role in storing and transferring electrons in cellular respiration, which is the most proficient process through which cells gather energy from consumed food. According to the molecular functions, the electron transport chain components could be formed with five complexes with several different electron carriers and functions. Therefore, identifying the molecular functions in the electron transport chain is vital for helping biologists understand the electron transport chain process and energy production in cells. This work includes two phases for discriminating electron transport proteins from transport proteins and classifying categories of five complexes in electron transport proteins. In the first phase, the performances from PSSM with AAIndex feature set were successful in identifying electron transport proteins in transport proteins with achieved sensitivity of 73.2%, specificity of 94.1%, and accuracy of 91.3%, with MCC of 0.64 for independent data set. With the second phase, our method can approach a precise model for identifying of five complexes with different molecular functions in electron transport proteins. The PSSM with AAIndex properties in five complexes achieved MCC of 0.51, 0.47, 0.42, 0.74, and 1.00 for independent data set, respectively. We suggest that our study could be a power model for determining new proteins that belongs into which molecular function of electron transport proteins. Copyright © 2017 Elsevier Inc. All rights reserved.

Effects of the Cognitive-Behavioral Therapy for Stress Management on Executive Function Components.

Science.gov (United States)

Santos-Ruiz, Ana; Robles-Ortega, Humbelina; Pérez-García, Miguel; Peralta-Ramírez, María Isabel

2017-02-13

This study aims to determine whether it is possible to modify executive function in stressed individuals by means of cognitive-behavioral therapy for stress management. Thirty-one people with high levels of perceived stress were recruited into the study (treatment group = 18; wait-list group = 13). The treatment group received 14 weeks of stress management program. Psychological and executive function variables were evaluated in both groups pre and post-intervention. The treatment group showed improved psychological variables of perceived stress (t = 5.492; p = .001), vulnerability to stress (t = 4.061; p = .001) and superstitious thinking (t = 2.961; p = .009). Likewise, the results showed statistically significant differences in personality variables related to executive function, positive urgency (t = 3.585; p = .002) and sensitivity to reward (t = -2.201; p = .042), which improved after the therapy. These variables showed a moderate to high effect size (oscillates between 1.30 for perceived stress and .566 for sensitivity to reward). The cognitive-behavioral therapy for stress management may be an appropriate strategy for improving personality construct components related to executive function, however effects of the therapy are not showed on performance on the tests of executive function applied, as presented studies previous.

Molecular markers of neuropsychological functioning and Alzheimer's disease.

Science.gov (United States)

Edwards, Melissa; Balldin, Valerie Hobson; Hall, James; O'Bryant, Sid

2015-03-01

The current project sought to examine molecular markers of neuropsychological functioning among elders with and without Alzheimer's disease (AD) and determine the predictive ability of combined molecular markers and select neuropsychological tests in detecting disease presence. Data were analyzed from 300 participants (n = 150, AD and n = 150, controls) enrolled in the Texas Alzheimer's Research and Care Consortium. Linear regression models were created to examine the link between the top five molecular markers from our AD blood profile and neuropsychological test scores. Logistical regressions were used to predict AD presence using serum biomarkers in combination with select neuropsychological measures. Using the neuropsychological test with the least amount of variance overlap with the molecular markers, the combined neuropsychological test and molecular markers was highly accurate in detecting AD presence. This work provides the foundation for the generation of a point-of-care device that can be used to screen for AD.

Early-life adversity programs emotional functions and the neuroendocrine stress system: the contribution of nutrition, metabolic hormones and epigenetic mechanisms.

Science.gov (United States)

Yam, Kit-Yi; Naninck, Eva F G; Schmidt, Mathias V; Lucassen, Paul J; Korosi, Aniko

2015-01-01

Clinical and pre-clinical studies have shown that early-life adversities, such as abuse or neglect, can increase the vulnerability to develop psychopathologies and cognitive decline later in life. Remarkably, the lasting consequences of stress during this sensitive period on the hypothalamic-pituitary-adrenal axis and emotional function closely resemble the long-term effects of early malnutrition and suggest a possible common pathway mediating these effects. During early-life, brain development is affected by both exogenous factors, like nutrition and maternal care as well as by endogenous modulators including stress hormones. These elements, while mostly considered for their independent actions, clearly do not act alone but rather in a synergistic manner. In order to better understand how the programming by early-life stress takes place, it is important to gain further insight into the exact interplay of these key elements, the possible common pathways as well as the underlying molecular mechanisms that mediate their effects. We here review evidence that exposure to both early-life stress and early-life under-/malnutrition similarly lead to life-long alterations on the neuroendocrine stress system and modify emotional functions. We further discuss how the different key elements of the early-life environment interact and affect one another and next suggest a possible role for the early-life adversity induced alterations in metabolic hormones and nutrient availability in shaping later stress responses and emotional function throughout life, possibly via epigenetic mechanisms. Such knowledge will help to develop intervention strategies, which gives the advantage of viewing the synergistic action of a more complete set of changes induced by early-life adversity.

Stress tolerances of nullmutants of function-unknown genes encoding menadione stress-responsive proteins in Aspergillus nidulans.

Science.gov (United States)

Leiter, Éva; Bálint, Mihály; Miskei, Márton; Orosz, Erzsébet; Szabó, Zsuzsa; Pócsi, István

2016-07-01

A group of menadione stress-responsive function-unkown genes of Aspergillus nidulans (Locus IDs ANID_03987.1, ANID_06058.1, ANID_10219.1, and ANID_10260.1) was deleted and phenotypically characterized. Importantly, comparative and phylogenetic analyses of the tested A. nidulans genes and their orthologs shed light only on the presence of a TANGO2 domain with NRDE protein motif in the translated ANID_06058.1 gene but did not reveal any recognizable protein-encoding domains in other protein sequences. The gene deletion strains were subjected to oxidative, osmotic, and metal ion stress and, surprisingly, only the ΔANID_10219.1 mutant showed an increased sensitivity to 0.12 mmol l(-1) menadione sodium bisulfite. The gene deletions affected the stress sensitivities (tolerances) irregularly, for example, some strains grew more slowly when exposed to various oxidants and/or osmotic stress generating agents, meanwhile the ΔANID_10260.1 mutant possessed a wild-type tolerance to all stressors tested. Our results are in line with earlier studies demonstrating that the deletions of stress-responsive genes do not confer necessarily any stress-sensitivity phenotypes, which can be attributed to compensatory mechanisms based on other elements of the stress response system with overlapping functions. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Production of functional proteins: balance of shear stress and gravity

Science.gov (United States)

Goodwin, Thomas John (Inventor); Hammond, Timothy Grant (Inventor); Kaysen, James Howard (Inventor)

2011-01-01

A method for the production of functional proteins including hormones by renal cells in a three dimensional culturing process responsive to shear stress uses a rotating wall vessel. Natural mixture of renal cells expresses the enzyme 1-.alpha.-hydroxylase which can be used to generate the active form of vitamin D: 1,25-diOH vitamin D.sub.3. The fibroblast cultures and co-culture of renal cortical cells express the gene for erythropoietin and secrete erythropoietin into the culture supernatant. Other shear stress response genes are also modulated by shear stress, such as toxin receptors megalin and cubulin (gp280). Also provided is a method of treating an in-need individual with the functional proteins produced in a three dimensional co-culture process responsive to shear stress using a rotating wall vessel.

Genome-wide analysis of the Hsp70 family genes in pepper (Capsicum annuum L.) and functional identification of CaHsp70-2 involvement in heat stress.

Science.gov (United States)

Guo, Meng; Liu, Jin-Hong; Ma, Xiao; Zhai, Yu-Fei; Gong, Zhen-Hui; Lu, Ming-Hui

2016-11-01

Hsp70s function as molecular chaperones and are encoded by a multi-gene family whose members play a crucial role in plant response to stress conditions, and in plant growth and development. Pepper (Capsicum annuum L.) is an important vegetable crop whose genome has been sequenced. Nonetheless, no overall analysis of the Hsp70 gene family is reported in this crop plant to date. To assess the functionality of Capsicum annuum Hsp70 (CaHsp70) genes, pepper genome database was analyzed in this research. A total of 21 CaHsp70 genes were identified and their characteristics were also described. The promoter and transcript expression analysis revealed that CaHsp70s were involved in pepper growth and development, and heat stress response. Ectopic expression of a cytosolic gene, CaHsp70-2, regulated expression of stress-related genes and conferred increased thermotolerance in transgenic Arabidopsis. Taken together, our results provide the basis for further studied to dissect CaHsp70s' function in response to heat stress as well as other environmental stresses. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

DMPD: Molecular mechanisms of the anti-inflammatory functions of interferons. [Dynamic Macrophage Pathway CSML Database

Lifescience Database Archive (English)

Full Text Available 18086388 Molecular mechanisms of the anti-inflammatory functions of interferons. Ko....csml) Show Molecular mechanisms of the anti-inflammatory functions of interferons. PubmedID 18086388 Title ...Molecular mechanisms of the anti-inflammatory functions of interferons. Authors K

Estimation of flow stress of radiation induced F/M steels using molecular dynamics and discrete dislocation dynamics approach

International Nuclear Information System (INIS)

More, Ameya; Dutta, B.K.; Durgaprasad, P.V.; Arya, A.K.

2012-01-01

Fe-Cr based Ferritic/Martensitic (F/M) steels are the candidate structural materials for future fusion reactors. In this work, a multi-scale approach comprising atomistic Molecular Dynamics (MD) simulations and Discrete Dislocation Dynamics (DDD) simulations are used to model the effect of irradiation dose on the flow stress of F/M steels. At the atomic scale, molecular dynamics simulations are used to study the dislocation interaction with irradiation induced defects, i.e. voids and He bubbles. Whereas, the DDD simulations are used to estimate the change in flow stress of the material as a result of irradiation hardening. (author)

Optimised cut-off function for Tersoff-like potentials for a BN nanosheet: a molecular dynamics study

International Nuclear Information System (INIS)

Kumar, Rajesh; Rajasekaran, G; Parashar, Avinash

2016-01-01

In this article, molecular dynamics based simulations were carried out to study the tensile behaviour of boron nitride nanosheets (BNNSs). Four different sets of Tersoff potential parameters were used in the simulations for estimating the interatomic interactions between boron and nitrogen atoms. Modifications were incorporated in the Tersoff cut-off function to improve the accuracy of results with respect to fracture stress, fracture strain and Young’s modulus. In this study, the original cut-off function was optimised in such a way that small and large cut-off distances were made equal, and hence a single cut-off distance was used with all sets of Tersoff potential parameters. The single value of cut-off distance for the Tersoff potential was chosen after analysing the potential energy and bond forces experienced by boron and nitrogen atoms subjected to bond stretching. The simulations performed with the optimised cut-off function help in identifying the Tersoff potential parameters that reproduce the experimentally evaluated mechanical behaviour of BNNSs. (paper)

Latino parent acculturation stress: Longitudinal effects on family functioning and youth emotional and behavioral health.

Science.gov (United States)

Lorenzo-Blanco, Elma I; Meca, Alan; Unger, Jennifer B; Romero, Andrea; Gonzales-Backen, Melinda; Piña-Watson, Brandy; Cano, Miguel Ángel; Zamboanga, Byron L; Des Rosiers, Sabrina E; Soto, Daniel W; Villamar, Juan A; Lizzi, Karina M; Pattarroyo, Monica; Schwartz, Seth J

2016-12-01

Latino parents can experience acculturation stressors, and according to the Family Stress Model (FSM), parent stress can influence youth mental health and substance use by negatively affecting family functioning. To understand how acculturation stressors come together and unfold over time to influence youth mental health and substance use outcomes, the current study investigated the trajectory of a latent parent acculturation stress factor and its influence on youth mental health and substance use via parent-and youth-reported family functioning. Data came from a 6-wave, school-based survey with 302 recent (stress loaded onto a latent factor of acculturation stress at each of the first 4 time points. Earlier levels of and increases in parent acculturation stress predicted worse youth-reported family functioning. Additionally, earlier levels of parent acculturation stress predicted worse parent-reported family functioning and increases in parent acculturation stress predicted better parent-reported family functioning. While youth-reported positive family functioning predicted higher self-esteem, lower symptoms of depression, and lower aggressive and rule-breaking behavior in youth, parent-reported family positive functioning predicted lower youth alcohol and cigarette use. Findings highlight the need for Latino youth preventive interventions to target parent acculturation stress and family functioning. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Leaf sodium accumulation facilitates salt stress adaptation and preserves photosystem functionality in salt stressed Ocimum basilicum

NARCIS (Netherlands)

Mancarella, S.; Orsini, F.; Oosten, van M.J.; Sanoubar, R.; Stanghellini, C.; Kondo, S.; Gianquinto, G.; Maggio, A.

2016-01-01

In this study, plant growth, water relations, ABA levels, ion accumulation patterns and chlorophyll fluorescence were functionally linked to salt stress tolerance of two basil cultivars (Napoletano and Genovese) with different stress sensitivity levels. Plants were treated with salty water at 0,

Artificial muscle-like function from hierarchical supramolecular assembly of photoresponsive molecular motors.

Science.gov (United States)

Chen, Jiawen; Leung, Franco King-Chi; Stuart, Marc C A; Kajitani, Takashi; Fukushima, Takanori; van der Giessen, Erik; Feringa, Ben L

2018-02-01

A striking feature of living systems is their ability to produce motility by amplification of collective molecular motion from the nanoscale up to macroscopic dimensions. Some of nature's protein motors, such as myosin in muscle tissue, consist of a hierarchical supramolecular assembly of very large proteins, in which mechanical stress induces a coordinated movement. However, artificial molecular muscles have often relied on covalent polymer-based actuators. Here, we describe the macroscopic contractile muscle-like motion of a supramolecular system (comprising 95% water) formed by the hierarchical self-assembly of a photoresponsive amphiphilic molecular motor. The molecular motor first assembles into nanofibres, which further assemble into aligned bundles that make up centimetre-long strings. Irradiation induces rotary motion of the molecular motors, and propagation and accumulation of this motion lead to contraction of the fibres towards the light source. This system supports large-amplitude motion, fast response, precise control over shape, as well as weight-lifting experiments in water and air.

Artificial muscle-like function from hierarchical supramolecular assembly of photoresponsive molecular motors

Science.gov (United States)

Chen, Jiawen; Leung, Franco King-Chi; Stuart, Marc C. A.; Kajitani, Takashi; Fukushima, Takanori; van der Giessen, Erik; Feringa, Ben L.

2018-02-01

A striking feature of living systems is their ability to produce motility by amplification of collective molecular motion from the nanoscale up to macroscopic dimensions. Some of nature's protein motors, such as myosin in muscle tissue, consist of a hierarchical supramolecular assembly of very large proteins, in which mechanical stress induces a coordinated movement. However, artificial molecular muscles have often relied on covalent polymer-based actuators. Here, we describe the macroscopic contractile muscle-like motion of a supramolecular system (comprising 95% water) formed by the hierarchical self-assembly of a photoresponsive amphiphilic molecular motor. The molecular motor first assembles into nanofibres, which further assemble into aligned bundles that make up centimetre-long strings. Irradiation induces rotary motion of the molecular motors, and propagation and accumulation of this motion lead to contraction of the fibres towards the light source. This system supports large-amplitude motion, fast response, precise control over shape, as well as weight-lifting experiments in water and air.

Early life stress determines the effects of glucocorticoids and stress on hippocampal function: Electrophysiological and behavioral evidence respectively.

Science.gov (United States)

Pillai, Anup G; Arp, Marit; Velzing, Els; Lesuis, Sylvie L; Schmidt, Mathias V; Holsboer, Florian; Joëls, Marian; Krugers, Harm J

2018-05-01

Exposure to early-life adversity may program brain function to prepare individuals for adaptation to matching environmental contexts. In this study we tested this hypothesis in more detail by examining the effects of early-life stress - induced by raising offspring with limited nesting and bedding material from postnatal days 2-9 - in various behavioral tasks and on synaptic function in adult mice. Early-life stress impaired adult performance in the hippocampal dependent low-arousing object-in-context recognition memory task. This effect was absent when animals were exposed to a single stressor before training. Early-life stress did not alter high-arousing context and auditory fear conditioning. Early-life stress-induced behavioral modifications were not associated with alterations in the dendritic architecture of hippocampal CA1 pyramidal neurons or principal neurons of the basolateral amygdala. However, early-life stress reduced the ratio of NMDA to AMPA receptor-mediated excitatory postsynaptic currents and glutamate release probability specifically in hippocampal CA1 neurons, but not in the basolateral amygdala. These ex vivo effects in the hippocampus were abolished by acute glucocorticoid treatment. Our findings support that early-life stress can hamper object-in-context learning via pre- and postsynaptic mechanisms that affect hippocampal function but these effects are counteracted by acute stress or elevated glucocorticoid levels. Copyright © 2018. Published by Elsevier Ltd.

Development of thermal stress screening method. Application of green function method

International Nuclear Information System (INIS)

Furuhashi, Ichiro; Shibamoto, Hiroshi; Kasahara, Naoto

2004-01-01

This work was achieved for the development of the screening method of thermal transient stresses in FBR components. We proposed an approximation method for evaluations of thermal stress under variable heat transfer coefficients (non-linear problems) using the Green functions of thermal stresses with constant heat transfer coefficients (linear problems). Detailed thermal stress analyses provided Green functions for a skirt structure and a tube-sheet of Intermediate Heat Exchanger. The upper bound Green functions were obtained by the analyses using those upper bound heat transfer coefficients. The medium and the lower bound Green functions were got by the analyses of those under medium and the lower bound heat transfer coefficients. Conventional evaluations utilized the upper bound Green functions. On the other hand, we proposed a new evaluation method by using the upper bound, medium and the lower bound Green functions. The comparison of above results gave the results as follows. The conventional evaluations were conservative and appropriate for the cases under one fluid thermal transient structure such as the skirt. The conventional evaluations were generally conservative for the complicated structures under two or more fluids thermal transients such as the tube-sheet. But the danger locations could exists for the complicated structures under two or more fluids transients, namely the conventional evaluations were non-conservative. The proposed evaluations gave good estimations for these complicated structures. Though above results, we have made the basic documents of the screening method of thermal transient stresses using the conventional method and the new method. (author)

Cytoskeleton Molecular Motors: Structures and Their Functions in Neuron.

Science.gov (United States)

Xiao, Qingpin; Hu, Xiaohui; Wei, Zhiyi; Tam, Kin Yip

2016-01-01

Cells make use of molecular motors to transport small molecules, macromolecules and cellular organelles to target region to execute biological functions, which is utmost important for polarized cells, such as neurons. In particular, cytoskeleton motors play fundamental roles in neuron polarization, extension, shape and neurotransmission. Cytoskeleton motors comprise of myosin, kinesin and cytoplasmic dynein. F-actin filaments act as myosin track, while kinesin and cytoplasmic dynein move on microtubules. Cytoskeleton motors work together to build a highly polarized and regulated system in neuronal cells via different molecular mechanisms and functional regulations. This review discusses the structures and working mechanisms of the cytoskeleton motors in neurons.

[Impact of Socioeconomic Risk Exposure on Maternal Sensitivity, Stress and Family Functionality].

Science.gov (United States)

Sidor, Anna; Köhler, Hubert; Cierpka, Manfred

2018-03-01

Impact of Socioeconomic Risk Exposure on Maternal Sensitivity, Stress and Family Functionality Parental stress exposure can influence the parent-child relationship, child development and child wellbeing in negative ways. The aim of this study was to investigate the impact of socio-economic risk exposure on the quality of the mother-child-interaction and family functionality. A sample of 294 mother-infant dyads at psychosocial risk was compared with a lower-risk, middle-class sample of 125 mother-infant-dyads in regard to maternal sensitivity/child's cooperation (CARE-Index), maternal stress (PSI-SF) and family functionality (FB-K). Lower levels of maternal sensitivity/child's cooperation and by trend also of the family functionality were found among the mothers from the at-risk sample in comparison to the low-risk sample. The level of maternal stress was similar in both samples. The results underpin the negative effects of a socio-economic risk exposure on the mother-child relationship. An early, sensitivity-focused family support could be encouraged to counteract the negative effects of early socioeconomic stress.

Determination of Hot-Carrier Distribution Functions in Uniaxially Stressed p-Type Germanium

DEFF Research Database (Denmark)

Christensen, Ove

1973-01-01

This paper gives a description of an experimental determination of distribution functions in k→ space of hot holes in uniaxially compressed germanium. The hot-carrier studies were made at 85°K at fields up to 1000 V/cm and uniaxial stresses up to 11 800 kg/cm2. The field and stress were always in...... probabilities with stress. A model based on the nonparabolicity of the upper p3 / 2 level is proposed for the negative differential conductivity in stressed p-type Ge....... function has been assumed. The parameters of the distribution function are then fitted to the experimental modulation. The calculation of absorption was performed numerically, using a four-band k→·p→ model. This model was checked for consistency by comparing with piezoabsorption measurements performed...... in thermal equilibrium. The average carrier energy calculated from the distribution function shows a fast increase with stress and almost saturates when the strain splitting of the two p3 / 2 levels reaches the optical-phonon energy. This saturation is interpreted in terms of the change in scattering...

Stress and brain functional changes in patients with Crohn's disease: A functional magnetic resonance imaging study.

Science.gov (United States)

Agostini, A; Ballotta, D; Righi, S; Moretti, M; Bertani, A; Scarcelli, A; Sartini, A; Ercolani, M; Nichelli, P; Campieri, M; Benuzzi, F

2017-10-01

In Crohn's disease (CD) patients, stress is believed to influence symptoms generation. Stress may act via central nervous system pathways to affect visceral sensitivity and motility thus exacerbating gastrointestinal symptoms. The neural substrate underpinning these mechanisms needs to be investigated in CD. We conducted an explorative functional magnetic resonance imaging (fMRI) study in order to investigate potential differences in the brain stress response in CD patients compared to controls. 17 CD patients and 17 healthy controls underwent a fMRI scan while performing a stressful task consisting in a Stroop color-word interference task designed to induce mental stress in the fMRI environment. Compared to controls, in CD patients the stress task elicited greater blood oxygen level dependent (BOLD) signals in the midcingulate cortex (MCC). The MCC integrate "high" emotional processes with afferent sensory information ascending from the gut. In light of these integrative functions, the stress-evoked MCC hyperactivity in CD patients might represent a plausible neural substrate for the association between stress and symptomatic disease. The MCC dysfunction might be involved in mechanisms of central disinhibition of nociceptive inputs leading to amplify the visceral sensitivity. Finally, the stress-evoked MCC hyperactivity might affect the regulation of intestinal motility resulting in exacerbation of disease symptoms and the autonomic and neuroendocrine regulation of inflammation resulting in enhanced inflammatory activity. © 2017 John Wiley & Sons Ltd.

Heat Shock Proteins: A Review of the Molecular Chaperones for Plant Immunity.

Science.gov (United States)

Park, Chang-Jin; Seo, Young-Su

2015-12-01

As sessile organisms, plants are exposed to persistently changing stresses and have to be able to interpret and respond to them. The stresses, drought, salinity, chemicals, cold and hot temperatures, and various pathogen attacks have interconnected effects on plants, resulting in the disruption of protein homeostasis. Maintenance of proteins in their functional native conformations and preventing aggregation of non-native proteins are important for cell survival under stress. Heat shock proteins (HSPs) functioning as molecular chaperones are the key components responsible for protein folding, assembly, translocation, and degradation under stress conditions and in many normal cellular processes. Plants respond to pathogen invasion using two different innate immune responses mediated by pattern recognition receptors (PRRs) or resistance (R) proteins. HSPs play an indispensable role as molecular chaperones in the quality control of plasma membrane-resident PRRs and intracellular R proteins against potential invaders. Here, we specifically discuss the functional involvement of cytosolic and endoplasmic reticulum (ER) HSPs/chaperones in plant immunity to obtain an integrated understanding of the immune responses in plant cells.

Heat Shock Proteins: A Review of the Molecular Chaperones for Plant Immunity

Directory of Open Access Journals (Sweden)

Chang-Jin Park

2015-12-01

Full Text Available As sessile organisms, plants are exposed to persistently changing stresses and have to be able to interpret and respond to them. The stresses, drought, salinity, chemicals, cold and hot temperatures, and various pathogen attacks have interconnected effects on plants, resulting in the disruption of protein homeostasis. Maintenance of proteins in their functional native conformations and preventing aggregation of non-native proteins are important for cell survival under stress. Heat shock proteins (HSPs functioning as molecular chaperones are the key components responsible for protein folding, assembly, translocation, and degradation under stress conditions and in many normal cellular processes. Plants respond to pathogen invasion using two different innate immune responses mediated by pattern recognition receptors (PRRs or resistance (R proteins. HSPs play an indispensable role as molecular chaperones in the quality control of plasma membrane-resident PRRs and intracellular R proteins against potential invaders. Here, we specifically discuss the functional involvement of cytosolic and endoplasmic reticulum (ER HSPs/chaperones in plant immunity to obtain an integrated understanding of the immune responses in plant cells.

Child Behavior Problems, Teacher Executive Functions, and Teacher Stress in Head Start Classrooms.

Science.gov (United States)

Friedman-Krauss, Allison H; Raver, C Cybele; Neuspiel, Juliana M; Kinsel, John

2014-01-01

The current article explores the relationship between teachers' perceptions of child behavior problems and preschool teacher job stress, as well as the possibility that teachers' executive functions moderate this relationship. Data came from 69 preschool teachers in 31 early childhood classrooms in 4 Head Start centers and were collected using Web-based surveys and Web-based direct assessment tasks. Multilevel models revealed that higher levels of teachers' perceptions of child behavior problems were associated with higher levels of teacher job stress and that higher teacher executive function skills were related to lower job stress. However, findings did not yield evidence for teacher executive functions as a statistical moderator. Many early childhood teachers do not receive sufficient training for handling children's challenging behaviors. Child behavior problems increase a teacher's workload and consequently may contribute to feelings of stress. However, teachers' executive function abilities may enable them to use effective, cognitive-based behavior management and instructional strategies during interactions with students, which may reduce stress. Providing teachers with training on managing challenging behaviors and enhancing executive functions may reduce their stress and facilitate their use of effective classroom practices, which is important for children's school readiness skills and teachers' health.

Oxidative stress and lung function profiles of male smokers free from ...

African Journals Online (AJOL)

Oxidative stress and lung function profiles of male smokers free from COPD compared to those with COPD: A case-control study. ... However, conclusions about the role of blood or lung oxidative stress markers were disparate. Aims: To ... Keywords: inflammation; lung disease; spirometry; tobacco; sedentarily; stress oxidant ...

Extended Lagrangian Density Functional Tight-Binding Molecular Dynamics for Molecules and Solids

International Nuclear Information System (INIS)

Aradi, Balint; Frauenheim, Thomas

2015-01-01

A computationally fast quantum mechanical molecular dynamics scheme using an extended Lagrangian density functional tight-binding formulation has been developed and implemented in the DFTB+ electronic structure program package for simulations of solids and molecular systems. The scheme combines the computational speed of self-consistent density functional tight-binding theory with the efficiency and long-term accuracy of extended Lagrangian Born-Oppenheimer molecular dynamics. Furthermore, for systems without self-consistent charge instabilities, only a single diagonalization or construction of the single-particle density matrix is required in each time step. The molecular dynamics simulation scheme can also be applied to a broad range of problems in materials science, chemistry, and biology

Extended Lagrangian Density Functional Tight-Binding Molecular Dynamics for Molecules and Solids.

Science.gov (United States)

Aradi, Bálint; Niklasson, Anders M N; Frauenheim, Thomas

2015-07-14

A computationally fast quantum mechanical molecular dynamics scheme using an extended Lagrangian density functional tight-binding formulation has been developed and implemented in the DFTB+ electronic structure program package for simulations of solids and molecular systems. The scheme combines the computational speed of self-consistent density functional tight-binding theory with the efficiency and long-term accuracy of extended Lagrangian Born-Oppenheimer molecular dynamics. For systems without self-consistent charge instabilities, only a single diagonalization or construction of the single-particle density matrix is required in each time step. The molecular dynamics simulation scheme can be applied to a broad range of problems in materials science, chemistry, and biology.

A Novel Shape-Free Plane Quadratic Polygonal Hybrid Stress-Function Element

Directory of Open Access Journals (Sweden)

Pei-Lei Zhou

2015-01-01

Full Text Available A novel plane quadratic shape-free hybrid stress-function (HS-F polygonal element is developed by employing the principle of minimum complementary energy and the fundamental analytical solutions of the Airy stress function. Without construction of displacement interpolation function, the formulations of the new model are much simpler than those of the displacement-based polygonal elements and can be degenerated into triangular or quadrilateral elements directly. In particular, it is quite insensitive to various mesh distortions and even can keep precision when element shape is concave. Furthermore, the element does not show any spurious zero energy modes. Numerical examples show the excellent performance of the new element, denoted by HSF-AP-19β, in both displacement and stress solutions.

Transcriptome Profiling of Louisiana iris Root and Identification of Genes Involved in Lead-Stress Response

Directory of Open Access Journals (Sweden)

Songqing Tian

2015-11-01

Full Text Available Louisiana iris is tolerant to and accumulates the heavy metal lead (Pb. However, there is limited knowledge of the molecular mechanisms behind this feature. We describe the transcriptome of Louisiana iris using Illumina sequencing technology. The root transcriptome of Louisiana iris under control and Pb-stress conditions was sequenced. Overall, 525,498 transcripts representing 313,958 unigenes were assembled using the clean raw reads. Among them, 43,015 unigenes were annotated and their functions classified using the euKaryotic Orthologous Groups (KOG database. They were divided into 25 molecular families. In the Gene Ontology (GO database, 50,174 unigenes were categorized into three GO trees (molecular function, cellular component and biological process. After analysis of differentially expressed genes, some Pb-stress-related genes were selected, including biosynthesis genes of chelating compounds, metal transporters, transcription factors and antioxidant-related genes. This study not only lays a foundation for further studies on differential genes under Pb stress, but also facilitates the molecular breeding of Louisiana iris.

Stress intensity factors and weight functions for cracks in front of notches

International Nuclear Information System (INIS)

Fett, T.

1993-12-01

The knowledge of stress intensity factors for cracks at notch roots is important for the fracture mechanical treatment of real components. Stress intensity factor solutions are available only for special notches and externally applied loads. For the treatment of more complex loadings as thermal stresses near the notch root the weight function is needed in addition. In the first part of this report weight functions for cracks in front of internal notches are derived from stress intensity factor solutions under external loading available in the literature. The second part deals with cracks in front of edge notches. Limit cases of stress intensity factors are derived which allow to estimate stress intensity factors for cracks in front of internal elliptical notches with arbitrary aspect ratio of the ellipse and for external notches. (orig.) [de

Density functional study of molecular interactions in secondary structures of proteins.

Science.gov (United States)

Takano, Yu; Kusaka, Ayumi; Nakamura, Haruki

2016-01-01

Proteins play diverse and vital roles in biology, which are dominated by their three-dimensional structures. The three-dimensional structure of a protein determines its functions and chemical properties. Protein secondary structures, including α-helices and β-sheets, are key components of the protein architecture. Molecular interactions, in particular hydrogen bonds, play significant roles in the formation of protein secondary structures. Precise and quantitative estimations of these interactions are required to understand the principles underlying the formation of three-dimensional protein structures. In the present study, we have investigated the molecular interactions in α-helices and β-sheets, using ab initio wave function-based methods, the Hartree-Fock method (HF) and the second-order Møller-Plesset perturbation theory (MP2), density functional theory, and molecular mechanics. The characteristic interactions essential for forming the secondary structures are discussed quantitatively.

Effects of heat stress on baroreflex function in humans

Science.gov (United States)

Crandall, Craig G.; Cui, Jian; Wilson, Thad E.

2003-01-01

INTRODUCTION: Heat stress significantly reduces orthostatic tolerance in humans. The mechanism(s) causing this response remain unknown. The purpose of this review article is to present data pertaining to the hypothesis that reduced orthostatic tolerance in heat stressed individuals is a result of heat stress induced alterations in baroflex function. METHODS: In both normothermic and heat stressed conditions baroreflex responsiveness was assessed via pharmacological and non-pharmacological methods. In addition, the effects of heat stress on post-synaptic vasoconstrictor responsiveness were assessed. RESULTS: Generally, whole body heating did not alter baroreflex sensitivity defined as the gain of the linear portion of the baroreflex curve around the operating point. However, whole body heating shifted the baroreflex curve to the prevailing (i.e. elevated) heart rate and muscle sympathetic nerve activity. Finally, the heat stress impaired vasoconstrictor responses to exogenous administration of adrenergic agonists. CONCLUSION: Current data do not support the hypothesis that reduced orthostatic tolerance associated with heat stress in humans is due to impaired baroreflex responsiveness. This phenomenon may be partially due to the effects of heat stress on reducing vasoconstrictor responsiveness.

The challenges of understanding glycolipid functions: An open outlook based on molecular simulations

DEFF Research Database (Denmark)

Manna, M.; Rog, T.; Vattulainen, I.

2014-01-01

and molecular simulations can be used to shed light on the role of glycolipids in membrane structure and dynamics, receptor function, and other phenomena related to emergence of diseases such as Parkinson's. The cases we discuss highlight the challenge to understand how glycolipids function in cell membranes......, and the significant added value that one would gain by bridging molecular simulations with experiments. This article is part of a Special Issue entitled Tools to study lipid functions. (C) 2014 Elsevier B.V. All rights reserved.......Glycolipids are the most complex lipid type in cell membranes, characterized by a great diversity of different structures and functions. The underlying atomistic/molecular interactions and mechanisms associated with these functions are not well understood. Here we discuss how atomistic...

Optical Absorption in Molecular Crystals from Time-Dependent Density Functional Theory

Science.gov (United States)

2017-04-23

Our approach represents a full solid-state calculation, allowing for polarization ef- fects while still capable of capturing inter-molecular dis...AFRL-AFOSR-UK-TR-2017-0030 Optical absorption in molecular crystals from time-dependent density functional theory Leeor Kronik WEIZMANN INSTITUTE OF...from time-dependent density functional theory 5a.  CONTRACT NUMBER 5b.  GRANT NUMBER FA9550-15-1-0290 5c.  PROGRAM ELEMENT NUMBER 61102F 6. AUTHOR(S

Child Behavior Problems, Teacher Executive Functions, and Teacher Stress in Head Start Classrooms

Science.gov (United States)

Friedman-Krauss, Allison H.; Raver, C. Cybele; Neuspiel, Juliana M.; Kinsel, John

2017-01-01

Research Findings The current article explores the relationship between teachers’ perceptions of child behavior problems and preschool teacher job stress, as well as the possibility that teachers’ executive functions moderate this relationship. Data came from 69 preschool teachers in 31 early childhood classrooms in 4 Head Start centers and were collected using Web-based surveys and Web-based direct assessment tasks. Multilevel models revealed that higher levels of teachers’ perceptions of child behavior problems were associated with higher levels of teacher job stress and that higher teacher executive function skills were related to lower job stress. However, findings did not yield evidence for teacher executive functions as a statistical moderator. Practice or Policy Many early childhood teachers do not receive sufficient training for handling children’s challenging behaviors. Child behavior problems increase a teacher’s workload and consequently may contribute to feelings of stress. However, teachers’ executive function abilities may enable them to use effective, cognitive-based behavior management and instructional strategies during interactions with students, which may reduce stress. Providing teachers with training on managing challenging behaviors and enhancing executive functions may reduce their stress and facilitate their use of effective classroom practices, which is important for children’s school readiness skills and teachers’ health. PMID:28596698

Linear and non-linear dose-response functions reveal a hormetic relationship between stress and learning.

