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Sample records for interference mechanisms caused

  1. Do media players cause interference with pacemakers?

    Science.gov (United States)

    Thaker, Jay P; Patel, Mehul B; Shah, Ashok J; Liepa, Valdis V; Brunett, Joseph D; Jongnarangsin, Krit; Gardiner, Joseph C; Thakur, Ranjan

    2009-11-01

    Electrical devices generate electromagnetic fields that may interfere with pacemakers. Media players cause telemetry interference with pacemakers, but it is not known whether they cause direct interference with pacemakers. The purpose of this study was to examine the interaction between pacemakers and 3 different media players. In this prospective, randomized study, 54 patients with dual chamber pacemakers who were in sinus rhythm underwent baseline observation, followed by observation under telemetry communication. These patients were then randomly evaluated with 3 media players (iPod 3G, iPod Photo, and iPod Touch Apple, Cupertino, CA) with and without telemetry communication for 1 minute each. Patients were monitored for pacemaker malfunction using a single-channel ECG during exposure to media players. The pacemaker was interrogated after each exposure and an interrogation report was printed for evaluation. Pacemaker interference was categorized as type I, II, or III. Types I and II interference described telemetry interference and type III interference was defined as any direct interference with pacemaker function or programmed parameters. A total of 54 patients (29 men and 25 women; mean age 77.2 +/- 9.3 y) were evaluated. In total, of the 162 tests (for telemetry interference) 36.4% were positive (Type I and II). Type III interference was also evaluated in 162 tests and none showed any evidence of direct interference. Media players cause telemetry interference with pacemakers, but they do not directly interfere with pacemaker function.

  2. Electromagnetic interference with pacemakers caused by portable media players.

    Science.gov (United States)

    Thaker, Jay P; Patel, Mehul B; Jongnarangsin, Krit; Liepa, Valdis V; Thakur, Ranjan K

    2008-04-01

    Electromagnetic fields generated by electrical devices may cause interference with permanent pacemakers. Media players are becoming a common mode of portable entertainment. The most common media players used worldwide are iPods. These devices are often carried in a shirt chest pocket, which may place the devices close to an implanted pacemaker. The purpose of this study was to determine if iPods cause interference with pacemakers. In this prospective, single-blinded study, 100 patients who had cardiac pacemakers were tested with four types of iPods to assess for interference. Patients were monitored by a single-channel ECG monitor as well as the respective pacemaker programmer via the telemetry wand. iPods were tested by placing them 2 inches anterior to the pacemaker and wand for up to 10 seconds. To simulate actual use, standard-issue headphones were plugged into the iPods. To maintain consistency, the volume was turned up maximally, and the equalizer was turned off. A subset of 25 patients underwent testing on 2 separate days to assess for reproducibility of interference. Pacemaker interference was categorized as type I or type II telemetry interference. Type I interference was associated with atrial and/or ventricular high rates on rate histograms. Type II interference did not affect pacemaker rate counters. Electromagnetic emissions from the four iPods also were evaluated in a Faraday cage to determine the mechanism of the observed interference. One hundred patients (63 men and 37 women; mean age 77.1 +/- 7.6 years) with 11 single-chamber pacemakers and 89 dual-chamber pacemakers underwent 800 tests. The incidence of any type of interference was 51% of patients and 20% of tests. Type I interference was seen in 19% of patients and type II in 32% of patients. Reproducibility testing confirmed that interference occurred regardless of pacing configuration (unipolar or bipolar), pacing mode (AAI, VVI, or DDD), and from one day to the next. Electromagnetic emissions

  3. Automotive radar - investigation of mutual interference mechanisms

    Science.gov (United States)

    Goppelt, M.; Blöcher, H.-L.; Menzel, W.

    2010-09-01

    In the past mutual interference between automotive radar sensors has not been regarded as a major problem. With an increasing number of such systems, however, this topic is receiving more and more attention. The investigation of mutual interference and countermeasures is therefore one topic of the joint project "Radar on Chip for Cars" (RoCC) funded by the German Federal Ministry of Education and Research (BMBF). RoCC's goal is to pave the way for the development of high-performance, low-cost 79 GHz radar sensors based on Silicon-Germanium (SiGe) Monolithic Microwave Integrated Circuits (MMICs). This paper will present some generic interference scenarios and report on the current status of the analysis of interference mechanisms.

  4. New Interference Mechanism Controls Ultracold Chemistry

    Science.gov (United States)

    Kendrick, Brian K.; Hazra, Jisha; Balakrishnan, N.

    2016-05-01

    A newly discovered interference mechanism has been shown to control the outcome of ultracold chemical reactions. The mechanism originates from the unique properties associated with ultracold collisions, namely: (1) isotropic (s-wave) scattering and (2) an effective quantization of the scattering phase shift (which originates from the bound state structure of the molecule). These two properties can lead to maximum constructive or destructive interference between two interfering reaction pathways (such as exchange and non-exchange in systems with two or more identical nuclei). If the molecular system exhibits a conical intersection, then the associated geometric phase is shown to act as a ``quantum switch'' which can turn the reactivity on or off. Reaction rate coefficients for the O + OH --> H + O2 and H + H2, reactions are presented which explicitly demonstrate the effect. Experimentalists might exploit this new mechanism to control ultracold reactions by the application of external electric or magnetic fields or by the selection of a particular nuclear spin state. This work was supported in part by the LDRD program (Grant No. 20140309ER) at LANL (B.K.) and by NSF Grant PHY-1505557 (N.B.) and ARO MURI Grant No. W911NF-12-1-0476 (N.B.).

  5. Static energy meter errors caused by conducted electromagnetic interference

    NARCIS (Netherlands)

    Leferink, Frank Bernardus Johannes; Keyer, Cornelis H.A.; Melentjev, Anton

    2017-01-01

    Static, or electronic, energy meters are replacing the conventional electromechanical meters. Consumers are some-times complaining about higher energy readings and billing after the change to a static meter, but there is not a clear common or root cause at present. Electromagnetic interference has

  6. Static energy meter errors caused by conducted electromagnetic interference

    NARCIS (Netherlands)

    Leferink, Frank; Keyer, Cees; Melentjev, Anton

    2017-01-01

    Static, or electronic, energy meters are replacing the conventional electromechanical meters. Consumers are some-times complaining about higher energy readings and billing after the change to a static meter, but there is not a clear common or root cause at present. Electromagnetic interference has b

  7. 47 CFR 15.711 - Interference avoidance mechanisms.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 1 2010-10-01 2010-10-01 false Interference avoidance mechanisms. 15.711... Television Band Devices § 15.711 Interference avoidance mechanisms. (a) Except as provided in § 15.717... mechanism described in paragraph (b) of this section or spectrum sensing described in paragraph (c) of...

  8. Ruling Out Multi-Order Interference in Quantum Mechanics

    CERN Document Server

    Sinha, Urbasi; Jennewein, Thomas; Laflamme, Raymond; Weihs, Gregor

    2010-01-01

    Quantum mechanics and gravitation are two pillars of modern physics. Despite their success in describing the physical world around us, they seem to be incompatible theories. There are suggestions that one of these theories must be generalized to achieve unification. For example, Born's rule, one of the axioms of quantum mechanics could be violated. Born's rule predicts that quantum interference, as shown by a double slit diffraction experiment, occurs from pairs of paths. A generalized version of quantum mechanics might allow multi-path, i.e. higher order interferences thus leading to a deviation from the theory. We performed a three slit experiment with photons and bounded the magnitude of three path interference to less than 10-2 of the expected two-path interference, thus ruling out third and higher order interference and providing a bound on the accuracy of Born's rule. Our experiment is consistent with the postulate both in semi-classical and quantum regimes.

  9. Ruling out multi-order interference in quantum mechanics.

    Science.gov (United States)

    Sinha, Urbasi; Couteau, Christophe; Jennewein, Thomas; Laflamme, Raymond; Weihs, Gregor

    2010-07-23

    Quantum mechanics and gravitation are two pillars of modern physics. Despite their success in describing the physical world around us, they seem to be incompatible theories. There are suggestions that one of these theories must be generalized to achieve unification. For example, Born's rule--one of the axioms of quantum mechanics--could be violated. Born's rule predicts that quantum interference, as shown by a double-slit diffraction experiment, occurs from pairs of paths. A generalized version of quantum mechanics might allow multipath (i.e., higher-order) interference, thus leading to a deviation from the theory. We performed a three-slit experiment with photons and bounded the magnitude of three-path interference to less than 10(-2) of the expected two-path interference, thus ruling out third- and higher-order interference and providing a bound on the accuracy of Born's rule. Our experiment is consistent with the postulate both in semiclassical and quantum regimes.

  10. Multiple scattering mechanisms causing interference effects in the differential cross sections of H + D2 → HD(v' = 4, j') + D at 3.26 eV collision energy

    Science.gov (United States)

    Sneha, Mahima; Gao, Hong; Zare, Richard N.; Jambrina, P. G.; Menéndez, M.; Aoiz, F. J.