Science.gov (United States)

Zoladz, Phillip R; Diamond, David M

2008-10-16

Over a century of behavioral research has shown that stress can enhance or impair learning and memory. In the present review, we have explored the complex effects of stress on cognition and propose that they are characterized by linear and non-linear dose-response functions, which together reveal a hormetic relationship between stress and learning. We suggest that stress initially enhances hippocampal function, resulting from amygdala-induced excitation of hippocampal synaptic plasticity, as well as the excitatory effects of several neuromodulators, including corticosteroids, norepinephrine, corticotropin-releasing hormone, acetylcholine and dopamine. We propose that this rapid activation of the amygdala-hippocampus brain memory system results in a linear dose-response relation between emotional strength and memory formation. More prolonged stress, however, leads to an inhibition of hippocampal function, which can be attributed to compensatory cellular responses that protect hippocampal neurons from excitotoxicity. This inhibition of hippocampal functioning in response to prolonged stress is potentially relevant to the well-described curvilinear dose-response relationship between arousal and memory. Our emphasis on the temporal features of stress-brain interactions addresses how stress can activate, as well as impair, hippocampal functioning to produce a hormetic relationship between stress and learning.

A novel heat shock protein alpha 8 (Hspa8) molecular network mediating responses to stress- and ethanol-related behaviors.

Science.gov (United States)

Urquhart, Kyle R; Zhao, Yinghong; Baker, Jessica A; Lu, Ye; Yan, Lei; Cook, Melloni N; Jones, Byron C; Hamre, Kristin M; Lu, Lu

2016-04-01

Genetic differences mediate individual differences in susceptibility and responses to stress and ethanol, although, the specific molecular pathways that control these responses are not fully understood. Heat shock protein alpha 8 (Hspa8) is a molecular chaperone and member of the heat shock protein family that plays an integral role in the stress response and that has been implicated as an ethanol-responsive gene. Therefore, we assessed its role in mediating responses to stress and ethanol across varying genetic backgrounds. The hippocampus is an important mediator of these responses, and thus, was examined in the BXD family of mice in this study. We conducted bioinformatic analyses to dissect genetic factors modulating Hspa8 expression, identify downstream targets of Hspa8, and examined its role. Hspa8 is trans-regulated by a gene or genes on chromosome 14 and is part of a molecular network that regulates stress- and ethanol-related behaviors. To determine additional components of this network, we identified direct or indirect targets of Hspa8 and show that these genes, as predicted, participate in processes such as protein folding and organic substance metabolic processes. Two phenotypes that map to the Hspa8 locus are anxiety-related and numerous other anxiety- and/or ethanol-related behaviors significantly correlate with Hspa8 expression. To more directly assay this relationship, we examined differences in gene expression following exposure to stress or alcohol and showed treatment-related differential expression of Hspa8 and a subset of the members of its network. Our findings suggest that Hspa8 plays a vital role in genetic differences in responses to stress and ethanol and their interactions.

Family functioning, parenting stress and quality of life in mothers and fathers of Polish children with high functioning autism or Asperger syndrome.

Science.gov (United States)

Pisula, Ewa; Porębowicz-Dörsmann, Anna

2017-01-01

The aim of the study was to investigate the perception of the family functioning in parents of children with autism spectrum disorders (ASD) with normal-range intelligence and the relationships between family functioning, parenting stress and quality of life. Dyads of parents of children with ASD without intellectual disability and parents of typically developing children (controls) completed a set of self-report questionnaires. Parents of children with ASD reported lower functioning of the family as a whole and their own functioning as family members; they exhibited higher levels of parenting stress and lower quality of life. Mothers of children with ASD experienced more stress in personal domain than fathers. Relationships between family functioning, parenting stress and quality of life have been established. There were also moderate to strong correlations in mother-father dyads between their assessments of family functioning, parenting stress and QoL in social relationships and environmental domains.

Molecular excited states from the SCAN functional

Science.gov (United States)

Tozer, David J.; Peach, Michael J. G.

2018-06-01

The performance of the strongly constrained and appropriately normed (SCAN) meta-generalised gradient approximation exchange-correlation functional is investigated for the calculation of time-dependent density-functional theory molecular excitation energies of local, charge-transfer and Rydberg character, together with the excited ? potential energy curve in H2. The SCAN results frequently resemble those obtained using a global hybrid functional, with either a standard or increased fraction of exact orbital exchange. For local excitations, SCAN can exhibit significant triplet instability problems, resulting in imaginary triplet excitation energies for a number of cases. The Tamm-Dancoff approximation offers a simple approach to improve the situation, but the excitation energies are still significantly underestimated. Understanding the origin of these (near)-triplet instabilities may provide useful insight into future functional development.

Population Structure, Genetic Diversity and Molecular Marker-Trait Association Analysis for High Temperature Stress Tolerance in Rice.

Directory of Open Access Journals (Sweden)

Sharat Kumar Pradhan

Full Text Available Rice exhibits enormous genetic diversity, population structure and molecular marker-traits associated with abiotic stress tolerance to high temperature stress. A set of breeding lines and landraces representing 240 germplasm lines were studied. Based on spikelet fertility percent under high temperature, tolerant genotypes were broadly classified into four classes. Genetic diversity indicated a moderate level of genetic base of the population for the trait studied. Wright's F statistic estimates showed a deviation of Hardy-Weinberg expectation in the population. The analysis of molecular variance revealed 25 percent variation between population, 61 percent among individuals and 14 percent within individuals in the set. The STRUCTURE analysis categorized the entire population into three sub-populations and suggested that most of the landraces in each sub-population had a common primary ancestor with few admix individuals. The composition of materials in the panel showed the presence of many QTLs representing the entire genome for the expression of tolerance. The strongly associated marker RM547 tagged with spikelet fertility under stress and the markers like RM228, RM205, RM247, RM242, INDEL3 and RM314 indirectly controlling the high temperature stress tolerance were detected through both mixed linear model and general linear model TASSEL analysis. These markers can be deployed as a resource for marker-assisted breeding program of high temperature stress tolerance.

Population Structure, Genetic Diversity and Molecular Marker-Trait Association Analysis for High Temperature Stress Tolerance in Rice.

Science.gov (United States)

Pradhan, Sharat Kumar; Barik, Saumya Ranjan; Sahoo, Ambika; Mohapatra, Sudipti; Nayak, Deepak Kumar; Mahender, Anumalla; Meher, Jitandriya; Anandan, Annamalai; Pandit, Elssa

2016-01-01

Rice exhibits enormous genetic diversity, population structure and molecular marker-traits associated with abiotic stress tolerance to high temperature stress. A set of breeding lines and landraces representing 240 germplasm lines were studied. Based on spikelet fertility percent under high temperature, tolerant genotypes were broadly classified into four classes. Genetic diversity indicated a moderate level of genetic base of the population for the trait studied. Wright's F statistic estimates showed a deviation of Hardy-Weinberg expectation in the population. The analysis of molecular variance revealed 25 percent variation between population, 61 percent among individuals and 14 percent within individuals in the set. The STRUCTURE analysis categorized the entire population into three sub-populations and suggested that most of the landraces in each sub-population had a common primary ancestor with few admix individuals. The composition of materials in the panel showed the presence of many QTLs representing the entire genome for the expression of tolerance. The strongly associated marker RM547 tagged with spikelet fertility under stress and the markers like RM228, RM205, RM247, RM242, INDEL3 and RM314 indirectly controlling the high temperature stress tolerance were detected through both mixed linear model and general linear model TASSEL analysis. These markers can be deployed as a resource for marker-assisted breeding program of high temperature stress tolerance.

Dynamic regulation of NMDAR function in the adult brain by the stress hormone corticosterone

Directory of Open Access Journals (Sweden)

Yiu Chung eTse

2012-03-01

Full Text Available Stress and corticosteroids dynamically modulate the expression of synaptic plasticity at glutamatergic synapses in the developed brain. Together with alpha-amino-3-hydroxy-methyl-4-isoxazole propionic acid receptors (AMPAR, N-methyl-D-aspartate receptors (NMDAR are critical mediators of synaptic function and are essential for the induction of many forms of synaptic plasticity. Regulation of NMDAR function by cortisol/corticosterone (CORT may be fundamental to the effects of stress on synaptic plasticity. Recent reports of the efficacy of NMDAR antagonists in treating certain stress-associated psychopathologies further highlight the importance of understanding the regulation of NMDAR function by CORT. Knowledge of how corticosteroids regulate NMDAR function within the adult brain is relatively sparse, perhaps due to a common belief that NMDAR function is relatively stable in the adult brain. We review recent results from our laboratory and others demonstrating dynamic regulation of NMDAR function by CORT in the adult brain. In addition, we consider the issue of how differences in the early life environment may program differential sensitivity to modulation of NMDAR function by CORT and how this may influence synaptic function during stress. Findings from these studies demonstrate that NMDAR function in the adult hippocampus remains sensitive to even brief exposures to CORT and that the capacity for modulation of NMDAR may be programmed, in part, by the early life environment. Modulation of NMDAR function may contribute to dynamic regulation of synaptic plasticity and adaptation in the face of stress, however enhanced NMDAR function may be implicated in mechanisms of stress related psychopathologies including depression.

Parenting stress in pediatric IBD: relations with child psychopathology, family functioning, and disease severity.

Science.gov (United States)

Gray, Wendy N; Graef, Danielle M; Schuman, Shana S; Janicke, David M; Hommel, Kevin A

2013-05-01

Parenting stress in pediatric inflammatory bowel disease (IBD) has been under-examined. Data validating use of the Pediatric Inventory for Parents (PIP), a measure of parenting stress associated with caring for a chronically ill child, in chronic diseases with intermittent, unpredictable disease courses, such as IBD, are needed. This study presents validity data in support of the PIP in pediatric IBD and examines relations between parenting stress and important psychosocial and medical outcomes. Adolescents (N = 130) with IBD and their caregivers across 3 sites completed measures of parenting stress, family functioning, and emotional/behavioral functioning. Disease severity was also assessed for each participant. The PIP demonstrates excellent internal consistency. Parenting stress was significantly higher among those with unhealthy general family functioning and those with children with borderline or clinically elevated internalizing symptoms. Caregiving stress was greater among parents of youth with more active Crohn's disease. Results supported the reliability and validity of the PIP for assessing caregiving stress in pediatric IBD. Routine assessment of parenting stress is recommended, particularly among parents reporting unhealthy family functioning and parents of youth with borderline or clinically elevated internalizing symptoms and more active disease.

Molecular and functional expression of high conductance Ca 2+ activated K+ channels in the eel intestinal epithelium

DEFF Research Database (Denmark)

Lionetto, Maria G; Rizzello, Antonia; Giordano, Maria E

2008-01-01

Several types of K(+) channels have been identified in epithelial cells. Among them high conductance Ca(2+)-activated K(+) channels (BK channels) are of relevant importance for their involvement in regulatory volume decrease (RVD) response following hypotonic stress. The aim of the present work...... was to investigate the functional and molecular expression of BK in the eel intestine, which is a useful experimental model for cell volume regulation research. In the present paper using rat BK channel-specific primer, a RT-PCR signal of 696 pb cDNA was detected in eel intestine, whole nucleotide sequence showed...... high similarity (83%) to the alpha subunit of BK channel family. BK channel protein expression was verified by immunoblotting and confocal microscopy, while the functional role of BK channels in epithelial ion transport mechanisms and cell volume regulation was examined by electrophysiological...

Executive Functions in Students With Depression, Anxiety, and Stress Symptoms.

Science.gov (United States)

Ajilchi, Bita; Nejati, Vahid

2017-01-01

This study aimed to investigate and compare the executive functions of students with depression, anxiety, and stress symptoms with those functions in healthy ones. This study was a comparative and non-clinical analysis. The study population comprised all students of Shahid Beheshti University, Tehran, Iran. A total of 448 students were recruited using convenience sampling method. They were also screened using the Depression Anxiety Stress Scales (DASS) test comprising 21 items. Of study participants, 30 people were depressed, 27 had anxiety, and 15 suffered from stress. Then, 50 control people were matched with them. Next, both groups were compared using the Stroop test, Wisconsin card sorting, and cognitive ability test. Using MANOVA test, data analysis revealed no significant differences among 4 groups with regard to selective attention and shifting attention. Depressed group reacted rapidly as opposed to the anxiety group with regard to measures of shifting attention and cognitive abilities; it was observed that the memory, inhibition control, planning, and flexibility of the healthy group were better than those of the 3 other groups. The findings of this research raised specific issues in relation to the role of depression, anxiety, and stress in the disruption of the executive functions of sufferers. Selective and shifting attention and cognitive abilities are specifically affected in this regard. Meanwhile, the role of stress in impairing decision making and the major role of anxiety in impairing sustained attention was shown to be considerable.

Hsp90 molecular chaperone: structure, functions and participation in cardio-vascular pathologies

Directory of Open Access Journals (Sweden)

Kroupskaya I. V.

2009-10-01

Full Text Available The review is devoted to the analysis of structural and functional properties of molecular chaperon Hsp90. Hsp90 is a representative of highly widespread family of heat shock proteins. The protein is found in eubacteria and all branches of eukarya, but it is apparently absent in archaea. It is one of key regulators of numerous signalling pathways, cell growth and development, apoptosis, induction of autoimmunity, and progression of heart failure. The full functional activity of Hsp90 shows up in a complex with other molecular chaperones and co-chaperones. Molecular interactions between chaperones, different signalling proteins and protein-partners are highly crucial for the normal functioning of signalling pathways and their destruction causes an alteration in the cell physiology up to its death.

Maternal Parenting Stress and Child Perception of Family Functioning Among Families Affected by HIV.

Science.gov (United States)

Schulte, Marya T; Armistead, Lisa; Marelich, William D; Payne, Diana L; Goodrum, Nada M; Murphy, Debra A

Mothers living with HIV (MLWH) experience stressors inherent to parenting, often within a context characterized by poverty, stigma, and/or limited social support. Our study assessed the relationship between parenting stress and child perceptions of family functioning in families with MLWH who have healthy school-age children. MLWH and their children (N = 102 pairs) completed measures addressing parenting stress and perceptions of family functioning (i.e., parent-child communication, family routines, and family cohesion). We used covariance structural modeling to evaluate the relationship between these factors, with results showing greater maternal parenting stress associated with poorer family functioning outcomes (reported by both the child and the mother). Findings offer support for the parenting stress-family functioning relationship by providing the child perspective along with the maternal perspective, and point to the need for interventions aimed at minimizing the impact of maternal parenting stress on family functioning. Copyright © 2017 Association of Nurses in AIDS Care. Published by Elsevier Inc. All rights reserved.

Stress assessment based on EEG univariate features and functional connectivity measures.

Science.gov (United States)

Alonso, J F; Romero, S; Ballester, M R; Antonijoan, R M; Mañanas, M A

2015-07-01

The biological response to stress originates in the brain but involves different biochemical and physiological effects. Many common clinical methods to assess stress are based on the presence of specific hormones and on features extracted from different signals, including electrocardiogram, blood pressure, skin temperature, or galvanic skin response. The aim of this paper was to assess stress using EEG-based variables obtained from univariate analysis and functional connectivity evaluation. Two different stressors, the Stroop test and sleep deprivation, were applied to 30 volunteers to find common EEG patterns related to stress effects. Results showed a decrease of the high alpha power (11 to 12 Hz), an increase in the high beta band (23 to 36 Hz, considered a busy brain indicator), and a decrease in the approximate entropy. Moreover, connectivity showed that the high beta coherence and the interhemispheric nonlinear couplings, measured by the cross mutual information function, increased significantly for both stressors, suggesting that useful stress indexes may be obtained from EEG-based features.

Density functional theory, comparative vibrational spectroscopic studies, highest occupied molecular orbital and lowest unoccupied molecular orbital analysis of Linezolid

Science.gov (United States)

Rajalakshmi, K.; Gunasekaran, S.; Kumaresan, S.

2015-06-01

The Fourier transform infrared spectra and Fourier transform Raman spectra of Linezolid have been recorded in the regions 4,000-400 and 4,000-100 cm-1, respectively. Utilizing the observed Fourier transform infrared spectra and Fourier transform Raman spectra data, a complete vibrational assignment and analysis of the fundamental modes of the compound have been carried out. The optimum molecular geometry, harmonic vibrational frequencies, infrared intensities and Raman scattering activities, have been calculated by density functional theory with 6-31G(d,p), 6-311G(d,p) and M06-2X/6-31G(d,p) levels. The difference between the observed and scaled wavenumber values of most of the fundamentals is very small. A detailed interpretation of the infrared and Raman spectra of Linezolid is reported. Mulliken's net charges have also been calculated. Ultraviolet-visible spectrum of the title molecule has also been calculated using time-dependent density functional method. Besides, molecular electrostatic potential, highest occupied molecular orbital and lowest unoccupied molecular orbital analysis and several thermodynamic properties have been performed by the density functional theoretical method.

Changes in ventricular function during emotional stress and cold exposure

International Nuclear Information System (INIS)

Kiess, M.C.; Moore, R.A.; Dimsdale, J.; Alpert, N.M.; Boucher, C.A.; Strauss, H.W.

1984-01-01

Patients with cardiac disease frequently develop symptoms with emotional stress or cold exposure. To investigate the effects of these stresses in normal subjects, an ambulatory ventricular function monitor (VEST) (previously reported to measure EFs which correlate well with gamma camera measurements) was employed to record sequential 2 minute time activity curves from the left ventricles of 6 healthy men (ages 19-24) during a control period and during a 30 minute stress interview with a psychiatrist. Four of the subjects were also monitored in a cold room (1 0 C) for 20 min. In addition to the left ventricular time-activity curve, heart rate (HR), and BP (cuff) were recorded. All subjects had increases in HR, BP and EF during the stress interview. Cold, however, produced decreases in HR and EF and an increase in BP. The results (mean +- SD) are tabulated. End-systolic and end-diastolic counts and hence volume decreased during the interview and increased during cold exposure. The results suggest that (1) ambulatory changes in ventricular function can be measured with the VEST, and (2) significant changes in cardiovascular physiology are seen in normal subjects during a stress interview and exposure to cold

Quantitative analysis of localized stresses in irradiated stainless steels using high resolution electron backscatter diffraction and molecular dynamics modeling

International Nuclear Information System (INIS)

Johnson, D.C.; Kuhr, B.; Farkas, D.; Was, G.S.

2016-01-01

Quantitative measurements of stress near dislocation channel–grain boundary (DC–GB) interaction sites were made using high resolution electron backscatter diffraction (HREBSD) and have been compared with molecular dynamics (MD) simulations. Tensile stress normal to the grain boundary was significantly elevated at discontinuous DC–GB intersections with peak magnitudes roughly an order of magnitude greater than at sites where slip transfer occurred. These results constitute the first measurement of stress amplification at DC–GB intersections and provide support to the theory that high normal stress at the grain boundary may be a key driver for the initiation of irradiation assisted stress corrosion cracks.

Molecular mechanisms and new strategies to fight stresses in egg-producing birds

Directory of Open Access Journals (Sweden)

E. Shatskikh

2015-03-01

Full Text Available Abstract. Commercial egg production is associated with various stresses decreasing productive and reproductive performance of layers. A growing body of evidence indicates that most of stresses in poultry production at the cellular level are associated with oxidative stress due to excess of free radical production or inadequate antioxidant protection. Recently, a concept of the cellular antioxidant defence has been revised with a special attention paid to cell signalling. Indeed, in animals, redox signalling pathways use reactive oxygen species (ROS to transfer signals from different sources to the nucleus to regulate a number of various functions including growth, differentiation, proliferation and apoptosis. The vitagene concept of fighting stresses emerged as a new direction in a nutritional research. Indeed, by improving the adaptive ability of animals to stress it is possible tosubstantially decrease negative consequences of various stresses in poultry and farm animal production. The analysis of recently published data clearly showed that the anti-stress composition developed on the vitagene concept and supplied with drinking water is an effective means in fighting stresses in poultry production.

Family functioning, parenting stress and quality of life in mothers and fathers of Polish children with high functioning autism or Asperger syndrome.

Directory of Open Access Journals (Sweden)

Ewa Pisula

Full Text Available The aim of the study was to investigate the perception of the family functioning in parents of children with autism spectrum disorders (ASD with normal-range intelligence and the relationships between family functioning, parenting stress and quality of life. Dyads of parents of children with ASD without intellectual disability and parents of typically developing children (controls completed a set of self-report questionnaires. Parents of children with ASD reported lower functioning of the family as a whole and their own functioning as family members; they exhibited higher levels of parenting stress and lower quality of life. Mothers of children with ASD experienced more stress in personal domain than fathers. Relationships between family functioning, parenting stress and quality of life have been established. There were also moderate to strong correlations in mother-father dyads between their assessments of family functioning, parenting stress and QoL in social relationships and environmental domains.

Teacher Stress Predicts Child Executive Function: Moderation by School Poverty

Science.gov (United States)

Neuenschwander, Regula; Friedman-Krauss, Allison; Raver, Cybele; Blair, Clancy

2017-01-01

Research Findings: Recent research has explored relations between classroom quality and child executive function (EF), but little is known about how teachers' well-being, including stress, relates to child EF--a crucial component of self-regulation. We hypothesized that teacher stress is negatively or curvilinearly related to child EF and…

Psychological Stress and Mitochondria: A Systematic Review.

Science.gov (United States)

Picard, Martin; McEwen, Bruce S

Mitochondria are multifunctional life-sustaining organelles that represent a potential intersection point between psychosocial experiences and biological stress responses. This article provides a systematic review of the effects of psychological stress on mitochondrial structure and function. A systematic review of the literature investigating the effects of psychological stress on mitochondrial function was conducted. The review focused on experimentally controlled studies allowing us to draw causal inference about the effect of induced psychological stress on mitochondria. A total of 23 studies met the inclusion criteria. All studies involved male laboratory animals, and most demonstrated that acute and chronic stressors influenced specific facets of mitochondrial function, particularly within the brain. Nineteen studies showed significant adverse effects of psychological stress on mitochondria and four found increases in function or size after stress. In humans, only six observational studies were available, none with experimental designs, and most only measured biological markers that do not directly reflect mitochondrial function, such as mitochondrial DNA copy number. Overall, evidence supports the notion that acute and chronic stressors influence various aspects of mitochondrial biology, and that chronic stress exposure can lead to molecular and functional recalibrations among mitochondria. Limitations of current animal and human studies are discussed. Maladaptive mitochondrial changes that characterize this subcellular state of stress are termed mitochondrial allostatic load. Prospective studies with sensitive measures of specific mitochondrial outcomes will be needed to establish the link between psychosocial stressors, emotional states, the resulting neuroendocrine and immune processes, and mitochondrial energetics relevant to mind-body research in humans.

Wheat EST resources for functional genomics of abiotic stress

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Links Matthew G

2006-06-01

Full Text Available Abstract Background Wheat is an excellent species to study freezing tolerance and other abiotic stresses. However, the sequence of the wheat genome has not been completely characterized due to its complexity and large size. To circumvent this obstacle and identify genes involved in cold acclimation and associated stresses, a large scale EST sequencing approach was undertaken by the Functional Genomics of Abiotic Stress (FGAS project. Results We generated 73,521 quality-filtered ESTs from eleven cDNA libraries constructed from wheat plants exposed to various abiotic stresses and at different developmental stages. In addition, 196,041 ESTs for which tracefiles were available from the National Science Foundation wheat EST sequencing program and DuPont were also quality-filtered and used in the analysis. Clustering of the combined ESTs with d2_cluster and TGICL yielded a few large clusters containing several thousand ESTs that were refractory to routine clustering techniques. To resolve this problem, the sequence proximity and "bridges" were identified by an e-value distance graph to manually break clusters into smaller groups. Assembly of the resolved ESTs generated a 75,488 unique sequence set (31,580 contigs and 43,908 singletons/singlets. Digital expression analyses indicated that the FGAS dataset is enriched in stress-regulated genes compared to the other public datasets. Over 43% of the unique sequence set was annotated and classified into functional categories according to Gene Ontology. Conclusion We have annotated 29,556 different sequences, an almost 5-fold increase in annotated sequences compared to the available wheat public databases. Digital expression analysis combined with gene annotation helped in the identification of several pathways associated with abiotic stress. The genomic resources and knowledge developed by this project will contribute to a better understanding of the different mechanisms that govern stress tolerance in

Perpetual pavement – absorbing stress and functional maintenance

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Rong Gao

2017-03-01

Full Text Available Perpetual Pavement combines the well documented smoothness and safety advantages of asphalt with an advanced, multi-layer paving design process, that with routine maintenance, extends the useful life of a roadway. Perpetual provides long lasting road and smoothness for the construction purposes. This study has the design key points of perpetual pavement based on the idea of life cycle, which has a new direction for the new highway construction, reconstruction and expansion. First, the structure of long life pavement design is studied to analyze the effect of stress absorbing layer. Second, researches on stress absorbing layer from the aspects of raw materials, mix proportion are implemented. Third, the design index of stress absorbing layer is determined by the shear strength test. The results show that the design idea of composite perpetual pavement can be realized by reasonable design of the stress absorbing layer and carrying out the surface functional maintenance can ensure the pavement to avoid structural damage in the operation stage.

Metal-molecular assembly for functional materials

CERN Document Server

Matsuo, Yutaka; Negishi, Yuichi; Yoshizawa, Michito; Uemura, Takashi; Takaya, Hikaru; Takeuchi, Masayuki; Yoshimoto, Soichiro

2013-01-01

This book focuses on modern coordination chemistry, covering porous coordination polymers, metalloproteins, metallopeptides, nanoclusters, nanocapsules, aligned polymers, and fullerenes. As well, it deals with applications to electronic devices and surface characterization. These wide-ranging topics are integrally described from the perspectives of dimensionality (one-, two-, and three-dimension), new materials design, synthesis, molecular assembly, function and application. The nine chapters making up this book have been authored by scientists who are at the cutting edge of research in this p

The posttraumatic stress disorder project in Brazil: neuropsychological, structural and molecular neuroimaging studies in victims of urban violence.

Science.gov (United States)

Bressan, Rodrigo A; Quarantini, Lucas C; Andreoli, Sérgio B; Araújo, Celia; Breen, Gerome; Guindalini, Camila; Hoexter, Marcelo; Jackowski, Andrea P; Jorge, Miguel R; Lacerda, Acioly L T; Lara, Diogo R; Malta, Stella; Moriyama, Tais S; Quintana, Maria I; Ribeiro, Wagner S; Ruiz, Juliana; Schoedl, Aline F; Shih, Ming C; Figueira, Ivan; Koenen, Karestan C; Mello, Marcelo F; Mari, Jair J

2009-06-01

Life trauma is highly prevalent in the general population and posttraumatic stress disorder is among the most prevalent psychiatric consequences of trauma exposure. Brazil has a unique environment to conduct translational research about psychological trauma and posttraumatic stress disorder, since urban violence became a Brazilian phenomenon, being particularly related to the rapid population growth of its cities. This research involves three case-control studies: a neuropsychological, a structural neuroimaging and a molecular neuroimaging study, each focusing on different objectives but providing complementary information. First, it aims to examine cognitive functioning of PTSD subjects and its relationships with symptomatology. The second objective is to evaluate neurostructural integrity of orbitofrontal cortex and hippocampus in PTSD subjects. The third aim is to evaluate if patients with PTSD have decreased dopamine transporter density in the basal ganglia as compared to resilient controls subjects. This paper shows the research rationale and design for these three case-control studies. Cases and controls will be identified through an epidemiologic survey conducted in the city of São Paulo. Subjects exposed to traumatic life experiences resulting in posttraumatic stress disorder (cases) will be compared to resilient victims of traumatic life experiences without PTSD (controls) aiming to identify biological variables that might protect or predispose to PTSD. In the neuropsychological case-control study, 100 patients with PTSD, will be compared with 100 victims of trauma without posttraumatic stress disorder, age- and sex-matched controls. Similarly, 50 cases and 50 controls will be enrolled for the structural study and 25 cases and 25 controls in the functional neuroimaging study. All individuals from the three studies will complete psychometrics and a structured clinical interview (the Structured Clinical Interview for DSM-IV and the Clinician

The posttraumatic stress disorder project in Brazil: neuropsychological, structural and molecular neuroimaging studies in victims of urban violence

Directory of Open Access Journals (Sweden)

Bressan Rodrigo A

2009-06-01

Full Text Available Abstract Background Life trauma is highly prevalent in the general population and posttraumatic stress disorder is among the most prevalent psychiatric consequences of trauma exposure. Brazil has a unique environment to conduct translational research about psychological trauma and posttraumatic stress disorder, since urban violence became a Brazilian phenomenon, being particularly related to the rapid population growth of its cities. This research involves three case-control studies: a neuropsychological, a structural neuroimaging and a molecular neuroimaging study, each focusing on different objectives but providing complementary information. First, it aims to examine cognitive functioning of PTSD subjects and its relationships with symptomatology. The second objective is to evaluate neurostructural integrity of orbitofrontal cortex and hippocampus in PTSD subjects. The third aim is to evaluate if patients with PTSD have decreased dopamine transporter density in the basal ganglia as compared to resilient controls subjects. This paper shows the research rationale and design for these three case-control studies. Methods and design Cases and controls will be identified through an epidemiologic survey conducted in the city of São Paulo. Subjects exposed to traumatic life experiences resulting in posttraumatic stress disorder (cases will be compared to resilient victims of traumatic life experiences without PTSD (controls aiming to identify biological variables that might protect or predispose to PTSD. In the neuropsychological case-control study, 100 patients with PTSD, will be compared with 100 victims of trauma without posttraumatic stress disorder, age- and sex-matched controls. Similarly, 50 cases and 50 controls will be enrolled for the structural study and 25 cases and 25 controls in the functional neuroimaging study. All individuals from the three studies will complete psychometrics and a structured clinical interview (the Structured

Evaluation of molecular brain changes associated with environmental stress in rodent models compared to human major depressive disorder: A proteomic systems approach.

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Cox, David Alan; Gottschalk, Michael Gerd; Stelzhammer, Viktoria; Wesseling, Hendrik; Cooper, Jason David; Bahn, Sabine

2016-11-25

Rodent models of major depressive disorder (MDD) are indispensable when screening for novel treatments, but assessing their translational relevance with human brain pathology has proved difficult. Using a novel systems approach, proteomics data obtained from post-mortem MDD anterior prefrontal cortex tissue (n = 12) and matched controls (n = 23) were compared with equivalent data from three commonly used preclinical models exposed to environmental stressors (chronic mild stress, prenatal stress and social defeat). Functional pathophysiological features associated with depression-like behaviour were identified in these models through enrichment of protein-protein interaction networks. A cross-species comparison evaluated which model(s) represent human MDD pathology most closely. Seven functional domains associated with MDD and represented across at least two models such as "carbohydrate metabolism and cellular respiration" were identified. Through statistical evaluation using kernel-based machine learning techniques, the social defeat model was found to represent MDD brain changes most closely for four of the seven domains. This is the first study to apply a method for directly evaluating the relevance of the molecular pathology of multiple animal models to human MDD on the functional level. The methodology and findings outlined here could help to overcome translational obstacles of preclinical psychiatric research.

Cytological, molecular mechanisms and temperature stress regulating production of diploid male gametes in Dianthus caryophyllus L.

Science.gov (United States)

Zhou, Xuhong; Mo, Xijun; Gui, Min; Wu, Xuewei; Jiang, Yalian; Ma, Lulin; Shi, Ziming; Luo, Ying; Tang, Wenru

2015-12-01

In plant evolution, because of its key role in sexual polyploidization or whole genome duplication events, diploid gamete formation is considered as an important component in diversification and speciation. Environmental stress often triggers unreduced gamete production. However, the molecular, cellular mechanisms and adverse temperature regulating diplogamete production in carnation remain poorly understood. Here, we investigate the cytological basis for 2n male gamete formation and describe the isolation and characterization of the first gene, DcPS1 (Dianthus Caryophyllus Parallel Spindle 1). In addition, we analyze influence of temperature stress on diploid gamete formation and transcript levels of DcPS1. Cytological evidence indicated that 2n male gamete formation is attributable to abnormal spindle orientation at male meiosis II. DcPS1 protein is conserved throughout the plant kingdom and carries domains suggestive of a regulatory function. DcPS1 expression analysis show DcPS1 gene probably have a role in 2n pollen formation. Unreduced pollen formation in various cultivation was sensitive to high or low temperature which was probably regulated by the level of DcPS1 transcripts. In a broader perspective, these findings can have potential applications in fundamental polyploidization research and plant breeding programs. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

Small molecular antioxidants effectively protect from PUVA-induced oxidative stress responses underlying fibroblast senescence and photoaging.

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Briganti, Stefania; Wlaschek, Meinhard; Hinrichs, Christina; Bellei, Barbara; Flori, Enrica; Treiber, Nicolai; Iben, Sebastian; Picardo, Mauro; Scharffetter-Kochanek, Karin

2008-09-01

Exposure of human fibroblasts to 8-methoxypsoralen plus ultraviolet-A irradiation (PUVA) results in stress-induced cellular senescence in fibroblasts. We here studied the role of the antioxidant defense system in the accumulation of reactive oxygen species (ROS) and the effect of the antioxidants alpha-tocopherol, N-acetylcysteine, and alpha-lipoic acid on PUVA-induced cellular senescence. PUVA treatment induced an immediate and increasing generation of intracellular ROS. Supplementation of PUVA-treated fibroblasts with alpha-tocopherol (alpha-Toc), N-acetylcysteine (NAC), or alpha-lipoic acid (alpha-LA) abrogated the increased ROS generation and rescued fibroblasts from the ROS-dependent changes into the cellular senescence phenotype, such as cytoplasmic enlargement, enhanced expression of senescence-associated-beta-galactosidase and matrix-metalloproteinase-1, hallmarks of photoaging and intrinsic aging. PUVA treatment disrupted the integrity of cellular membranes and impaired homeostasis and function of the cellular antioxidant system with a significant decrease in glutathione and hydrogen peroxide-detoxifying enzymes activities. Supplementation with NAC, alpha-LA, and alpha-Toc counteracted these changes. Our data provide causal evidence that (i) oxidative stress due to an imbalance in the overall cellular antioxidant capacity contributes to the induction and maintenance of the PUVA-induced fibroblast senescence and that (ii) low molecular antioxidants protect effectively against these deleterious alterations.

Screening disrupted molecular functions and pathways associated with clear cell renal cell carcinoma using Gibbs sampling.

Science.gov (United States)

Nan, Ning; Chen, Qi; Wang, Yu; Zhai, Xu; Yang, Chuan-Ce; Cao, Bin; Chong, Tie

2017-10-01

To explore the disturbed molecular functions and pathways in clear cell renal cell carcinoma (ccRCC) using Gibbs sampling. Gene expression data of ccRCC samples and adjacent non-tumor renal tissues were recruited from public available database. Then, molecular functions of expression changed genes in ccRCC were classed to Gene Ontology (GO) project, and these molecular functions were converted into Markov chains. Markov chain Monte Carlo (MCMC) algorithm was implemented to perform posterior inference and identify probability distributions of molecular functions in Gibbs sampling. Differentially expressed molecular functions were selected under posterior value more than 0.95, and genes with the appeared times in differentially expressed molecular functions ≥5 were defined as pivotal genes. Functional analysis was employed to explore the pathways of pivotal genes and their strongly co-regulated genes. In this work, we obtained 396 molecular functions, and 13 of them were differentially expressed. Oxidoreductase activity showed the highest posterior value. Gene composition analysis identified 79 pivotal genes, and survival analysis indicated that these pivotal genes could be used as a strong independent predictor of poor prognosis in patients with ccRCC. Pathway analysis identified one pivotal pathway - oxidative phosphorylation. We identified the differentially expressed molecular functions and pivotal pathway in ccRCC using Gibbs sampling. The results could be considered as potential signatures for early detection and therapy of ccRCC. Copyright © 2017 Elsevier Ltd. All rights reserved.