    2016-07-01

    Differential cross sections (DCSs) for the H + D2 → HD(v' = 4, j') + D reaction at 3.26 eV collision energy have been measured using the photoloc technique, and the results have been compared with those from quantum and quasiclassical scattering calculations. The quantum mechanical DCSs are in good overall agreement with the experimental measurements. In common with previous results at 1.97 eV, clear interference patterns which appear as fingerlike structures have been found at 3.26 eV but in this case for vibrational states as high as v' = 4. The oscillatory structure is prominent for low rotational states and progressively disappears as j' increases. A detailed analysis, similar to that carried out at 1.97 eV, shows that the origin of these structures could be traced to interferences between well defined classical mechanisms. In addition, at this energy, we do not observe the anomalous positive j'-θ trend found for the v' = 4 manifold at lower collision energies, thus reinforcing our explanation that the anomalous distribution for HD(v' = 4, j') at 1.97 eV only takes place for those states associated with low product recoil energies.

  11. Pseudohypobicarbonatemia caused by an endogenous assay interferent: a new entity.

    Science.gov (United States)

    Goldwasser, Philip; Manjappa, Nagarathna G; Luhrs, Carol A; Barth, Robert H

    2011-10-01

    Serum total carbon dioxide, measured using a chemistry analyzer, and gas panel-derived plasma bicarbonate, calculated from the pH and partial pressure of carbon dioxide, often are used interchangeably for clinical purposes. When they disagree, there is a tendency to accept total carbon dioxide and discredit gas panel-derived plasma bicarbonate values. We report a patient who, during a 5-month hospitalization, had persistently low total carbon dioxide levels (12.4 ± 2.7 [standard deviation] mEq/L [12.4 ± 2.7 mmol/L]), measured using an enzymatic/photometric assay, and a high anion gap (19.2 ± 3.1 mEq/L [19.2 ± 3.1 mmol/L]), suggesting high-anion-gap metabolic acidosis, but who had gas panel-derived plasma bicarbonate (24.0 ± 0.9 mEq/L [24.0 ± 0.9 mmol/L]) and arterial pH values in the reference range. Organic anion levels in blood and urine were unremarkable. Negative interference with the enzymatic assay by the patient's serum was shown by the findings that total carbon dioxide level was 7.0 ± 0.1 mEq/L (7.0 ± 0.1 mmol/L) higher when measured using the electrode-based method than using the enzymatic method (P < 0.01), and the patient's serum, but not control serum, altered the reaction kinetics of the enzymatic assay by producing turbidity, resulting in an initial increase in absorbance and a falsely low total carbon dioxide value. The turbidity may have resulted from precipitation of 1 of 2 paraproteins in the patient's serum or an endogenous antibody binding with an animal protein included in the assay reagents. In summary, a discrepancy between total carbon dioxide level measured using an enzymatic assay and gas panel-derived plasma bicarbonate level was found to be the result of turbidity caused by an endogenous interferent with the total carbon dioxide assay, a novel artifact. When total carbon dioxide and gas panel-derived plasma bicarbonate values disagree, measurement error in total carbon dioxide level should be considered.

  12. 47 CFR 25.162 - Cause for termination of interference protection.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 2 2010-10-01 2010-10-01 false Cause for termination of interference protection. 25.162 Section 25.162 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON... Reinstatement of Station Authorization § 25.162 Cause for termination of interference protection. The...

  13. Stochastic Analysis of Mean Interference for RTS/CTS Mechanism

    CERN Document Server

    Zhong, Yi

    2012-01-01

    The RTS/CTS handshake mechanism in WLAN is studied using stochastic geometry. The effect of RTS/CTS is treated as a thinning procedure for a spatially distributed point process that models the potential transceivers in a WLAN, and the resulting concurrent transmission processes are described. Exact formulas for the intensity of the concurrent transmission processes and the mean interference experienced by a typical receiver are established. The analysis yields useful results for understanding how the design parameters of RTS/CTS affect the network interference.

  14. Extracommunicative functions of language: verbal interference causes selective categorization impairments.

    Science.gov (United States)

    Lupyan, Gary

    2009-08-01

    In addition to its communicative functions, language has been argued to have a variety of extracommunicative functions, as assessed by its causal involvement in putatively nonlinguistic tasks. In the present work, I argue that language may be critically involved in the ability of human adults to categorize objects on a specific dimension (e.g., color) while abstracting over other dimensions (e.g., size). This ability is frequently impaired in aphasic patients. The present work demonstrates that normal participants placed under conditions of verbal interference show a pattern of deficits strikingly similar to that of aphasic patients: impaired taxonomic categorization along perceptual dimensions, and preserved thematic categorization. A control experiment using a visuospatial-interference task failed to find this selective pattern of deficits. The present work has implications for understanding the online role of language in normal cognition and supports the claim that language is causally involved in nonverbal cognition.

  15. Observation of quantum interference between separated mechanical oscillator wavepackets

    CERN Document Server

    Kienzler, D; Negnevitsky, V; Lo, H -Y; Marinelli, M; Nadlinger, D; Home, J P

    2015-01-01

    The ability of matter to be superposed at two different locations while being intrinsically connected by a quantum phase is among the most counterintuitive predictions of quantum physics. While such superpositions have been created for a variety of systems, the in-situ observation of the phase coherence has remained out of reach. Using a heralding measurement on a spin-oscillator entangled state, we project a mechanical trapped-ion oscillator into a superposition of two spatially separated states, a situation analogous to Schr\\"odinger's cat. Quantum interference is clearly observed by extracting the occupations of the energy levels. For larger states, we encounter problems in measuring the energy distribution, which we overcome by performing the analogous measurement in a squeezed Fock basis with each basis element stretched along the separation axis. Using 8 dB of squeezing we observe quantum interference for cat states with phase space separations of $\\Delta \\alpha = 15.6$, corresponding to wavepackets wit...

  16. Water Pollution (Causes, Mechanisms, Solution).

    Science.gov (United States)

    Strandberg, Carl

    Written for the general public, this book illustrates the causes, status, problem areas, and prediction and control of water pollution. Water pollution is one of the most pressing issues of our time and the author communicates the complexities of this problem to the reader in common language. The purpose of the introductory chapter is to show what…

  17. Water Pollution (Causes, Mechanisms, Solution).

    Science.gov (United States)

    Strandberg, Carl

    Written for the general public, this book illustrates the causes, status, problem areas, and prediction and control of water pollution. Water pollution is one of the most pressing issues of our time and the author communicates the complexities of this problem to the reader in common language. The purpose of the introductory chapter is to show what…

  18. Biological mechanisms determining the success of RNA interference in insects.

    Science.gov (United States)

    Wynant, Niels; Santos, Dulce; Vanden Broeck, Jozef

    2014-01-01

    Insects constitute the largest group of animals on this planet, having a huge impact on our environment, as well as on our quality of life. RNA interference (RNAi) is a posttranscriptional gene silencing mechanism triggered by double-stranded (ds)RNA fragments. This process not only forms the basis of a widely used reverse genetics research method in many different eukaryotes but also holds great promise to contribute to the species-specific control of agricultural pests and to combat viral infections in beneficial and disease vectoring insects. However, in many economically important insect species, such as flies, mosquitoes, and caterpillars, systemic delivery of naked dsRNA does not trigger effective gene silencing. Although many components of the RNAi pathway have initially been deciphered in the fruit fly, Drosophila melanogaster, it will be of major importance to investigate this process in a wider variety of species, including dsRNA-sensitive insects such as locusts and beetles, to elucidate the factors responsible for the remarkable variability in RNAi efficiency, as observed in different insects. In this chapter, we review the current knowledge on the RNAi pathway, as well as the most recent insights into the mechanisms that might determine successful RNAi in insects.

  19. RNA Interference in Moths: Mechanisms, Applications, and Progress

    Science.gov (United States)

    Xu, Jin; Wang, Xia-Fei; Chen, Peng; Liu, Fang-Tao; Zheng, Shuai-Chao; Ye, Hui; Mo, Ming-He

    2016-01-01

    The vast majority of lepidopterans, about 90%, are moths. Some moths, particularly their caterpillars, are major agricultural and forestry pests in many parts of the world. However, some other members of moths, such as the silkworm Bombyx mori, are famous for their economic value. Fire et al. in 1998 initially found that exogenous double-stranded RNA (dsRNA) can silence the homolog endogenous mRNA in organisms, which is called RNA interference (RNAi). Soon after, the RNAi technique proved to be very promising not only in gene function determination but also in pest control. However, later studies demonstrate that performing RNAi in moths is not as straightforward as shown in other insect taxa. Nevertheless, since 2007, especially after 2010, an increasing number of reports have been published that describe successful RNAi experiments in different moth species either on gene function analysis or on pest management exploration. So far, more than 100 peer-reviewed papers have reported successful RNAi experiments in moths, covering 10 families and 25 species. By using classic and novel dsRNA delivery methods, these studies effectively silence the expression of various target genes and determine their function in larval development, reproduction, immunology, resistance against chemicals, and other biological processes. In addition, a number of laboratory and field trials have demonstrated that RNAi is also a potential strategy for moth pest management. In this review, therefore, we summarize and discuss the mechanisms and applications of the RNAi technique in moths by focusing on recent progresses. PMID:27775569

  20. The interference aerodynamics caused by the wing elasticity during store separation

    Science.gov (United States)

    Lei, Yang; Zheng-yin, Ye

    2016-04-01

    Air-launch-to-orbit is the technology that has stores carried aloft and launched the store from the plane to the orbit. The separation between the aircraft and store is one of the most important and difficult phases in air-launch-to-orbit technology. There exists strong aerodynamic interference between the aircraft and the store in store separation. When the aspect ratio of the aircraft is large, the elastic deformations of the wing must be considered. The main purpose of this article is to study the influence of the interference aerodynamics caused by the elastic deformations of the wing to the unsteady aerodynamics of the store. By solving the coupled functions of unsteady Navier-Stokes equations, six degrees of freedom dynamic equations and structural dynamic equations simultaneously, the store separation with the elastic deformation of the aircraft considered is simulated numerically. And the interactive aerodynamic forces are analyzed. The study shows that the interference aerodynamics is obvious at earlier time during the separation, and the dominant frequency of the elastic wing determines the aerodynamic forces frequencies of the store. Because of the effect of the interference aerodynamics, the roll angle response and pitch angle response increase. When the store is mounted under the wingtip, the additional aerodynamics caused by the wingtip vortex is obvious, which accelerate the divergence of the lateral force and the lateral-directional attitude angle of the store. This study supports some beneficial conclusions to the engineering application of the air-launch-to-orbit.

  1. Automotive radar – investigation of mutual interference mechanisms

    OpenAIRE

    2010-01-01

    In the past mutual interference between automotive radar sensors has not been regarded as a major problem. With an increasing number of such systems, however, this topic is receiving more and more attention. The investigation of mutual interference and countermeasures is therefore one topic of the joint project "Radar on Chip for Cars" (RoCC) funded by the German Federal Ministry of Education and Research (BMBF). RoCC's goal is to pave the way for the development of high-per...

  2. Exploiting CRISPR/Cas: Interference Mechanisms and Applications

    Directory of Open Access Journals (Sweden)

    André Plagens

    2013-07-01

    Full Text Available The discovery of biological concepts can often provide a framework for the development of novel molecular tools, which can help us to further understand and manipulate life. One recent example is the elucidation of the prokaryotic adaptive immune system, clustered regularly interspaced short palindromic repeats (CRISPR/CRISPR-associated (Cas that protects bacteria and archaea against viruses or conjugative plasmids. The immunity is based on small RNA molecules that are incorporated into versatile multi-domain proteins or protein complexes and specifically target viral nucleic acids via base complementarity. CRISPR/Cas interference machines are utilized to develop novel genome editing tools for different organisms. Here, we will review the latest progress in the elucidation and application of prokaryotic CRISPR/Cas systems and discuss possible future approaches to exploit the potential of these interference machineries.

  3. Exploiting CRISPR/Cas: Interference Mechanisms and Applications

    Science.gov (United States)

    Richter, Hagen; Randau, Lennart; Plagens, André

    2013-01-01

    The discovery of biological concepts can often provide a framework for the development of novel molecular tools, which can help us to further understand and manipulate life. One recent example is the elucidation of the prokaryotic adaptive immune system, clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated (Cas) that protects bacteria and archaea against viruses or conjugative plasmids. The immunity is based on small RNA molecules that are incorporated into versatile multi-domain proteins or protein complexes and specifically target viral nucleic acids via base complementarity. CRISPR/Cas interference machines are utilized to develop novel genome editing tools for different organisms. Here, we will review the latest progress in the elucidation and application of prokaryotic CRISPR/Cas systems and discuss possible future approaches to exploit the potential of these interference machineries. PMID:23857052

  4. Effect of Toll-Like Receptor 4 on Synovial Injury of Temporomandibular Joint in Rats Caused by Occlusal Interference

    Directory of Open Access Journals (Sweden)

    Jingjing Kong

    2016-01-01

    Full Text Available Synovitis is an important disease that causes intractable pain in TMJ. Some investigations suggested that the increasing expression of IL-1β secreted by synovial lining cells plays an important role in synovial inflammation and cartilage destruction in TMJ. In our previous research, the results demonstrated that TLR4 is involved in the expression of IL-1β in SFs from TMJ with lipopolysaccharide stimulation. However, the inflammatory response that occurred in synovial membrane is not caused by bacterial infection. In the current study, we investigated whether or not TLR4 participates in the inflammatory responses and the expression of IL-1β in synovial membrane of rats induced by occlusal interference. The results showed that obvious inflammation changes were observed in the synovial membranes and the expression of TLR4 and IL-1β was increased at both mRNA and protein levels in the occlusal interference rats. In addition, the inflammation reactions and the increased expression of IL-1β could be restrained by treatment with TAK-242, a blocker of TLR4 signaling. The results prompted us that the activation of TLR4 may be involved in the inflammatory reactions and increased expression of IL-1β in patients with synovitis and participate in the mechanisms of the initiation and development of synovial injury by regulating the expression of inflammatory mediators like IL-1β in synovial membranes.

  5. RNA Interference in Caenorhabditis elegans : Mechanism and Application

    NARCIS (Netherlands)

    Simmer, Femke

    2003-01-01

    Viruses exploit their host by using many compounds of the host and cause damage by replication and spreading through the organism. Transposons are DNA elements that can move and multiply themselves within their host genome. As a result, they can cause damaging mutations. This thesis is about a defen

  6. Understanding the influence of watershed storage caused by human interferences on ET variance

    Science.gov (United States)

    Zeng, R.; Cai, X.

    2014-12-01

    Understanding the temporal variance of evapotranspiration (ET) at the watershed scale remains a challenging task, because it is affected by complex climate conditions, soil properties, vegetation, groundwater and human activities. In a changing environment with extensive and intensive human interferences, understanding ET variance and its factors is important for sustainable water resources management. This study presents an analysis of the effect of storage change caused by human activities on ET variance Irrigation usually filters ET variance through the use of surface and groundwater; however, over-amount irrigation may cause the depletion of watershed storage, which changes the coincidence of water availability and energy supply for ET. This study develops a framework by incorporating the water balance and the Budyko Hypothesis. It decomposes the ET variance to the variances of precipitation, potential ET, catchment storage change, and their covariances. The contributions of ET variance from the various components are scaled by some weighting functions, expressed as long-term climate conditions and catchment properties. ET variance is assessed by records from 32 major river basins across the world. It is found that ET variance is dominated by precipitation variance under hot-dry condition and by evaporative demand variance under cool-wet condition; while the coincidence of water and energy supply controls ET variance under moderate climate condition. Watershed storage change plays an increasing important role in determining ET variance with relatively shorter time scale. By incorporating storage change caused by human interferences, this framework corrects the over-estimation of ET variance in hot-dry climate and under-estimation of ET variance in cool-wet climate. Furthermore, classification of dominant factors on ET variance shows similar patterns as geographic zonation.

  7. Interference between Parts of a Mechanical Assembly Contained in a STEP File

    Directory of Open Access Journals (Sweden)

    Edwin Estévez Parra

    2015-01-01

    Full Text Available Obtaining interferences among parts of a product contributes to determine the feasibility of the assembly sequences according to the geometry of the parts involved. However, in assembly may exist partswith freeform surfaces which make difficult to determine the interference relationship between themautomatically. The objective of this research is to present a method for obtaining interference among assembly parts with prismatic, cylindric and form free surfaces. The method is automated with a software developed on PythonOCC open source framework, which is based on OpenCascade. The techniques for extracting assembly geometric information which is contained in a 3D CAD file withSTEP standard format, the detection of collisions between the parts in disassembly directions, and the generation of interference matrices are described. Two examples of mechanical assemblies are analyzed to demonstrate the effectiveness of the method and the interferences matrices corresponding to the six principal axis disassembly directions are obtained as a result.

  8. A case study of arithmetic facts dyscalculia caused by a hypersensitivity-to-interference in memory.

    Science.gov (United States)

    De Visscher, Alice; Noël, Marie-Pascale

    2013-01-01

    While the heterogeneity of developmental dyscalculia is increasingly recognized, the different profiles have not yet been clearly established. Among the features underpinning types of developmental dyscalculia suggested in the literature, an impairment in arithmetic fact retrieval is particularly prominent. In this paper, we present a case study of an adult woman (DB) with very good cognitive capacities suffering from a specific and developmental arithmetic fact retrieval deficit. We test the main hypotheses about developmental dyscalculia derived from literature. We first explore the influential hypothesis of an approximate number system deficit, through estimation tasks, comparison tasks and a priming comparison task. Secondly, we evaluate whether DB's mathematical deficiencies are caused by a rote verbal memory deficit, using tasks involving completion of expressions, and reciting automatic series such as the alphabet and the months of the year. Alternatively, taking into account the extreme similarity of the arithmetic facts, we propose that a heightened sensitivity to interference could have prevented DB from memorizing the arithmetic facts. The pattern of DB's results on different tasks supports this hypothesis. Our findings identify a new etiology of a specific impairment of arithmetic facts storage, namely a hypersensitivity-to-interference.