Stress and Fear Extinction

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Maren, Stephen; Holmes, Andrew

2016-01-01

Stress has a critical role in the development and expression of many psychiatric disorders, and is a defining feature of posttraumatic stress disorder (PTSD). Stress also limits the efficacy of behavioral therapies aimed at limiting pathological fear, such as exposure therapy. Here we examine emerging evidence that stress impairs recovery from trauma by impairing fear extinction, a form of learning thought to underlie the suppression of trauma-related fear memories. We describe the major structural and functional abnormalities in brain regions that are particularly vulnerable to stress, including the amygdala, prefrontal cortex, and hippocampus, which may underlie stress-induced impairments in extinction. We also discuss some of the stress-induced neurochemical and molecular alterations in these brain regions that are associated with extinction deficits, and the potential for targeting these changes to prevent or reverse impaired extinction. A better understanding of the neurobiological basis of stress effects on extinction promises to yield novel approaches to improving therapeutic outcomes for PTSD and other anxiety and trauma-related disorders. PMID:26105142

Late-Onset Cognitive Impairments after Early-Life Stress Are Shaped by Inherited Differences in Stress Reactivity

Science.gov (United States)

McIlwrick, Silja; Pohl, Tobias; Chen, Alon; Touma, Chadi

2017-01-01

Early-life stress (ELS) has been associated with lasting cognitive impairments and with an increased risk for affective disorders. A dysregulation of the hypothalamus-pituitary-adrenal (HPA) axis, the body’s main stress response system, is critically involved in mediating these long-term consequences of adverse early-life experience. It remains unclear to what extent an inherited predisposition for HPA axis sensitivity or resilience influences the relationship between ELS and cognitive impairments, and which neuroendocrine and molecular mechanisms may be involved. To investigate this, we exposed animals of the stress reactivity mouse model, consisting of three independent lines selectively bred for high (HR), intermediate (IR), or low (LR) HPA axis reactivity to a stressor, to ELS and assessed their cognitive performance, neuroendocrine function and hippocampal gene expression in early and in late adulthood. Our results show that HR animals that were exposed to ELS exhibited an HPA axis hyper-reactivity in early and late adulthood, associated with cognitive impairments in hippocampus-dependent tasks, as well as molecular changes in transcript levels involved in the regulation of HPA axis activity (Crh) and in neurotrophic action (Bdnf). In contrast, LR animals showed intact cognitive function across adulthood, with no change in stress reactivity. Intriguingly, LR animals that were exposed to ELS even showed significant signs of enhanced cognitive performance in late adulthood, which may be related to late-onset changes observed in the expression of Crh and Crhr1 in the dorsal hippocampus of these animals. Collectively, our findings demonstrate that the lasting consequences of ELS at the level of cognition differ as a function of inherited predispositions and suggest that an innate tendency for low stress reactivity may be protective against late-onset cognitive impairments after ELS. PMID:28261058

Molecular stress response in the CNS of mice after systemic exposureto interferon-alpha, ionizing radiation and ketamine

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Lowe, Xiu R.; Marchetti, Francesco; Lu, Xiaochen; Wyrobek, Andrew J.

2009-03-03

We previously showed that the expression of troponin T1 (Tnnt 1) was induced in the central nervous system (CNS) of adultmice 30 min after treatment with ketamine, a glutamate N-methyl-D-aspartic acid (NMDA) receptor antagonist. We hypothesized that Tnnt 1 expression may be an early molecular biomarker of stress response in the CNS of mice. To further evaluate this hypothesis, we investigated the regional expression of Tnnt 1 in the mouse brain using RNA in situ hybridization 4 h after systemic exposure to interferon-a (IFN-a) and gamma ionizing radiation, both of which have be associated with wide ranges of neuropsychiatric complications. Adult B6C3F1 male mice were treated with either human IFN-a (a single i.p. injection at 1 x 105 IU/kg) or whole body gamma-radiation (10 cGy or 2 Gy). Patterns of Tnnt 1 transcript expression were compared in various CNS regions after IFN-a, radiation and ketamine treatments (previous study). Tnnt 1 expression was consistently induced in pyramidal neurons of cerebral cortex and hippocampus after all treatment regimens including 10 cGy of ionizing radiation. Regional expression of Tnnt 1 was induced in Purkinje cells of cerebellum after ionizing radiation and ketamine treatment; but not after IFN-a treatment. None of the three treatments induced Tnnt 1 expression in glial cells. The patterns of Tnnt 1 expression in pyramidal neurons of cerebral cortex andhippocampus, which are both known to play important roles in cognitive function, memory and emotion, suggest that the expression of Tnnt 1 may be an early molecular biomarker of induced CNS stress.

DNA replication stress: from molecular mechanisms to human disease.

Science.gov (United States)

Muñoz, Sergio; Méndez, Juan

2017-02-01

The genome of proliferating cells must be precisely duplicated in each cell division cycle. Chromosomal replication entails risks such as the possibility of introducing breaks and/or mutations in the genome. Hence, DNA replication requires the coordinated action of multiple proteins and regulatory factors, whose deregulation causes severe developmental diseases and predisposes to cancer. In recent years, the concept of "replicative stress" (RS) has attracted much attention as it impinges directly on genomic stability and offers a promising new avenue to design anticancer therapies. In this review, we summarize recent progress in three areas: (1) endogenous and exogenous factors that contribute to RS, (2) molecular mechanisms that mediate the cellular responses to RS, and (3) the large list of diseases that are directly or indirectly linked to RS.

Socioeconomic Status, Subjective Social Status, and Perceived Stress: Associations with Stress Physiology and Executive Functioning.

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Ursache, Alexandra; Noble, Kimberly G; Blair, Clancy

2015-01-01

Several studies have investigated associations between socioeconomic status (SES) and indicators of children's physiological and cognitive self-regulation. Although objective measures of family SES may be good proxies for families' experiences of disadvantage, less is known about subjective aspects of families' experiences. We hypothesize that subjective social status (SSS) and perceived stress may be important independent predictors of children's stress physiology and executive functioning (EF). Eighty-two children from diverse SES backgrounds were administered EF measures and provided saliva samples for cortisol assay. Caregivers reported on objective SES, SSS, and perceived stress. Results suggest that SES and SSS are both independently and positively related to EF. In models predicting stress physiology, higher perceived stress was associated with lower baseline cortisol. Moreover, SES and age interacted to predict cortisol levels such that among younger children, lower SES was associated with higher cortisol, whereas among older children, lower SES was associated with lower cortisol. Results highlight the importance of considering both objective and subjective indicators of families' SES and stressful experiences in relation to multiple aspects of children's self-regulation.

Cranked cluster wave function for molecular states

International Nuclear Information System (INIS)

Horiuchi, Hisashi; Yabana, Kazuhiro; Wada, Takahiro.

1986-01-01

Construction of the cranked cluster wave function is discussed by focussing on three problems; the self-consistency between the potential and the density distribution, the properties of the rotational angular frequency which is strongly influenced by the inter-cluster Pauli principle and by the parity projection, and the spin alignment along the rotation axis with the resulting structure-change of the molecular state. (author)

Towards refactoring the Molecular Function Ontology with a UML profile for function modeling.

Science.gov (United States)

Burek, Patryk; Loebe, Frank; Herre, Heinrich

2017-10-04

Gene Ontology (GO) is the largest resource for cataloging gene products. This resource grows steadily and, naturally, this growth raises issues regarding the structure of the ontology. Moreover, modeling and refactoring large ontologies such as GO is generally far from being simple, as a whole as well as when focusing on certain aspects or fragments. It seems that human-friendly graphical modeling languages such as the Unified Modeling Language (UML) could be helpful in connection with these tasks. We investigate the use of UML for making the structural organization of the Molecular Function Ontology (MFO), a sub-ontology of GO, more explicit. More precisely, we present a UML dialect, called the Function Modeling Language (FueL), which is suited for capturing functions in an ontologically founded way. FueL is equipped, among other features, with language elements that arise from studying patterns of subsumption between functions. We show how to use this UML dialect for capturing the structure of molecular functions. Furthermore, we propose and discuss some refactoring options concerning fragments of MFO. FueL enables the systematic, graphical representation of functions and their interrelations, including making information explicit that is currently either implicit in MFO or is mainly captured in textual descriptions. Moreover, the considered subsumption patterns lend themselves to the methodical analysis of refactoring options with respect to MFO. On this basis we argue that the approach can increase the comprehensibility of the structure of MFO for humans and can support communication, for example, during revision and further development.

[Molecular imaging; current status and future prospects in USA].

Science.gov (United States)

Kobayashi, Hisataka

2007-02-01

The goal of this review is to introduce the definition, current status, and future prospects of the molecular imaging, which has recently been a hot topic in medicine and the biological science in USA. In vivo imaging methods to visualize the molecular events and functions in organs or animals/humans are overviewed and discussed especially in combinations of imaging modalities (machines) and contrast agents(chemicals) used in the molecular imaging. Next, the close relationship between the molecular imaging and the nanotechnology, an important part of nanomedicine, is stressed from the aspect of united multidisciplinary sciences such as physics, chemistry, biology, and medicine.

Stresses and elastic constants of crystalline sodium, from molecular dynamics

International Nuclear Information System (INIS)

Schiferl, S.K.

1985-02-01

The stresses and the elastic constants of bcc sodium are calculated by molecular dynamics (MD) for temperatures to T = 340K. The total adiabatic potential of a system of sodium atoms is represented by pseudopotential model. The resulting expression has two terms: a large, strictly volume-dependent potential, plus a sum over ion pairs of a small, volume-dependent two-body potential. The stresses and the elastic constants are given as strain derivatives of the Helmholtz free energy. The resulting expressions involve canonical ensemble averages (and fluctuation averages) of the position and volume derivatives of the potential. An ensemble correction relates the results to MD equilibrium averages. Evaluation of the potential and its derivatives requires the calculation of integrals with infinite upper limits of integration, and integrand singularities. Methods for calculating these integrals and estimating the effects of integration errors are developed. A method is given for choosing initial conditions that relax quickly to a desired equilibrium state. Statistical methods developed earlier for MD data are extended to evaluate uncertainties in fluctuation averages, and to test for symmetry. 45 refs., 10 figs., 4 tabs

Molecular and Functional Properties of Regional Astrocytes in the Adult Brain.

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Morel, Lydie; Chiang, Ming Sum R; Higashimori, Haruki; Shoneye, Temitope; Iyer, Lakshmanan K; Yelick, Julia; Tai, Albert; Yang, Yongjie

2017-09-06

The molecular signature and functional properties of astroglial subtypes in the adult CNS remain largely undefined. By using translational ribosome affinity purification followed by RNA-Seq, we profiled astroglial ribosome-associated (presumably translating) mRNAs in major cortical and subcortical brain regions (cortex, hippocampus, caudate-putamen, nucleus accumbens, thalamus, and hypothalamus) of BAC aldh1l1 -translational ribosome affinity purification (TRAP) mice (both sexes). We found that the expression of astroglial translating mRNAs closely follows the dorsoventral axis, especially from cortex/hippocampus to thalamus/hypothalamus posteriorly. This region-specific expression pattern of genes, such as synaptogenic modulator sparc and transcriptional factors ( emx2 , lhx2 , and hopx ), was validated by qRT-PCR and immunostaining in brain sections. Interestingly, cortical or subcortical astrocytes selectively promote neurite growth and synaptic activity of neurons only from the same region in mismatched cocultures, exhibiting region-matched astrocyte to neuron communication. Overall, these results generated new molecular signature of astrocyte types in the adult CNS, providing insights into their origin and functional diversity. SIGNIFICANCE STATEMENT We investigated the in vivo molecular and functional heterogeneity of astrocytes inter-regionally from adult brain. Our results showed that the expression pattern of ribosome-associated mRNA profiles in astrocytes closely follows the dorsoventral axis, especially posteriorly from cortex/hippocampus to thalamus/hypothalamus. In line with this, our functional results further demonstrated region-selective roles of cortical and subcortical astrocytes in regulating cortical or subcortical neuronal synaptogenesis and maturation. These in vivo studies provide a previously uncharacterized and important molecular atlas for exploring region-specific astroglial functions. Copyright © 2017 the authors 0270-6474/17/378706-12$15.00/0.

Diabetes and mitochondrial function: Role of hyperglycemia and oxidative stress

International Nuclear Information System (INIS)

Rolo, Anabela P.; Palmeira, Carlos M.

2006-01-01

Hyperglycemia resulting from uncontrolled glucose regulation is widely recognized as the causal link between diabetes and diabetic complications. Four major molecular mechanisms have been implicated in hyperglycemia-induced tissue damage: activation of protein kinase C (PKC) isoforms via de novo synthesis of the lipid second messenger diacylglycerol (DAG), increased hexosamine pathway flux, increased advanced glycation end product (AGE) formation, and increased polyol pathway flux. Hyperglycemia-induced overproduction of superoxide is the causal link between high glucose and the pathways responsible for hyperglycemic damage. In fact, diabetes is typically accompanied by increased production of free radicals and/or impaired antioxidant defense capabilities, indicating a central contribution for reactive oxygen species (ROS) in the onset, progression, and pathological consequences of diabetes. Besides oxidative stress, a growing body of evidence has demonstrated a link between various disturbances in mitochondrial functioning and type 2 diabetes. Mutations in mitochondrial DNA (mtDNA) and decreases in mtDNA copy number have been linked to the pathogenesis of type 2 diabetes. The study of the relationship of mtDNA to type 2 diabetes has revealed the influence of the mitochondria on nuclear-encoded glucose transporters, glucose-stimulated insulin secretion, and nuclear-encoded uncoupling proteins (UCPs) in β-cell glucose toxicity. This review focuses on a range of mitochondrial factors important in the pathogenesis of diabetes. We review the published literature regarding the direct effects of hyperglycemia on mitochondrial function and suggest the possibility of regulation of mitochondrial function at a transcriptional level in response to hyperglycemia. The main goal of this review is to include a fresh consideration of pathways involved in hyperglycemia-induced diabetic complications

Life stress versus traumatic stress: The impact of life events on psychological functioning in children with and without serious illness.

Science.gov (United States)

Willard, Victoria W; Long, Alanna; Phipps, Sean

2016-01-01

To determine the differential impact of potentially traumatic events (PTEs) and other stressful life events on psychological functioning in 2 groups of children: those with cancer and those without history of serious illness. Children with cancer age 8-17 (n = 254) and age-, sex-, and race/ethnicity-matched controls (n = 142) completed self-report measures of stressful life events and psychological functioning. Stressful life events included those that may meet Diagnostic and Statistical Manual of Mental Disorders (4th ed.; DSM-IV; American Psychiatric Association, 2000) A1 criteria (PTEs; 9 events) and others that would likely not (other events; 21 events). Children with cancer endorsed significantly more PTEs than control children. There were no differences between groups in number of other events experienced. Hierarchical regression analyses revealed that number of other events accounted for significant variance in psychological functioning, above and beyond group status, demographic factors (age and socioeconomic status), and number of PTEs. The number of cumulative other events experienced is a significant predictor of psychological functioning in both youth with serious illness and controls. In contrast, cumulative PTEs appear to have a minor (albeit significant) impact on children's psychological functioning. Assessment of psychological functioning would benefit from a thorough history of stressful life events, regardless of their potential traumatic impact. (c) 2016 APA, all rights reserved).

Bench to bedside molecular functional imaging in translational cancer medicine: to image or to imagine?

International Nuclear Information System (INIS)

Mahajan, A.; Goh, V.; Basu, S.; Vaish, R.; Weeks, A.J.; Thakur, M.H.; Cook, G.J.

2015-01-01

Ongoing research on malignant and normal cell biology has substantially enhanced the understanding of the biology of cancer and carcinogenesis. This has led to the development of methods to image the evolution of cancer, target specific biological molecules, and study the anti-tumour effects of novel therapeutic agents. At the same time, there has been a paradigm shift in the field of oncological imaging from purely structural or functional imaging to combined multimodal structure–function approaches that enable the assessment of malignancy from all aspects (including molecular and functional level) in a single examination. The evolving molecular functional imaging using specific molecular targets (especially with combined positron-emission tomography [PET] computed tomography [CT] using 2- [ 18 F]-fluoro-2-deoxy-D-glucose [FDG] and other novel PET tracers) has great potential in translational research, giving specific quantitative information with regard to tumour activity, and has been of pivotal importance in diagnoses and therapy tailoring. Furthermore, molecular functional imaging has taken a key place in the present era of translational cancer research, producing an important tool to study and evolve newer receptor-targeted therapies, gene therapies, and in cancer stem cell research, which could form the basis to translate these agents into clinical practice, popularly termed “theranostics”. Targeted molecular imaging needs to be developed in close association with biotechnology, information technology, and basic translational scientists for its best utility. This article reviews the current role of molecular functional imaging as one of the main pillars of translational research. -- Highlights: •Molecular functional imaging (MFI) gives insight into the tumor biology and intratumoral heterogeneity. •It has potential role in identifying radiomic signatures associated with underlying gene-expression. •Radiomics can be used to create a road map

New model for surface fracture induced by dynamical stress

OpenAIRE

Andersen, J. V.; Lewis, L. J.

1997-01-01

We introduce a model where an isotropic, dynamically-imposed stress induces fracture in a thin film. Using molecular dynamics simulations, we study how the integrated fragment distribution function depends on the rate of change and magnitude of the imposed stress, as well as on temperature. A mean-field argument shows that the system becomes unstable for a critical value of the stress. We find a striking invariance of the distribution of fragments for fixed ratio of temperature and rate of ch...

Aroma Effects on Physiologic and Cognitive Function Following Acute Stress: A Mechanism Investigation

OpenAIRE

Chamine, Irina; Oken, Barry S.

2016-01-01

Objective: Aromas may improve physiologic and cognitive function after stress, but associated mechanisms remain unknown. This study evaluated the effects of lavender aroma, which is commonly used for stress reduction, on physiologic and cognitive functions. The contribution of pharmacologic, hedonic, and expectancy-related mechanisms of the aromatherapy effects was evaluated.

Molecular and functional definition of the developing human striatum.

Science.gov (United States)

Onorati, Marco; Castiglioni, Valentina; Biasci, Daniele; Cesana, Elisabetta; Menon, Ramesh; Vuono, Romina; Talpo, Francesca; Laguna Goya, Rocio; Lyons, Paul A; Bulfamante, Gaetano P; Muzio, Luca; Martino, Gianvito; Toselli, Mauro; Farina, Cinthia; Barker, Roger A; Biella, Gerardo; Cattaneo, Elena

2014-12-01

The complexity of the human brain derives from the intricate interplay of molecular instructions during development. Here we systematically investigated gene expression changes in the prenatal human striatum and cerebral cortex during development from post-conception weeks 2 to 20. We identified tissue-specific gene coexpression networks, differentially expressed genes and a minimal set of bimodal genes, including those encoding transcription factors, that distinguished striatal from neocortical identities. Unexpected differences from mouse striatal development were discovered. We monitored 36 determinants at the protein level, revealing regional domains of expression and their refinement, during striatal development. We electrophysiologically profiled human striatal neurons differentiated in vitro and determined their refined molecular and functional properties. These results provide a resource and opportunity to gain global understanding of how transcriptional and functional processes converge to specify human striatal and neocortical neurons during development.

Green's Function and Stress Fields in Stochastic Heterogeneous Continua

Science.gov (United States)

Negi, Vineet

Many engineering materials used today are heterogenous in composition e.g. Composites - Polymer Matrix Composites, Metal Matrix Composites. Even, conventional engineering materials - metals, plastics, alloys etc. - may develop heterogeneities, like inclusions and residual stresses, during the manufacturing process. Moreover, these materials may also have intrinsic heterogeneities at a nanoscale in the form of grain boundaries in metals, crystallinity in amorphous polymers etc. While, the homogenized constitutive models for these materials may be satisfactory at a macroscale, recent studies of phenomena like fatigue failure, void nucleation, size-dependent brittle-ductile transition in polymeric nanofibers reveal a major play of micro/nanoscale physics in these phenomena. At this scale, heterogeneities in a material may no longer be ignored. Thus, this demands a study into the effects of various material heterogeneities. In this work, spatial heterogeneities in two material properties - elastic modulus and yield stress - have been investigated separately. The heterogeneity in the elastic modulus is studied in the context of Green's function. The Stochastic Finite Element method is adopted to get the mean statistics of the Green's function defined on a stochastic heterogeneous 2D infinite space. A study of the elastic-plastic transition in a domain having stochastic heterogenous yield stress was done using Mont-Carlo methods. The statistics for various stress and strain fields during the transition were obtained. Further, the effects of size of the domain and the strain-hardening rate on the stress fields during the heterogeneous elastic-plastic transition were investigated. Finally, a case is made for the role of the heterogenous elastic-plastic transition in damage nucleation and growth.

Molecular simulation of the thermophysical properties of N-functionalized alkylimidazoles.

Science.gov (United States)

Turner, C Heath; Cooper, Alex; Zhang, Zhongtao; Shannon, Matthew S; Bara, Jason E

2012-06-07

Molecular simulations are used to probe the thermophysical properties of a series of N-functionalized alkylimidazoles, ranging from N-methylimidazole to N-heptylimidazole. These compounds have been previously synthesized, and their solvation properties have been shown to be potentially useful for CO(2) capture from industrial sources. In this work, we use first-principles calculations to fit electrostatic charges to the molecular models, which are then used to perform a series of molecular dynamics simulations. Over a range of different temperatures, we benchmark the simulated densities and heat capacities against experimental measurements. Also, we predict the Henry's constants for CO(2) absorption and probe the solvents' structures using molecular simulation techniques, such as fractional free volume analysis and void distributions. We find that our simulations are able to closely reproduce the experimental benchmarks and add additional insight into the molecular structure of these fluids, with respect to their observed solvent properties.

Application of numerical methods to the determination of molecular wave functions

International Nuclear Information System (INIS)

Douady, Jerome

1969-01-01

A simplified SCF Method is developed. The wave function of molecular systems and spin densities in the case of free radicals are computed from geometrical data. This method, including at the beginning a delocalization of electrons over all the molecular system, two methods which clear out bonding and anti-bonding interactions have been studied and programmed: a) overlap population analysis, b) localisation of molecular orbitals. These methods have been carried out in the case of organic compounds and free radicals. (author) [fr

Differentiation of molecular chain entanglement structure through laser Raman spectrum measurement of High strength PET fibers under stress

Science.gov (United States)

Go, D.; Takarada, W.; Kikutani, T.

2017-10-01

The aim of this study was to investigate the mechanism for the improvement of mechanical properties of poly(ethylene terephthalate) (PET) fibers based on the concept of controlling the state of molecular entanglement. For this purpose, five different PET fibers were prepared through either the conventional melt spinning and drawing/annealing process or the high-speed melt spinning process. In both cases, the melt spinning process was designed so as to realize different Deborah number conditions. The prepared fibers were subjected to the laser Raman spectroscopy measurement and the characteristics of the scattering peak at around 1616 cm-1, which corresponds to the C-C/C=C stretching mode of the aromatic ring in the main chain, were investigated in detail. It was revealed that the fibers drawn and annealed after the melt spinning process of lower Deborah number showed higher tensile strength as well as lower value of full width at half maximum (FWHM) in the laser Raman spectrum. Narrow FWHM was considered to represent the homogeneous state of entanglement structure, which may lead to the higher strength and toughness of fibers because individual molecular chains tend to bare similar level of tensile stress when the fiber is stretched. In case of high-speed spun fibers prepared with a high Deborah number condition, the FWHM was narrow presumably because much lower tensile stress in comparison with the drawing/annealing process was applied when the fiber structure was developed, however the value increased significantly upon applying tensile load to the fibers during the laser Raman spectrum measurement. From these results, it was concluded that the Laser Raman spectroscopy could differentiate molecular chain entanglement structure of various fiber samples, in that low FWHM, which corresponds to either homogeneous state of molecular entanglement or lower level of mean residual stress, and small increase of FWTH upon applying tensile stress are considered to be the key

The Effects of Acute Stress on Core Executive Functions: A Meta-Analysis and Comparison with Cortisol

Science.gov (United States)

Shields, Grant S.; Sazma, Matthew A.; Yonelinas, Andrew P.

2016-01-01

Core executive functions such as working memory, inhibition, and cognitive flexibility are integral to daily life. A growing body of research has suggested that acute stress may impair core executive functions. However, there are a number of inconsistencies in the literature, leading to uncertainty about how or even if acute stress influences core executive functions. We addressed this by conducting a meta-analysis of acute stress effects on working memory, inhibition, and cognitive flexibility. We found that stress impaired working memory and cognitive flexibility, whereas it had nuanced effects on inhibition. Many of these effects were moderated by other variables, such as sex. In addition, we compared effects of acute stress on core executive functions to effects of cortisol administration and found some striking differences. Our findings indicate that stress works through mechanisms aside from or in addition to cortisol to produce a state characterized by more reactive processing of salient stimuli but greater control over actions. We conclude by highlighting some important future directions for stress and executive function research. PMID:27371161

Impaired Functional Connectivity in the Prefrontal Cortex: A Mechanism for Chronic Stress-Induced Neuropsychiatric Disorders

Directory of Open Access Journals (Sweden)

Ignacio Negrón-Oyarzo

2016-01-01

Full Text Available Chronic stress-related psychiatric diseases, such as major depression, posttraumatic stress disorder, and schizophrenia, are characterized by a maladaptive organization of behavioral responses that strongly affect the well-being of patients. Current evidence suggests that a functional impairment of the prefrontal cortex (PFC is implicated in the pathophysiology of these diseases. Therefore, chronic stress may impair PFC functions required for the adaptive orchestration of behavioral responses. In the present review, we integrate evidence obtained from cognitive neuroscience with neurophysiological research with animal models, to put forward a hypothesis that addresses stress-induced behavioral dysfunctions observed in stress-related neuropsychiatric disorders. We propose that chronic stress impairs mechanisms involved in neuronal functional connectivity in the PFC that are required for the formation of adaptive representations for the execution of adaptive behavioral responses. These considerations could be particularly relevant for understanding the pathophysiology of chronic stress-related neuropsychiatric disorders.

Molecular dynamics simulations

International Nuclear Information System (INIS)

Alder, B.J.

1985-07-01

The molecular dynamics computer simulation discovery of the slow decay of the velocity autocorrelation function in fluids is briefly reviewed in order to contrast that long time tail with those observed for the stress autocorrelation function in fluids and the velocity autocorrelation function in the Lorentz gas. For a non-localized particle in the Lorentz gas it is made plausible that even if it behaved quantum mechanically its long time tail would be the same as the classical one. The generalization of Fick's law for diffusion for the Lorentz gas, necessary to avoid divergences due to the slow decay of correlations, is presented. For fluids, that generalization has not yet been established, but the region of validity of generalized hydrodynamics is discussed. 20 refs., 5 figs

Aroma Effects on Physiologic and Cognitive Function Following Acute Stress: A Mechanism Investigation.

Science.gov (United States)

Chamine, Irina; Oken, Barry S

2016-09-01

Aromas may improve physiologic and cognitive function after stress, but associated mechanisms remain unknown. This study evaluated the effects of lavender aroma, which is commonly used for stress reduction, on physiologic and cognitive functions. The contribution of pharmacologic, hedonic, and expectancy-related mechanisms of the aromatherapy effects was evaluated. Ninety-two healthy adults (mean age, 58.0 years; 79.3% women) were randomly assigned to three aroma groups (lavender, perceptible placebo [coconut], and nonperceptible placebo [water] and to two prime subgroups (primed, with a suggestion of inhaling a powerful stress-reducing aroma, or no prime). Participants' performance on a battery of cognitive tests, physiologic responses, and subjective stress were evaluated at baseline and after exposure to a stress battery during which aromatherapy was present. Participants also rated the intensity and pleasantness of their assigned aroma. Pharmacologic effects of lavender but not placebo aromas significantly benefited post-stress performance on the working memory task (F(2, 86) = 5.41; p = 0.006). Increased expectancy due to positive prime, regardless of aroma type, facilitated post-stress performance on the processing speed task (F(1, 87) = 8.31; p = 0.005). Aroma hedonics (pleasantness and intensity) played a role in the beneficial lavender effect on working memory and physiologic function. The observable aroma effects were produced by a combination of mechanisms involving aroma-specific pharmacologic properties, aroma hedonic properties, and participant expectations. In the future, each of these mechanisms could be manipulated to produce optimal functioning.

Electronic properties of single-molecule junction: Effect of the molecular distortion

International Nuclear Information System (INIS)

Gao, W.; Zhao, M.; Jiang, Q.

2009-01-01

For a model system consisting of a benzenedithio (BDT) molecule sandwiched between two Au plates, the electronic properties as a function of different BDT geometry are investigated using density functional theory. The distorted BDT structures are got through stretching the electrode distance. The corresponding electronic properties, including the spatial distribution of the frontier orbits, the gap between the highest occupied molecular orbital and the lowest unoccupied molecular orbital levels and density of states at the Fermi energy are determined. It reveals that the molecular distortion essentially determines electronic structures. The result should be beneficial to understand the stress-dependent or structure-dependent transport mechanism of electrons of the BDT junction.

A dependent stress-strength interference model based on mixed copula function

Energy Technology Data Exchange (ETDEWEB)

Gao, Jian Xiong; An, Zong Wen; Liu, Bo [School of Mechatronics Engineering, Lanzhou University of Technology, Lanzhou (China)

2016-10-15

In the traditional Stress-strength interference (SSI) model, stress and strength must satisfy the basic assumption of mutual independence. However, a complex dependence between stress and strength exists in practical engineering. To evaluate structural reliability under the case that stress and strength are dependent, a mixed copula function is introduced to a new dependent SSI model. This model can fully characterize the dependence between stress and strength. The residual square sum method and genetic algorithm are also used to estimate the unknown parameters of the model. Finally, the validity of the proposed model is demonstrated via a practical case. Results show that traditional SSI model ignoring the dependence between stress and strength more easily overestimates product reliability than the new dependent SSI model.

Functional porous composites by blending with solution-processable molecular pores.

Science.gov (United States)

Jiang, S; Chen, L; Briggs, M E; Hasell, T; Cooper, A I

2016-05-25

We present a simple method for rendering non-porous materials porous by solution co-processing with organic cage molecules. This method can be used both for small functional molecules and for polymers, thus creating porous composites by molecular blending, rather than the more traditional approach of supporting functional molecules on pre-frabricated porous supports.

Endoplasmic reticulum: ER stress regulates mitochondrial bioenergetics

Science.gov (United States)

Bravo, Roberto; Gutierrez, Tomás; Paredes, Felipe; Gatica, Damián; Rodriguez, Andrea E.; Pedrozo, Zully; Chiong, Mario; Parra, Valentina; Quest, Andrew F.G.; Rothermel, Beverly A.; Lavandero, Sergio

2014-01-01

Endoplasmic reticulum (ER) stress activates an adaptive unfolded protein response (UPR) that facilitates cellular repair, however, under prolonged ER stress, the UPR can ultimately trigger apoptosis thereby terminating damaged cells. The molecular mechanisms responsible for execution of the cell death program are relatively well characterized, but the metabolic events taking place during the adaptive phase of ER stress remain largely undefined. Here we discuss emerging evidence regarding the metabolic changes that occur during the onset of ER stress and how ER influences mitochondrial function through mechanisms involving calcium transfer, thereby facilitating cellular adaptation. Finally, we highlight how dysregulation of ER–mitochondrial calcium homeostasis during prolonged ER stress is emerging as a novel mechanism implicated in the onset of metabolic disorders. PMID:22064245

The BEACH Domain Protein SPIRRIG Is Essential for Arabidopsis Salt Stress Tolerance and Functions as a Regulator of Transcript Stabilization and Localization.

Directory of Open Access Journals (Sweden)

Alexandra Steffens

2015-07-01

Full Text Available Members of the highly conserved class of BEACH domain containing proteins (BDCPs have been established as broad facilitators of protein-protein interactions and membrane dynamics in the context of human diseases like albinism, bleeding diathesis, impaired cellular immunity, cancer predisposition, and neurological dysfunctions. Also, the Arabidopsis thaliana BDCP SPIRRIG (SPI is important for membrane integrity, as spi mutants exhibit split vacuoles. In this work, we report a novel molecular function of the BDCP SPI in ribonucleoprotein particle formation. We show that SPI interacts with the P-body core component DECAPPING PROTEIN 1 (DCP1, associates to mRNA processing bodies (P-bodies, and regulates their assembly upon salt stress. The finding that spi mutants exhibit salt hypersensitivity suggests that the local function of SPI at P-bodies is of biological relevance. Transcriptome-wide analysis revealed qualitative differences in the salt stress-regulated transcriptional response of Col-0 and spi. We show that SPI regulates the salt stress-dependent post-transcriptional stabilization, cytoplasmic agglomeration, and localization to P-bodies of a subset of salt stress-regulated mRNAs. Finally, we show that the PH-BEACH domains of SPI and its human homolog FAN (Factor Associated with Neutral sphingomyelinase activation interact with DCP1 isoforms from plants, mammals, and yeast, suggesting the evolutionary conservation of an association of BDCPs and P-bodies.

Stress and resilience in functional somatic syndromes--a structural equation modeling approach.

Directory of Open Access Journals (Sweden)

Susanne Fischer

Full Text Available BACKGROUND: Stress has been suggested to play a role in the development and perpetuation of functional somatic syndromes. The mechanisms of how this might occur are not clear. PURPOSE: We propose a multi-dimensional stress model which posits that childhood trauma increases adult stress reactivity (i.e., an individual's tendency to respond strongly to stressors and reduces resilience (e.g., the belief in one's competence. This in turn facilitates the manifestation of functional somatic syndromes via chronic stress. We tested this model cross-sectionally and prospectively. METHODS: Young adults participated in a web survey at two time points. Structural equation modeling was used to test our model. The final sample consisted of 3'054 participants, and 429 of these participated in the follow-up survey. RESULTS: Our proposed model fit the data in the cross-sectional (χ2(21  = 48.808, p<.001, CFI  = .995, TLI  = .992, RMSEA  = .021, 90% CI [.013.029] and prospective analyses (χ2(21  =  32.675, p<.05, CFI  = .982, TLI  = .969, RMSEA  = .036, 90% CI [.001.059]. DISCUSSION: Our findings have several clinical implications, suggesting a role for stress management training in the prevention and treatment of functional somatic syndromes.

Effects of stress on immune function: the good, the bad, and the beautiful.

Science.gov (United States)

Dhabhar, Firdaus S

2014-05-01

Although the concept of stress has earned a bad reputation, it is important to recognize that the adaptive purpose of a physiological stress response is to promote survival during fight or flight. While long-term stress is generally harmful, short-term stress can be protective as it prepares the organism to deal with challenges. This review discusses the immune effects of biological stress responses that can be induced by psychological, physiological, or physical (including exercise) stressors. We have proposed that short-term stress is one of the nature's fundamental but under-appreciated survival mechanisms that could be clinically harnessed to enhance immunoprotection. Short-term (i.e., lasting for minutes to hours) stress experienced during immune activation enhances innate/primary and adaptive/secondary immune responses. Mechanisms of immuno-enhancement include changes in dendritic cell, neutrophil, macrophage, and lymphocyte trafficking, maturation, and function as well as local and systemic production of cytokines. In contrast, long-term stress suppresses or dysregulates innate and adaptive immune responses by altering the Type 1-Type 2 cytokine balance, inducing low-grade chronic inflammation, and suppressing numbers, trafficking, and function of immunoprotective cells. Chronic stress may also increase susceptibility to some types of cancer by suppressing Type 1 cytokines and protective T cells and increasing regulatory/suppressor T cell function. Here, we classify immune responses as being protective, pathological, or regulatory, and discuss "good" versus "bad" effects of stress on health. Thus, short-term stress can enhance the acquisition and/or expression of immunoprotective (wound healing, vaccination, anti-infectious agent, anti-tumor) or immuno-pathological (pro-inflammatory, autoimmune) responses. In contrast, chronic stress can suppress protective immune responses and/or exacerbate pathological immune responses. Studies such as the ones discussed

Linear and Non-Linear Dose-Response Functions Reveal a Hormetic Relationship Between Stress and Learning

OpenAIRE

Zoladz, Phillip R.; Diamond, David M.