  9. Investigating and Improving Student Understanding of Quantum Mechanics in the Context of Single Photon Interference

    Science.gov (United States)

    Marshman, Emily; Singh, Chandralekha

    2017-01-01

    Single photon experiments involving a Mach-Zehnder interferometer can illustrate the fundamental principles of quantum mechanics, e.g., the wave-particle duality of a single photon, single photon interference, and the probabilistic nature of quantum measurement involving single photons. These experiments explicitly make the connection between the…

  10. RNA interference as a resistance mechanism against crop parasites in Africa: a 'Trojan horse' approach.

    Science.gov (United States)

    Runo, Steven; Alakonya, Amos; Machuka, Jesse; Sinha, Neelima

    2011-02-01

    Biological crop pests cause serious economic losses. In Africa, the most prevalent parasites are insect pests, plant pathogenic root-knot nematodes, viruses and parasitic plants. African smallholder farmers struggle to overcome these parasitic constraints to agricultural production. Crop losses and the host range of these parasites have continued to increase in spite of the use of widely advocated control methods. A sustainable method to overcome biological pests in Africa would be to develop crop germplasm resistant to parasites. This is achievable using either genetic modification (GM) or a non-GM approach. However, there is a paucity of resistant genes available for introduction. Additionally, the biological processes underpinning host parasite resistance are not sufficiently well understood. The authors review a technology platform for using RNA-mediated interference (RNAi) as bioengineered resistance to important crop parasites in Africa. To achieve acquired resistance, a host crop is stably transformed with a transgene that encodes a hairpin RNA targeting essential parasitic genes. The RNAi sequence is chosen in such a way that it shares no homology with the host's genes, so it remains 'inactive' until parasitism. Upon parasitism, the RNAi sequence enters the parasite and post-transcriptional gene silencing (PTGS) mechanisms are activated, leading to the death of the parasite. Copyright © 2010 Society of Chemical Industry.

  11. Simultaneous Wireless Information and Power Transfer Mechanism in Interference Alignment Relay Networks

    Directory of Open Access Journals (Sweden)

    Fahui Wu

    2016-01-01

    Full Text Available This paper considers a simultaneous wireless information and power transfer (SWIPT mechanism in an interference alignment (IA relay system, in which source nodes send wireless information and energy simultaneously to relay nodes, and relay nodes forward the received signal to destination nodes powered by harvested energy. To manage interference and utilize interference as energy source, two-SWIPT receiver is designed, namely, power splitting (PS, and antennas switching (AS has been considered for relay system. The performance of AS- and PS-based IA relay systems is considered, as is a new energy cooperation (ECop scheme that is proposed to improve system performance. Numerical results are provided to evaluate the performance of all schemes and it is shown from the simulations that the performance of proposed ECop outperformed both AS and PS.

  12. The time-course of feature interference in agreement comprehension: Multiple mechanisms and asymmetrical attraction.

    Science.gov (United States)

    Tanner, Darren; Nicol, Janet; Brehm, Laurel

    2014-10-01

    Attraction interference in language comprehension and production may be as a result of common or different processes. In the present paper, we investigate attraction interference during language comprehension, focusing on the contexts in which interference arises and the time-course of these effects. Using evidence from event-related brain potentials (ERPs) and sentence judgment times, we show that agreement attraction in comprehension is best explained as morphosyntactic interference during memory retrieval. This stands in contrast to attraction as a message-level process involving the representation of the subject NP's number features, which is a strong contributor to attraction in production. We thus argue that the cognitive antecedents of agreement attraction in comprehension are non-identical with those of attraction in production, and moreover, that attraction in comprehension is primarily a consequence of similarity-based interference in cue-based memory retrieval processes. We suggest that mechanisms responsible for attraction during language comprehension are a subset of those involved in language production.

  13. A statistical model of uplink inter-cell interference with slow and fast power control mechanisms

    KAUST Repository

    Tabassum, Hina

    2013-09-01

    Uplink power control is in essence an interference mitigation technique that aims at minimizing the inter-cell interference (ICI) in cellular networks by reducing the transmit power levels of the mobile users while maintaining their target received signal quality levels at base stations. Power control mechanisms directly impact the interference dynamics and, thus, affect the overall achievable capacity and consumed power in cellular networks. Due to the stochastic nature of wireless channels and mobile users\\' locations, it is important to derive theoretical models for ICI that can capture the impact of design alternatives related to power control mechanisms. To this end, we derive and verify a novel statistical model for uplink ICI in Generalized-K composite fading environments as a function of various slow and fast power control mechanisms. The derived expressions are then utilized to quantify numerically key network performance metrics that include average resource fairness, average reduction in power consumption, and ergodic capacity. The accuracy of the derived expressions is validated via Monte-Carlo simulations. Results are generated for multiple network scenarios, and insights are extracted to assess various power control mechanisms as a function of system parameters. © 1972-2012 IEEE.

  14. Increasing Reliability by Means of Root Cause Aware HARQ and Interference Coordination

    DEFF Research Database (Denmark)

    Soret, Beatriz; Gerardino, Guillermo Andrés Pocovi; Pedersen, Klaus I.

    2015-01-01

    The arrival of mission critical applications in the context of vehicular, medical and industrial wireless communications calls for reliability constraints never seen before in cellular systems. Enhanced Inter-Cell Interference Coordination (eICIC) has been widely investigated in the context of LT...

  15. Ground-State Cooling of a Mechanical Oscillator by Interference in Andreev Reflection

    Science.gov (United States)

    Stadler, P.; Belzig, W.; Rastelli, G.

    2016-11-01

    We study the ground-state cooling of a mechanical oscillator linearly coupled to the charge of a quantum dot inserted between a normal metal and a superconducting contact. Such a system can be realized, e.g., by a suspended carbon nanotube quantum dot with a capacitive coupling to a gate contact. Focusing on the subgap transport regime, we analyze the inelastic Andreev reflections which drive the resonator to a nonequilibrium state. For small coupling, we obtain that vibration-assisted reflections can occur through two distinct interference paths. The interference determines the ratio between the rates of absorption and emission of vibrational energy quanta. We show that ground-state cooling of the mechanical oscillator can be achieved for many of the oscillator's modes simultaneously or for single modes selectively, depending on the experimentally tunable coupling to the superconductor.

  16. Interference from a hand held radiofrequency remote control causing discharge of an implantable defibrillator.

    Science.gov (United States)

    Man, K C; Davidson, T; Langberg, J J; Morady, F; Kalbfleisch, S J

    1993-08-01

    A 46-year-old man with a history of sustained monomorphic ventricular tachycardia underwent an implantation of a third generation multiprogrammable implantable cardioverter defibrillator. One year post implant, while manipulating a remote control to a radiofrequency modulated toy car, the patient experienced a defibrillator discharge not preceded by an arrhythmia prodrome. Subsequent interrogation of the defibrillator revealed that a 34-joule shock had been delivered and had been preceded by RR intervals ranging from 141-406 msec, consistent with sensing lead noise. The remote control utilizes a 12-volt battery and has a carrier frequency of 75.95 MHz and a modulating frequency of 50 Hz. Evaluation of the remote control and defibrillator interaction revealed that the remote control was able to trigger tachyarrhythmia sensing and reproduce the clinical episode. Interference was present only when the remote control was within 8 cm of the pulse generator and at specific angles relative to the device and only when the antenna length was > 45 cm. Interference was eliminated when a ground wire was attached to the antenna and when an aluminium shield was placed between the pulse generator and the remote control. This case report suggests that patients with third generation multiprogrammable defibrillators should be cautioned against close contact with potential sources of electromagnetic interference, such as remote control units.

  17. Neural mechanisms of semantic interference and false recognition in short-term memory.

    Science.gov (United States)

    Atkins, Alexandra S; Reuter-Lorenz, Patricia A

    2011-06-01

    Decades of research using the Deese-Roediger-McDermott (DRM) paradigm have demonstrated that episodic memory is vulnerable to semantic distortion, and neuroimaging investigations of this phenomenon have shown dissociations between the neural mechanisms subserving true and false retrieval from long-term memory. Recently, false short-term memories have also been demonstrated, with false recognition of items related in meaning to memoranda encoded less than 5s earlier. Semantic interference is also evident in short-term memory, such that correct rejection of related lures is slowed relative to correct rejection of unrelated lures. The present research constitutes the first fMRI investigation of false recognition and semantic interference in short-term memory using a short-term DRM paradigm in which participants retained 4 semantic associates over a short 4-s filled retention interval. Results showed increased activation in the left mid-ventrolateral prefrontal cortex (BA45) associated with semantic interference, and significant correlations between these increases and behavioral measures of interference across subjects. Furthermore, increases in dorsolateral PFC occurred when related lures were correctly rejected versus falsely remembered. Compared with false recognition, true recognition was associated with increases in left fusiform gyrus, a finding consistent with the notion that increased perceptual processing may distinguish true from false recognition over both short and long retention intervals. Findings are discussed in relation to current models of interference resolution in short-term memory, and suggest that false short-term recognition occurs as a consequence of the failure of frontally mediated cognitive control processes which adjudicate semantic familiarity in support of accurate mnemonic retrieval.

  18. Mechanisms and neuronal networks involved in reactive and proactive cognitive control of interference in working memory.

    Science.gov (United States)

    Irlbacher, Kerstin; Kraft, Antje; Kehrer, Stefanie; Brandt, Stephan A

    2014-10-01

    Cognitive control can be reactive or proactive in nature. Reactive control mechanisms, which support the resolution of interference, start after its onset. Conversely, proactive control involves the anticipation and prevention of interference prior to its occurrence. The interrelation of both types of cognitive control is currently under debate: Are they mediated by different neuronal networks? Or are there neuronal structures that have the potential to act in a proactive as well as in a reactive manner? This review illustrates the way in which integrating knowledge gathered from behavioral studies, functional imaging, and human electroencephalography proves useful in answering these questions. We focus on studies that investigate interference resolution at the level of working memory representations. In summary, different mechanisms are instrumental in supporting reactive and proactive control. Distinct neuronal networks are involved, though some brain regions, especially pre-SMA, possess functions that are relevant to both control modes. Therefore, activation of these brain areas could be observed in reactive, as well as proactive control, but at different times during information processing.

  19. Dissecting contact mechanics from quantum interference in single-molecule junctions of stilbene derivatives.

    Science.gov (United States)

    Aradhya, Sriharsha V; Meisner, Jeffrey S; Krikorian, Markrete; Ahn, Seokhoon; Parameswaran, Radha; Steigerwald, Michael L; Nuckolls, Colin; Venkataraman, Latha

    2012-03-14

    Electronic factors in molecules such as quantum interference and cross-conjugation can lead to dramatic modulation and suppression of conductance in single-molecule junctions. Probing such effects at the single-molecule level requires simultaneous measurements of independent junction properties, as conductance alone cannot provide conclusive evidence of junction formation for molecules with low conductivity. Here, we compare the mechanics of the conducting para-terminated 4,4'-di(methylthio)stilbene and moderately conducting 1,2-bis(4-(methylthio)phenyl)ethane to that of insulating meta-terminated 3,3'-di(methylthio)stilbene single-molecule junctions. We simultaneously measure force and conductance across single-molecule junctions and use force signatures to obtain independent evidence of junction formation and rupture in the meta-linked cross-conjugated molecule even when no clear low-bias conductance is measured. By separately quantifying conductance and mechanics, we identify the formation of atypical 3,3'-di(methylthio)stilbene molecular junctions that are mechanically stable but electronically decoupled. While theoretical studies have envisaged many plausible systems where quantum interference might be observed, our experiments provide the first direct quantitative study of the interplay between contact mechanics and the distinctively quantum mechanical nature of electronic transport in single-molecule junctions.

  20. Interference of Lithium in Measuring Magnesium by Complexometry: Discussions of the Mechanism

    Directory of Open Access Journals (Sweden)

    Jie Gao

    2013-01-01

    Full Text Available There is usually a large concentration of magnesium in the brine of salt lakes and as a consequence it is difficult to measure Mg2+ accurately with the complexometric titration by ethylenediaminetetraacetic acid disodium salt (EDTA because of the large levels of Li+ also coexisting in brine samples. In this study, a relationship between the relative error related to the number of drops of the indicator and the NMR spectra of anhydrous ethanol and n-butanol, with or without LiCl, was analyzed and compared. It was then possible to suggest a mechanism to explain the interference of Li+ when measuring Mg2+ and to control the interference in the alcohol mixture because Li+ can then complex with the alcohols and mainly form a complex with n-butanol.

  1. Quantum interference between H + D2 quasiclassical reaction mechanisms.

    Science.gov (United States)

    Jambrina, Pablo G; Herráez-Aguilar, Diego; Aoiz, F Javier; Sneha, Mahima; Jankunas, Justinas; Zare, Richard N

    2015-08-01

    Interferences are genuine quantum phenomena that appear whenever two seemingly distinct classical trajectories lead to the same outcome. They are common in elastic scattering but are seldom observable in chemical reactions. Here we report experimental measurements of the state-to-state angular distribution for the H + D2 reaction using the 'photoloc' technique. For products in low rotational and vibrational states, a characteristic oscillation pattern governs backward scattering. The comparison between the experiments, rigorous quantum calculations and classical trajectories on an accurate potential energy surface allows us to trace the origin of that structure to the quantum interference between different quasiclassical mechanisms, a phenomenon analogous to that observed in the double-slit experiment.

  2. RNA干扰的途径和机制%Pathway and Mechanism of RNA Interference

    Institute of Scientific and Technical Information of China (English)

    李绍祥; 郭汉斌; 曹建彪

    2012-01-01

    RNA interference ( RNAi ) is sequence-specific gene silencing phenomena mediated by double-stranded RNA, and it can block gene expression at the level of transcription, post-transcription and translation, with high efficiency and high specificity. The characteristics and mechanisms of the two pathways of RNAi, including short interfering RNA and microRNA, are reviewed in this paper.%RNA干扰(RNA interference,RNAi)是由双链RNA介导的序列特异的基因沉默现象,它在转录水平、转录后水平和翻译水平上阻断基因的表达,具有高效性和高特异性的特点.现就RNAi的两种途径:小干扰RNA和微小RNA的特点和机制作一综述.

  3. Assay interference caused by antibodies reacting with rat kappa light-chain in human sera.

    Science.gov (United States)

    Degn, Søren E; Andersen, Stig Henrik; Jensen, Lisbeth; Thiel, Steffen; Jensenius, Jens C

    2011-09-30

    The enzyme-linked immunosorbent assay (ELISA) and its derivatives are powerful tools used in research, in the clinic, and in many other analytical and quality control settings. In general, ELISAs are robust, reproducible and reliable. However, a number of pitfalls of ELISAs have been described over the years. The issue of rheumatoid factor (RF), autoantibodies against the Fc portion of IgG, is well recognized (yet often forgotten), as are problems arising from heterophilic antibodies induced by external antigens that cross-react with self-antigens. A few years ago focus was on human anti-mouse antibodies (HAMA) concomitant with the increased use of mouse monoclonal antibody therapy, a problem that is now diminishing due to development of humanized antibodies. Issues pertaining to food antigens or environmentally encountered antigens are less recognized. We report a recently encountered example of the latter resulting in interference in a solid-phase sandwich assay. Due to the set-up employing a monoclonal rat IgG for capture and a monoclonal rat IgM for development the interference had to be human antibodies reacting with rat light-chain. Out of 102 Danish Caucasian blood donors we found a prevalence of anti-rat kappa light chain antibodies of close to 40% (39/102, defined as at least 2-fold elevated measurements), with around 6% (6/102) having very high levels (defined as at least 4-fold elevated measurements), yielding significantly higher measurements in the assay designed to measure the complement component MAp19 in serum samples. The interference could be blocked by the addition of rat immunoglobulin to the sample buffer. An individual, who had been followed over time, demonstrated a periodic increase of interfering antibodies, highlighting that it is an independently varying parameter and thereby a variable interference in assays. Our results highlight a major pitfall of potential relevance to many sandwich-type assays, as well as an approach to rectify such

  4. Statistical evaluation of telephone noise interference caused by AC power line harmonic currents

    Energy Technology Data Exchange (ETDEWEB)

    Kuussaari, M. (Imatran Voima Oy, Vantaa (Finland))

    1993-04-01

    A statistical approach is applied for the evaluation of the limits for harmonic currents in AC power lines, the goal being to prevent excessive telephone noise interference voltages in subscriber cables in rural areas. The analysis is based on Monte-Carlo simulation which takes into account the effect of the experiental probability distributions of the relevant parameters. In the Finnish conditions, the properties of communication cables permit equivalent disturbing phase currents of 8 to 10 A. The digital exchanges permit approximately the same currents. Some new telephone types that have a low balance may make it necessary to limit the currents to a level that is somewhat lower.

  5. Increase of Carrier-to-Noise Ratio in GPS Receivers Caused by Continuous-Wave Interference

    Directory of Open Access Journals (Sweden)

    J. Li

    2016-09-01

    Full Text Available The increased use of personal private devices (PPDs is drawing greater attention to the effects of continuous-wave interference (CWI on the performance of global positioning system (GPS receivers. The effective carrier-to-noise density ratio (C/N0, an essential index of GNSS receiver performance, is studied in this paper. Receiver tracking performance deteriorates in the presence of interference. Hence, the effective C/N0, which measures tracking performance, decreases. However, simulations and bench tests have shown that the effective C/N0 may increase in the presence of CWI. The reason is that a sinusoidal signal is induced by the CWI in the correlator and may be tracked by the carrier tracking loop. Thus, the effective carrier power depends on the power of the signal induced by the CWI, and the effective C/N0 increases with the power of the CWI. The filtering of the CWI in the carrier tracking loop correlator and its effect on the phase locked loop (PLL tracking performance are analyzed. A mathematical model of the effect of the CWI on the effective C/N0 is derived. Simulation results show that the proposed model is more accurate than existing models, especially when the jam-to-signal ratio (JSR is greater than 30 dBc.