2008-01-01

Over a century of behavioral research has shown that stress can enhance or impair learning and memory. In the present review, we have explored the complex effects of stress on cognition and propose that they are characterized by linear and non-linear dose-response functions, which together reveal a hormetic relationship between stress and learning. We suggest that stress initially enhances hippocampal function, resulting from amygdala-induced excitation of hippocampal synaptic plasticity, as ...

[Future perspectives for diagnostic imaging in urology: from anatomic and functional to molecular imaging].

Science.gov (United States)

Macis, Giuseppe; Di Giovanni, Silvia; Di Franco, Davide; Bonomo, Lorenzo

2013-01-01

The future approach of diagnostic imaging in urology follows the technological progress, which made the visualization of in vivo molecular processes possible. From anatomo-morphological diagnostic imaging and through functional imaging molecular radiology is reached. Based on molecular probes, imaging is aimed at assessing the in vivo molecular processes, their physiology and function at cellular level. The future imaging will investigate the complex tumor functioning as metabolism, aerobic glycolysis in particular, angiogenesis, cell proliferation, metastatic potential, hypoxia, apoptosis and receptors expressed by neoplastic cells. Methods for performing molecular radiology are CT, MRI, PET-CT, PET-MRI, SPECT and optical imaging. Molecular ultrasound combines technological advancement with targeted contrast media based on microbubbles, this allowing the selective registration of microbubble signal while that of stationary tissues is suppressed. An experimental study was carried out where the ultrasound molecular probe BR55 strictly bound to prostate tumor results in strong enhancement in the early phase after contrast, this contrast being maintained in the late phase. This late enhancement is markedly significant for the detection of prostatic cancer foci and to guide the biopsy sampling. The 124I-cG250 molecular antibody which is strictly linked to cellular carbonic anhydrase IX of clear cell renal carcinoma, allows the acquisition of diagnostic PET images of clear cell renal carcinoma without biopsy. This WG-250 (RENCAREX) antibody was used as a therapy in metastatic clear cell renal carcinoma. Future advancements and applications will result in early cancer diagnosis, personalized therapy that will be specific according to the molecular features of cancer and leading to the development of catheter-based multichannel molecular imaging devices for cystoscopy-based molecular imaging diagnosis and intervention.

Hypothalamic-pituitary-adrenal axis genetic variation and early stress moderates amygdala function.

Science.gov (United States)

Di Iorio, Christina R; Carey, Caitlin E; Michalski, Lindsay J; Corral-Frias, Nadia S; Conley, Emily Drabant; Hariri, Ahmad R; Bogdan, Ryan

2017-06-01

Early life stress may precipitate psychopathology, at least in part, by influencing amygdala function. Converging evidence across species suggests that links between childhood stress and amygdala function may be dependent upon hypothalamic-pituitary-adrenal (HPA) axis function. Using data from college-attending non-Hispanic European-Americans (n=308) who completed the Duke Neurogenetics Study, we examined whether early life stress (ELS) and HPA axis genetic variation interact to predict threat-related amygdala function as well as psychopathology symptoms. A biologically-informed multilocus profile score (BIMPS) captured HPA axis genetic variation (FKBP5 rs1360780, CRHR1 rs110402; NR3C2 rs5522/rs4635799) previously associated with its function (higher BIMPS are reflective of higher HPA axis activity). BOLD fMRI data were acquired while participants completed an emotional face matching task. ELS and depression and anxiety symptoms were measured using the childhood trauma questionnaire and the mood and anxiety symptom questionnaire, respectively. The interaction between HPA axis BIMPS and ELS was associated with right amygdala reactivity to threat-related stimuli, after accounting for multiple testing (empirical-p=0.016). Among individuals with higher BIMPS (i.e., the upper 21.4%), ELS was positively coupled with threat-related amygdala reactivity, which was absent among those with average or low BIMPS. Further, higher BIMPS were associated with greater self-reported anxious arousal, though there was no evidence that amygdala function mediated this relationship. Polygenic variation linked to HPA axis function may moderate the effects of early life stress on threat-related amygdala function and confer risk for anxiety symptomatology. However, what, if any, neural mechanisms may mediate the relationship between HPA axis BIMPS and anxiety symptomatology remains unclear. Copyright © 2017 Elsevier Ltd. All rights reserved.

Coherent molecular transistor: control through variation of the gate wave function.

Science.gov (United States)

Ernzerhof, Matthias

2014-03-21

In quantum interference transistors (QUITs), the current through the device is controlled by variation of the gate component of the wave function that interferes with the wave function component joining the source and the sink. Initially, mesoscopic QUITs have been studied and more recently, QUITs at the molecular scale have been proposed and implemented. Typically, in these devices the gate lead is subjected to externally adjustable physical parameters that permit interference control through modifications of the gate wave function. Here, we present an alternative model of a molecular QUIT in which the gate wave function is directly considered as a variable and the transistor operation is discussed in terms of this variable. This implies that we specify the gate current as well as the phase of the gate wave function component and calculate the resulting current through the source-sink channel. Thus, we extend on prior works that focus on the phase of the gate wave function component as a control parameter while having zero or certain discrete values of the current. We address a large class of systems, including finite graphene flakes, and obtain analytic solutions for how the gate wave function controls the transistor.

Coherent molecular transistor: Control through variation of the gate wave function

International Nuclear Information System (INIS)

Ernzerhof, Matthias

2014-01-01

In quantum interference transistors (QUITs), the current through the device is controlled by variation of the gate component of the wave function that interferes with the wave function component joining the source and the sink. Initially, mesoscopic QUITs have been studied and more recently, QUITs at the molecular scale have been proposed and implemented. Typically, in these devices the gate lead is subjected to externally adjustable physical parameters that permit interference control through modifications of the gate wave function. Here, we present an alternative model of a molecular QUIT in which the gate wave function is directly considered as a variable and the transistor operation is discussed in terms of this variable. This implies that we specify the gate current as well as the phase of the gate wave function component and calculate the resulting current through the source-sink channel. Thus, we extend on prior works that focus on the phase of the gate wave function component as a control parameter while having zero or certain discrete values of the current. We address a large class of systems, including finite graphene flakes, and obtain analytic solutions for how the gate wave function controls the transistor

Corticosterone response to gestational stress and postpartum memory function in mice.

Science.gov (United States)

Jafari, Zahra; Mehla, Jogender; Afrashteh, Navvab; Kolb, Bryan E; Mohajerani, Majid H

2017-01-01

Maternal stress is a common adversity during pregnancy. Gestational corticosterone alternations are thought to contribute to the etiology of postpartum behavioral disturbances. However, the impact of stress during pregnancy, in particular noise exposure, on gestational corticosterone fluctuations and spatial cognition in postpartum mice has not been fully understood yet. We hypothesized that noise exposure during pregnancy negatively affects gestational corticosterone levels and postpartum memory function in the dams similar to the physical stressors. Pregnant C57BL/6 mice were randomly assigned to either one of two stress conditions or a control condition. The noise stress (NS) was induced by presenting a loud intermittent 3000 Hz frequency on gestational days (GDs) 12, 14, and 16 for 24 hours, whereas the physical stress (PS) consisted of restraint and exposure to an elevated platform on GDs 12-16. Plasma corticosterone level was collected on GDs 11 and 17, and Morris water task (MWT) was carried out 30 days after parturition. Compared to the control group, the level of corticosterone in the stressed groups was significantly increased on GD17 relative to GD11. Significantly longer swim time and lower swim speed were observed in both stressed groups relative to the control group. Probe time was significantly shorter in the NS group than the other groups. The delta corticosterone level was significantly correlated with the swim time as well as the probe time in the three groups. Given the results, the adverse effects of gestational noise exposure on the hypothalamic pituitary-adrenal (HPA) axis activation and postpartum spatial learning and memory function were as large as/ or a bit stronger than the physical stresses. The findings suggest the significance of conservation against loud noise exposure in daily living, as well as need to further notice to the different aspects of gestational stress in mothers' behavior like offspring.

Polymer friction Molecular Dynamics

DEFF Research Database (Denmark)

Sivebæk, Ion Marius; Samoilov, Vladimir N.; Persson, Bo N. J.

We present molecular dynamics friction calculations for confined hydrocarbon solids with molecular lengths from 20 to 1400 carbon atoms. Two cases are considered: a) polymer sliding against a hard substrate, and b) polymer sliding on polymer. In the first setup the shear stresses are relatively...... independent of molecular length. For polymer sliding on polymer the friction is significantly larger, and dependent on the molecular chain length. In both cases, the shear stresses are proportional to the squeezing pressure and finite at zero load, indicating an adhesional contribution to the friction force....

Decreased hepatic contents of coenzyme A molecular species in mice after subchronic mild social defeat stress.

Science.gov (United States)

Kubota, Yoshifumi; Goto, Tatsuhiko; Hagiya, Yuki; Chohnan, Shigeru; Toyoda, Atsushi

2016-01-01

Social stress may precipitate psychiatric disorders such as depression, which is related to the occurrence of the metabolic syndrome, including obesity and type 2 diabetes. We have evaluated the effects of social stress on central and peripheral metabolism using a model of depression in mice. In the present study, we focused on coenzyme A (CoA) molecular species [i.e. non-esterified CoA (CoASH), acetyl-CoA and malonyl-CoA] which play important roles in numerous metabolic pathways, and we analyzed changes in expression of these molecules in the hypothalamus and liver of adult male mice (C57BL/6J) subjected to 10 days of subchronic mild social defeat stress (sCSDS) with ICR mice as aggressors. Mice (n = 12) exposed to showed hyperphagia- and polydipsia-like symptoms and increased body weight gain compared with control mice which were not affected by exposure to ICR mice (n = 12). To elucidate the underlying metabolic features in the sCSDS model, acetyl-CoA, malonyl-CoA and CoASH tissue levels were analyzed using the acyl-CoA cycling method. The levels of hypothalamic malonyl-CoA, which decreases feeding behavior, were not influenced by sCSDS. However, sCSDS reduced levels of acetyl-CoA, malonyl-CoA and total CoA (sum of the three CoA molecular species) in the liver. Hence, hyperphagia-like symptoms in sCSDS mice evidently occurred independently of hypothalamic malonyl-CoA, but might consequently lead to down-regulation of hepatic CoA via altered expression of nudix hydrolase 7. Future studies should investigate the molecular mechanism(s) underlying the down-regulation of liver CoA pools in sCSDS mice.

Family functioning, burden and parenting stress 2 years after very preterm birth.

Science.gov (United States)

Treyvaud, Karli; Doyle, Lex W; Lee, Katherine J; Roberts, Gehan; Cheong, Jeanie L Y; Inder, Terrie E; Anderson, Peter J

2011-06-01

Examining rates of difficulties in family functioning following very preterm birth has been a relatively neglected area of research. To examine family functioning, burden and parenting stress in families with very preterm compared with term born children, and investigate influences of parental mental health problems and child neurodevelopmental disability on family outcomes in families with preterm children. Participants were 184 very preterm and 71 term children and their parents. Parents completed the Family Assessment Device, Parenting Stress Index and Impact on Family questionnaires when their children were 2 years old (corrected for prematurity). Parental mental health and social risk information were also collected. Children were assessed for neurodevelopmental disability. Families with very preterm children reported poorer family functioning (p=.03) compared with families with term born children, with less evidence for differences between families with very preterm and term born children in parenting stress and family burden. Within very preterm families, parental mental health problems were associated with higher levels of parenting stress (p=.001), and parents of children with a neurodevelopmental disability were more likely to report higher family burden (p=.04). For families with very preterm children, parental mental health symptoms and child neurodevelopmental disability may identify families at risk of greater stress and burden who may benefit from additional support. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Probing molecular mechanisms of the Hsp90 chaperone: biophysical modeling identifies key regulators of functional dynamics.

Directory of Open Access Journals (Sweden)

Anshuman Dixit

Full Text Available Deciphering functional mechanisms of the Hsp90 chaperone machinery is an important objective in cancer biology aiming to facilitate discovery of targeted anti-cancer therapies. Despite significant advances in understanding structure and function of molecular chaperones, organizing molecular principles that control the relationship between conformational diversity and functional mechanisms of the Hsp90 activity lack a sufficient quantitative characterization. We combined molecular dynamics simulations, principal component analysis, the energy landscape model and structure-functional analysis of Hsp90 regulatory interactions to systematically investigate functional dynamics of the molecular chaperone. This approach has identified a network of conserved regions common to the Hsp90 chaperones that could play a universal role in coordinating functional dynamics, principal collective motions and allosteric signaling of Hsp90. We have found that these functional motifs may be utilized by the molecular chaperone machinery to act collectively as central regulators of Hsp90 dynamics and activity, including the inter-domain communications, control of ATP hydrolysis, and protein client binding. These findings have provided support to a long-standing assertion that allosteric regulation and catalysis may have emerged via common evolutionary routes. The interaction networks regulating functional motions of Hsp90 may be determined by the inherent structural architecture of the molecular chaperone. At the same time, the thermodynamics-based "conformational selection" of functional states is likely to be activated based on the nature of the binding partner. This mechanistic model of Hsp90 dynamics and function is consistent with the notion that allosteric networks orchestrating cooperative protein motions can be formed by evolutionary conserved and sparsely connected residue clusters. Hence, allosteric signaling through a small network of distantly connected

Objective effect manifestation of pectus excavatum on load-stressed pulmonary function testing: a case report

Directory of Open Access Journals (Sweden)

Chan Jason

2011-12-01

Full Text Available Abstract Introduction Pectus excavatum is the most common congenital deformity of the anterior chest wall that, under certain conditions, may pose functional problems due to cardiopulmonary compromise and exercise intolerance. Case presentation We present the case of an otherwise physically-adept 21-year-old Chinese sportsman with idiopathic pectus excavatum, whose symptoms manifested only on bearing a loaded body vest and backpack during physical exercise. Corroborative objective evidence was obtained via load-stressed pulmonary function testing, which demonstrated restrictive lung function. Conclusion This report highlights the possible detrimental synergism of thoracic load stress and pectus excavatum on cardiopulmonary function. Thoracic load-stressed pulmonary function testing provides objective evidence in support of such a synergistic relationship.

Forebrain CRF1 Modulates Early-Life Stress-Programmed Cognitive Deficits

Science.gov (United States)

Wang, Xiao-Dong; Rammes, Gerhard; Kraev, Igor; Wolf, Miriam; Liebl, Claudia; Scharf, Sebastian H.; Rice, Courtney J.; Wurst, Wolfgang; Holsboer, Florian; Deussing, Jan M.; Baram, Tallie Z.; Stewart, Michael G.; Müller, Marianne B.; Schmidt, Mathias V.

2012-01-01

Childhood traumatic events hamper the development of the hippocampus and impair declarative memory in susceptible individuals. Persistent elevations of hippocampal corticotropin-releasing factor (CRF), acting through CRF receptor 1 (CRF1), in experimental models of early-life stress have suggested a role for this endogenous stress hormone in the resulting structural modifications and cognitive dysfunction. However, direct testing of this possibility has been difficult. In the current study, we subjected conditional forebrain CRF1 knock-out (CRF1-CKO) mice to an impoverished postnatal environment and examined the role of forebrain CRF1 in the long-lasting effects of early-life stress on learning and memory. Early-life stress impaired spatial learning and memory in wild-type mice, and postnatal forebrain CRF overexpression reproduced these deleterious effects. Cognitive deficits in stressed wild-type mice were associated with disrupted long-term potentiation (LTP) and a reduced number of dendritic spines in area CA3 but not in CA1. Forebrain CRF1 deficiency restored cognitive function, LTP and spine density in area CA3, and augmented CA1 LTP and spine density in stressed mice. In addition, early-life stress differentially regulated the amount of hippocampal excitatory and inhibitory synapses in wild-type and CRF1-CKO mice, accompanied by alterations in the neurexin-neuroligin complex. These data suggest that the functional, structural and molecular changes evoked by early-life stress are at least partly dependent on persistent forebrain CRF1 signaling, providing a molecular target for the prevention of cognitive deficits in adults with a history of early-life adversity. PMID:21940453

Minority stress and relationship functioning among young male same-sex couples: An examination of actor-partner interdependence models.

Science.gov (United States)

Feinstein, Brian A; McConnell, Elizabeth; Dyar, Christina; Mustanski, Brian; Newcomb, Michael E

2018-05-01

In different-sex couples, individual and partner stress can both have a negative impact on relationship functioning (actor and partner effects). Gay and bisexual men experience unique stress (sexual minority stress), but few studies have examined the effects of this stress on relationship functioning among young male couples. The current study examined (a) actor and partner effects of general and minority stress (internalized stigma, microaggressions, victimization, and outness) on relationship functioning (relationship quality and negative relationship interactions), (b) interactions between individual and partner stress as predictors of relationship functioning, and (c) dyadic coping and relationship length as moderators of actor and partner effects. Actor-partner interdependence models were tested using data from 153 young male couples. There was strong support for actor effects. Higher general stress and internalized stigma were associated with lower relationship quality, but only for those in longer relationships. Additionally, higher general stress, internalized stigma, and microaggressions, and lower outness, were associated with more negative relationship interactions. There was limited support for partner effects. Having a partner with higher internalized stigma was associated with more negative relationship interactions, but none of the other partner effects were significant. There was no support for individual and partner stress interacting to predict relationship functioning or for dyadic coping as a stress buffer. Findings highlight the influence of one's own experiences of general and minority stress on relationship functioning, but raise questions about how partner stress influences relationship functioning among young male couples. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Blunted amygdala functional connectivity during a stress task in alcohol dependent individuals: A pilot study

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Natasha E. Wade, M.S.

2017-12-01

Full Text Available Background: Scant research has been conducted on neural mechanisms underlying stress processing in individuals with alcohol dependence (AD. We examined neural substrates of stress in AD individuals compared with controls using an fMRI task previously shown to induce stress, assessing amygdala functional connectivity to medial prefrontal cortex (mPFC. Materials and methods: For this novel pilot study, 10 abstinent AD individuals and 11 controls completed a modified Trier stress task while undergoing fMRI acquisition. The amygdala was used as a seed region for whole-brain seed-based functional connectivity analysis. Results: After controlling for family-wise error (p = 0.05, there was significantly decreased left and right amygdala connectivity with frontal (specifically mPFC, temporal, parietal, and cerebellar regions. Subjective stress, but not craving, increased from pre-to post-task. Conclusions: This study demonstrated decreased connectivity between the amygdala and regions important for stress and emotional processing in long-term abstinent individuals with AD. These results suggest aberrant stress processing in individuals with AD even after lengthy periods of abstinence. Keywords: Alcohol dependence, fMRI, Stress task, Functional connectivity, Amygdala

The effect of additional equilibrium stress functions on the three-node hybrid-mixed curved beam element

International Nuclear Information System (INIS)

Kim, Jin Gon; Park, Yong Kuk

2008-01-01

To develop an effective hybrid-mixed element, it is extremely critical as to how to assume the stress field. This research article demonstrates the effect of additional equilibrium stress functions to enhance the numerical performance of the locking-free three-node hybrid-mixed curved beam element, proposed in Saleeb and Chang's previous work. It is exceedingly complicated or even infeasible to determine the stress functions to satisfy fully both the equilibrium conditions and suppression of kinematic deformation modes in the three-node hybrid-mixed formulation. Accordingly, the additional stress functions to satisfy partially or fully equilibrium conditions are incorporated in this study. Several numerical examples for static and dynamic problems confirm that the newly proposed element with these additional stress functions is highly effective regardless of the slenderness ratio and curvature of arches in static and dynamic analyses

The Relationship between Stress and Social Functioning in Adults with Autism Spectrum Disorder and without Intellectual Disability

Science.gov (United States)

Bishop-Fitzpatrick, Lauren; Mazefsky, Carla A.; Minshew, Nancy J.; Eack, Shaun M.

2014-01-01

Scientific Abstract Adults with autism spectrum disorder (ASD) face substantial challenges accomplishing basic tasks associated with daily living, which are exacerbated by their broad and pervasive difficulties with social interactions. These challenges put people with ASD at increased risk for psychophysiological distress, which likely factors heavily into social functioning for adults with ASD, as suggested by a growing literature on stress in children that indicates that children with ASD have differential responses to stress than healthy children. We hypothesized that adults with ASD and without intellectual disability (n=38) would experience more stress than healthy volunteers (n=37) and that there would be an inverse relationship between stress and social functioning in individuals with ASD. Baseline, semi-structured interview data from a randomized-controlled trial of two treatments for adults with ASD were used to assess differences in stress between adults with ASD and healthy volunteers and to assess the relationship between stress response and social functioning in adults with ASD. Findings indicate that adults with ASD experience greater perceived and interviewer-observed stress than did healthy volunteers and that stress is significantly related to social functioning in adults with ASD. These findings highlight the role of stress in adult functioning and outcomes and suggest the need to develop and assess treatments designed to target stress and coping in adults with ASD. PMID:25524571

Loss of melanocortin-4 receptor function attenuates HPA responses to psychological stress

DEFF Research Database (Denmark)

Ryan, Karen K; Mul, Joram D; Clemmensen, Christoffer

2014-01-01

function. These results support the hypothesis that endogenous MC4R signaling contributes to the HPA axis response to stress. Because MC4R plays a critical role in the regulation of energy balance, the present work suggests that it may also serve as an important communication link between brain metabolic...... in hypothalamic-pituitary-adrenocortical axis (HPA) regulation. The present work investigated the role of chronic Mc4r function to modulate basal HPA axis tone and to facilitate acute HPA responses to psychological stress, using a novel rat model with Mc4r loss-of-function. In this study, adult male rats were......The melanocortin 4 receptor (MC4R), well-known for its role in the regulation of energy balance, is widely expressed in stress-regulatory brain regions, including the paraventricular nucleus of the hypothalamus (PVH) and the medial amygdala (MeA). In agreement with this, MC4R has been implicated...

Dynamic functional connectivity and individual differences in emotions during social stress.

Science.gov (United States)

Tobia, Michael J; Hayashi, Koby; Ballard, Grey; Gotlib, Ian H; Waugh, Christian E

2017-12-01

Exposure to acute stress induces multiple emotional responses, each with their own unique temporal dynamics. Dynamic functional connectivity (dFC) measures the temporal variability of network synchrony and captures individual differences in network neurodynamics. This study investigated the relationship between dFC and individual differences in emotions induced by an acute psychosocial stressor. Sixteen healthy adult women underwent fMRI scanning during a social evaluative threat (SET) task, and retrospectively completed questionnaires that assessed individual differences in subjectively experienced positive and negative emotions about stress and stress relief during the task. Group dFC was decomposed with parallel factor analysis (PARAFAC) into 10 components, each with a temporal signature, spatial network of functionally connected regions, and vector of participant loadings that captures individual differences in dFC. Participant loadings of two networks were positively correlated with stress-related emotions, indicating the existence of networks for positive and negative emotions. The emotion-related networks involved the ventromedial prefrontal cortex, cingulate cortex, anterior insula, and amygdala, among other distributed brain regions, and time signatures for these emotion-related networks were uncorrelated. These findings demonstrate that individual differences in stress-induced positive and negative emotions are each uniquely associated with large-scale brain networks, and suggest that dFC is a mechanism that generates individual differences in the emotional components of the stress response. Hum Brain Mapp 38:6185-6205, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

HEATING AND ULTRAVIOLET LIGHT ACTIVATE ANTI-STRESS GENE FUNCTIONS IN HUMANS

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Victor Fadeevitch Semenkov

2015-07-01

Full Text Available All types of cell stress are accompanied by the activation of anti-stress genes that can suppress ROS synthesis. We hypothesized that different environmental factors would affect organisms through the activation of anti-stress genes by autologous serum (AS proteins, followed by the synthesis of molecules that increase cell resistance to oxidative stress. The goal of this work was to study the influence of AS on ROS production by peripheral blood neutrophils isolated from donors in different age groups. Neutrophils were isolated from 59 donors (38-94 years old. AS was heated at 100˚C for 30 sec. or irradiated by ultraviolet light (UV at 200-280 nm and 8 W for 10 min. Neutrophils were exposed to heat shock at 42˚C for 1 min. (short-term heating stress or 43˚C for 10 min., followed by the determination of the chemiluminescence reaction induced by zymosan. AS can increase or decrease ROS production by neutrophils depending on the structure of the proteins in the serum; these structures can be changed by heating or UV treatment and the temperature of their interaction (4˚C or 37˚C. We propose that the effect of environmental factors on AS proteins can cause an adverse increase in oxidative stress levels due to the functional reduction of anti-stress genes. We found a negative correlation between the quantity of intracellular Hsp70 and levels of intracellular ROS production following 10 minutes of heat shock at 43°C. Short-term heating stress (1 minute at 42°C was followed by a prominent reduction in ROS production. This effect may be a result of the impact of the hormone adrenaline on the functions of anti-stress genes. Indeed, the same effect was observed after treatment of the neutrophils with adrenaline at concentrations of 10-4 M and 10-5 M. In contrast, dexamethasone from the other stress hormone group did not evoke the same effect at the same concentrations.

From transcriptome to biological function: environmental stress in an ectothermic vertebrate, the coral reef fish Pomacentrus moluccensis

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Ward Alister C

2007-10-01

Full Text Available Abstract Background Our understanding of the importance of transcriptional regulation for biological function is continuously improving. We still know, however, comparatively little about how environmentally induced stress affects gene expression in vertebrates, and the consistency of transcriptional stress responses to different types of environmental stress. In this study, we used a multi-stressor approach to identify components of a common stress response as well as components unique to different types of environmental stress. We exposed individuals of the coral reef fish Pomacentrus moluccensis to hypoxic, hyposmotic, cold and heat shock and measured the responses of approximately 16,000 genes in liver. We also compared winter and summer responses to heat shock to examine the capacity for such responses to vary with acclimation to different ambient temperatures. Results We identified a series of gene functions that were involved in all stress responses examined here, suggesting some common effects of stress on biological function. These common responses were achieved by the regulation of largely independent sets of genes; the responses of individual genes varied greatly across different stress types. In response to heat exposure over five days, a total of 324 gene loci were differentially expressed. Many heat-responsive genes had functions associated with protein turnover, metabolism, and the response to oxidative stress. We were also able to identify groups of co-regulated genes, the genes within which shared similar functions. Conclusion This is the first environmental genomic study to measure gene regulation in response to different environmental stressors in a natural population of a warm-adapted ectothermic vertebrate. We have shown that different types of environmental stress induce expression changes in genes with similar gene functions, but that the responses of individual genes vary between stress types. The functions of heat

Association Between Parenting Stress and Functional Impairment Among Children Diagnosed with Neurodevelopmental Disorders.

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Almogbel, Yasser S; Goyal, Rohit; Sansgiry, Sujit S

2017-05-01

The objective of this study was to examine the association between parenting stress and functional impairment among children with Neurodevelopmental Disorder (NDD). A sample of 150 parents of children diagnosed with NDD were recruited from schools that offer special education services. Parents completed a self-administered survey containing the parenting stress index-short form (PSI-SF) scale and the Columbia Impairment Scale. The multiple logistic regression conducted to compare those with clinically significant PSI-SF scores indicated that the risk of parents with clinically significant scores of parenting stress increased 5.5 times with functionally impaired children with NDD. Further the risk of stress increased 4.6 times when these parents reported having their own disorder/disease. The risk of stress was reduced by 57% for those who had higher than a college level education compared to those with a college level education or below. These findings might help health care providers to initiate early intervention strategies such as peer support and education that can prevent parenting stress and reduce the risk of potential incidence of depression.

Immediate and long-term effects of meditation on acute stress reactivity, cognitive functions, and intelligence.

Science.gov (United States)

Singh, Yogesh; Sharma, Ratna; Talwar, Anjana

2012-01-01

With the current globalization of the world's economy and demands for enhanced performance, stress is present universally. Life's stressful events and daily stresses cause both deleterious and cumulative effects on the human body. The practice of meditation might offer a way to relieve that stress. The research team intended to study the effects of meditation on stress-induced changes in physiological parameters, cognitive functions, intelligence, and emotional quotients. The research team conducted the study in two phases, with a month between them. Each participant served as his own control, and the first phase served as the control for the second phase. In phase 1, the research team studied the effects of a stressor (10 minutes playing a computer game) on participants' stress levels. In phase 2, the research team examined the effects of meditation on stress levels. The research team conducted the study in a lab setting at the All India Institute of Medical Sciences (AIIMS), New Delhi, India. The participants were 34 healthy, male volunteers who were students. To study the effects of long-term meditation on stress levels, intelligence, emotional quotients, and cognitive functions participants meditated daily for 1 month, between phases 1 and 2. To study the immediate effects of meditation on stress levels, participants meditated for 15 minutes after playing a computer game to induce stress. The research team measured galvanic skin response (GSR), heart rate (HR), and salivary cortisol and administered tests for the intelligence and emotional quotients (IQ and EQ), acute and perceived stress (AS and PS), and cognitive functions (ie, the Sternberg memory test [short-term memory] and the Stroop test [cognitive flexibility]). Using a pre-post study design, the team performed this testing (1) prior to the start of the study (baseline); (2) in phase 1, after induced stress; (3) in part 1 of phase 2, after 1 month of daily meditation, and (4) in part 2 of phase 2, after

Stressful Life Events in Children With Functional Defecation Disorders

NARCIS (Netherlands)

Philips, Elise M.; Peeters, Babette; Teeuw, Arianne H.; Leenders, Arnold G. E.; Boluyt, Nicole; Brilleslijper-Kater, Sonja N.; Benninga, Marc A.

2015-01-01

The aim of the study was to determine the prevalence of stressful life events including (sexual) abuse in children with functional defecation disorders by performing a systematic review. We searched MEDLINE, EMBASE, and PsycINFO for cohort, case-control and cross-sectional studies investigating the

Time-course profiling of molecular stress responses to silver nanoparticles in the earthworm Eisenia fetida

DEFF Research Database (Denmark)

Hayashi, Yuya; Heckmann, Lars-Henrik; Simonsen, Vibeke

2013-01-01

) with reference to dissolved silver salt (AgNO3). Principal component analysis of selected gene and enzyme response profiles revealed dissimilar patterns between AgNO3 and AgNP treatments and also over time. Despite the observed difference in molecular profiles, the body burdens of total Ag were within the same...... range (10–40 mg/kg dry weight worm) for both treatments with apparent correlation to the induction pattern of metallothionein. AgNO3 induced the genes and enzymes related to oxidative stress at day 1, after which markers of energy metabolism were all suppressed at day 2. Exposure to AgNPs likewise led...... to induction of oxidative stress genes at day 2, but with a temporal pattern shift to immune genes at day 14 following metabolic upregulation at day 7. The involvement of oxidative stress and subsequent alterations in immune gene regulation were as predicted by our in vitro study reported previously...

Resistance of functional Lactobacillus plantarum strains against food stress conditions.

Science.gov (United States)

Ferrando, Verónica; Quiberoni, Andrea; Reinhemer, Jorge; Suárez, Viviana

2015-06-01

The survival of three Lactobacillus plantarum strains (Lp 790, Lp 813 and Lp 998) with functional properties was studied taking into account their resistance to thermal, osmotic and oxidative stress factors. Stress treatments applied were: 52 °C-15 min (Phosphate Buffer pH 7, thermal shock), H2O2 0.1% (p/v) - 30 min (oxidative shock) and NaCl aqueous solution at 17, 25 and 30% (p/v) (room temperature - 1 h, osmotic shock). The osmotic stress was also evaluated on cell growth in MRS broth added of 2, 4, 6, 8 and 10% (p/v) of NaCl, during 20 h at 30 °C. The cell thermal adaptation was performed in MRS broth, selecting 45 °C for 30 min as final conditions for all strains. Two strains (Lp 813 and Lp 998) showed, in general, similar behaviour against the three stress factors, being clearly more resistant than Lp 790. An evident difference in growth kinetics in presence of NaCl was observed between Lp 998 and Lp 813, Lp998 showing a higher optical density (OD570nm) than Lp 813 at the end of the assay. Selected thermal adaptation improved by 2 log orders the thermal resistance of both strains, but cell growth in presence of NaCl was enhanced only in Lp 813. Oxidative resistance was not affected with this thermal pre-treatment. These results demonstrate the relevance of cell technological resistance when selecting presumptive "probiotic" cultures, since different stress factors might considerably affect viability or/and performance of the strains. The incidence of stress conditions on functional properties of the strains used in this work are currently under research in our group. Copyright © 2014 Elsevier Ltd. All rights reserved.

Glucocorticoid Mechanisms of Functional Connectivity Changes in Stress-Related Neuropsychiatric Disorders.

Science.gov (United States)

Hall, Baila S; Moda, Rachel N; Liston, Conor

2015-01-01

Stress-especially chronic, uncontrollable stress-is an important risk factor for many neuropsychiatric disorders. The underlying mechanisms are complex and multifactorial, but they involve correlated changes in structural and functional measures of neuronal connectivity within cortical microcircuits and across neuroanatomically distributed brain networks. Here, we review evidence from animal models and human neuroimaging studies implicating stress-associated changes in functional connectivity in the pathogenesis of PTSD, depression, and other neuropsychiatric conditions. Changes in fMRI measures of corticocortical connectivity across distributed networks may be caused by specific structural alterations that have been observed in the prefrontal cortex, hippocampus, and other vulnerable brain regions. These effects are mediated in part by glucocorticoids, which are released from the adrenal gland in response to a stressor and also oscillate in synchrony with diurnal rhythms. Recent work indicates that circadian glucocorticoid oscillations act to balance synapse formation and pruning after learning and during development, and chronic stress disrupts this balance. We conclude by considering how disrupted glucocorticoid oscillations may contribute to the pathophysiology of depression and PTSD in vulnerable individuals, and how circadian rhythm disturbances may affect non-psychiatric populations, including frequent travelers, shift workers, and patients undergoing treatment for autoimmune disorders.

Molecular hydrogen is involved in phytohormone signaling and stress responses in plants.

Directory of Open Access Journals (Sweden)

Jiqing Zeng

Full Text Available Molecular hydrogen (H2 metabolism in bacteria and algae has been well studied from an industrial perspective because H2 is viewed as a potential future energy source. A number of clinical trials have recently reported that H2 is a therapeutic antioxidant and signaling molecule. Although H2 metabolism in higher plants was reported in some early studies, its biological effects remain unclear. In this report, the biological effects of H2 and its involvement in plant hormone signaling pathways and stress responses were determined. Antioxidant enzyme activity was found to be increased and the transcription of corresponding genes altered when the effects of H2 on the germination of mung bean seeds treated with phytohormones was investigated. In addition, upregulation of several phytohormone receptor genes and genes that encode a few key factors involved in plant signaling pathways was detected in rice seedlings treated with HW. The transcription of putative rice hydrogenase genes, hydrogenase activity, and endogenous H2 production were also determined. H2 production was found to be induced by abscisic acid, ethylene, and jasmonate acid, salt, and drought stress and was consistent with hydrogenase activity and the expression of putative hydrogenase genes in rice seedlings. Together, these results suggest that H2 may have an effect on rice stress tolerance by modulating the output of hormone signaling pathways.