  6. Electromagnetic Interference from Swimming Pool Generator Current Causing Inappropriate ICD Discharges

    Directory of Open Access Journals (Sweden)

    Edward Samuel Roberto

    2017-01-01

    Full Text Available Electromagnetic interference (EMI includes any electromagnetic field signal that can be detected by device circuitry, with potentially serious consequences: incorrect sensing, pacing, device mode switching, and defibrillation. This is a unique case of extracardiac EMI by alternating current leakage from a submerged motor used to recycle chlorinated water, resulting in false rhythm detection and inappropriate ICD discharge. A 31-year-old female with arrhythmogenic right ventricular cardiomyopathy and Medtronic dual-chamber ICD placement presented after several inappropriate ICD shocks at the public swimming pool. Patient had never received prior shocks and device was appropriate at all regular follow-ups. Intracardiac electrograms revealed unique, high-frequency signals at exactly 120 msec suggestive of EMI from a strong external source of alternating current. Electrical artifact was incorrectly sensed as a ventricular arrhythmia which resulted in discharge. ICD parameters including sensing, pacing thresholds, and impedance were all normal suggesting against device malfunction. With device failure and intracardiac sources excluded, EMI was therefore strongly suspected. Avoidance of EMI source brought complete resolution with no further inappropriate shocks. After exclusion of intracardiac interference, device malfunction, and abnormal settings, extracardiac etiologies such as EMI must be thoughtfully considered and excluded. Elimination of inappropriate shocks is to “first, do no harm.”

  7. The Cause and Mechanism of Cardiac Electrical Instability. Defibrillation Mechanism

    Directory of Open Access Journals (Sweden)

    Rustam G. Habchabov

    2012-06-01

    Full Text Available The reason for the ominous arrhythmias pathway, causing sudden somatic death from cardiovascular diseases is still not clear, cardiological examinations of this phenomenon are conducted throughout the world. Laceration of connective insulating tissue membrane of heart pathway with ectopic nodes oxidation may cause ominous arrhythmias; nobody has considered this cause as a cardiac electrical instability before. Defibrillator electric discharges cannot penetrate into myocardium due to the connective insulating tissue membrane, nobody has considered nervous system, transmitting electricity.

  8. Antidote treatment for cyanide poisoning with hydroxocobalamin causes bright pink discolouration and chemical-analytical interferences.

    Science.gov (United States)

    Brunel, C; Widmer, C; Augsburger, M; Dussy, F; Fracasso, T

    2012-11-30

    Here we report the case of a 70-year-old woman who committed suicide by cyanide poisoning. During resuscitation cares, she underwent an antidote treatment by hydroxocobalamin. Postmortem investigations showed marked bright pink discolouration of organs and fluids, and a lethal cyanide blood concentration of 43 mg/L was detected by toxicological investigation. Discolouration of hypostasis and organs has widely been studied in forensic literature. In our case, we interpreted the unusual pink coloration as the result of the presence of hydroxocobalamin. This substance is a known antidote against cyanide poisoning, indicated because of its efficiency and poor adverse effects. However, its main drawback is to interfere with measurements of many routine biochemical parameters. We have tested the potential influence of this molecule in some routine postmortem investigations. The results are discussed.

  9. Promoter competition as a mechanism of transcriptional interference mediated by retrotransposons.

    Science.gov (United States)

    Conte, Caroline; Dastugue, Bernard; Vaury, Chantal

    2002-07-15

    Enhancers can function over great distances and interact with almost any kind of promoter, but insulators or promoter competition generally limit their effect to a single gene. We provide in vivo evidence that retroelements may establish promoter competition with their neighboring genes and restrict the range of action of an enhancer. We report that the retroelement Idefix from Drosophila melanogaster inhibits white gene expression in testes by a promoter competition mechanism that does not occur in the eyes. The sequence specificity of the two TATA-less promoters of white and Idefix is a prime determinant in the competition that takes place in tissues where both are transcriptionally active. This study brings to light a novel mechanism whereby transcriptional interference by an active retrotransposon may perturb expression of neighboring genes. This capacity to interfere with the transcriptional regulation of their host, together with the facts that retroelements preferentially move within the germline and do not excise to replicate, suggest that these elements are cis-regulatory sequences able to imprint specific and heritable controls essential for eukaryotic gene regulation.

  10. Higher Order Modulation Intersymbol Interference Caused by Traveling-wave Tube Amplifiers

    Science.gov (United States)

    Kory, Carol L.; Andro, Monty; Williams, W. D. (Technical Monitor)

    2002-01-01

    For the first time, a time-dependent, physics-based computational model has been used to provide a direct description of the effects of the traveling wave tube amplifier (TWTA) on modulated digital signals. The TWT model comprehensively takes into account the effects of frequency dependent AM/AM and AM/PM conversion; gain and phase ripple; drive-induced oscillations; harmonic generation; intermodulation products; and backward waves, Thus, signal integrity can be investigated in the presence of these sources of potential distortion as a function of the physical geometry and operating characteristics of the high power amplifier and the operational digital signal. This method promises superior predictive fidelity compared to methods using TWT models based on swept-amplitude and/or swept-frequency data. First, the TWT model using the three dimensional (3D) electromagnetic code MAFIA is presented. Then, this comprehensive model is used to investigate approximations made in conventional TWT black-box models used in communication system level simulations, To quantitatively demonstrate the effects these approximations have on digital signal performance predictions, including intersymbol interference (ISI), the MAFIA results are compared to the system level analysis tool, Signal Processing, Workstation (SPW), using high order modulation schemes including 16 and 64-QAM.

  11. Simulation on Mechanical Behaviors of Oil-film Bearing Sleeve by Elastic Interference Fit

    Institute of Scientific and Technical Information of China (English)

    HUANG Qingxue; WANG Jianmei; ZHAO Chunjiang; MA Lifeng

    2006-01-01

    Oil film bearing, which works on thin film between sleeve and bush, is widely used in steel industry due to the characteristics of high efficiency and low noise, etc. The backup roll of 1 580PC hot strip mill invested by some steel corporation has been equipped with such bearing. During the process of setup&disassembly and usage period, the sleeve has been dramatically damaged, which results in production accidents and decreases its service life, thus heavily influencing steel production. Aimed at such puzzles, under specific loadcase, mechanical properties of bearing sleeve, as well as estimation of contact status and adhesive force of sleeve by interference fit, are quantitatively simulated by finite element method, which establishes an mechanical foundation for improving the load capacity of bearing and decreasing its wear and adhesion damages. Finally, some measures and conclusions are drawn.

  12. Fundamental mechanism underlying subwavelength optics of metamaterials: Charge oscillation-induced light emission and interference

    CERN Document Server

    Huang, X R; Wang, Mu

    2009-01-01

    Interactions between light and conducting nanostructures can result in a variety of novel and fascinating phenomena. These properties may have wide applications, but their underlying mechanisms have not been completely understood. From calculations of surface charge density waves on conducting gratings and by comparing them with classical surface plasmons, we revealed a general yet concrete picture about coupling of light to free electron oscillation on structured conducting surfaces that can lead to oscillating subwavelength charge patterns (i.e., spoof surface plasmons but without the dispersion property of classical surface plasmons). New wavelets emitted from these light sources then destructively interfere to form evanescent waves. This principle, usually combined with other mechanisms (e.g. resonance), is mainly a geometrical effect that can be universally involved in light scattering from all periodic and nonperiodic structures containing free electrons, including perfect conductors. The spoof surface ...

  13. Evolution of recombination in eutherian mammals: insights into mechanisms that affect recombination rates and crossover interference.

    Science.gov (United States)

    Segura, Joana; Ferretti, Luca; Ramos-Onsins, Sebastián; Capilla, Laia; Farré, Marta; Reis, Fernanda; Oliver-Bonet, Maria; Fernández-Bellón, Hugo; Garcia, Francisca; Garcia-Caldés, Montserrat; Robinson, Terence J; Ruiz-Herrera, Aurora

    2013-11-22

    Recombination allows faithful chromosomal segregation during meiosis and contributes to the production of new heritable allelic variants that are essential for the maintenance of genetic diversity. Therefore, an appreciation of how this variation is created and maintained is of critical importance to our understanding of biodiversity and evolutionary change. Here, we analysed the recombination features from species representing the major eutherian taxonomic groups Afrotheria, Rodentia, Primates and Carnivora to better understand the dynamics of mammalian recombination. Our results suggest a phylogenetic component in recombination rates (RRs), which appears to be directional, strongly punctuated and subject to selection. Species that diversified earlier in the evolutionary tree have lower RRs than those from more derived phylogenetic branches. Furthermore, chromosome-specific recombination maps in distantly related taxa show that crossover interference is especially weak in the species with highest RRs detected thus far, the tiger. This is the first example of a mammalian species exhibiting such low levels of crossover interference, highlighting the uniqueness of this species and its relevance for the study of the mechanisms controlling crossover formation, distribution and resolution.

  14. Interference-Aware Opportunistic Dynamic Energy Saving Mechanism for Wi-Fi Enabled IoTs

    Directory of Open Access Journals (Sweden)

    Il-Gu Lee

    2017-07-01

    Full Text Available The wireless local area network (WLAN is one of the most popular wireless technologies offering connectivity today, and one of the candidates for the internet of things (IoTs. However, WLAN’s inefficiency in terms of complexity and relatively large power consumption compared with other wireless standards has been reported as a major barrier for IoTs applications. This paper proposes an interference-aware opportunistic dynamic energy saving mechanism to improve energy efficiency for Wi-Fi enabled IoTs. The proposed scheme optimizes operating clock frequencies adaptively for signal processing when the mobile station transmits packets in partial sub-channels. Evaluation results demonstrate that the proposed scheme improves energy efficiency by approximately 34%.

  15. Depletion of hCINAP by RNA interference causes defects in Cajal body formation, histone transcription, and cell viability.

    Science.gov (United States)

    Zhang, Jinfang; Zhang, Feiyun; Zheng, Xiaofeng

    2010-06-01

    hCINAP is a highly conserved and ubiquitously expressed protein in eukaryotic organisms and its overexpression decreases the average number of Cajal bodies (CBs) with diverse nuclear functions. Here, we report that hCINAP is associated with important components of CBs. Depletion of hCINAP by RNA interference causes defects in CB formation and disrupts subcellular localizations of its components including coilin, survival motor neurons protein, spliceosomal small nuclear ribonucleoproteins, and nuclear protein ataxia-telangiectasia. Moreover, knockdown of hCINAP expression results in marked reduction of histone transcription, lower levels of U small nuclear RNAs (U1, U2, U4, and U5), and a loss of cell viability. Detection of increased caspase-3 activities in hCINAP-depleted cells indicate that apoptosis is one of the reasons for the loss of viability. Altogether, these data suggest that hCINAP is essential for the formation of canonical CBs, histone transcription, and cell viability.

  16. Interference in DNA replication can cause mitotic chromosomal breakage unassociated with double-strand breaks.

    Directory of Open Access Journals (Sweden)

    Mari Fujita

    Full Text Available Morphological analysis of mitotic chromosomes is used to detect mutagenic chemical compounds and to estimate the dose of ionizing radiation to be administered. It has long been believed that chromosomal breaks are always associated with double-strand breaks (DSBs. We here provide compelling evidence against this canonical theory. We employed a genetic approach using two cell lines, chicken DT40 and human Nalm-6. We measured the number of chromosomal breaks induced by three replication-blocking agents (aphidicolin, 5-fluorouracil, and hydroxyurea in DSB-repair-proficient wild-type cells and cells deficient in both homologous recombination and nonhomologous end-joining (the two major DSB-repair pathways. Exposure of cells to the three replication-blocking agents for at least two cell cycles resulted in comparable numbers of chromosomal breaks for RAD54(-/-/KU70(-/- DT40 clones and wild-type cells. Likewise, the numbers of chromosomal breaks induced in RAD54(-/-/LIG4(-/- Nalm-6 clones and wild-type cells were also comparable. These data indicate that the replication-blocking agents can cause chromosomal breaks unassociated with DSBs. In contrast with DSB-repair-deficient cells, chicken DT40 cells deficient in PIF1 or ATRIP, which molecules contribute to the completion of DNA replication, displayed higher numbers of mitotic chromosomal breaks induced by aphidicolin than did wild-type cells, suggesting that single-strand gaps left unreplicated may result in mitotic chromosomal breaks.

  17. How man-made interference might cause gas bubble emboli in deep diving whales

    Directory of Open Access Journals (Sweden)

    Andreas eFahlman

    2014-01-01

    Full Text Available Recent cetacean mass strandings in close temporal and spatial association with sonar activity has raised the concern that anthropogenic sound may harm breath-hold diving marine mammals. Necropsy results of the stranded whales have shown evidence of bubbles in the tissues, similar to those in human divers suffering from decompression sickness (DCS. It has been proposed that changes in behavior or physiological responses during diving could increase tissue and blood N2 levels, thereby increasing DCS risk. Dive data recorded from sperm, killer, long-finned pilot, Blainville’s beaked and Cuvier’s beaked whales before and during exposure to low- (1-2 kHz and mid- (2-7 kHz frequency active sonar were used to estimate the changes in blood and tissue N2 tension (PN2. Our objectives were to determine if differences in 1 dive behavior or 2 physiological responses to sonar are plausible risk factors for bubble formation. The theoretical estimates indicate that all species may experience high N2 levels. However, unexpectedly, deep diving generally result in higher end-dive PN2 as compared with shallow diving. In this focused review we focus on three possible explanations: 1 We revisit an old hypothesis that CO2, because of its much higher diffusivity, form bubble precursors that continue to grow in N2 supersaturated tissues. Such a mechanism would be less dependent on the alveolar collapse depth but affected by elevated levels of CO2 following a burst of activity during sonar exposure. 2 During deep dives, a greater duration of time might be spent at depths where gas exchange continues as compared with shallow dives. The resulting elevated levels of N2 in deep diving whales might also make them more susceptible to anthropogenic disturbances. 3 Extended duration of dives even at depths beyond where the alveoli collapse could result in slow continuous accumulation of N2 in the adipose tissues that eventually becomes a liability.

  18. Immunoregulation by interference RNA (iRNA – mechanisms, role, perspective

    Directory of Open Access Journals (Sweden)

    Emilia Sikora

    2011-08-01

    Full Text Available The functioning of an organism depends on the precise control mechanisms, constantly adjusted to the actual state. Therefore, there is a need for efficient communication between both adjacent and distant cells, which may be executed by proteins such as hormones, neurotransmitters and cytokines. Recently another means of regulation has emerged – short regulatory RNAs (srRNAs. Although discovered only a couple of years ago, the mechanism of RNA interference has already become a topic of thousands of publications, defining its roles in both physiological and pathological processes, such as cancerogenesis and autoimmunization.RNAs regulating cell function may be coded in its genome (both exons and introns or be introduced from the external environment. In mammals microRNAs (miRNAs cooperate with proteins from the Ago/PIWI family to form effector ribonucleoprotein complexes, and owing to their complementarity to the target mRNA, control genes’ expression at the posttranscriptional level, either through the suppression of mRNA translation or through mRNA degradation.SrRNAs are crucial regulators throughout the development of immune cells, starting from hematopoietic stem cells, up to the effector cells of the adaptive immune response. Moreover, some of the regulatory cells perform their function by releasing miRNAs, which are then transported to the target cells, possibly enclosed in the exosomes.

  19. A novel interference mechanism by a type IIIB CRISPR-Cmr module in Sulfolobus

    DEFF Research Database (Denmark)

    Deng, Ling; Garrett, Roger Antony; Shah, Shiraz Ali

    2013-01-01

    Recent studies on CRISPR-based adaptive immune systems have revealed extensive structural and functional diversity of the interference complexes which often coexist intracellularly. The archaeon Sulfolobus islandicus REY15A encodes three interference modules, one of type IA and two of type IIIB...... targeting. A rationale is provided for the intracellular coexistence of the different interference systems in S.¿islandicus REY15A which cooperate functionally by sharing a single Cas6 protein for crRNA processing and utilize crRNA products from identical CRISPR spacers....

  20. Evaluation of the immunogenicity and diagnostic interference caused by M. tuberculosis SO2 vaccination against tuberculosis in goats.

    Science.gov (United States)

    Bezos, Javier; Casal, Carmen; Puentes, Eugenia; Díez-Guerrier, Alberto; Romero, Beatriz; Aguiló, Nacho; de Juan, Lucía; Martín, Carlos; Domínguez, Lucas

    2015-12-01

    The immunogenicity and diagnostic interference caused by M. tuberculosis SO2, a prototype vaccine first time tested in goats was evaluated. Tuberculosis-free goats were distributed in four groups: [1], non-vaccinated; [2], subcutaneously (SC) BCG vaccinated; [3], intranasally (IN) SO2 vaccinated and [4], SC SO2 vaccinated. Intradermal tuberculin and IFN-γ tests using PPDs and alternative antigenic cocktails containing mainly ESAT-6 and CFP-10 (E/C) were applied at different times post-vaccination. Results showed a significant (p<0.05) increase in the number of reactors detected using both PPD-based intradermal and IFN-γ tests at different times in all the vaccinated groups. No intradermal reactivity was detected in the vaccinated goats using a cocktail containing E/C, Rv3615c and Rv3020c. A higher overall reactivity was observed in the group [4] in comparison with the other vaccinated groups. Results showed that antigens used to differentiate BCG vaccinated animals could be potentially used to differentiate SO2 vaccinated ones.

  1. Normalization of Overexpressed α-Synuclein Causing Parkinson's Disease By a Moderate Gene Silencing With RNA Interference

    Directory of Open Access Journals (Sweden)

    Masaki Takahashi

    2015-01-01

    Full Text Available The α-synuclein (SNCA gene is a responsible gene for Parkinson's disease (PD; and not only nucleotide variations but also overexpression of SNCA appears to be involved in the pathogenesis of PD. A specific inhibition against mutant SNCA genes carrying nucleotide variations may be feasible by a specific silencing such as an allele-specific RNA interference (RNAi; however, there is no method for restoring the SNCA overexpression to a normal level. Here, we show that an atypical RNAi using small interfering RNAs (siRNAs that confer a moderate level of gene silencing is capable of controlling overexpressed SNCA genes to return to a normal level; named “expression-control RNAi” (ExCont-RNAi. ExCont-RNAi exhibited little or no significant off-target effects in its treated PD patient's fibroblasts that carry SNCA triplication. To further assess the therapeutic effect of ExCont-RNAi, PD-model flies that carried the human SNCA gene underwent an ExCont-RNAi treatment. The treated PD-flies demonstrated a significant improvement in their motor function. Our current findings suggested that ExCont-RNAi might be capable of becoming a novel therapeutic procedure for PD with the SNCA overexpression, and that siRNAs conferring a moderate level of gene silencing to target genes, which have been abandoned as useless siRNAs so far, might be available for controlling abnormally expressed disease-causing genes without producing adverse effects.