The modified couple stress functionally graded Timoshenko beam formulation

International Nuclear Information System (INIS)

Asghari, M.; Rahaeifard, M.; Kahrobaiyan, M.H.; Ahmadian, M.T.

2011-01-01

In this paper, a size-dependent formulation is presented for Timoshenko beams made of a functionally graded material (FGM). The formulation is developed on the basis of the modified couple stress theory. The modified couple stress theory is a non-classic continuum theory capable to capture the small-scale size effects in the mechanical behavior of structures. The beam properties are assumed to vary through the thickness of the beam. The governing differential equations of motion are derived for the proposed modified couple-stress FG Timoshenko beam. The generally valid closed-form analytic expressions are obtained for the static response parameters. As case studies, the static and free vibration of the new model are respectively investigated for FG cantilever and FG simply supported beams in which properties are varying according to a power law. The results indicate that modeling beams on the basis of the couple stress theory causes more stiffness than modeling based on the classical continuum theory, such that for beams with small thickness, a significant difference between the results of these two theories is observed.

Attentional avoidance of fearful facial expressions following early life stress is associated with impaired social functioning.

Science.gov (United States)

Humphreys, Kathryn L; Kircanski, Katharina; Colich, Natalie L; Gotlib, Ian H

2016-10-01

Early life stress is associated with poorer social functioning. Attentional biases in response to threat-related cues, linked to both early experience and psychopathology, may explain this association. To date, however, no study has examined attentional biases to fearful facial expressions as a function of early life stress or examined these biases as a potential mediator of the relation between early life stress and social problems. In a sample of 154 children (ages 9-13 years) we examined the associations among interpersonal early life stressors (i.e., birth through age 6 years), attentional biases to emotional facial expressions using a dot-probe task, and social functioning on the Child Behavior Checklist. High levels of early life stress were associated with both greater levels of social problems and an attentional bias away from fearful facial expressions, even after accounting for stressors occurring in later childhood. No biases were found for happy or sad facial expressions as a function of early life stress. Finally, attentional biases to fearful faces mediated the association between early life stress and social problems. Attentional avoidance of fearful facial expressions, evidenced by a bias away from these stimuli, may be a developmental response to early adversity and link the experience of early life stress to poorer social functioning. © 2016 Association for Child and Adolescent Mental Health.

Chronic stress and pituitary-adrenal function in female pigs

NARCIS (Netherlands)

Janssens, C.J.J.G.

1994-01-01

Introduction

The main purpose of the studies described in this thesis was to gain more insight in the regulation of the hypothalamic-pituitary-adrenocorticaI (HPA) system and the mechanisms underlying adaptation to chronic stress in female pigs. The function of the HPA axis, which

Functional characterization of Dihydroflavonol-4-reductase in anthocyanin biosynthesis of purple sweet potato underlies the direct evidence of anthocyanins function against abiotic stresses.

Science.gov (United States)

Wang, Hongxia; Fan, Weijuan; Li, Hong; Yang, Jun; Huang, Jirong; Zhang, Peng

2013-01-01

Dihydroflavonol-4-reductase (DFR) is a key enzyme in the catalysis of the stereospecific reduction of dihydroflavonols to leucoanthocyanidins in anthocyanin biosynthesis. In the purple sweet potato (Ipomoea batatas Lam.) cv. Ayamurasaki, expression of the IbDFR gene was strongly associated with anthocyanin accumulation in leaves, stems and roots. Overexpression of the IbDFR in Arabidopsis tt3 mutants fully complemented the pigmentation phenotype of the seed coat, cotyledon and hypocotyl. Downregulation of IbDFR expression in transgenic sweet potato (DFRi) using an RNAi approach dramatically reduced anthocyanin accumulation in young leaves, stems and storage roots. In contrast, the increase of flavonols quercetin-3-O-hexose-hexoside and quercetin-3-O-glucoside in the leaves and roots of DFRi plants is significant. Therefore, the metabolic pathway channeled greater flavonol influx in the DFRi plants when their anthocyanin and proanthocyanidin accumulation were decreased. These plants also displayed reduced antioxidant capacity compared to the wild type. After 24 h of cold treatment and 2 h recovery, the wild-type plants were almost fully restored to the initial phenotype compared to the slower recovery of DFRi plants, in which the levels of electrolyte leakage and hydrogen peroxide accumulation were dramatically increased. These results provide direct evidence of anthocyanins function in the protection against oxidative stress in the sweet potato. The molecular characterization of the IbDFR gene in the sweet potato not only confirms its important roles in flavonoid metabolism but also supports the protective function of anthocyanins of enhanced scavenging of reactive oxygen radicals in plants under stressful conditions.

Functional characterization of Dihydroflavonol-4-reductase in anthocyanin biosynthesis of purple sweet potato underlies the direct evidence of anthocyanins function against abiotic stresses.

Directory of Open Access Journals (Sweden)

Hongxia Wang

Full Text Available Dihydroflavonol-4-reductase (DFR is a key enzyme in the catalysis of the stereospecific reduction of dihydroflavonols to leucoanthocyanidins in anthocyanin biosynthesis. In the purple sweet potato (Ipomoea batatas Lam. cv. Ayamurasaki, expression of the IbDFR gene was strongly associated with anthocyanin accumulation in leaves, stems and roots. Overexpression of the IbDFR in Arabidopsis tt3 mutants fully complemented the pigmentation phenotype of the seed coat, cotyledon and hypocotyl. Downregulation of IbDFR expression in transgenic sweet potato (DFRi using an RNAi approach dramatically reduced anthocyanin accumulation in young leaves, stems and storage roots. In contrast, the increase of flavonols quercetin-3-O-hexose-hexoside and quercetin-3-O-glucoside in the leaves and roots of DFRi plants is significant. Therefore, the metabolic pathway channeled greater flavonol influx in the DFRi plants when their anthocyanin and proanthocyanidin accumulation were decreased. These plants also displayed reduced antioxidant capacity compared to the wild type. After 24 h of cold treatment and 2 h recovery, the wild-type plants were almost fully restored to the initial phenotype compared to the slower recovery of DFRi plants, in which the levels of electrolyte leakage and hydrogen peroxide accumulation were dramatically increased. These results provide direct evidence of anthocyanins function in the protection against oxidative stress in the sweet potato. The molecular characterization of the IbDFR gene in the sweet potato not only confirms its important roles in flavonoid metabolism but also supports the protective function of anthocyanins of enhanced scavenging of reactive oxygen radicals in plants under stressful conditions.

Description of the electrodynamics of a gas by molecular-electromagnetic correlation functions

International Nuclear Information System (INIS)

Coulter, C.A.; Howgate, D.W.

1985-01-01

Starting from basic principles, we develop a description of the electromagnetic interactions of a molecular gas in terms of a set of correlation functions which we call the molecular-electromagnetic correlation functions (MECF's). First we use the energy eigenfunctions for an isolated molecule of the species of interest to define a set of molecular creation and annihilation operators. We then derive a closed set of operator equations for these molecular creation and annihilation operators and the electromagnetic vector potential. Explicit definitions of the lowest-order MECF's are given in terms of these operators, and it is shown how the operator equations which have been obtained can be used to derive equations of motion for the MECF's. Finally, we illustrate the use of the MECF's in describing physical properties of the molecular gas and the electromagnetic field. Brief indications are given of the application of the MECF formulation to the semiclassical approximation and to the description of quantum emission of radiation, topics which are treated in greater detail in subsequent papers. The basic MECF formulation described here contains three rather mild approximations: (1) Atomic nuclei are treated as elementary particles; (2) nuclei and electrons are treated nonrelativistically; and (3) the effect of molecular collisions with the container walls on the internal molecular state is neglected. Consequently, the physical description contained in the formulation is rather complete; and the MECF results can be used both to provide a sound basis for some aspects of the usual heuristic models, and to ascertain the ways in which those models are incomplete

Stress evolution of GaN/AlN heterostructure grown on 6H-SiC substrate by plasma assisted molecular beam epitaxy

Science.gov (United States)

Agrawal, M.; Ravikiran, L.; Dharmarasu, N.; Radhakrishnan, K.; Karthikeyan, G. S.; Zheng, Y.

2017-01-01

The stress evolution of GaN/AlN heterostructure grown on 6H-SiC substrate by plasma assisted molecular beam epitaxy (PA-MBE) has been studied. AlN nucleation layer and GaN layer were grown as a function of III/V ratio. GaN/AlN structure is found to form buried cracks when AlN is grown in the intermediate growth regime(III/V˜1)and GaN is grown under N-rich growth regime (III/VHEMT) heterostructure was demonstrated on 2-inch SiC that showed good two dimensional electron gas (2DEG) properties with a sheet resistance of 480 Ω/sq, mobility of 1280 cm2/V.s and sheet carrier density of 1×1013 cm-2.

Stressful life events predict delayed functional recovery following treatment for mania in bipolar disorder.

Science.gov (United States)

Yan-Meier, Leslie; Eberhart, Nicole K; Hammen, Constance L; Gitlin, Michael; Sokolski, Kenneth; Altshuler, Lori

2011-04-30

Identifying predictors of functional recovery in bipolar disorder is critical to treatment efforts to help patients re-establish premorbid levels of role adjustment following an acute manic episode. The current study examined the role of stressful life events as potential obstacles to recovery of functioning in various roles. 65 patients with bipolar I disorder participated in a longitudinal study of functional recovery following clinical recovery from a manic episode. Stressful life events were assessed as predictors of concurrent vs. delayed recovery of role functioning in 4 domains (friends, family, home duties, work/school). Despite clinical recovery, a subset of patients experienced delayed functional recovery in various role domains. Moreover, delayed functional recovery was significantly associated with presence of one or more stressors in the prior 3 months, even after controlling for mood symptoms. Presence of a stressor predicted longer time to functional recovery in life domains, up to 112 days in work/school. Interventions that provide monitoring, support, and problem-solving may be needed to help prevent or mitigate the effects of stress on functional recovery. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

Molecular Mechanisms of Stress-Induced Increases in Fear Memory Consolidation within the Amygdala

OpenAIRE

Aubry, Antonio V.; Serrano, Peter A.; Burghardt, Nesha S.

2016-01-01

Stress can significantly impact brain function and increase the risk for developing various psychiatric disorders. Many of the brain regions that are implicated in psychiatric disorders and are vulnerable to the effects of stress are also involved in mediating emotional learning. Emotional learning has been a subject of intense investigation for the past 30 years, with the vast majority of studies focusing on the amygdala and its role in associative fear learning. However, the mechanisms by w...

Molecular Mechanisms of Stress-Induced Increases in Fear Memory Consolidation Within the Amygdala

OpenAIRE

Antonio Aubry; Antonio Aubry; Peter Serrano; Peter Serrano; Nesha Burghardt; Nesha Burghardt

2016-01-01

Stress can significantly impact brain function and increase the risk for developing various psychiatric disorders. Many of the brain regions that are implicated in psychiatric disorders and are vulnerable to the effects of stress are also involved in mediating emotional learning. Emotional learning has been a subject of intense investigation for the past 30 years, with the vast majority of studies focusing on the amygdala and its role in associative fear learning. However, the mechanisms by...

The Impact of Midurethral Sling Surgery on Sexual Activity and Function in Women With Stress Urinary Incontinence

NARCIS (Netherlands)

Mengerink, Bianca B.; van Leijsen, Sanne A. L.; Vierhout, Mark E.; IntHout, Joanna; Mol, Ben W. J.; Milani, Alfredo L.; Roovers, Jan-Paul W. R.; van Eijndhoven, Hugo W. F.; van der Vaart, Carl H.; van Gestel, Iris; Hartog, Francis E.; Heesakkers, John F. A.; Kluivers, Kirsten B.

2016-01-01

Introduction: Stress urinary incontinence has a negative impact on sexual function. Aim: To assess the effect of midurethral sling surgery on sexual activity and function in women with stress urinary incontinence. Methods: This is a secondary analysis of the Value of Urodynamics Prior to Stress

first principles derivation of a stress function for axially symmetric

African Journals Online (AJOL)

HOD

governing partial differential equations of linear isotropic elasticity were reduced to the solution of the biharmonic ... The stress function was then applied to solve the axially symmetric ..... [1] Borg S.K.: Fundamentals of Engineering Elasticity,.

Traumatic stress and psychological functioning in a South African adolescent community sample

OpenAIRE

Swain, Karl D.; Pillay, Basil J.; Kliewer, Wendy

2017-01-01

Background: Traumatic stress may arise from various incidents often leading to posttraumatic stress disorder (PTSD). The lifetime prevalence of PTSD is estimated at 1% – 2% in Western Europe, 6% – 9% in North America and at just over 10% in countries exposed to long-term violence. In South Africa, the lifetime prevalence for PTSD in the general population is estimated at 2.3%. Aim: To examine the prevalence of posttraumatic stress symptomatology and related psychological functioning in a ...

Mitochondrial Stress Signalling: HTRA2 and Parkinson's Disease

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Enrico Desideri

2012-01-01

Full Text Available Mitochondria are cellular energy generators whose activity requires a continuous supply of oxygen. Recent genetic analysis has suggested that defects in mitochondrial quality control may be key factors in the development of Parkinson’s disease (PD. Mitochondria have a crucial role in supplying energy to the brain, and their deterioration can affect the function and viability of neurons, contributing to neurodegeneration. These organelles can sow the seeds of their own demise because they generate damaging oxygen-free radicals as a byproduct of their intrinsic physiological functions. Mitochondria have therefore evolved specific molecular quality control mechanisms to compensate for the action of damaging agents such as oxygen-free radicals. PTEN-induced putative kinase 1 (PINK1 and high-temperature-regulated A2 (HTRA2, a mitochondrial protease, have recently been proposed to be key modulators of mitochondrial molecular quality control. Here, we review some of the most recent advances in our understanding of mitochondria stress-control pathways, focusing on how signalling by the p38 stress kinase pathway may regulate mitochondrial stress by modulating the activity of HTRA2 via PINK1 and cyclin-dependent kinase 5 (CDK5. We also propose how defects in this pathway may contribute to PD.

Interactions between Temperament, Stress, and Immune Function in Cattle

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N. C. Burdick

2011-01-01

Full Text Available The detrimental effects caused by stressors encountered by animals during routine handling can pose economic problems for the livestock industry due to increased costs ultimately borne by the producer and the consumer. Stress adversely affects key physiological processes of the reproductive and immune systems. In recent years stress responsiveness has been associated with cattle behavior, specifically temperament. Cattle with more excitable temperaments, as measured by chute score, pen score, and exit velocity (flight speed, exhibit greater basal concentrations of glucocorticoids and catecholamines. Similar to stressed cattle, more temperamental cattle (i.e., cattle exhibiting greater exit velocity or pen and chute scores have poorer growth performance, carcass characteristics, and immune responses. Thus, understanding the interrelationship of stress and temperament can help in the development of selection and management practices that reduce the negative influence of temperament on growth and productivity of cattle. This paper discusses the relationship between stress and temperament and the developing evidence of an effect of temperament on immune function of cattle that have been handled or restrained. Specifically, the paper discusses different methodologies used to measure temperament, including chute score, pen score, and exit velocity, and discusses the reaction of cattle to different stressors including handling and restraint.

A parity function for studying the molecular electronic structure

DEFF Research Database (Denmark)

Schmider, Hartmut

1996-01-01

Sections through the molecular Wigner function with zero momentum variable are shown to provide important information about the off-diagonal regions of the spinless one-particle reduced density matrix. Since these regions are characteristic for the bonding situation in molecules, the sections...... are qualitatively even more affected by the presence of chemical bonds than a complementary projection, the reciprocal form factor. In this paper we discuss, on the grounds of a variety of examples, how this rather simple function may aid the understanding of the chemical bond on a one-particle level. (C) 1996...

Identification of water stress genes in Pinus pinaster Ait. by controlled progressive stress and suppression-subtractive hybridization.

Science.gov (United States)

Perdiguero, Pedro; Collada, Carmen; Barbero, María Del Carmen; García Casado, Gloria; Cervera, María Teresa; Soto, Alvaro

2012-01-01

Climate change is a major challenge particularly for forest tree species, which will have to face the severe alterations of environmental conditions with their current genetic pool. Thus, an understanding of their adaptive responses is of the utmost interest. In this work we have selected Pinus pinaster as a model species. This pine is one of the most important conifers (for which molecular tools and knowledge are far more scarce than for angiosperms) in the Mediterranean Basin, which is characterised in all foreseen scenarios as one of the regions most drastically affected by climate change, mainly because of increasing temperature and, particularly, by increasing drought. We have induced a controlled, increasing water stress by adding PEG to a hydroponic culture. We have generated a subtractive library, with the aim of identifying the genes induced by this stress and have searched for the most reliable expressional candidate genes, based on their overexpression during water stress, as revealed by microarray analysis and confirmed by RT-PCR. We have selected a set of 67 candidate genes belonging to different functional groups that will be useful molecular tools for further studies on drought stress responses, adaptation, and population genomics in conifers, as well as in breeding programs. Copyright © 2011 Elsevier Masson SAS. All rights reserved.

Stress-responsive expression patterns and functional characterization of cold shock domain proteins in cabbage (Brassica rapa) under abiotic stress conditions.

Science.gov (United States)

Choi, Min Ji; Park, Ye Rin; Park, Su Jung; Kang, Hunseung

2015-11-01

Although the functional roles of cold shock domain proteins (CSDPs) have been demonstrated during the growth, development, and stress adaptation of Arabidopsis (Arabidopsis thaliana), rice (Oryza sativa), and wheat (Triticum aestivum), the functions of CSDPs in other plants species, including cabbage (Brassica rapa), are largely unknown. To gain insight into the roles of CSDPs in cabbage under stress conditions, the genes encoding CSDPs in cabbage were isolated, and the functional roles of CSDPs in response to environmental stresses were analyzed. Real-time RT-PCR analysis revealed that the levels of BrCSDP transcripts increased during cold, salt, or drought stress, as well as upon ABA treatment. Among the five BrCSDP genes found in the cabbage genome, one CSDP (BRU12051), named BrCSDP3, was unique in that it is localized to the chloroplast as well as to the nucleus. Ectopic expression of BrCSDP3 in Arabidopsis resulted in accelerated seed germination and better seedling growth compared to the wild-type plants under high salt or dehydration stress conditions, and in response to ABA treatment. BrCSDP3 did not affect the splicing of intron-containing genes and processing of rRNAs in the chloroplast. BrCSDP3 had the ability to complement RNA chaperone-deficient Escherichia coli mutant cells under low temperatures as well as DNA- and RNA-melting abilities, suggesting that it possesses RNA chaperone activity. Taken together, these results suggest that BrCSDP3, harboring RNA chaperone activity, plays a role as a positive regulator in seed germination and seedling growth under stress conditions. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

Structural phase transitions in boron carbide under stress

International Nuclear Information System (INIS)

Korotaev, P; Pokatashkin, P; Yanilkin, A

2016-01-01

Structural transitions in boron carbide B 4 C under stress were studied by means of first-principles molecular dynamics in the framework of density functional theory. The behavior depends strongly on degree of non-hydrostatic stress. Under hydrostatic stress continuous bending of the three-atom C–B–C chain was observed up to 70 GPa. The presence of non-hydrostatic stress activates abrupt reversible chain bending, which is displacement of the central boron atom in the chain with the formation of weak bonds between this atom and atoms in the nearby icosahedra. Such structural change can describe a possible reversible phase transition in dynamical loading experiments. High non-hydrostatic stress achieved in uniaxial loading leads to disordering of the initial structure. The formation of carbon chains is observed as one possible transition route. (paper)

Effect of Stress Urinary Incontinence on the Sexual Function of Couples and the Quality of Life of Patients.

Science.gov (United States)

Lim, Renly; Liong, Men Long; Leong, Wing Seng; Khan, Nurzalina Abdul Karim; Yuen, Kah Hay

2016-07-01

Studies of the effects of stress urinary incontinence on the sexual function of couples are scarce. We prospectively evaluated couple sexual function and the relationship between sexual function and quality of life. We also compared quality of life in females with vs without stress urinary incontinence. Sexually active females at least 21 years old with or without stress urinary incontinence and their partners were recruited for study. To assess sexual function the couples completed GRISS (Golombok Rust Inventory of Sexual Satisfaction) and a 1-item question on overall sexual experience, "Over the past 4 weeks, how satisfied have you been with your overall sexual life?" Additionally, females completed ICIQ-LUTSqol (International Consultation on Incontinence Questionnaire-Lower Urinary Tract Symptoms Quality of Life) to assess quality of life. For sexual function assessment 66 of 134 couples with (49.3%) and 95 of 176 without (54.0%) stress urinary incontinence were recruited. Females with stress urinary incontinence had lower overall sexual function, lower frequency of sexual intercourse, less satisfaction (each p stress urinary incontinence had more problems with erectile dysfunction (p = 0.027), less satisfaction (p = 0.006) and lower frequency of sexual intercourse (p = 0.001) but no difference in overall GRISS score (p = 0.093). Couples with stress urinary incontinence had poorer overall sexual experience (p stress urinary incontinence had poorer quality of life than those without stress urinary incontinence (120 of 134, response rate 89.6% vs 145 of 176, response rate 82.4%, p life did not significantly correlate (r = 0.001, p = 0.997). Stress urinary incontinence in females is negatively associated not only with female quality of life and sexual function but also with partner sexual function. Copyright © 2016 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

Effect of stress hyperglycemia and intensive rehabilitation therapy in non-diabetic hemorrhagic stroke: Korean Stroke Cohort for Functioning and Rehabilitation.

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Yoon, J A; Kim, D Y; Sohn, M K; Lee, J; Lee, S-G; Lee, Y-S; Han, E Y; Joo, M C; Oh, G-J; Han, J; Lee, S W; Park, M; Chang, W H; Shin, Y-I; Kim, Y-H

2016-11-01

We investigated the effect of stress hyperglycemia on the functional outcomes of non-diabetic hemorrhagic stroke. In addition, we investigated the usefulness of intensive rehabilitation for improving functional outcomes in patients with stress hyperglycemia. Non-diabetic hemorrhagic stroke patients were recruited and divided into two groups: intracerebral hemorrhage (ICH) (n = 165) and subarachnoid hemorrhage (SAH) (n = 156). Each group was divided into non-diabetics with or without stress hyperglycemia. Functional assessments were performed at 7 days and 3, 6 and 12 months after stroke onset. The non-diabetic with stress hyperglycemia groups were again divided into two groups who either received or did not receive intensive rehabilitation treatment. Serial functional outcome was compared between groups. For the ICH group, patients with stress hyperglycemia had worse modified Rankin Scale, National Institutes of Health Stroke Scale, Functional Ambulatory Category and Korean Mini-Mental State Examination scores than patients without stress hyperglycemia. For the SAH group, patients with stress hyperglycemia had worse scores on all functional assessments than patients without stress hyperglycemia at all time-points. After intensive rehabilitation treatment of patients with stress hyperglycemia, the ICH group had better scores on Functional Ambulatory Category and the SAH group had better scores on all functional assessments than patients without intensive rehabilitation treatment. Stress hyperglycemia affects the long-term prognosis of non-diabetic hemorrhagic stroke patients. Among stress hyperglycemia patients, intensive rehabilitation can enhance functional improvement after stroke. © 2016 EAN.

Molecular Mechanisms of Stress-Induced Increases in Fear Memory Consolidation within the Amygdala.

Science.gov (United States)

Aubry, Antonio V; Serrano, Peter A; Burghardt, Nesha S

2016-01-01

Stress can significantly impact brain function and increase the risk for developing various psychiatric disorders. Many of the brain regions that are implicated in psychiatric disorders and are vulnerable to the effects of stress are also involved in mediating emotional learning. Emotional learning has been a subject of intense investigation for the past 30 years, with the vast majority of studies focusing on the amygdala and its role in associative fear learning. However, the mechanisms by which stress affects the amygdala and amygdala-dependent fear memories remain unclear. Here we review the literature on the enhancing effects of acute and chronic stress on the acquisition and/or consolidation of a fear memory, as measured by auditory Pavlovian fear conditioning, and discuss potential mechanisms by which these changes occur in the amygdala. We hypothesize that stress-mediated activation of glucocorticoid receptors (GR) and norepinephrine release within the amygdala leads to the mobilization of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors to the synapse, which underlies stress-induced increases in fear memory. We discuss the implications of this hypothesis for evaluating the effects of stress on extinction and for developing treatments for anxiety disorders. Understanding how stress-induced changes in glucocorticoid and norepinephrine signaling might converge to affect emotional learning by increasing the trafficking of AMPA receptors and enhancing amygdala excitability is a promising area for future research.

Molecular Mechanisms of Stress-Induced Increases in Fear Memory Consolidation Within the Amygdala

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Antonio Aubry

2016-10-01

Full Text Available Stress can significantly impact brain function and increase the risk for developing various psychiatric disorders. Many of the brain regions that are implicated in psychiatric disorders and are vulnerable to the effects of stress are also involved in mediating emotional learning. Emotional learning has been a subject of intense investigation for the past 30 years, with the vast majority of studies focusing on the amygdala and its role in associative fear learning. However, the mechanisms by which stress affects the amygdala and amygdala-dependent fear memories remain unclear. Here we review the literature on the enhancing effects of acute and chronic stress on the acquisition and/or consolidation of a fear memory, as measured by auditory Pavlovian fear conditioning, and discuss potential mechanisms by which these changes occur in the amygdala. We hypothesize that stress-mediated activation of glucocorticoid receptors (GR and norepinephrine release within the amygdala leads to the mobilization of AMPA receptors to the synapse, which underlies stress-induced increases in fear memory. We discuss the implications of this hypothesis for evaluating the effects of stress on extinction and for developing treatments for anxiety disorders. Understanding how stress-induced changes in glucocorticoid and norepinephrine signaling might converge to affect emotional learning by increasing the trafficking of AMPA receptors and enhancing amygdala excitability is a promising area for future research.

Parametric peak stress functions of 90o pipe bends with ovality under steady-state creep conditions

International Nuclear Information System (INIS)

Yaghi, A.H.; Hyde, T.H.; Becker, A.A.; Sun, W.

2009-01-01

Stress-based life prediction techniques are commonly used to estimate the failure life of pressurised pipe-related components, such as welds and bends, under creep conditions. Previous research has shown that reasonable life predictions can be obtained, based on the steady-state peak stresses, compared with the life predictions obtained from creep damage modelling. In this work, a series of parametric steady-state peak rupture stress functions of right-angled pipe bends with ovality are presented, which are based on the results obtained from finite element (FE) analyses, covering a number of material property and geometry parameters in practical ranges. Methods used to determine the stress functions are described. The FE analyses have been performed using axisymmetric models, subjected to internal pressure only, with a Norton creep law. Typical examples of parametric peak stress curve fitting are shown. In particular, the accuracy of the interpolation and extrapolation abilities of the stress functions is assessed. The results show that in most cases the interpolated and extrapolated peak stresses are accurate to within ±3% and ±5%, respectively.

The Design, Synthesis, and Study of Solid-State Molecular Rotors: Structure/Function Relationships for Condensed-Phase Anisotropic Dynamics

Science.gov (United States)

Vogelsberg, Cortnie Sue

Amphidynamic crystals are an extremely promising platform for the development of artificial molecular machines and stimuli-responsive materials. In analogy to skeletal muscle, their function will rely upon the collective operation of many densely packed molecular machines (i.e. actin-bound myosin) that are self-assembled in a highly organized anisotropic medium. By choosing lattice-forming elements and moving "parts" with specific functionalities, individual molecular machines may be synthesized and self-assembled in order to carry out desirable functions. In recent years, efforts in the design of amphidynamic materials based on molecular gyroscopes and compasses have shown that a certain amount of free volume is essential to facilitate internal rotation and reorientation within a crystal. In order to further establish structure/function relationships to advance the development of increasingly complex molecular machinery, molecular rotors and a molecular "spinning" top were synthesized and incorporated into a variety of solid-state architectures with different degrees of periodicity, dimensionality, and free volume. Specifically, lamellar molecular crystals, hierarchically ordered periodic mesoporous organosilicas, and metal-organic frameworks were targeted for the development of solid-state molecular machines. Using an array of solid-state nuclear magnetic resonance spectroscopy techniques, the dynamic properties of these novel molecular machine assemblies were determined and correlated with their corresponding structural features. It was found that architecture type has a profound influence on functional dynamics. The study of layered molecular crystals, composed of either molecular rotors or "spinning" tops, probed functional dynamics within dense, highly organized environments. From their study, it was discovered that: 1) crystallographically distinct sites may be utilized to differentiate machine function, 2) halogen bonding interactions are sufficiently

Integrative Analysis of Sex-Specific microRNA Networks Following Stress in Mouse Nucleus Accumbens.

Science.gov (United States)

Pfau, Madeline L; Purushothaman, Immanuel; Feng, Jian; Golden, Sam A; Aleyasin, Hossein; Lorsch, Zachary S; Cates, Hannah M; Flanigan, Meghan E; Menard, Caroline; Heshmati, Mitra; Wang, Zichen; Ma'ayan, Avi; Shen, Li; Hodes, Georgia E; Russo, Scott J

2016-01-01

Adult women are twice as likely as men to suffer from affective and anxiety disorders, although the mechanisms underlying heightened female stress susceptibility are incompletely understood. Recent findings in mouse Nucleus Accumbens (NAc) suggest a role for DNA methylation-driven sex differences in genome-wide transcriptional profiles. However, the role of another epigenetic process-microRNA (miR) regulation-has yet to be explored. We exposed male and female mice to Subchronic Variable Stress (SCVS), a stress paradigm that produces depression-like behavior in female, but not male, mice, and performed next generation mRNA and miR sequencing on NAc tissue. We applied a combination of differential expression, miR-mRNA network and functional enrichment analyses to characterize the transcriptional and post-transcriptional landscape of sex differences in NAc stress response. We find that male and female mice exhibit largely non-overlapping miR and mRNA profiles following SCVS. The two sexes also show enrichment of different molecular pathways and functions. Collectively, our results suggest that males and females mount fundamentally different transcriptional and post-transcriptional responses to SCVS and engage sex-specific molecular processes following stress. These findings have implications for the pathophysiology and treatment of stress-related disorders in women.

Anion channels: master switches of stress responses.

Science.gov (United States)

Roelfsema, M Rob G; Hedrich, Rainer; Geiger, Dietmar

2012-04-01

During stress, plant cells activate anion channels and trigger the release of anions across the plasma membrane. Recently, two new gene families have been identified that encode major groups of anion channels. The SLAC/SLAH channels are characterized by slow voltage-dependent activation (S-type), whereas ALMT genes encode rapid-activating channels (R-type). Both S- and R-type channels are stimulated in guard cells by the stress hormone ABA, which leads to stomatal closure. Besides their role in ABA-dependent stomatal movement, anion channels are also activated by biotic stress factors such as microbe-associated molecular patterns (MAMPs). Given that anion channels occur throughout the plant kingdom, they are likely to serve a general function as master switches of stress responses. Copyright © 2012 Elsevier Ltd. All rights reserved.

Effect of Mindfulness Meditation on Perceived Stress Scores and Autonomic Function Tests of Pregnant Indian Women.

Science.gov (United States)

Muthukrishnan, Shobitha; Jain, Reena; Kohli, Sangeeta; Batra, Swaraj

2016-04-01

Various pregnancy complications like hypertension, preeclampsia have been strongly correlated with maternal stress. One of the connecting links between pregnancy complications and maternal stress is mind-body intervention which can be part of Complementary and Alternative Medicine (CAM). Biologic measures of stress during pregnancy may get reduced by such interventions. To evaluate the effect of Mindfulness meditation on perceived stress scores and autonomic function tests of pregnant Indian women. Pregnant Indian women of 12 weeks gestation were randomised to two treatment groups: Test group with Mindfulness meditation and control group with their usual obstetric care. The effect of Mindfulness meditation on perceived stress scores and cardiac sympathetic functions and parasympathetic functions (Heart rate variation with respiration, lying to standing ratio, standing to lying ratio and respiratory rate) were evaluated on pregnant Indian women. There was a significant decrease in perceived stress scores, a significant decrease of blood pressure response to cold pressor test and a significant increase in heart rate variability in the test group (pwomen. The results of this study suggest that mindfulness meditation improves parasympathetic functions in pregnant women and is a powerful modulator of the sympathetic nervous system during pregnancy.

Family Stress and Adolescents’ Cognitive Functioning: Sleep as a Protective Factor

Science.gov (United States)

El-Sheikh, Mona; Tu, Kelly M.; Erath, Stephen A.; Buckhalt, Joseph A.

2014-01-01

We examined two sleep-wake parameters as moderators of the associations between exposure to family stressors and adolescent cognitive functioning. Participants were 252 school-recruited adolescents (M = 15.79 years; 66% European American, 34% African American). Youths reported on three dimensions of family stress: marital conflict, harsh parenting, and parental psychological control. Cognitive functioning was indexed through performance on the Woodcock-Johnson III Tests of Cognitive Abilities. Sleep minutes and efficiency were measured objectively using actigraphy. Towards identifying unique effects, path models controlled for two family stress variables while estimating the third. Analyses revealed that sleep efficiency moderated the associations between negative parenting (harsh parenting and parental psychological control) and adolescents’ cognitive functioning. The highest level of cognitive performance was predicted for adolescents with higher levels of sleep efficiency in conjunction with lower levels of either harsh parenting or psychological control. The effects of sleep were more pronounced at lower levels of negative parenting where adolescents with higher sleep efficiency performed better than their counterparts with poorer sleep. At higher levels of either harsh parenting or psychological control, similar levels of cognitive performance were observed regardless of sleep. Results are discussed in comparison to other recent studies on interrelations among family stress, sleep, and cognitive performance in childhood and adolescence. PMID:25329625

Functional Molecular Diversity of Marine Dissolved Organic Matter Is Reduced during Degradation

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Andrea Mentges

2017-06-01

Full Text Available Dissolved organic matter (DOM is a highly diverse mixture of compounds, accounting for one of the world's largest active carbon pools. The surprising recalcitrance of some DOM compounds to bacterial degradation has recently been associated with its diversity. However, little is known about large-scale patterns of marine DOM diversity and its change through degradation, in particular considering the functional diversity of DOM. Here, we analyze the development of marine DOM diversity during degradation in two data sets comprising DOM of very different ages: a three-year mesocosm experiment and highly-resolved field samples from the Atlantic and Southern Ocean. The DOM molecular composition was determined using ultra-high resolution mass spectrometry. We quantify DOM diversity using three conceptually different diversity measures, namely richness of molecular formulas, abundance-based diversity, and functional molecular diversity. Using these measures we find stable molecular richness of DOM with age >1 year, systematic changes in the molecules' abundance distribution with degradation state, and increasing homogeneity with respect to chemical properties for more degraded DOM. Coinciding with differences in sea water density, the spatial field data separated clearly into regions of high and low diversity. The joint application of different diversity measures yields a comprehensive overview on temporal and spatial patterns of molecular diversity, valuable for general conclusions on drivers and consequences of marine DOM diversity.

The effect of surgical and psychological stress on learning and memory function in aged C57BL/6 mice.

Science.gov (United States)

Zhang, C; Li, C; Xu, Z; Zhao, S; Li, P; Cao, J; Mi, W

2016-04-21

Postoperative cognitive dysfunction (POCD) is an important complication following major surgery and general anesthesia in older patients. However, the etiology of POCD remains largely to be determined. It is unknown how surgical stress and psychological stress affect the postoperative learning and memory function in geriatric patients. We therefore established a pre-clinical model in aged C57BL/6 mice and aimed to investigate the effects of surgical stress and psychological stress on learning and memory function and the possible roles of the protein kinase B/mammalian target of rapamycin (AKT/mTOR) pathway. The surgical stress was induced by abdominal surgery under local anesthesia, and the psychological stress was induced by a communication box. Cognitive functions and markers of the AKT/mTOR pathway were assessed at 1, 3 and 7 days following the stress. The impairments of learning and memory function existed for up to 7 days following surgical stress and surgical stress plus psychological stress, whereas the psychological stress did not affect the cognitive function alone or combined with surgical stress. Analysis of brain tissue revealed a significant involvement of the AKT/mTOR pathway in the impairment of cognition. These data suggested that surgical stress could induce cognitive impairment in aged mice and perioperative psychological stress is not a constitutive factor of POCD. The AKT/mTOR pathway is likely involved as one of the underlying mechanisms of the development of POCD. Copyright © 2016 IBRO. Published by Elsevier Ltd. All rights reserved.

Stress evolution of GaN/AlN heterostructure grown on 6H-SiC substrate by plasma assisted molecular beam epitaxy

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M. Agrawal

2017-01-01

Full Text Available The stress evolution of GaN/AlN heterostructure grown on 6H-SiC substrate by plasma assisted molecular beam epitaxy (PA-MBE has been studied. AlN nucleation layer and GaN layer were grown as a function of III/V ratio. GaN/AlN structure is found to form buried cracks when AlN is grown in the intermediate growth regime(III/V∼1and GaN is grown under N-rich growth regime (III/V<1. The III/V ratio determines the growth mode of the layers that influences the lattice mismatch at the GaN/AlN interface. The lattice mismatch induced interfacial stress at the GaN/AlN interface relaxes by the formation of buried cracks in the structure. Additionally, the stress also relaxes by misorienting the AlN resulting in two misorientations with different tilts. Crack-free layers were obtained when AlN and GaN were grown in the N-rich growth regime (III/V<1 and metal rich growth regime (III/V≥1, respectively. AlGaN/GaN high electron mobility transistor (HEMT heterostructure was demonstrated on 2-inch SiC that showed good two dimensional electron gas (2DEG properties with a sheet resistance of 480 Ω/sq, mobility of 1280 cm2/V.s and sheet carrier density of 1×1013 cm−2.

Evaluation of a functional medicine approach to treating fatigue, stress, and digestive issues in women.

Science.gov (United States)

Cutshall, Susanne M; Bergstrom, Larry R; Kalish, Daniel J

2016-05-01

Fatigue, stress, and digestive disorders are common among adults, especially women. We conducted a 28-week pilot study to assess the efficacy of a functional medicine approach to improving stress, energy, fatigue, digestive issues, and quality of life in middle-aged women. Findings showed significant improvements in many stress, fatigue, and quality-of-life measures. The treatment program increased mean salivary dehydroepiandrosterone levels and the cortisol-dehydroepiandrosterone ratio. Stool sample analyses suggested that these treatments reduced Helicobacter pylori infections. This study suggests that functional medicine may be an effective approach to managing stress and gastrointestinal symptoms. Copyright © 2016 Elsevier Ltd. All rights reserved.

Psychological and psychobiological stress in the relationship between basic cognitive function and school performance

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Eugenia Fernández-Martín

2015-01-01

Full Text Available This study analyses the role played by daily stress, assessed through self-report and at the psychobiological level, in relation to basic cognitive function when predicting school performance. The sample comprised 100 schoolchildren (55 girls and 45 boys, age range 8 to 11 years from a state school in the city of Malaga (Spain. Daily stress was assessed through the Children's Daily Stress Inventory (IIEC m Spanish; Tnanes et al., 2009. Psychobiological stress was measured through the cortisol/DHEAS ratio, derived from saliva samples taken in the morning on two consecutive days. Basic cognitive skills were assessed by means of the Computerized Cognitive Assessment System (CDR battery; Wesnes et al., 2003, 2000. Finally, the measure of school performance was the mean value of the final grades recorded in the child's school report. In addition to descriptive and correlational statistical analyses, multiple regression analyses were conducted in order to assess the model. The results show that children's daily stress self-reported contributes to predict school performance, and has proven to be more influential than basic cognitive function when it comes to predict school performance. Therefore, in order to achieve good school performance, a pupil not only requires good basic cognitive function, but must also present low levels of self-reported daily stress. These findings suggest a new way of explaining and predicting school failure.

Contribution of molecular analysis to the typification of the non-functioning pituitary adenomas

Science.gov (United States)

Sanchez-Ortiga, Ruth; Aranda, Francisco Ignacio

2017-01-01

Aim The WHO Classification of Tumours of Endocrine Organs considers the inmunohistochemical characterization of pituitary adenomas (PA) as mandatory for patient diagnosis. Recent advances in the knowledge of the molecular patterns of these tumours could complement this classification with gene expression profiling. Methods Within the context of the Spanish Molecular Registry of Pituitary Adenomas (REMAH), a multicentre clinical-basic research project, we analysed the molecular phenotype of 142 PAs with complete IHC and clinical information. Gene expression levels of all pituitary hormones, type 1 corticotrophin-releasing hormone receptor, dopamine receptors and arginine vasopressin receptor 1b were measured by quantitative real-time polymerase chain reaction. In addition, we used three housekeeping genes for normalization and a pool of nine healthy pituitary glands from autopsies as calibration reference standard. Results Based on the clinically functioning PA (FPA: somatotroph, corticotroph, thyrotroph and lactotroph adenomas), we established the interquartile range of relative expression for all genes studied in each PA subtype. That allowed molecularly the different PA subtypes, including the clinically non-functioning PA (NFPA). Afterwards, we estimated the concordance of the molecular and immunohistochemical classification with clinical diagnosis in FPA and between them in NFPA. The kappa values were higher in molecular than in immunohistochemical classification in FPA and showed a bad concordance in all NFPA subtypes. Conclusions According to these results, the molecular characterization of the PA complements the IHC analysis, allowing a better typification of the NFPA. PMID:28692683

Contribution of molecular analysis to the typification of the non-functioning pituitary adenomas.

Directory of Open Access Journals (Sweden)

Laura Sanchez-Tejada

Full Text Available The WHO Classification of Tumours of Endocrine Organs considers the inmunohistochemical characterization of pituitary adenomas (PA as mandatory for patient diagnosis. Recent advances in the knowledge of the molecular patterns of these tumours could complement this classification with gene expression profiling.Within the context of the Spanish Molecular Registry of Pituitary Adenomas (REMAH, a multicentre clinical-basic research project, we analysed the molecular phenotype of 142 PAs with complete IHC and clinical information. Gene expression levels of all pituitary hormones, type 1 corticotrophin-releasing hormone receptor, dopamine receptors and arginine vasopressin receptor 1b were measured by quantitative real-time polymerase chain reaction. In addition, we used three housekeeping genes for normalization and a pool of nine healthy pituitary glands from autopsies as calibration reference standard.Based on the clinically functioning PA (FPA: somatotroph, corticotroph, thyrotroph and lactotroph adenomas, we established the interquartile range of relative expression for all genes studied in each PA subtype. That allowed molecularly the different PA subtypes, including the clinically non-functioning PA (NFPA. Afterwards, we estimated the concordance of the molecular and immunohistochemical classification with clinical diagnosis in FPA and between them in NFPA. The kappa values were higher in molecular than in immunohistochemical classification in FPA and showed a bad concordance in all NFPA subtypes.According to these results, the molecular characterization of the PA complements the IHC analysis, allowing a better typification of the NFPA.

Four-point correlation function of stress-energy tensors in N=4 superconformal theories

CERN Document Server

Korchemsky, G P

2015-01-01

We derive the explicit expression for the four-point correlation function of stress-energy tensors in four-dimensional N=4 superconformal theory. We show that it has a remarkably simple and suggestive form allowing us to predict a large class of four-point correlation functions involving the stress-energy tensor and other conserved currents. We then apply the obtained results on the correlation functions to computing the energy-energy correlations, which measure the flow of energy in the final states created from the vacuum by a source. We demonstrate that they are given by a universal function independent of the choice of the source. Our analysis relies only on N=4 superconformal symmetry and does not use the dynamics of the theory.

Work stress, anthropometry, lung function, blood pressure, and blood-based biomarkers

DEFF Research Database (Denmark)

Magnusson Hanson, Linda L.; Westerlund, Hugo; Goldberg, Marcel

2017-01-01

-based biomarkers. Linear regression analyses before and after multivariable adjustment for age, socioeconomic status, depressive symptoms, health-related behaviours, and chronic conditions showed that work stress was associated with higher BMI, waist circumference, waist-hip ratio, alanine transaminase, white......Work stress is a risk factor for cardio-metabolic diseases, but few large-scale studies have examined the clinical profile of individuals with work stress. To address this limitation, we conducted a cross-sectional study including 43,593 working adults from a French population-based sample aged 18......–72 years (the CONSTANCES cohort). According to the Effort-Reward Imbalance model, work stress was defined as an imbalance between perceived high efforts and low rewards at work. A standardized health examination included measures of anthropometry, lung function, blood pressure and standard blood...

ER Stress and Lipid Metabolism in Adipocytes

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Beth S. Zha

2012-01-01

Full Text Available The role of endoplasmic reticulum (ER stress is a rapidly emerging field of interest in the pathogenesis of metabolic diseases. Recent studies have shown that chronic activation of ER stress is closely linked to dysregulation of lipid metabolism in several metabolically important cells including hepatocytes, macrophages, β-cells, and adipocytes. Adipocytes are one of the major cell types involved in the pathogenesis of the metabolic syndrome. Recent advances in dissecting the cellular and molecular mechanisms involved in the regulation of adipogenesis and lipid metabolism indicate that activation of ER stress plays a central role in regulating adipocyte function. In this paper, we discuss the current understanding of the potential role of ER stress in lipid metabolism in adipocytes. In addition, we touch upon the interaction of ER stress and autophagy as well as inflammation. Inhibition of ER stress has the potential of decreasing the pathology in adipose tissue that is seen with energy overbalance.

SOYBEAN - MOLECULAR ASPECTS OF BREEDING

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Aleksandra Sudarić

2012-12-01

Full Text Available The book Soybean: Molecular Aspects of Breeding focuses recent progress in our understanding of the genetics and molecular biology of soybean. This book is divided into four parts and contains 22 chapters. Part I, Molecular Biology and Biotechnology focuses advances in molecular biology and laboratory procedures that have been developed recently to manipulate DNA. Part II, Breeding for abiotic stress covers proteomics approaches form as a powerful tool for investigating the molecular mechanisms of the plant responses to various types of abiotic stresses. Part III, Breeding for biotic stress addresses issues related to application of molecular based strategies in order to increase soybean resistance to various biotic factors. Part IV, Recent Technology reviews recent technologies into the realm of soybean monitoring, processing and product use. While the information accumulated in this book is of primary interest for plant breeders, valuable insights are also offered to agronomists, molecular biologists, physiologists, plant pathologists, food scientists and students. The book is a result of efforts made by many experts from different countries (USA, Japan, Croatia, Serbia, China, Canada, Malawi, Iran, Hong Kong, Brasil, Mexico.

A Meta-Analysis Detailing Overall Sexual Function and Orgasmic Function in Women Undergoing Midurethral Sling Surgery for Stress Incontinence

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Nicole Szell, DO

2017-06-01

Szell N, Komisaruk B, Goldstein SW, et al. A Meta-Analysis Detailing Overall Sexual Function and Orgasmic Function in Women Undergoing Midurethral Sling Surgery for Stress Incontinence. Sex Med 2017;5:e84–e93.

Resistance to Aspergillus flavus in maize and peanut: Molecular biology, breeding, environmental stress, and future perspectives

Directory of Open Access Journals (Sweden)

Jake C. Fountain

2015-06-01

Full Text Available The colonization of maize (Zea mays L. and peanut (Arachis hypogaea L. by the fungal pathogen Aspergillus flavus results in the contamination of kernels with carcinogenic mycotoxins known as aflatoxins leading to economic losses and potential health threats to humans. The regulation of aflatoxin biosynthesis in various Aspergillus spp. has been extensively studied, and has been shown to be related to oxidative stress responses. Given that environmental stresses such as drought and heat stress result in the accumulation of reactive oxygen species (ROS within host plant tissues, host-derived ROS may play an important role in cross-kingdom communication between host plants and A. flavus. Recent technological advances in plant breeding have provided the tools necessary to study and apply knowledge derived from metabolomic, proteomic, and transcriptomic studies in the context of productive breeding populations. Here, we review the current understanding of the potential roles of environmental stress, ROS, and aflatoxin in the interaction between A. flavus and its host plants, and the current status in molecular breeding and marker discovery for resistance to A. flavus colonization and aflatoxin contamination in maize and peanut. We will also propose future directions and a working model for continuing research efforts linking environmental stress tolerance and aflatoxin contamination resistance in maize and peanut.

The aftermath of terrorism: posttraumatic stress and functional impairment after the 2011 Oslo bombing.

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Solberg, Øivind; Blix, Ines; Heir, Trond

2015-01-01

In the present study we wanted to investigate the link between exposure, posttraumatic stress symptomatology, and functional impairment in the aftermath of terrorism. Posttraumatic stress symptomatology and functional impairment related to the Oslo bombing 22nd of July, 2011, in directly and indirectly exposed individuals (N = 1927) were assessed together with demographics, exposure, peri-traumatic reactions, and event centrality approximately 1 year after the attack. Directly and indirectly exposed individuals qualifying for posttraumatic stress disorder (PTSD) reported similar peri-traumatic reactions, event centrality, and functional impairment. However, clusters within the PTSD symptomatology were differentially associated with impairment as a function of their exposure. In the directly exposed group, all clusters within the PTSD symptomatology were associated with impairment in function, while only emotional numbing was associated with impairment within the indirectly exposed group. Considering that terror attacks frequently involve directly exposed individuals and a larger population of indirectly exposed individuals, this finding is of importance, especially in the design of intervention programs and the development of treatment policies.

Bulk stress auto-correlation function in simple liquids-sum rules

International Nuclear Information System (INIS)

Tankeshwar, K.; Bhandari, R.; Pathak, K.N.

1990-10-01

Expressions for the zeroth, second and fourth frequency sum rules of the bulk stress auto correlation function have been derived. The exact expressions involve static correlation function up to four particles. Because of the non availability of any information about static quadruplet correlation function we use a low order decoupling approximation for this. In this work, we have obtained, separately, the sum rules for the different mechanism of momentum transfer in the fluids. The results are expected to be useful in the study of bulk viscosity of the fluids. (author). 9 refs

Using biotechnology and genomics to improve biotic and abiotic stress in apple

Science.gov (United States)

Genomic sequencing, molecular biology, and transformation technologies are providing valuable tools to better understand the complexity of how plants develop, function, and respond to biotic and abiotic stress. These approaches should complement but not replace a solid understanding of whole plant ...

Circadian Clocks and the Interaction between Stress Axis and Adipose Function

Directory of Open Access Journals (Sweden)

Isa Kolbe

2015-01-01

Full Text Available Many physiological processes and most endocrine functions show fluctuations over the course of the day. These so-called circadian rhythms are governed by an endogenous network of cellular clocks and serve as an adaptation to daily and, thus, predictable changes in the organism’s environment. Circadian clocks have been described in several tissues of the stress axis and in adipose cells where they regulate the rhythmic and stimulated release of stress hormones, such as glucocorticoids, and various adipokine factors. Recent work suggests that both adipose and stress axis clock systems reciprocally influence each other and adrenal-adipose rhythms may be key players in the development and therapy of metabolic disorders. In this review, we summarize our current understanding of adrenal and adipose tissue rhythms and clocks and how they might interact to regulate energy homoeostasis and stress responses under physiological conditions. Potential chronotherapeutic strategies for the treatment of metabolic and stress disorders are discussed.

In-situ preparation of functionalized molecular sieve material and a methodology to remove template

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Yadav, Rekha; Ahmed, Maqsood; Singh, Arvind Kumar; Sakthivel, Ayyamperumal

2016-03-01

A series of diaminosilane-functionalized silicoaluminophosphate molecular sieve (SAPO-37) was prepared by in-situ synthesis, and a novel method was developed for the selective removal of structure directing agent (SDA)/template from the functionalized SAPO-37.The complete removal of the SDA was evident according to FT-IR, TGA, 13C MAS-NMR and elemental analysis. The developed method was found to be efficient for removal of template from microporous molecular sieve viz., SAPO-37 and can be applied for other microporous molecular sieves such as SAPO-5, SAPO-40, etc. The powder XRD pattern of the template-removed samples showed a highly crystalline SAPO-37 phase. Argentometric titration revealed that more than 90% of diamine functionality exposed on the surface was accessible for catalytic applications. The resultant materials showed promising activity for ring opening of epoxide with aniline to yield β-amino-alcohol.

In-situ preparation of functionalized molecular sieve material and a methodology to remove template.

Science.gov (United States)

Yadav, Rekha; Ahmed, Maqsood; Singh, Arvind Kumar; Sakthivel, Ayyamperumal

2016-03-10

A series of diaminosilane-functionalized silicoaluminophosphate molecular sieve (SAPO-37) was prepared by in-situ synthesis, and a novel method was developed for the selective removal of structure directing agent (SDA)/template from the functionalized SAPO-37.The complete removal of the SDA was evident according to FT-IR, TGA, (13)C MAS-NMR and elemental analysis. The developed method was found to be efficient for removal of template from microporous molecular sieve viz., SAPO-37 and can be applied for other microporous molecular sieves such as SAPO-5, SAPO-40, etc. The powder XRD pattern of the template-removed samples showed a highly crystalline SAPO-37 phase. Argentometric titration revealed that more than 90% of diamine functionality exposed on the surface was accessible for catalytic applications. The resultant materials showed promising activity for ring opening of epoxide with aniline to yield β-amino-alcohol.

Oxidative stress, neuroendocrine function and behavior in an animal model of extended longevity

NARCIS (Netherlands)

Berry, Alessandra

2010-01-01

Stress and oxidative stress (OS) might act synergistically to exacerbate the neuronal decay associated with aging. Recent evidence has shown a redox regulation of the function of the glucocorticoid receptors as nuclear transcription factors. The lack of the p66Shc gene reduces OS and increases

Uniaxial stress-driven coupled grain boundary motion in hexagonal close-packed metals: A molecular dynamics study

International Nuclear Information System (INIS)

Zong, Hongxiang; Ding, Xiangdong; Lookman, Turab; Li, Ju; Sun, Jun

2015-01-01

Stress-driven grain boundary (GB) migration has been evident as a dominant mechanism accounting for plastic deformation in crystalline solids. Using molecular dynamics (MD) simulations on a Ti bicrystal model, we show that a uniaxial stress-driven coupling is associated with the recently observed 90° GB reorientation in shock simulations and nanopillar compression measurements. This is not consistent with the theory of shear-induced coupled GB migration. In situ atomic configuration analysis reveals that this GB motion is accompanied by the glide of two sets of parallel dislocation arrays, and the uniaxial stress-driven coupling is explained through a composite action of symmetrically distributed dislocations and deformation twins. In addition, the coupling factor is calculated from MD simulations over a wide range of temperatures. We find that the coupled motion can be thermally damped (i.e., not thermally activated), probably due to the absence of the collective action of interface dislocations. This uniaxial coupled mechanism is believed to apply to other hexagonal close-packed metals

Differential expression of molecular markers of synaptic plasticity in the hippocampus, prefrontal cortex, and amygdala in response to spatial learning, predator exposure, and stress-induced amnesia.

Science.gov (United States)

Zoladz, Phillip R; Park, Collin R; Halonen, Joshua D; Salim, Samina; Alzoubi, Karem H; Srivareerat, Marisa; Fleshner, Monika; Alkadhi, Karim A; Diamond, David M

2012-03-01

We have studied the effects of spatial learning and predator stress-induced amnesia on the expression of calcium/calmodulin-dependent protein kinase II (CaMKII), brain-derived neurotrophic factor (BDNF) and calcineurin in the hippocampus, basolateral amygdala (BLA), and medial prefrontal cortex (mPFC). Adult male rats were given a single training session in the radial-arm water maze (RAWM) composed of 12 trials followed by a 30-min delay period, during which rats were either returned to their home cages or given inescapable exposure to a cat. Immediately following the 30-min delay period, the rats were given a single test trial in the RAWM to assess their memory for the hidden platform location. Under control (no stress) conditions, rats exhibited intact spatial memory and an increase in phosphorylated CaMKII (p-CaMKII), total CaMKII, and BDNF in dorsal CA1. Under stress conditions, rats exhibited impaired spatial memory and a suppression of all measured markers of molecular plasticity in dorsal CA1. The molecular profiles observed in the BLA, mPFC, and ventral CA1 were markedly different from those observed in dorsal CA1. Stress exposure increased p-CaMKII in the BLA, decreased p-CaMKII in the mPFC, and had no effect on any of the markers of molecular plasticity in ventral CA1. These findings provide novel observations regarding rapidly induced changes in the expression of molecular plasticity in response to spatial learning, predator exposure, and stress-induced amnesia in brainregions involved in different aspects of memory processing. Copyright © 2011 Wiley Periodicals, Inc.

Complex basis functions for molecular resonances: Methodology and applications

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White, Alec; McCurdy, C. William; Head-Gordon, Martin

The computation of positions and widths of metastable electronic states is a challenge for molecular electronic structure theory because, in addition to the difficulty of the many-body problem, such states obey scattering boundary conditions. These resonances cannot be addressed with naïve application of traditional bound state electronic structure theory. Non-Hermitian electronic structure methods employing complex basis functions is one way that we may rigorously treat resonances within the framework of traditional electronic structure theory. In this talk, I will discuss our recent work in this area including the methodological extension from single determinant SCF-based approaches to highly correlated levels of wavefunction-based theory such as equation of motion coupled cluster and many-body perturbation theory. These approaches provide a hierarchy of theoretical methods for the computation of positions and widths of molecular resonances. Within this framework, we may also examine properties of resonances including the dependence of these parameters on molecular geometry. Some applications of these methods to temporary anions and dianions will also be discussed.

Cognitive reserve and self-efficacy as moderators of the relationship between stress exposure and executive functioning among spousal dementia caregivers.

Science.gov (United States)

Pertl, M M; Hannigan, C; Brennan, S; Robertson, I H; Lawlor, B A

2017-04-01

A substantial literature has reported that stress negatively impacts on cognitive processes. As dementia caregiving can be stressful, it has been hypothesized that the challenges of dementia care may increase caregivers' own vulnerability to cognitive decline. Prefrontal processes are thought to be most vulnerable to stress; however, few studies have examined whether greater caregiver stress predicts poorer executive dysfunction, and no previous research has considered potential moderators of this relationship. We examined (1) whether greater psychological stress mediated a relationship between caregiver stress exposure and executive functioning and (2) whether greater self-efficacy and cognitive reserve (CR) moderated this relationship. Spousal dementia caregivers (n = 253) completed the Neuropsychiatric Inventory Questionnaire (stress exposure), the Perceived Stress Scale, the National Adult Reading Test (CR), the Fortinsky dementia-specific caregiver self-efficacy scale, and the Color Trails Test (executive functioning). Moderated mediation was tested using the PROCESS macro. Age, gender, and dementia risk factors were included as covariates. Greater stress exposure indirectly predicted executive functioning through psychological stress. Stronger relationships between greater psychological stress and poorer executive functioning were observed among caregivers with lower CR; there was no evidence that self-efficacy moderated the relationship between stress exposure and psychological stress. Our findings are in line with the idea that greater psychological stress in response to challenges associated with dementia care predicts poorer caregiver executive functioning, particularly among caregivers with low CR. However, these findings are cross sectional; it is also possible that poorer executive functioning contributes to greater caregiver stress.

Lateralized kappa opioid receptor signaling from the amygdala central nucleus promotes stress-induced functional pain.

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Nation, Kelsey M; De Felice, Milena; Hernandez, Pablo I; Dodick, David W; Neugebauer, Volker; Navratilova, Edita; Porreca, Frank

2018-05-01

The response of diffuse noxious inhibitory controls (DNIC) is often decreased, or lost, in stress-related functional pain syndromes. Because the dynorphin/kappa opioid receptor (KOR) pathway is activated by stress, we determined its role in DNIC using a model of stress-induced functional pain. Male, Sprague-Dawley rats were primed for 7 days with systemic morphine resulting in opioid-induced hyperalgesia. Fourteen days after priming, when hyperalgesia was resolved, rats were exposed to environmental stress and DNIC was evaluated by measuring hind paw response threshold to noxious pressure (test stimulus) after capsaicin injection in the forepaw (conditioning stimulus). Morphine priming without stress did not alter DNIC. However, stress produced a loss of DNIC in morphine-primed rats in both hind paws that was abolished by systemic administration of the KOR antagonist, nor-binaltorphimine (nor-BNI). Microinjection of nor-BNI into the right, but not left, central nucleus of the amygdala (CeA) prevented the loss of DNIC in morphine-primed rats. Diffuse noxious inhibitory controls were not modulated by bilateral nor-BNI in the rostral ventromedial medulla. Stress increased dynorphin content in both the left and right CeA of primed rats, reaching significance only in the right CeA; no change was observed in the rostral ventromedial medulla or hypothalamus. Although morphine priming alone is not sufficient to influence DNIC, it establishes a state of latent sensitization that amplifies the consequences of stress. After priming, stress-induced dynorphin/KOR signaling from the right CeA inhibits DNIC in both hind paws, likely reflecting enhanced descending facilitation that masks descending inhibition. Kappa opioid receptor antagonists may provide a new therapeutic strategy for stress-related functional pain disorders.

Structure, function and networks of transcription factors involved in abiotic stress responses

DEFF Research Database (Denmark)

Lindemose, Søren; O'Shea, Charlotte; Jensen, Michael Krogh

2013-01-01

Transcription factors (TFs) are master regulators of abiotic stress responses in plants. This review focuses on TFs from seven major TF families, known to play functional roles in response to abiotic stresses, including drought, high salinity, high osmolarity, temperature extremes...... and the phytohormone ABA. Although ectopic expression of several TFs has improved abiotic stress tolerance in plants, fine-tuning of TF expression and protein levels remains a challenge to avoid crop yield loss. To further our understanding of TFs in abiotic stress responses, emerging gene regulatory networks based...... on TFs and their direct targets genes are presented. These revealed components shared between ABA-dependent and independent signaling as well as abiotic and biotic stress signaling. Protein structure analysis suggested that TFs hubs of large interactomes have extended regions with protein intrinsic...

Peroxisomal monodehydroascorbate reductase. Genomic clone characterization and functional analysis under environmental stress conditions.

Science.gov (United States)

Leterrier, Marina; Corpas, Francisco J; Barroso, Juan B; Sandalio, Luisa M; del Río, Luis A

2005-08-01

peroxisomal MDAR 1 transcripts in pea plants grown under the mentioned stress conditions. These findings show that the peroxisomal MDAR 1 has a differential regulation that could be indicative of its specific function in peroxisomes. All these biochemical and molecular data represent a significant step to understand the specific physiological role of each MDAR isoenzyme and its participation in the antioxidant mechanisms of plant cells.

Transcriptome analysis of skeletal muscle tissue to identify genes involved in pre-slaughter stress response in pigs

Directory of Open Access Journals (Sweden)

Vincenzo Russo

2010-01-01

Full Text Available The knowledge of genes and molecular processes controlling stress reactions and involved in the genetic system determining resistance to stress in pigs could be important for the improvement of meat quality. This research aimed to compare the expression profiles of skeletal muscle between physically stressed and not stressed pigs of different breeds immediately before slaughter. DNA microarray analysis showed that different functional categories of genes are up-regulated in stressed compared to not stressed pigs and relevant differences among breeds were found.

Molecular dynamics simulations of thermally activated edge dislocation unpinning from voids in α -Fe

Science.gov (United States)

Byggmästar, J.; Granberg, F.; Nordlund, K.

2017-10-01

In this study, thermal unpinning of edge dislocations from voids in α -Fe is investigated by means of molecular dynamics simulations. The activation energy as a function of shear stress and temperature is systematically determined. Simulations with a constant applied stress are compared with dynamic simulations with a constant strain rate. We found that a constant applied stress results in a temperature-dependent activation energy. The temperature dependence is attributed to the elastic softening of iron. If the stress is normalized with the softening of the specific shear modulus, the activation energy is shown to be temperature-independent. From the dynamic simulations, the activation energy as a function of critical shear stress was determined using previously developed methods. The results from the dynamic simulations are in good agreement with the constant stress simulations, after the normalization. This indicates that the computationally more efficient dynamic method can be used to obtain the activation energy as a function of stress and temperature. The obtained relation between stress, temperature, and activation energy can be used to introduce a stochastic unpinning event in larger-scale simulation methods, such as discrete dislocation dynamics.

Molecular monolayers for electrical passivation and functionalization of silicon-based solar energy devices

NARCIS (Netherlands)

Veerbeek, Janneke; Firet, Nienke J.; Vijselaar, Wouter; Elbersen, R.; Gardeniers, Han; Huskens, Jurriaan

2017-01-01

Silicon-based solar fuel devices require passivation for optimal performance yet at the same time need functionalization with (photo)catalysts for efficient solar fuel production. Here, we use molecular monolayers to enable electrical passivation and simultaneous functionalization of silicon-based

Nucleoli and stress granules: connecting distant relatives.

Science.gov (United States)

Mahboubi, Hicham; Stochaj, Ursula

2014-10-01

Nucleoli and cytoplasmic stress granules (SGs) are subcellular compartments that modulate the response to endogenous and environmental signals to control cell survival. In our opinion, nucleoli and SGs are functionally linked; they are distant relatives that combine forces when cellular homeostasis is threatened. Several lines of evidence support this idea; nucleoli and SGs share molecular building blocks, are regulated by common signaling pathways and communicate when vital cellular functions become compromised. Together, nucleoli and SGs orchestrate physiological responses that are directly relevant to stress and human health. As both compartments have established roles in neurodegenerative diseases, cancer and virus infections, we propose that these conditions will benefit from therapeutic interventions that target simultaneously nucleoli and SGs. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

The Application of Normal Stress Reduction Function in Tilt Tests for Different Block Shapes

Science.gov (United States)

Kim, Dong Hyun; Gratchev, Ivan; Hein, Maw; Balasubramaniam, Arumugam

2016-08-01

This paper focuses on the influence of the shapes of rock cores, which control the sliding or toppling behaviours in tilt tests for the estimation of rock joint roughness coefficients (JRC). When the JRC values are estimated by performing tilt tests, the values are directly proportional to the basic friction of the rock material and the applied normal stress on the sliding planes. Normal stress obviously varies with the shape of the sliding block, and the basic friction angle is also affected by the sample shapes in tilt tests. In this study, the shapes of core blocks are classified into three representative shapes and those are created using plaster. Using the various shaped artificial cores, a set of tilt tests is carried out to identify the shape influences on the normal stress and the basic friction angle in tilt tests. The test results propose a normal stress reduction function to estimate the normal stress for tilt tests according to the sample shapes based on Barton's empirical equation. The proposed normal stress reduction functions are verified by tilt tests using artificial plaster joints and real rock joint sets. The plaster joint sets are well matched and cast in detailed printed moulds using a 3D printing technique. With the application of the functions, the obtained JRC values from the tilt tests using the plaster samples and the natural rock samples are distributed within a reasonable JRC range when compared with the measured values.

Oxidative Stress, Redox Signaling, and Autophagy: Cell Death Versus Survival

Science.gov (United States)

Navarro-Yepes, Juliana; Burns, Michaela; Anandhan, Annadurai; Khalimonchuk, Oleh; del Razo, Luz Maria; Quintanilla-Vega, Betzabet; Pappa, Aglaia; Panayiotidis, Mihalis I.

2014-01-01

Abstract Significance: The molecular machinery regulating autophagy has started becoming elucidated, and a number of studies have undertaken the task to determine the role of autophagy in cell fate determination within the context of human disease progression. Oxidative stress and redox signaling are also largely involved in the etiology of human diseases, where both survival and cell death signaling cascades have been reported to be modulated by reactive oxygen species (ROS) and reactive nitrogen species (RNS). Recent Advances: To date, there is a good understanding of the signaling events regulating autophagy, as well as the signaling processes by which alterations in redox homeostasis are transduced to the activation/regulation of signaling cascades. However, very little is known about the molecular events linking them to the regulation of autophagy. This lack of information has hampered the understanding of the role of oxidative stress and autophagy in human disease progression. Critical Issues: In this review, we will focus on (i) the molecular mechanism by which ROS/RNS generation, redox signaling, and/or oxidative stress/damage alter autophagic flux rates; (ii) the role of autophagy as a cell death process or survival mechanism in response to oxidative stress; and (iii) alternative mechanisms by which autophagy-related signaling regulate mitochondrial function and antioxidant response. Future Directions: Our research efforts should now focus on understanding the molecular basis of events by which autophagy is fine tuned by oxidation/reduction events. This knowledge will enable us to understand the mechanisms by which oxidative stress and autophagy regulate human diseases such as cancer and neurodegenerative disorders. Antioxid. Redox Signal. 21, 66–85. PMID:24483238

Blunted amygdala functional connectivity during a stress task in alcohol dependent individuals: A pilot study.

Science.gov (United States)

Wade, Natasha E; Padula, Claudia B; Anthenelli, Robert M; Nelson, Erik; Eliassen, James; Lisdahl, Krista M

2017-12-01

Scant research has been conducted on neural mechanisms underlying stress processing in individuals with alcohol dependence (AD). We examined neural substrates of stress in AD individuals compared with controls using an fMRI task previously shown to induce stress, assessing amygdala functional connectivity to medial prefrontal cortex (mPFC). For this novel pilot study, 10 abstinent AD individuals and 11 controls completed a modified Trier stress task while undergoing fMRI acquisition. The amygdala was used as a seed region for whole-brain seed-based functional connectivity analysis. After controlling for family-wise error (p = 0.05), there was significantly decreased left and right amygdala connectivity with frontal (specifically mPFC), temporal, parietal, and cerebellar regions. Subjective stress, but not craving, increased from pre-to post-task. This study demonstrated decreased connectivity between the amygdala and regions important for stress and emotional processing in long-term abstinent individuals with AD. These results suggest aberrant stress processing in individuals with AD even after lengthy periods of abstinence.

Transcriptomic Analysis Reveals the Molecular Mechanisms of Drought-Stress-Induced Decreases in Camellia sinensis Leaf Quality

Science.gov (United States)

Wang, Weidong; Xin, Huahong; Wang, Mingle; Ma, Qingping; Wang, Le; Kaleri, Najeeb A.; Wang, Yuhua; Li, Xinghui

2016-01-01

The tea plant [Camellia sinensis (L.) O. Kuntze] is an important commercial crop rich in bioactive ingredients, especially catechins, caffeine, theanine and other free amino acids, which the quality of tea leaves depends on. Drought is the most important environmental stress affecting the yield and quality of this plant. In this study, the effects of drought stress on the phenotype, physiological characteristics and major bioactive ingredients accumulation of C. sinensis leaves were examined, and the results indicated that drought stress resulted in dehydration and wilt of the leaves, and significant decrease in the total polyphenols and free amino acids and increase in the total flavonoids. In addition, HPLC analysis showed that the catechins, caffeine, theanine and some free amino acids in C. sinensis leaves were significantly reduced in response to drought stress, implying that drought stress severely decreased the quality of C. sinensis leaves. Furthermore, differentially expressed genes (DEGs) related to amino acid metabolism and secondary metabolism were identified and quantified in C. sinensis leaves under drought stress using high-throughput Illumina RNA-Seq technology, especially the key regulatory genes of the catechins, caffeine, and theanine biosynthesis pathways. The expression levels of key regulatory genes were consistent with the results from the HPLC analysis, which indicate a potential molecular mechanism for the above results. Taken together, these data provide further insights into the mechanisms underlying the change in the quality of C. sinensis leaves under environmental stress, which involve changes in the accumulation of major bioactive ingredients, especially catechins, caffeine, theanine and other free amino acids. PMID:27066035

Biomarkers of Aging: From Function to Molecular Biology

Directory of Open Access Journals (Sweden)

Karl-Heinz Wagner

2016-06-01

Full Text Available Aging is a major risk factor for most chronic diseases and functional impairments. Within a homogeneous age sample there is a considerable variation in the extent of disease and functional impairment risk, revealing a need for valid biomarkers to aid in characterizing the complex aging processes. The identification of biomarkers is further complicated by the diversity of biological living situations, lifestyle activities and medical treatments. Thus, there has been no identification of a single biomarker or gold standard tool that can monitor successful or healthy aging. Within this short review the current knowledge of putative biomarkers is presented, focusing on their application to the major physiological mechanisms affected by the aging process including physical capability, nutritional status, body composition, endocrine and immune function. This review emphasizes molecular and DNA-based biomarkers, as well as recent advances in other biomarkers such as microRNAs, bilirubin or advanced glycation end products.

Genome-wide characterization of the WRKY gene family in radish (Raphanus sativus L.) reveals its critical functions under different abiotic stresses.

Science.gov (United States)

Karanja, Bernard Kinuthia; Fan, Lianxue; Xu, Liang; Wang, Yan; Zhu, Xianwen; Tang, Mingjia; Wang, Ronghua; Zhang, Fei; Muleke, Everlyne M'mbone; Liu, Liwang

2017-11-01

The radish WRKY gene family was genome-widely identified and played critical roles in response to multiple abiotic stresses. The WRKY is among the largest transcription factors (TFs) associated with multiple biological activities for plant survival, including control response mechanisms against abiotic stresses such as heat, salinity, and heavy metals. Radish is an important root vegetable crop and therefore characterization and expression pattern investigation of WRKY transcription factors in radish is imperative. In the present study, 126 putative WRKY genes were retrieved from radish genome database. Protein sequence and annotation scrutiny confirmed that RsWRKY proteins possessed highly conserved domains and zinc finger motif. Based on phylogenetic analysis results, RsWRKYs candidate genes were divided into three groups (Group I, II and III) with the number 31, 74, and 20, respectively. Additionally, gene structure analysis revealed that intron-exon patterns of the WRKY genes are highly conserved in radish. Linkage map analysis indicated that RsWRKY genes were distributed with varying densities over nine linkage groups. Further, RT-qPCR analysis illustrated the significant variation of 36 RsWRKY genes under one or more abiotic stress treatments, implicating that they might be stress-responsive genes. In total, 126 WRKY TFs were identified from the R. sativus genome wherein, 35 of them showed abiotic stress-induced expression patterns. These results provide a genome-wide characterization of RsWRKY TFs and baseline for further functional dissection and molecular evolution investigation, specifically for improving abiotic stress resistances with an ultimate goal of increasing yield and quality of radish.

The Structural, Functional and Molecular Organization of the Brainstem

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Rudolf eNieuwenhuys

2011-06-01

Full Text Available According to Wilhelm His (1891, 1893 the brainstem consists of two longitudinal zones, the dorsal alar plate (sensory in nature and the ventral basal plate (motor in nature. Johnston and Herrick indicated that both plates can be subdivided into separate somatic and visceral zones, distinguishing somatosensory and viscerosensory zones within the alar plate, and visceromotor and somatomotor zones within the basal plate. To test the validity of this ‘four-functional-zones’ concept, I developed a topological procedure, surveying the spatial relationships of the various cell masses in the brainstem in a single figure. Brainstems of 16 different anamniote species were analyzed, and revealed that the brainstems are clearly divisible into four morphological zones, which correspond largely with the functional zones of Johnston and Herrick. Exceptions include (1 the magnocellular vestibular nucleus situated in the viscerosensory zone; (2 the basal plate containing a number of evidently non-motor centres (superior and inferior olives. Nevertheless the ‘functional zonal model’ has explanatory value. Thus, it is possible to interpret certain brain specializations related to particular behavioural profiles, as ‘local hypertrophies’ of one or two functional columns. Recent developmental molecular studies on brains of birds and mammals confirmed the presence of longitudinal zones, and also showed molecularly defined transverse bands or neuromeres throughout development. The intersecting boundaries of the longitudinal zones and the transverse bands appeared to delimit radially arranged histogenetic domains. Because neuromeres have been observed in embryonic and larval stages of numerous anamniote species, it may be hypothesized that the brainstems of all vertebrates share a basic organizational plan, in which intersecting longitudinal and transverse zones form fundamental histogenetic and genoarchitectonic units.

Total Correlation Function Integrals and Isothermal Compressibilities from Molecular Simulations

DEFF Research Database (Denmark)

Wedberg, Rasmus; Peters, Günther H.j.; Abildskov, Jens

2008-01-01

Generation of thermodynamic data, here compressed liquid density and isothermal compressibility data, using molecular dynamics simulations is investigated. Five normal alkane systems are simulated at three different state points. We compare two main approaches to isothermal compressibilities: (1...... in approximately the same amount of time. This suggests that computation of total correlation function integrals is a route to isothermal compressibility, as accurate and fast as well-established benchmark techniques. A crucial step is the integration of the radial distribution function. To obtain sensible results...

Comparative transcriptome profiling of chilling stress responsiveness in grafted watermelon seedlings.

Science.gov (United States)

Xu, Jinhua; Zhang, Man; Liu, Guang; Yang, Xingping; Hou, Xilin

2016-12-01

Rootstock grafting may improve the resistance of watermelon plants to low temperatures. However, information regarding the molecular responses of rootstock grafted plants to chilling stress is limited. To elucidate the molecular mechanisms of chilling tolerance in grafted plants, the transcriptomic responses of grafted watermelon under chilling stress were analyzed using RNA-seq analysis. Sequencing data were used for digital gene expression (DGE) analysis to characterize the transcriptomic responses in grafted watermelon seedlings. A total of 702 differentially-expressed genes (DEGs) were found in rootstock grafted (RG) watermelon relative to self-grafted (SG) watermelon; among these genes, 522 genes were up-regulated and 180 were down-regulated. Additionally, 164 and 953 genes were found to specifically expressed in RG and SG seedlings under chilling stress, respectively. Functional annotations revealed that up-regulated DEGs are involved in protein processing, plant-pathogen interaction and the spliceosome, whereas down-regulated DEGs are associated with photosynthesis. Moreover, 13 DEGs were randomly selected for quantitative real time PCR (qRT-PCR) analysis. The expression profiles of these 13 DEGs were consistent with those detected by the DGE analysis, supporting the reliability of the DGE data. This work provides additional insight into the molecular basis of grafted watermelon responses to chilling stress. Copyright © 2016. Published by Elsevier Masson SAS.

Research Paper: Executive Functions in Students With Depression, Anxiety, and Stress Symptoms

Directory of Open Access Journals (Sweden)

Bita Ajilchi

2017-05-01

Conclusion: The findings of this research raised specific issues in relation to the role of depression, anxiety, and stress in the disruption of the executive functions of sufferers. Selective and shifting attention and cognitive abilities are specifically affected in this regard. Meanwhile, the role of stress in impairing decision making and the major role of anxiety in impairing sustained attention was shown to be considerable.

Diversity of radioprobes targeted to tumor angiogenesis on molecular functional imaging

International Nuclear Information System (INIS)

Lu Xia; Zhang Huabei

2013-01-01

Molecular functional imaging could visualize, characterize, and measure the bio- logical processes including tumor angiogenesis at the molecular and cellular levels in humans and other living systems. The molecular probes labeled by a variety of radionuclide used in the field of the nuclear medicine play pivotal roles in molecular imaging of tumor angiogenesis. However, the regulatory role of different probes in tumor angiogenesis has not been systematically illustrated. The current status of tumor angiogenesis imaging with radiolabeled probes of peptide, monoclonal antibody as well as its fragment, especially nanoparticle-based probes to gain insights into the robust tumor angiogenesis development were summarized. It was recognized that only the probes such as nanoparticle-based probes, which truly target the tumor vasculature rather than tumor cells because of poor extravasation, are really tumor angiogenesis imaging agent. The research of molecular probe targeted to angiogenesis would meet its flourish just after the outstanding improvements in the in vivo stability and biocompatibility, tumor-targeting efficacy, and pharmacokinetics of tumor angiogenesis imaging probes are made. Translation to clinical applications will also be critical for the maximize benefits of these novel agents. The future of tumor angiogenesis imaging lies in liable imaging probes and multiple imaging modalities, imaging of protein-protein interactions, and quantitative molecular imaging. (authors)

Theory for site-site pair distribution functions of molecular fluids. II. Approximations for the Percus--Yevick site-site direct correlation functions

International Nuclear Information System (INIS)

Johnson, E.

1977-01-01

A theory for site-site pair distribution functions of molecular fluids is derived from the Ornstein-Zernike equation. Atom-atom pair distribution functions of this theory which were obtained by using different approximations for the Percus-Yevick site-site direct correlation functions are compared

Study on application of green's function method in thermal stress rapid calculation

International Nuclear Information System (INIS)

Zhang Guihe; Duan Yuangang; Xu Xiao; Chen Rong

2013-01-01

This paper presents a quick and accuracy thermal stress calculation method, the Green's Function Method, which is a combination of finite element method and numerical algorithm method. Thermal stress calculation of Safe Injection Nozzle of Reactor Coolant Line of PWR plant is performed with Green's function method for heatup and cooldown thermal transients as a demonstration example, and the result is compared with finite element method to verify the rationality and accuracy of this method. The advantage and disadvantage of the Green's function method and the finite element method are also compared. (authors)

Proceedings of DAE-BRNS life sciences symposium 2011 on advances in molecular and cell biology of stress response

International Nuclear Information System (INIS)

2011-01-01

is being elucidated. Chromatin remodelling is another emerging area in the context of differential gene expression following exposure to stressors in plants as well as mammalian systems. Its role in the development of functional dichotomy in helper T cells has been recently established. It will be interesting to look at changes in the methylation or acetylation of histones following continuous low level radiation exposure. Bacteria have provided intriguing model systems to investigate stress response, Deinococcus radiodurans being a challenging example. In plants the intensive basic research effort may provide mechanistic answers to the efficacy of biotic and abiotic stress tolerant varieties of crop plants that are or will be developed through plant breeding techniques. This symposium will bring together several leading lights in the field of molecular and cell biology of response to stress in different living organisms. Papers relevant to INIS are indexed separately

Molecular insights into the mechanisms of liver-associated diseases in early-lactating dairy cows: hypothetical role of endoplasmic reticulum stress.

Science.gov (United States)

Ringseis, R; Gessner, D K; Eder, K

2015-08-01

The transition period represents the most critical period in the productive life of high-yielding dairy cows due to both metabolic and inflammatory stimuli, which challenge the liver and predispose dairy cows to develop liver-associated diseases such as fatty liver and ketosis. Despite the fact that all high-yielding dairy cows are affected by marked metabolic stress due to a severe negative energy balance (NEB) during early lactation, not all cows develop liver-associated diseases. Although the reason for this is largely unknown, this indicates that the capacity of the liver to cope with metabolic and inflammatory challenges varies between individual high-yielding dairy cows. Convincing evidence exists that endoplasmic reticulum (ER) stress plays a key role in the development of fatty liver, and it has been recently shown that ER stress occurs in the liver of high-yielding dairy cows. This indicates that ER stress may be involved in the development of liver-associated diseases in dairy cows. The present review shows that the liver of dairy cows during early lactation is exposed to several metabolic and inflammatory challenges, such as non-esterified fatty acids, tumour necrosis factor α, interleukin-1β, reactive oxygen species and lipopolysaccharides, which are known inducers of ER stress. Thus, ER stress may represent a molecular basis for fatty liver development and account for the frequent occurrence of fatty liver and ketosis in high-yielding dairy cows. Interindividual differences between dairy cows in the activation of hepatic stress response pathways, such as nuclear factor E2-related factor 2, which is activated during ER stress and reduces the sensitivity of tissues to oxidative and inflammatory damage, might provide an explanation at the molecular level for differences in the capacity to cope with pathological inflammatory challenges during early lactation and the susceptibility to develop liver-associated diseases between early-lactating dairy cows

Intrinsic functional connectivity between amygdala and hippocampus during rest predicts enhanced memory under stress.

Science.gov (United States)

de Voogd, Lycia D; Klumpers, Floris; Fernández, Guillén; Hermans, Erno J

2017-01-01

Declarative memories of stressful events are less prone to forgetting than mundane events. Animal research has demonstrated that such stress effects on consolidation of hippocampal-dependent memories require the amygdala. In humans, it has been shown that during learning, increased amygdala-hippocampal interactions are related to more efficient memory encoding. Animal models predict that following learning, amygdala-hippocampal interactions are instrumental to strengthening the consolidation of such declarative memories. Whether this is the case in humans is unknown and remains to be empirically verified. To test this, we analyzed data from a sample of 120 healthy male participants who performed an incidental encoding task and subsequently underwent resting-state functional MRI in a stressful and a neutral context. Stress was assessed by measures of salivary cortisol, blood pressure, heart rate, and subjective ratings. Memory was tested afterwards outside of the scanner. Our data show that memory was stronger in the stress context compared to the neutral context and that stress-induced cortisol responses were associated with this memory enhancement. Interestingly, amygdala-hippocampal connectivity during post-encoding awake rest regardless of context (stress or neutral) was associated with the enhanced memory performance under stress. Thus, our findings are in line with a role for intrinsic functional connectivity during rest between the amygdala and the hippocampus in the state effects of stress on strengthening memory. Copyright © 2016 Elsevier Ltd. All rights reserved.

Effects of Exercise Intensity on Postexercise Endothelial Function and Oxidative Stress

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Conor McClean

2015-01-01

Full Text Available Purpose. To measure endothelial function and oxidative stress immediately, 90 minutes, and three hours after exercise of varying intensities. Methods. Sixteen apparently healthy men completed three exercise bouts of treadmill running for 30 minutes at 55% V˙O2max (mild; 20 minutes at 75% V˙O2max (moderate; or 5 minutes at 100% V˙O2max (maximal in random order. Brachial artery flow-mediated dilation (FMD was assessed with venous blood samples drawn for measurement of endothelin-1 (ET-1, lipid hydroperoxides (LOOHs, and lipid soluble antioxidants. Results. LOOH increased immediately following moderate exercise (P0.05. Conclusions. Acute exercise at different intensities elicits varied effects on oxidative stress, shear rate, and ET-1 that do not appear to mediate changes in endothelial function measured by FMD.

Comparison of intra-organellar chaperone capacity for dealing with stress-induced protein unfolding

NARCIS (Netherlands)

Hageman, Jurre; Vos, Michel J.; van Waarde, Maria A. W. H.; Kampinga, Harm H.

2007-01-01

Molecular chaperones are essential for cells to prevent that partially unfolded proteins form non-functional, toxic aggregates. This requirement is increased when cells experience protein unfolding stresses and such could affect all compartments in the eukaryotic cell. Whether all organelles are

Structural and Conformational Chemistry from Electrochemical Molecular Machines. Replicating Biological Functions. A Review.

Science.gov (United States)

Otero, Toribio F

2017-12-14

Each constitutive chain of a conducting polymer electrode acts as a reversible multi-step electrochemical molecular motor: reversible reactions drive reversible conformational movements of the chain. The reaction-driven cooperative actuation of those molecular machines generates, or destroys, inside the film the free volume required to lodge/expel balancing counterions and solvent: reactions drive reversible film volume variations, which basic structural components are here identified and quantified from electrochemical responses. The content of the reactive dense gel (chemical molecular machines, ions and water) mimics that of the intracellular matrix in living functional cells. Reaction-driven properties (composition-dependent properties) and devices replicate biological functions and organs. An emerging technological world of soft, wet, reaction-driven, multifunctional and biomimetic devices and the concomitant zoomorphic or anthropomorphic robots is presented. © 2017 The Chemical Society of Japan & Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Elastic Stress Analysis of Rotating Functionally Graded Annular Disk of Variable Thickness Using Finite Difference Method

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Mohammad Hadi Jalali

2018-01-01

Full Text Available Elastic stress analysis of rotating variable thickness annular disk made of functionally graded material (FGM is presented. Elasticity modulus, density, and thickness of the disk are assumed to vary radially according to a power-law function. Radial stress, circumferential stress, and radial deformation of the rotating FG annular disk of variable thickness with clamped-clamped (C-C, clamped-free (C-F, and free-free (F-F boundary conditions are obtained using the numerical finite difference method, and the effects of the graded index, thickness variation, and rotating speed on the stresses and deformation are evaluated. It is shown that using FG material could decrease the value of radial stress and increase the radial displacement in a rotating thin disk. It is also demonstrated that increasing the rotating speed can strongly increase the stress in the FG annular disk.

Deciphering hepatocellular responses to metabolic and oncogenic stress

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Kathrina L. Marcelo

2015-08-01

Full Text Available Each cell type responds uniquely to stress and fractionally contributes to global and tissue-specific stress responses. Hepatocytes, liver macrophages (MΦ, and sinusoidal endothelial cells (SEC play functionally important and interdependent roles in adaptive processes such as obesity and tumor growth. Although these cell types demonstrate significant phenotypic and functional heterogeneity, their distinctions enabling disease-specific responses remain understudied. We developed a strategy for the simultaneous isolation and quantification of these liver cell types based on antigenic cell surface marker expression. To demonstrate the utility and applicability of this technique, we quantified liver cell-specific responses to high-fat diet (HFD or diethylnitrosamine (DEN, a liver-specific carcinogen, and found that while there was only a marginal increase in hepatocyte number, MΦ and SEC populations were quantitatively increased. Global gene expression profiling of hepatocytes, MΦ and SEC identified characteristic gene signatures that define each cell type in their distinct physiological or pathological states. Integration of hepatic gene signatures with available human obesity and liver cancer microarray data provides further insight into the cell-specific responses to metabolic or oncogenic stress. Our data reveal unique gene expression patterns that serve as molecular “fingerprints” for the cell-centric responses to pathologic stimuli in the distinct microenvironment of the liver. The technical advance highlighted in this study provides an essential resource for assessing hepatic cell-specific contributions to metabolic and oncogenic stress, information that could unveil previously unappreciated molecular mechanisms for the cellular crosstalk that underlies the continuum from metabolic disruption to obesity and ultimately hepatic cancer.

circHIPK2-mediated σ-1R promotes endoplasmic reticulum stress in human pulmonary fibroblasts exposed to silica.

Science.gov (United States)

Cao, Zhouli; Xiao, Qingling; Dai, Xiaoniu; Zhou, Zewei; Jiang, Rong; Cheng, Yusi; Yang, Xiyue; Guo, Huifang; Wang, Jing; Xi, Zhaoqing; Yao, Honghong; Chao, Jie

2017-12-13

Silicosis is characterized by fibroblast accumulation and excessive deposition of extracellular matrix. Although the roles of SiO 2 -induced chemokines and cytokines released from alveolar macrophages have received significant attention, the direct effects of SiO 2 on protein production and functional changes in pulmonary fibroblasts have been less extensively studied. Sigma-1 receptor, which has been associated with cell proliferation and migration in the central nervous system, is expressed in the lung, but its role in silicosis remains unknown. To elucidate the role of sigma-1 receptor in fibrosis induced by silica, both the upstream molecular mechanisms and the functional effects on cell proliferation and migration were investigated. Both molecular biological assays and pharmacological techniques, combined with functional experiments, such as migration and proliferation, were applied in human pulmonary fibroblasts from adults to analyze the molecular and functional changes induced by SiO 2 . SiO 2 induced endoplasmic reticulum stress in association with enhanced expression of sigma-1 receptor. Endoplasmic reticulum stress promoted migration and proliferation of human pulmonary fibroblasts-adult exposed to SiO 2 , inducing the development of silicosis. Inhibition of sigma-1 receptor ameliorated endoplasmic reticulum stress and fibroblast functional changes induced by SiO 2 . circHIPK2 is involved in the regulation of sigma-1 receptor in human pulmonary fibroblasts-adult exposed to SiO 2 . Our study elucidated a link between SiO 2 -induced fibrosis and sigma-1 receptor signaling, thereby providing novel insight into the potential use of sigma-1 receptor/endoplasmic reticulum stress in the development of novel therapeutic strategies for silicosis treatment.

Peeling back the evolutionary layers of molecular mechanisms responsive to exercise-stress in the skeletal muscle of the racing horse.

Science.gov (United States)

Kim, Hyeongmin; Lee, Taeheon; Park, Woncheoul; Lee, Jin Woo; Kim, Jaemin; Lee, Bo-Young; Ahn, Hyeonju; Moon, Sunjin; Cho, Seoae; Do, Kyoung-Tag; Kim, Heui-Soo; Lee, Hak-Kyo; Lee, Chang-Kyu; Kong, Hong-Sik; Yang, Young-Mok; Park, Jongsun; Kim, Hak-Min; Kim, Byung Chul; Hwang, Seungwoo; Bhak, Jong; Burt, Dave; Park, Kyoung-Do; Cho, Byung-Wook; Kim, Heebal

2013-06-01

The modern horse (Equus caballus) is the product of over 50 million yrs of evolution. The athletic abilities of the horse have been enhanced during the past 6000 yrs under domestication. Therefore, the horse serves as a valuable model to understand the physiology and molecular mechanisms of adaptive responses to exercise. The structure and function of skeletal muscle show remarkable plasticity to the physical and metabolic challenges following exercise. Here, we reveal an evolutionary layer of responsiveness to exercise-stress in the skeletal muscle of the racing horse. We analysed differentially expressed genes and their co-expression networks in a large-scale RNA-sequence dataset comparing expression before and after exercise. By estimating genome-wide dN/dS ratios using six mammalian genomes, and FST and iHS using re-sequencing data derived from 20 horses, we were able to peel back the evolutionary layers of adaptations to exercise-stress in the horse. We found that the oldest and thickest layer (dN/dS) consists of system-wide tissue and organ adaptations. We further find that, during the period of horse domestication, the older layer (FST) is mainly responsible for adaptations to inflammation and energy metabolism, and the most recent layer (iHS) for neurological system process, cell adhesion, and proteolysis.

Enantiopure Functional Molecular Motors Obtained by a Switchable Chiral-Resolution Process

NARCIS (Netherlands)

van Leeuwen, Thomas; Gan, Jefri; Kistemaker, Jos C. M.; Pizzolato, Stefano F.; Chang, Mu-Chieh; Feringa, Ben L.

2016-01-01

Molecular switches, rotors, and motors play an important role in the development of nano-machines and devices, as well as responsive and adaptive functional materials. For unidirectional rotors based on chiral overcrowded alkenes, their stereochemical homogeneity is of crucial importance. Herein, a

The behavioral and molecular evaluation of effects of social instability stress as a model of stress-related disorders in adult female rats.

Science.gov (United States)

Nowacka-Chmielewska, Marta Maria; Kasprowska-Liśkiewicz, Daniela; Barski, Jarosław Jerzy; Obuchowicz, Ewa; Małecki, Andrzej

2017-11-01

The study aimed to test the hypotheses that chronic social instability stress (CSIS) alters behavioral and physiological parameters and expression of selected genes important for stress response and social behaviors. Adult female Sprague-Dawley rats were subjected to the 4-week CSIS procedure, which involves unpredictable rotation between phases of isolation and overcrowding. Behavioral analyses (Experiment 1) were performed on the same rats before and after CSIS (n = 16) and physiological and biochemical measurements (Experiment 2) were made on further control (CON; n = 7) and stressed groups (CSIS; n = 8). Behaviors in the open field test (locomotor and exploratory activities) and elevated-plus maze (anxiety-related behaviors) indicated anxiety after CSIS. CSIS did not alter the physiological parameters measured, i.e. body weight gain, regularity of estrous cycles, and circulating concentrations of stress hormones and sex steroids. QRT-PCR analysis of mRNA expression levels was performed on amygdala, hippocampus, prefrontal cortex (PFC), and hypothalamus. The main finding is that CSIS alters the mRNA levels for the studied genes in a region-specific manner. Hence, expression of POMC (pro-opiomelanocortin), AVPR1a (arginine vasopressin receptor), and OXTR (oxytocin receptor) significantly increased in the amygdala following CSIS, while in PFC and/or hypothalamus, POMC, AVPR1a, AVPR1b, OXTR, and ERβ (estrogen receptor beta) expression decreased. CSIS significantly reduced expression of CRH-R1 (corticotropin-releasing hormone receptor type 1) in the hippocampus. The directions of change in gene expression and the genes and regions affected indicate a molecular basis for the behavior changes. In conclusion, CSIS may be valuable for further analyzing the neurobiology of stress-related disorders in females.

The stress response and the hypothalamic-pituitary-adrenal axis: from molecule to melancholia.

LENUS (Irish Health Repository)

O'Connor, T M

2012-02-03

Organisms survive by maintaining equilibrium with their environment. The stress system is critical to this homeostasis. Glucocorticoids modulate the stress response at a molecular level by altering gene expression, transcription, and translation, among other pathways. The effect is the inhibition of the functions of inflammatory cells, predominantly mediated through inhibition of cytokines, such as IL-1, IL-6, and TNF-alpha. The central effectors of the stress response are the corticotrophin-releasing hormone (CRH) and locus coeruleus-norepinephrine (LC-NE)\\/sympathetic systems. The CRH system activates the stress response and is subject to modulation by cytokines, hormones, and neurotransmitters. Glucocorticoids also modulate the growth, reproductive and thyroid axes. Abnormalities of stress system activation have been shown in inflammatory diseases such as rheumatoid arthritis, as well as behavioural syndromes such as melancholic depression. These disorders are comparable to those seen in rats whose CRH system is genetically abnormal. Thus, the stress response is central to resistance to inflammatory and behavioural syndromes. In this review, we describe the response to stress at molecular, cellular, neuroendocrine and behavioural levels, and discuss the disease processes that result from a dysregulation of this response, as well as recent developments in their treatment.

Molecular basis for vulnerability to mitochondrial and oxidative stress in a neuroendocrine CRI-G1 cell line.

Directory of Open Access Journals (Sweden)

Natasha Chandiramani

2011-01-01

Full Text Available Many age-associated disorders (including diabetes, cancer, and neurodegenerative diseases are linked to mitochondrial dysfunction, which leads to impaired cellular bioenergetics and increased oxidative stress. However, it is not known what genetic and molecular pathways underlie differential vulnerability to mitochondrial dysfunction observed among different cell types.Starting with an insulinoma cell line as a model for a neuronal/endocrine cell type, we isolated a novel subclonal line (named CRI-G1-RS that was more susceptible to cell death induced by mitochondrial respiratory chain inhibitors than the parental CRI-G1 line (renamed CRI-G1-RR for clarity. Compared to parental RR cells, RS cells were also more vulnerable to direct oxidative stress, but equally vulnerable to mitochondrial uncoupling and less vulnerable to protein kinase inhibition-induced apoptosis. Thus, differential vulnerability to mitochondrial toxins between these two cell types likely reflects differences in their ability to handle metabolically generated reactive oxygen species rather than differences in ATP production/utilization or in downstream apoptotic machinery. Genome-wide gene expression analysis and follow-up biochemical studies revealed that, in this experimental system, increased vulnerability to mitochondrial and oxidative stress was associated with (1 inhibition of ARE/Nrf2/Keap1 antioxidant pathway; (2 decreased expression of antioxidant and phase I/II conjugation enzymes, most of which are Nrf2 transcriptional targets; (3 increased expression of molecular chaperones, many of which are also considered Nrf2 transcriptional targets; (4 increased expression of β cell-specific genes and transcription factors that specify/maintain β cell fate; and (5 reconstitution of glucose-stimulated insulin secretion.The molecular profile presented here will enable identification of individual genes or gene clusters that shape vulnerability to mitochondrial dysfunction and

Microsecond molecular dynamics simulations of intrinsically disordered proteins involved in the oxidative stress response.

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Elio A Cino

Full Text Available Intrinsically disordered proteins (IDPs are abundant in cells and have central roles in protein-protein interaction networks. Interactions between the IDP Prothymosin alpha (ProTα and the Neh2 domain of Nuclear factor erythroid 2-related factor 2 (Nrf2, with a common binding partner, Kelch-like ECH-associated protein 1(Keap1, are essential for regulating cellular response to oxidative stress. Misregulation of this pathway can lead to neurodegenerative diseases, premature aging and cancer. In order to understand the mechanisms these two disordered proteins employ to bind to Keap1, we performed extensive 0.5-1.0 microsecond atomistic molecular dynamics (MD simulations and isothermal titration calorimetry experiments to investigate the structure/dynamics of free-state ProTα and Neh2 and their thermodynamics of bindings. The results show that in their free states, both ProTα and Neh2 have propensities to form bound-state-like β-turn structures but to different extents. We also found that, for both proteins, residues outside the Keap1-binding motifs may play important roles in stabilizing the bound-state-like structures. Based on our findings, we propose that the binding of disordered ProTα and Neh2 to Keap1 occurs synergistically via preformed structural elements (PSEs and coupled folding and binding, with a heavy bias towards PSEs, particularly for Neh2. Our results provide insights into the molecular mechanisms Neh2 and ProTα bind to Keap1, information that is useful for developing therapeutics to enhance the oxidative stress response.

A systems approach identifies networks and genes linking sleep and stress: implications for neuropsychiatric disorders.

Science.gov (United States)

Jiang, Peng; Scarpa, Joseph R; Fitzpatrick, Karrie; Losic, Bojan; Gao, Vance D; Hao, Ke; Summa, Keith C; Yang, He S; Zhang, Bin; Allada, Ravi; Vitaterna, Martha H; Turek, Fred W; Kasarskis, Andrew

2015-05-05

Sleep dysfunction and stress susceptibility are comorbid complex traits that often precede and predispose patients to a variety of neuropsychiatric diseases. Here, we demonstrate multilevel organizations of genetic landscape, candidate genes, and molecular networks associated with 328 stress and sleep traits in a chronically stressed population of 338 (C57BL/6J × A/J) F2 mice. We constructed striatal gene co-expression networks, revealing functionally and cell-type-specific gene co-regulations important for stress and sleep. Using a composite ranking system, we identified network modules most relevant for 15 independent phenotypic categories, highlighting a mitochondria/synaptic module that links sleep and stress. The key network regulators of this module are overrepresented with genes implicated in neuropsychiatric diseases. Our work suggests that the interplay among sleep, stress, and neuropathology emerges from genetic influences on gene expression and their collective organization through complex molecular networks, providing a framework for interrogating the mechanisms underlying sleep, stress susceptibility, and related neuropsychiatric disorders. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

Differential changes of metabolic brain activity and interregional functional coupling in prefronto-limbic pathways during different stress conditions: Functional imaging in freely behaving rodent pups

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Joerg eBock

2012-05-01

Full Text Available The trumpet-tailed rat or degu (Octodon degus is an established model to investigate the consequences of early stress on the development of emotional brain circuits and behaviour. The aim of this study was to identify brain circuits, that respond to different stress conditions and to test if acute stress alters functional coupling of brain activity among prefrontal and limbic regions. Using functional imaging (2-Fluoro-deoxyglucose method in 8 day old male degu pups the following stress conditions were compared: (A pups together with parents and siblings (control, (B separation of the litter from the parents, (C individual separation from parents and siblings, (D individual separation and presentation of maternal calls. Condition (B significantly downregulated brain activity in the prefrontal cortex, hippocampus, nucleus accumbens and sensory areas compared to controls. Activity decrease was even more pronounced during condition (C, where, in contrast to all other regions, activity in the PAG was increased. Interestingly, brain activity in stress-associated brain regions such as the amygdala and habenula was not affected. In condition (D maternal vocalizations reactivated brain activity in the cingulate and precentral medial cortex, nucleus accumbens and striatum and in sensory areas. In contrast, reduced activity was measured in the prelimbic and infralimbic cortex and in the hippocampus and amygdala. Correlation analysis revealed complex, region- and situation-specific changes of interregional functional coupling among prefrontal and limbic brain regions during stress exposure. We show here for the first time that early life stress results in a widespread reduction of brain activity in the infant brain and changes interregional functional coupling. Moreover, maternal vocalizations can partly buffer stress-induced decrease in brain activity in some regions and evoked very different functional coupling patterns compared to the three other

Altered functional connectivity to stressful stimuli in prenatally cocaine-exposed adolescents.

Science.gov (United States)

Zakiniaeiz, Yasmin; Yip, Sarah W; Balodis, Iris M; Lacadie, Cheryl M; Scheinost, Dustin; Constable, R Todd; Mayes, Linda C; Sinha, Rajita; Potenza, Marc N

2017-11-01

Prenatal cocaine exposure (PCE) is linked to addiction and obesity vulnerability. Neural responses to stressful and appetitive cues in adolescents with PCE versus those without have been differentially linked to substance-use initiation. However, no prior studies have assessed cue-reactivity responses among PCE adolescents using a connectivity-based approach. Twenty-two PCE and 22 non-prenatally drug-exposed (NDE) age-, sex-, IQ- and BMI-matched adolescents participated in individualized guided imagery with appetitive (favorite-food), stressful and neutral-relaxing cue scripts during functional magnetic resonance imaging. Subjective favorite-food craving scores were collected before and after script exposure. A data-driven voxel-wise intrinsic connectivity distribution analysis was used to identify between-group differences and examine relationships with craving scores. A group-by-cue interaction effect identified a parietal lobe cluster where PCE versus NDE adolescents showed less connectivity during stressful and more connectivity during neutral-relaxing conditions. Follow-up seed-based connectivity analyses revealed that, among PCE adolescents, the parietal seed was positively connected to inferior parietal and sensory areas and negatively connected to corticolimbic during both stress and neutral-relaxing conditions. For NDE, greater parietal connectivity to parietal, cingulate and sensory areas and lesser parietal connectivity to medial prefrontal areas were found during stress compared to neutral-relaxing cueing. Craving scores inversely correlated with corticolimbic connectivity in PCE, but not NDE adolescents, during the favorite-food condition. Findings from this first data-driven intrinsic connectivity analysis of PCE influences on adolescent brain function indicate differences relating to PCE status and craving. These findings provide insight into the developmental impact of in utero drug exposure. Copyright © 2017 Elsevier B.V. All rights reserved.

Aux/IAA Gene Family in Plants: Molecular Structure, Regulation, and Function

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Jie Luo

2018-01-01

Full Text Available Auxin plays a crucial role in the diverse cellular and developmental responses of plants across their lifespan. Plants can quickly sense and respond to changes in auxin levels, and these responses involve several major classes of auxin-responsive genes, including the Auxin/Indole-3-Acetic Acid (Aux/IAA family, the auxin response factor (ARF family, small auxin upregulated RNA (SAUR, and the auxin-responsive Gretchen Hagen3 (GH3 family. Aux/IAA proteins are short-lived nuclear proteins comprising several highly conserved domains that are encoded by the auxin early response gene family. These proteins have specific domains that interact with ARFs and inhibit the transcription of genes activated by ARFs. Molecular studies have revealed that Aux/IAA family members can form diverse dimers with ARFs to regulate genes in various ways. Functional analyses of Aux/IAA family members have indicated that they have various roles in plant development, such as root development, shoot growth, and fruit ripening. In this review, recently discovered details regarding the molecular characteristics, regulation, and protein–protein interactions of the Aux/IAA proteins are discussed. These details provide new insights into the molecular basis of the Aux/IAA protein functions in plant developmental processes.

Cellular and Molecular Biological Approaches to Interpreting Ancient Biomarkers

Science.gov (United States)

Newman, Dianne K.; Neubauer, Cajetan; Ricci, Jessica N.; Wu, Chia-Hung; Pearson, Ann

2016-06-01

Our ability to read the molecular fossil record has advanced significantly in the past decade. Improvements in biomarker sampling and quantification methods, expansion of molecular sequence databases, and the application of genetic and cellular biological tools to problems in biomarker research have enabled much of this progress. By way of example, we review how attempts to understand the biological function of 2-methylhopanoids in modern bacteria have changed our interpretation of what their molecular fossils tell us about the early history of life. They were once thought to be biomarkers of cyanobacteria and hence the evolution of oxygenic photosynthesis, but we now believe that 2-methylhopanoid biosynthetic capacity originated in the Alphaproteobacteria, that 2-methylhopanoids are regulated in response to stress, and that hopanoid 2-methylation enhances membrane rigidity. We present a new interpretation of 2-methylhopanes that bridges the gap between studies of the functions of 2-methylhopanoids and their patterns of occurrence in the rock record.

EDITORIAL: Design and function of molecular and bioelectronics devices

Science.gov (United States)

Krstic, Predrag; Forzani, Erica; Tao, Nongjian; Korkin, Anatoli

2007-10-01

Further rapid progress of electronics, in particular the increase of computer power and breakthroughs in sensor technology for industrial, medical diagnostics and environmental applications, strongly depends on the scaling of electronic devices, ultimately to the size of molecules. Design of controllable molecular-scale devices may resolve the problem of energy dissipation at the nanoscale and take advantage of molecular self-assembly in the so-called bottom-up approach. This special issue of Nanotechnology is devoted to a better understanding of the function and design of molecular-scale devices that are relevant to future electronics and sensor technology. Papers contained in this special issue are selected from the symposium Nano and Giga Challenges in Electronics and Photonics: From Atoms to Materials to Devices to System Architecture (12-16 March, 2007, Phoenix, Arizona, USA), as well as from original and novel scientific contributions of invited world-renown researchers. It addresses both theoretical and experimental achievements in the fields of molecular and bioelectronics, chemical and biosensors at the molecular level, including carbon nanotubes, novel nanostructures, as well as related research areas and industrial applications. The conference series Nano and Giga Challenges in Electronics and Photonics was launched as a truly interdisciplinary forum to bridge scientists and engineers to work across boundaries in the design of future information technologies, from atoms to materials to devices to system architecture. Following the first two successful meetings in Moscow, Russia (NGCM2002) and Krakow, Poland (NGCM2004), the third Nano and Giga Forum (NGC2007) was held in 2007 hosted by Arizona State University. Besides this special issue of Nanotechnology, two other collections (in the journal Solid State Electronics and the tutorial book in the series Nanostructure Science and Technology Springer) have published additional selected and invited papers

Executive function in posttraumatic stress disorder (PTSD) and the influence of comorbid depression

NARCIS (Netherlands)

Olff, Miranda; Polak, A Rosaura; Witteveen, Anke B; Denys, D.

BACKGROUND: Posttraumatic stress disorder (PTSD) has been associated with neurocognitive deficits, such as impaired verbal memory and executive functioning. Less is known about executive function and the role of comorbid depression in PTSD. Recently, studies have shown that verbal memory impairments

Unravelling how plants benefit from ROS and NO reactions, while resisting oxidative stress.

Science.gov (United States)

Considine, Michael J; Sandalio, Luisa Maria; Foyer, Christine Helen

2015-09-01

Reactive oxygen species (ROS) and reactive nitrogen species (RNS), such as nitric oxide (NO), play crucial roles in the signal transduction pathways that regulate plant growth, development and defence responses, providing a nexus of reduction/oxidation (redox) control that impacts on nearly every aspect of plant biology. Here we summarize current knowledge and concepts that lay the foundations of a new vision for ROS/RNS functions – particularly through signalling hubs – for the next decade. Plants have mastered the art of redox control using ROS and RNS as secondary messengers to regulate a diverse range of protein functions through redox-based, post-translational modifications that act as regulators of molecular master-switches. Much current focus concerns the impact of this regulation on local and systemic signalling pathways, as well as understanding how such reactive molecules can be effectively used in the control of plant growth and stress responses. The spectre of oxidative stress still overshadows much of our current philosophy and understanding of ROS and RNS functions. While many questions remain to be addressed – for example regarding inter-organellar regulation and communication, the control of hypoxia and how ROS/RNS signalling is used in plant cells, not only to trigger acclimation responses but also to create molecular memories of stress – it is clear that ROS and RNS function as vital signals of living cells.

Non-invasive Imaging based Detection and Mapping of Brain Oxidative Stress and its Correlation with Cognitive Functions

Science.gov (United States)

2017-05-14

the impact of oxidative stress on brain function, but also enable development of reliable screening tools for cognitive performance of individuals in...of Brain Oxidative Stress and its Correlation with Cognitive Functions Date 04/20/2017 PI information: Dr. Pravat K. Mandal,Ph.D Professor...relationship between the brain oxidative status and stress at a cellular, physiological as well as a psychological level. These stressors, in turn, have

Knockdown of RMI1 impairs DNA repair under DNA replication stress.

Science.gov (United States)

Xu, Chang; Fang, Lianying; Kong, Yangyang; Xiao, Changyan; Yang, Mengmeng; Du, Li-Qing; Liu, Qiang

2017-12-09

RMI1 (RecQ-mediated genome instability protein 1) forms a conserved BTR complex with BLM, Topo IIIα, and RMI2, and its absence causes genome instability. It has been revealed that RMI1 localizes to nuclear foci with BLM and Topo IIIα in response to replication stress, and that RMI1 functions downstream of BLM in promoting replication elongation. However, the precise functions of RMI1 during replication stress are not completely understood. Here we report that RMI1 knockdown cells are hypersensitive to hydroxyurea (HU). Using comet assay, we show that RMI1 knockdown cells exhibit accumulation of broken DNAs after being released from HU treatment. Moreover, we demonstrate that RMI1 facilitates the recovery from activated checkpoint and resuming the cell cycle after replicative stress. Surprisingly, loss of RMI1 results in a failure of RAD51 loading onto DNA damage sites. These findings reveal the importance of RMI1 in response to replication stress, which could explain the molecular basis for its function in maintaining genome integrity. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

Functional Annotation of Ion Channel Structures by Molecular Simulation.

Science.gov (United States)

Trick, Jemma L; Chelvaniththilan, Sivapalan; Klesse, Gianni; Aryal, Prafulla; Wallace, E Jayne; Tucker, Stephen J; Sansom, Mark S P

2016-12-06

Ion channels play key roles in cell membranes, and recent advances are yielding an increasing number of structures. However, their functional relevance is often unclear and better tools are required for their functional annotation. In sub-nanometer pores such as ion channels, hydrophobic gating has been shown to promote dewetting to produce a functionally closed (i.e., non-conductive) state. Using the serotonin receptor (5-HT 3 R) structure as an example, we demonstrate the use of molecular dynamics to aid the functional annotation of channel structures via simulation of the behavior of water within the pore. Three increasingly complex simulation analyses are described: water equilibrium densities; single-ion free-energy profiles; and computational electrophysiology. All three approaches correctly predict the 5-HT 3 R crystal structure to represent a functionally closed (i.e., non-conductive) state. We also illustrate the application of water equilibrium density simulations to annotate different conformational states of a glycine receptor. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

Transactional relations between caregiving stress, executive functioning, and problem behavior from early childhood to early adolescence

Science.gov (United States)

LaGasse, Linda L.; Conradt, Elisabeth; Karalunas, Sarah L.; Dansereau, Lynne M.; Butner, Jonathan E.; Shankaran, Seetha; Bada, Henrietta; Bauer, Charles R.; Whitaker, Toni M.; Lester, Barry M.

2016-01-01

Developmental psychopathologists face the difficult task of identifying the environmental conditions that may contribute to early childhood behavior problems. Highly stressed caregivers can exacerbate behavior problems, while children with behavior problems may make parenting more difficult and increase caregiver stress. Unknown is: (1) how these transactions originate, (2) whether they persist over time to contribute to the development of problem behavior and (3) what role resilience factors, such as child executive functioning, may play in mitigating the development of problem behavior. In the present study, transactional relations between caregiving stress, executive functioning, and behavior problems were examined in a sample of 1,388 children with prenatal drug exposures at three developmental time points: early childhood (birth-age 5), middle childhood (ages 6 to 9), and early adolescence (ages 10 to 13). Transactional relations differed between caregiving stress and internalizing versus externalizing behavior. Targeting executive functioning in evidence-based interventions for children with prenatal substance exposure who present with internalizing problems and treating caregiving psychopathology, depression, and parenting stress in early childhood may be particularly important for children presenting with internalizing behavior. PMID:27427803

Stress reactivity in childhood functional abdominal pain or irritable bowel syndrome.

Science.gov (United States)

Gulewitsch, M D; Weimer, K; Enck, P; Schwille-Kiuntke, J; Hautzinger, M; Schlarb, A A

2017-01-01

Frequent abdominal pain (AP) in childhood has been shown to be associated with elevated experience of stress and with deficits in stress coping, but psychophysiological stress reactivity has been studied rarely. We examined whether children with frequent AP show altered reactions of the parasympathetic nervous system and the hypothalamic-pituitary-adrenal (HPA) axis during and following an afternoon laboratory social stress task in comparison to healthy children and children with anxiety disorders. Twenty-four children with frequent AP (18 with functional AP and six with irritable bowel syndrome; M = 9.9 years), and 24 healthy controls underwent stressful free speech and arithmetic tasks. Twelve children with anxiety disorders served as second comparison sample. Groups were compared regarding parasympathetic reaction and saliva cortisol concentration. We found no differences in parasympathetic withdrawal between the groups. Concerning the HPA axis, we detected an attenuated cortisol reactivity in children with AP compared to both other groups. This study provides preliminary evidence that childhood AP is not associated with altered parasympathetic withdrawal during stress. It seems to be related to a down-regulated reactivity of the HPA axis. This pattern was ascertained in comparison to healthy children and also in comparison to children with anxiety disorders. Childhood abdominal pain could be related to down-regulated HPA axis reactivity to stress but not to altered parasympathetic reaction. Children with abdominal pain and children with anxiety disorders exhibit a divergent stress-related HPA axis reaction. © 2016 European Pain Federation - EFIC®.

Stress, Social Support, and Psychosocial Functioning of Ethnically Diverse Students

Science.gov (United States)

Farrell, Michelle; Langrehr, Kimberly J.

2017-01-01

This study examined the stress-buffering role of social support on indicators of psychosocial functioning among a combined and split sample of ethnically diverse college students. Although high social support significantly moderated 2 relationships in the combined sample, high and low levels of social support significantly reduced the effect of…

Genomewide Expression and Functional Interactions of Genes under Drought Stress in Maize

Directory of Open Access Journals (Sweden)

Nepolean Thirunavukkarasu

2017-01-01

Full Text Available A genomewide transcriptome assay of two subtropical genotypes of maize was used to observe the expression of genes at seedling stage of drought stress. The number of genes expressed differentially was greater in HKI1532 (a drought tolerant genotype than in PC3 (a drought sensitive genotype, indicating primary differences at the transcriptional level in stress tolerance. The global coexpression networks of the two genotypes differed significantly with respect to the number of modules and the coexpression pattern within the modules. A total of 174 drought-responsive genes were selected from HKI1532, and their coexpression network revealed key correlations between different adaptive pathways, each cluster of the network representing a specific biological function. Transcription factors related to ABA-dependent stomatal closure, signalling, and phosphoprotein cascades work in concert to compensate for reduced photosynthesis. Under stress, water balance was maintained by coexpression of the genes involved in osmotic adjustments and transporter proteins. Metabolism was maintained by the coexpression of genes involved in cell wall modification and protein and lipid metabolism. The interaction of genes involved in crucial biological functions during stress was identified and the results will be useful in targeting important gene interactions to understand drought tolerance in greater detail.

Mindfulness meditation training alters stress-related amygdala resting state functional connectivity: a randomized controlled trial.

Science.gov (United States)

Taren, Adrienne A; Gianaros, Peter J; Greco, Carol M; Lindsay, Emily K; Fairgrieve, April; Brown, Kirk Warren; Rosen, Rhonda K; Ferris, Jennifer L; Julson, Erica; Marsland, Anna L; Bursley, James K; Ramsburg, Jared; Creswell, J David

2015-12-01

Recent studies indicate that mindfulness meditation training interventions reduce stress and improve stress-related health outcomes, but the neural pathways for these effects are unknown. The present research evaluates whether mindfulness meditation training alters resting state functional connectivity (rsFC) of the amygdala, a region known to coordinate stress processing and physiological stress responses. We show in an initial discovery study that higher perceived stress over the past month is associated with greater bilateral amygdala-subgenual anterior cingulate cortex (sgACC) rsFC in a sample of community adults (n = 130). A follow-up, single-blind randomized controlled trial shows that a 3-day intensive mindfulness meditation training intervention (relative to a well-matched 3-day relaxation training intervention without a mindfulness component) reduced right amygdala-sgACC rsFC in a sample of stressed unemployed community adults (n = 35). Although stress may increase amygdala-sgACC rsFC, brief training in mindfulness meditation could reverse these effects. This work provides an initial indication that mindfulness meditation training promotes functional neuroplastic changes, suggesting an amygdala-sgACC pathway for stress reduction effects. © The Author (2015). Published by Oxford University Press. For Permissions, please email: journals.permissions@oup.com.

Roles of water in protein structure and function studied by molecular liquid theory.

Science.gov (United States)

Imai, Takashi

2009-01-01

The roles of water in the structure and function of proteins have not been completely elucidated. Although molecular simulation has been widely used for the investigation of protein structure and function, it is not always useful for elucidating the roles of water because the effect of water ranges from atomic to thermodynamic level. The three-dimensional reference interaction site model (3D-RISM) theory, which is a statistical-mechanical theory of molecular liquids, can yield the solvation structure at the atomic level and calculate the thermodynamic quantities from the intermolecular potentials. In the last few years, the author and coworkers have succeeded in applying the 3D-RISM theory to protein aqueous solution systems and demonstrated that the theory is useful for investigating the roles of water. This article reviews some of the recent applications and findings, which are concerned with molecular recognition by protein, protein folding, and the partial molar volume of protein which is related to the pressure effect on protein.

Stable Molecular Diodes Based on π-π Interactions of the Molecular Frontier Orbitals with Graphene Electrodes.

Science.gov (United States)

Song, Peng; Guerin, Sarah; Tan, Sherman Jun Rong; Annadata, Harshini Venkata; Yu, Xiaojiang; Scully, Micheál; Han, Ying Mei; Roemer, Max; Loh, Kian Ping; Thompson, Damien; Nijhuis, Christian A

2018-03-01

In molecular electronics, it is important to control the strength of the molecule-electrode interaction to balance the trade-off between electronic coupling strength and broadening of the molecular frontier orbitals: too strong coupling results in severe broadening of the molecular orbitals while the molecular orbitals cannot follow the changes in the Fermi levels under applied bias when the coupling is too weak. Here, a platform based on graphene bottom electrodes to which molecules can bind via π-π interactions is reported. These interactions are strong enough to induce electronic function (rectification) while minimizing broadening of the molecular frontier orbitals. Molecular tunnel junctions are fabricated based on self-assembled monolayers (SAMs) of Fc(CH 2 ) 11 X (Fc = ferrocenyl, X = NH 2 , Br, or H) on graphene bottom electrodes contacted to eutectic alloy of gallium and indium top electrodes. The Fc units interact more strongly with graphene than the X units resulting in SAMs with the Fc at the bottom of the SAM. The molecular diodes perform well with rectification ratios of 30-40, and they are stable against bias stressing under ambient conditions. Thus, tunnel junctions based on graphene with π-π molecule-electrode coupling are promising platforms to fabricate stable and well-performing molecular diodes. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Oligo-Alginate with Low Molecular Mass Improves Growth and Physiological Activity of Eucomis autumnalis under Salinity Stress

Directory of Open Access Journals (Sweden)

Piotr Salachna

2018-04-01

Full Text Available Biopolymers have become increasingly popular as biostimulators of plant growth. One of them, oligo-alginate, is a molecule that regulates plant biological processes and may be used in horticultural practice as a plant growth regulator. Biostimulators are mainly used to improve plant tolerance to abiotic stresses, including salinity. The aim of the study was to assess the effects of salinity and oligo-alginate of various molecular masses on the growth and physiological activity of Eucomis autumnalis. The species is an ornamental and medicinal plant that has been used for a long time in the traditional medicine of South Africa. The bulbs of E. autumnalis were coated using depolymerized sodium alginate of molecular mass 32,000; 42,000, and 64,000 g mol−1. All of these oligo-alginates fractions stimulated plant growth, and the effect was the strongest for the fraction of 32,000 g mol−1. This fraction was then selected for the second stage of the study, when plants were exposed to salt stress evoked by the presence of 100 mM NaCl. We found that the oligo-alginate coating mitigated the negative effects of salinity. Plants treated with the oligomer and watered with NaCl showed smaller reduction in the weight of the above-ground parts and bulbs, pigment content and antioxidant activity as compared with those not treated with the oligo-alginate. The study demonstrated for the first time that low molecular mass oligo-alginate may be used as plant biostimulator that limits negative effects of salinity in E. autumnalis.

Permanent Set of Cross-Linking Networks: Comparison of Theory with Molecular Dynamics Simulations

DEFF Research Database (Denmark)

Rottach, Dana R.; Curro, John G.; Budzien, Joanne

2006-01-01

The permanent set of cross-linking networks is studied by molecular dynamics. The uniaxial stress for a bead-spring polymer network is investigated as a function of strain and cross-link density history, where cross-links are introduced in unstrained and strained networks. The permanent set...

Executive function in posttraumatic stress disorder (PTSD) and the influence of comorbid depression

NARCIS (Netherlands)

Olff, Miranda; Polak, A. Rosaura; Witteveen, Anke B.; Denys, Damiaan

2014-01-01

Posttraumatic stress disorder (PTSD) has been associated with neurocognitive deficits, such as impaired verbal memory and executive functioning. Less is known about executive function and the role of comorbid depression in PTSD. Recently, studies have shown that verbal memory impairments may be

Elastic-plastic potential functionals for rates and increments of stress and strain

International Nuclear Information System (INIS)

Feijoo, R.A.; Zouain, N.

1990-03-01

In this work attention is focused in the derivation of variational formulations of the constutive relationship in the form of conjugate potential functionals from which stress and strain rates are derived as elements of the corresponding sub-differential sets. The main result obtained is a pair of potential functionals. (A.C.A.S.) [pt

Executive functioning performance predicts subjective and physiological acute stress reactivity: preliminary results.

Science.gov (United States)

Hendrawan, Donny; Yamakawa, Kaori; Kimura, Motohiro; Murakami, Hiroki; Ohira, Hideki

2012-06-01

Individual differences in baseline executive functioning (EF) capacities have been shown to predict state anxiety during acute stressor exposure. However, no previous studies have clearly demonstrated the relationship between EF and physiological measures of stress. The present study investigated the efficacy of several well-known EF tests (letter fluency, Stroop test, and Wisconsin Card Sorting Test) in predicting both subjective and physiological stress reactivity during acute psychosocial stress exposure. Our results show that letter fluency served as the best predictor for both types of reactivity. Specifically, the higher the letter fluency score, the lower the acute stress reactivity after controlling for the baseline stress response, as indicated by lower levels of state anxiety, negative mood, salivary cortisol, and skin conductance. Moreover, the predictive power of the letter fluency test remained significant for state anxiety and cortisol indices even after further adjustments for covariates by adding the body mass index (BMI) as a covariate. Thus, good EF performance, as reflected by high letter fluency scores, may dampen acute stress responses, which suggests that EF processes are directly associated with aspects of stress regulation. Copyright © 2012 Elsevier B.V. All rights reserved.

The role of dehydroepiandrosterone on functional innate immune responses to acute stress.

Science.gov (United States)

Prall, Sean P; Larson, Emilee E; Muehlenbein, Michael P

2017-12-01

The androgen dehydroepiandrosterone (DHEA) responds to stress activation, exhibits anti-glucocorticoid properties, and modulates immunity in diverse ways, yet little is known of its role in acute stress responses. In this study, the effects of DHEA and its sulfate ester DHEA-S on human male immune function during exposure to an acute stressor is explored. Variation in DHEA, DHEA-S, testosterone, and cortisol, along with bacterial killing assays, was measured in response to a modified Trier Social Stress test in 27 young adult males. Cortisol was positively related to salivary innate immunity but only for participants who also exhibited high DHEA responses. Additionally, DHEA positively and DHEA-S negatively predicted salivary immunity, but the opposite was observed for serum-based innate immunity. The DHEA response to acute stress appears to be an important factor in stress-mediated immunological responses, with differential effects on immunity dependent upon the presence of other hormones, primarily cortisol and DHEA-S. These results suggest that DHEA plays an important role, alongside other hormones, in modulating immunological shifts during acute stress. Copyright © 2017 John Wiley & Sons, Ltd.

Influence of functional groups on charge transport in molecular junctions

DEFF Research Database (Denmark)

Mowbray, Duncan; Jones, Glenn; Thygesen, Kristian Sommer

2008-01-01

Using density functional theory (DFT), we analyze the influence of five classes of functional groups, as exemplified by NO2, OCH3, CH3, CCl3, and I, on the transport properties of a 1,4-benzenedithiolate (BDT) and 1,4-benzenediamine (BDA) molecular junction with gold electrodes. Our analysis...... demonstrates how ideas from functional group chemistry may be used to engineer a molecule's transport properties, as was shown experimentally and using a semiempirical model for BDA [Nano Lett. 7, 502 (2007)]. In particular, we show that the qualitative change in conductance due to a given functional group can...... be predicted from its known electronic effect (whether it is sigma/pi donating/withdrawing). However, the influence of functional groups on a molecule's conductance is very weak, as was also found in the BDA experiments. The calculated DFT conductances for the BDA species are five times larger than...

Molecular basis for arsenic-Induced alteration in nitric oxide production and oxidative stress: implication of endothelial dysfunction

International Nuclear Information System (INIS)

Kumagai, Yoshito; Pi Jingbo

2004-01-01

Accumulated epidemiological studies have suggested that prolonged exposure of humans to arsenic in drinking water is associated with vascular diseases. The exact mechanism of how this occurs currently unknown. Nitric oxide (NO), formed by endothelial NO synthase (eNOS), plays a crucial role in the vascular system. Decreased availability of biologically active NO in the endothelium is implicated in the pathophysiology of several vascular diseases and inhibition of eNOS by arsenic is one of the proposed mechanism s for arsenic-induced vascular diseases. In addition, during exposure to arsenic, overproduction of reactive oxygen species (ROS) can occur, resulting in oxidative stress, which is another major risk factor for vascular dysfunction. The molecular basis for decreased NO levels and increased oxidative stress during arsenic exposure is poorly understood. In this article, evidence for arsenic-mediated alteration in NO production and oxidative stress is reviewed. The results of a cross-sectional study in an endemic area of chronic arsenic poisoning and experimental animal studies to elucidate a potential mechanism for the impairment of NO formation and oxidative stress caused by prolonged exposure to arsenate in the drinking water are also reviewed

Parental alcohol use disorders and child delinquency: the mediating effects of executive functioning and chronic family stress.

Science.gov (United States)

Grekin, Emily R; Brennan, Patricia A; Hammen, Constance

2005-01-01

This study examines the relationship between parental alcohol use disorders (AUDs) and child violent and nonviolent delinquency. It also explores the mediating effects of executive functioning and chronic family stress on the parental AUD/child delinquency relationship. Participants were 816 families with children (414 boys and 402 girls) born between 1981 and 1984 at Mater Misericordiae Mother's Hospital in Brisbane, Australia. Parents and children completed semistructured interviews, questionnaires and neuropsychological tests that assessed parental alcohol use, family psychiatric history, chronic family stress, child delinquency and child executive functioning. Paternal (but not maternal) AUDs predicted child violent and nonviolent delinquency. Executive functioning mediated the relationship between paternal AUDs and violent delinquency, whereas family stress mediated the relationship between paternal AUDs and both violent and nonviolent delinquency. Results support a biosocial conceptualization of the paternal AUD/delinquency relationship. They suggest that paternal AUDs may be associated with child executive functioning and family stress, which may in turn lead to child delinquency.

Altered mitochondrial function and oxidative stress in leukocytes of anorexia nervosa patients.

Science.gov (United States)

Victor, Victor M; Rovira-Llopis, Susana; Saiz-Alarcon, Vanessa; Sangüesa, Maria C; Rojo-Bofill, Luis; Bañuls, Celia; Falcón, Rosa; Castelló, Raquel; Rojo, Luis; Rocha, Milagros; Hernández-Mijares, Antonio

2014-01-01

Anorexia nervosa is a common illness among adolescents and is characterised by oxidative stress. The effects of anorexia on mitochondrial function and redox state in leukocytes from anorexic subjects were evaluated. A multi-centre, cross-sectional case-control study was performed. Our study population consisted of 20 anorexic patients and 20 age-matched controls, all of which were Caucasian women. Anthropometric and metabolic parameters were evaluated in the study population. To assess whether anorexia nervosa affects mitochondrial function and redox state in leukocytes of anorexic patients, we measured mitochondrial oxygen consumption, membrane potential, reactive oxygen species production, glutathione levels, mitochondrial mass, and complex I and III activity in polymorphonuclear cells. Mitochondrial function was impaired in the leukocytes of the anorexic patients. This was evident in a decrease in mitochondrial O2 consumption (Panorexia takes place at mitochondrial complex I. Future research concerning mitochondrial dysfunction and oxidative stress should aim to determine the physiological mechanism involved in this effect and the physiological impact of anorexia.

The influence of work-related chronic stress on the regulation of emotion and on functional connectivity in the brain.

Directory of Open Access Journals (Sweden)

Armita Golkar

Full Text Available Despite mounting reports about the negative effects of chronic occupational stress on cognitive and emotional functions, the underlying mechanisms are unknown. Recent findings from structural MRI raise the question whether this condition could be associated with a functional uncoupling of the limbic networks and an impaired modulation of emotional stress. To address this, 40 subjects suffering from burnout symptoms attributed to chronic occupational stress and 70 controls were investigated using resting state functional MRI. The participants' ability to up- regulate, down-regulate, and maintain emotion was evaluated by recording their acoustic startle response while viewing neutral and negatively loaded images. Functional connectivity was calculated from amygdala seed regions, using explorative linear correlation analysis. Stressed subjects were less capable of down-regulating negative emotion, but had normal acoustic startle responses when asked to up-regulate or maintain emotion and when no regulation was required. The functional connectivity between the amygdala and the anterior cingulate cortex correlated with the ability to down-regulate negative emotion. This connectivity was significantly weaker in the burnout group, as was the amygdala connectivity with the dorsolateral prefrontal cortex and the motor cortex, whereas connectivity from the amygdala to the cerebellum and the insular cortex were stronger. In subjects suffering from chronic occupational stress, the functional couplings within the emotion- and stress-processing limbic networks seem to be altered, and associated with a reduced ability to down-regulate the response to emotional stress, providing a biological substrate for a further facilitation of the stress condition.

The Influence of Work-Related Chronic Stress on the Regulation of Emotion and on Functional Connectivity in the Brain

Science.gov (United States)

Golkar, Armita; Johansson, Emilia; Kasahara, Maki; Osika, Walter; Perski, Aleksander; Savic, Ivanka

2014-01-01

Despite mounting reports about the negative effects of chronic occupational stress on cognitive and emotional functions, the underlying mechanisms are unknown. Recent findings from structural MRI raise the question whether this condition could be associated with a functional uncoupling of the limbic networks and an impaired modulation of emotional stress. To address this, 40 subjects suffering from burnout symptoms attributed to chronic occupational stress and 70 controls were investigated using resting state functional MRI. The participants' ability to up- regulate, down-regulate, and maintain emotion was evaluated by recording their acoustic startle response while viewing neutral and negatively loaded images. Functional connectivity was calculated from amygdala seed regions, using explorative linear correlation analysis. Stressed subjects were less capable of down-regulating negative emotion, but had normal acoustic startle responses when asked to up-regulate or maintain emotion and when no regulation was required. The functional connectivity between the amygdala and the anterior cingulate cortex correlated with the ability to down-regulate negative emotion. This connectivity was significantly weaker in the burnout group, as was the amygdala connectivity with the dorsolateral prefrontal cortex and the motor cortex, whereas connectivity from the amygdala to the cerebellum and the insular cortex were stronger. In subjects suffering from chronic occupational stress, the functional couplings within the emotion- and stress-processing limbic networks seem to be altered, and associated with a reduced ability to down-regulate the response to emotional stress, providing a biological substrate for a further facilitation of the stress condition. PMID:25184294

Transcriptome analysis of hexaploid hulless oat in response to salinity stress.

Directory of Open Access Journals (Sweden)

Bin Wu

Full Text Available Oat is a cereal crop of global importance used for food, feed, and forage. Understanding salinity stress tolerance mechanisms in plants is an important step towards generating crop varieties that can cope with environmental stresses. To date, little is known about the salt tolerance of oat at the molecular level. To better understand the molecular mechanisms underlying salt tolerance in oat, we investigated the transcriptomes of control and salt-treated oat using RNA-Seq.Using Illumina HiSeq 4000 platform, we generated 72,291,032 and 356,891,432 reads from non-stressed control and salt-stressed oat, respectively. Assembly of 64 Gb raw sequence data yielded 128,414 putative unique transcripts with an average length of 1,189 bp. Analysis of the assembled unigenes from the salt stressed and control libraries indicated that about 65,000 unigenes were differentially expressed at different stages. Functional annotation showed that ABC transporters, plant hormone signal transduction, plant-pathogen interactions, starch and sucrose metabolism, arginine and proline metabolism, and other secondary metabolite pathways were enriched under salt stress. Based on the RPKM values of assembled unigenes, 24 differentially expressed genes under salt stress were selected for quantitative RT-PCR validation, which successfully confirmed the results of RNA-Seq. Furthermore, we identified 18,039 simple sequence repeats, which may help further elucidate salt tolerance mechanisms in oat.Our global survey of transcriptome profiles of oat plants in response to salt stress provides useful insights into the molecular mechanisms underlying salt tolerance in this crop. These findings also represent a rich resource for further analysis of salt tolerance and for breeding oat with improved salt tolerance through the use of salt-related genes.

Herboxidiene triggers splicing repression and abiotic stress responses in plants

KAUST Repository

Alshareef, Sahar

2017-03-27

Background Constitutive and alternative splicing of pre-mRNAs from multiexonic genes controls the diversity of the proteome; these precisely regulated processes also fine-tune responses to cues related to growth, development, and stresses. Small-molecule inhibitors that perturb splicing provide invaluable tools for use as chemical probes to uncover the molecular underpinnings of splicing regulation and as potential anticancer compounds. Results Here, we show that herboxidiene (GEX1A) inhibits both constitutive and alternative splicing. Moreover, GEX1A activates genome-wide transcriptional patterns involved in abiotic stress responses in plants. GEX1A treatment -activated ABA-inducible promoters, and led to stomatal closure. Interestingly, GEX1A and pladienolide B (PB) elicited similar cellular changes, including alterations in the patterns of transcription and splicing, suggesting that these compounds might target the same spliceosome complex in plant cells. Conclusions Our study establishes GEX1A as a potent splicing inhibitor in plants that can be used to probe the assembly, dynamics, and molecular functions of the spliceosome and to study the interplay between splicing stress and abiotic stresses, as well as having potential biotechnological applications.

On the nodal structure of atomic and molecular Wigner functions

International Nuclear Information System (INIS)

Dahl, J.P.; Schmider, H.

1996-01-01

In previous work on the phase-space representation of quantum mechanics, we have presented detailed pictures of the electronic one-particle reduced Wigner function for atoms and small molecules. In this communication, we focus upon the nodal structure of the function. On the basis of the simplest systems, we present an expression which relates the oscillatory decay of the Wigner function solely to the dot product of the position and momentum vector, if both arguments are large. We then demonstrate the regular behavior of nodal patterns for the larger systems. For the molecular systems, an argument analogous to the open-quotes bond-oscillatory principleclose quotes for momentum densities links the nuclear framework to an additional oscillatory term in momenta parallel to bonds. It is shown that these are visible in the Wigner function in terms of characteristic nodes

Functional and DNA-protein binding studies of WRKY transcription factors and their expression analysis in response to biotic and abiotic stress in wheat (Triticum aestivum L.).

Science.gov (United States)

Satapathy, Lopamudra; Kumar, Dhananjay; Kumar, Manish; Mukhopadhyay, Kunal

2018-01-01

WRKY, a plant-specific transcription factor family, plays vital roles in pathogen defense, abiotic stress, and phytohormone signalling. Little is known about the roles and function of WRKY transcription factors in response to rust diseases in wheat. In the present study, three TaWRKY genes encoding complete protein sequences were cloned. They belonged to class II and III WRKY based on the number of WRKY domains and the pattern of zinc finger structures. Twenty-two DNA-protein binding docking complexes predicted stable interactions of WRKY domain with W-box. Quantitative real-time-PCR using wheat near-isogenic lines with or without Lr28 gene revealed differential up- or down-regulation in response to biotic and abiotic stress treatments which could be responsible for their functional divergence in wheat. TaWRKY62 was found to be induced upon treatment with JA, MJ, and SA and reduced after ABA treatments. Maximum induction of six out of seven genes occurred at 48 h post inoculation due to pathogen inoculation. Hence, TaWRKY (49, 50 , 52 , 55 , 57, and 62 ) can be considered as potential candidate genes for further functional validation as well as for crop improvement programs for stress resistance. The results of the present study will enhance knowledge towards understanding the molecular basis of mode of action of WRKY transcription factor genes in wheat and their role during leaf rust pathogenesis in particular.

Altered mitochondrial function and oxidative stress in leukocytes of anorexia nervosa patients.

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Victor M Victor

Full Text Available CONTEXT: Anorexia nervosa is a common illness among adolescents and is characterised by oxidative stress. OBJECTIVE: The effects of anorexia on mitochondrial function and redox state in leukocytes from anorexic subjects were evaluated. DESIGN AND SETTING: A multi-centre, cross-sectional case-control study was performed. PATIENTS: Our study population consisted of 20 anorexic patients and 20 age-matched controls, all of which were Caucasian women. MAIN OUTCOME MEASURES: Anthropometric and metabolic parameters were evaluated in the study population. To assess whether anorexia nervosa affects mitochondrial function and redox state in leukocytes of anorexic patients, we measured mitochondrial oxygen consumption, membrane potential, reactive oxygen species production, glutathione levels, mitochondrial mass, and complex I and III activity in polymorphonuclear cells. RESULTS: Mitochondrial function was impaired in the leukocytes of the anorexic patients. This was evident in a decrease in mitochondrial O2 consumption (P<0.05, mitochondrial membrane potential (P<0.01 and GSH levels (P<0.05, and an increase in ROS production (P<0.05 with respect to control subjects. Furthermore, a reduction of mitochondrial mass was detected in leukocytes of the anorexic patients (P<0.05, while the activity of mitochondrial complex I (P<0.001, but not that of complex III, was found to be inhibited in the same population. CONCLUSIONS: Oxidative stress is produced in the leukocytes of anorexic patients and is closely related to mitochondrial dysfunction. Our results lead us to propose that the oxidative stress that occurs in anorexia takes place at mitochondrial complex I. Future research concerning mitochondrial dysfunction and oxidative stress should aim to determine the physiological mechanism involved in this effect and the physiological impact of anorexia.