  2. EFL Foreign Teacher Stress in Korea: Causes and Coping Mechanisms

    Science.gov (United States)

    Brundage, Gregory C.

    2007-01-01

    Survey study of 53 foreign EFL teachers in Jeonju City, South Korea looks at causes of teacher stress and coping mechanisms between the years of 2004 and 2006. Results show foreign EFL teachers report moderate levels of stress and attribute stresses in roughly equal measures to student misbehavior and school director/administrative sources. Survey…

  3. Ultrasonic Phased Array Evaluation of Control Rod Drive Mechanism (CRDM) Nozzle Interference Fit and Weld Region

    Energy Technology Data Exchange (ETDEWEB)

    Cinson, Anthony D.; Crawford, Susan L.; MacFarlan, Paul J.; Mathews, Royce; Hanson, Brady D.; Diaz, Aaron A.

    2011-07-31

    Ultrasonic phased array data were collected on a removed-from-service CRDM nozzle specimen to assess a previously reported leak path. First a mock-up CRDM specimen was evaluated that contained two 0.076-mm (3.0-mil) interference fit regions formed from an actual Inconel CRDM tube and two 152.4-mm (6.0-in.) thick carbon steel blocks. One interference fit region has a series of precision crafted electric discharge machining (EDM) notches at various lengths, widths, depths, and spatial separations for establishing probe sensitivity, resolution and calibration. The other interference fit has zones of boric acid (crystal form) spaced periodically between the tube and block to represent an actively leaking CRDM nozzle assembly in the field. Ultrasonic phased-array evaluations were conducted using an immersion 8-element annular 5.0-MHz probe from the tube inner diameter (ID). A variety of focal laws were employed to evaluate the interference fit regions and J grove weld, where applicable. Responses from the mock-up specimen were evaluated to determine detection limits and characterization ability as well as contrast the ultrasonic response differences with the presence of boric acid in the fit region. Nozzle 63, from the North Anna Unit-2 nuclear power plant, was evaluated to assess leakage path(s) and was destructively dismantled to allow a visual verification of the leak path(s).

  4. Isolating the Neural Mechanisms of Interference During Continuous Multisensory Dual-task Performance

    Science.gov (United States)

    2014-01-01

    sion accuracy in each task, the signal detection theory sensitivity measure of d0 was used (Macmillan & Creelman , 1991; Green & Swets, 1966). First...J. (1998). Sources of dual-task interference: Evidence from human electrophysiology. Psychological Science, 9, 223–227. Macmillan, N. A., & Creelman

  5. Intronic L1 retrotransposons and nested genes cause transcriptional interference by inducing intron retention, exonization and cryptic polyadenylation.

    Directory of Open Access Journals (Sweden)

    Kristel Kaer

    Full Text Available BACKGROUND: Transcriptional interference has been recently recognized as an unexpectedly complex and mostly negative regulation of genes. Despite a relatively few studies that emerged in recent years, it has been demonstrated that a readthrough transcription derived from one gene can influence the transcription of another overlapping or nested gene. However, the molecular effects resulting from this interaction are largely unknown. METHODOLOGY/PRINCIPAL FINDINGS: Using in silico chromosome walking, we searched for prematurely terminated transcripts bearing signatures of intron retention or exonization of intronic sequence at their 3' ends upstream to human L1 retrotransposons, protein-coding and noncoding nested genes. We demonstrate that transcriptional interference induced by intronic L1s (or other repeated DNAs and nested genes could be characterized by intron retention, forced exonization and cryptic polyadenylation. These molecular effects were revealed from the analysis of endogenous transcripts derived from different cell lines and tissues and confirmed by the expression of three minigenes in cell culture. While intron retention and exonization were comparably observed in introns upstream to L1s, forced exonization was preferentially detected in nested genes. Transcriptional interference induced by L1 or nested genes was dependent on the presence or absence of cryptic splice sites, affected the inclusion or exclusion of the upstream exon and the use of cryptic polyadenylation signals. CONCLUSIONS/SIGNIFICANCE: Our results suggest that transcriptional interference induced by intronic L1s and nested genes could influence the transcription of the large number of genes in normal as well as in tumor tissues. Therefore, this type of interference could have a major impact on the regulation of the host gene expression.

  6. 47 CFR 95.423 - (CB Rule 23) What must I do if the FCC tells me that my CB station is causing interference?

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false (CB Rule 23) What must I do if the FCC tells me...) Radio Service Other Things You Need to Know § 95.423 (CB Rule 23) What must I do if the FCC tells me that my CB station is causing interference? (a) If the FCC tells you that your CB station is...

  7. 47 CFR 95.220 - (R/C Rules 20) What must I do if the FCC tells me that my R/C station is causing interference?

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false (R/C Rules 20) What must I do if the FCC tells.../C) Radio Service Other Things You Need to Know § 95.220 (R/C Rules 20) What must I do if the FCC tells me that my R/C station is causing interference? (a) If the FCC tells you that your R/C station...

  8. The acylphloroglucinols hyperforin and myrtucommulone A cause mitochondrial dysfunctions in leukemic cells by direct interference with mitochondria.

    Science.gov (United States)

    Wiechmann, Katja; Müller, Hans; Fischer, Dagmar; Jauch, Johann; Werz, Oliver

    2015-11-01

    The acylphloroglucinols hyperforin (Hypf) and myrtucommulone A (MC A) induce death of cancer cells by triggering the intrinsic/mitochondrial pathway of apoptosis, accompanied by a loss of the mitochondrial membrane potential and release of cytochrome c. However, the upstream targets and mechanisms leading to these mitochondrial events in cancer cells remain elusive. Here we show that Hypf and MC A directly act on mitochondria derived from human leukemic HL-60 cells and thus, disrupt mitochondrial functions. In isolated mitochondria, Hypf and MC A efficiently impaired mitochondrial viability (EC50 = 0.2 and 0.9 µM, respectively), caused loss of the mitochondrial membrane potential (at 0.03 and 0.1 µM, respectively), and suppressed mitochondrial ATP synthesis (IC50 = 0.2 and 0.5 µM, respectively). Consequently, the compounds activated the adenosine monophosphate-activated protein kinase (AMPK) in HL-60 cells, a cellular energy sensor involved in apoptosis of cancer cells. Side by side comparison with the protonophore CCCP and the ATP synthase inhibitor oligomycin suggest that Hypf and MC A act as protonophores that primarily dissipate the mitochondrial membrane potential by direct interaction with the mitochondrial membrane. Together, Hypf and MC A abolish the mitochondrial proton motive force that on one hand impairs mitochondrial viability and on the other cause activation of AMPK due to lowered ATP levels which may further facilitate the intrinsic mitochondrial pathway of apoptosis.

  9. The perturbed magnetic fields caused by mechanical stress

    Institute of Scientific and Technical Information of China (English)

    QIN Fei; YAN Dong-mei

    2006-01-01

    In the framework of the linearized magnetoelastic theory,the perturbed magnetic fields caused by mechanical stress and deformation were investigated theoretically.Governing equations and boundary conditions to determine the perturbed fields were derived.The effect of mechanical deformation on the magnetic fields was taken into account by coupling structural displacement into the perturbed magnetic field continuous conditions on the boundary of the structure.As an example,the perturbed field of a half-plane magnetized structure caused by a point force was calculated by the Fourier transform method.The results show that the calculated magnetic intensity component normal to the boundary of the structure reaches its maximum at the point force acted while the component tangent to the boundary inverses its direction sharply.The magnetic induction of the perturbed field is proportional to the applied force.Magnitude analysis proved that since the applied magnetic field has a relative weak intensity such as the Earth's magnetic field, influence of the magnetic field on deformation of the structure can be neglected.

  10. Mechanism of dye response and interference in the Bradford protein assay.

    Science.gov (United States)

    Compton, S J; Jones, C G

    1985-12-01

    Bradford Coomassie brilliant blue G-250 protein-binding dye exists in three forms: cationic, neutral, and anionic. Although the anion is not freely present at the dye reagent pH, it is this form that complexes with protein. Dye binding requires a macromolecular form with certain reactive functional groups. Interactions are chiefly with arginine rather than primary amino groups; the other basic (His, Lys) and aromatic residues (Try, Tyr, and Phe) give slight responses. The binding behavior is attributed to Van der Waals forces and hydrophobic interactions. Assay interference by bases, detergents, and other compounds are explained in terms of their effects upon the equilibria between the three dye forms.

  11. Jaw lift causes less laryngeal interference during lightwand-guided intubation than combined jaw and tongue traction applied by single operator

    Directory of Open Access Journals (Sweden)

    Umesh Goneppanavar

    2011-01-01

    Full Text Available Lightwand-guided intubation is a semi-blind technique that takes advantage of the anterior location of the trachea in relation to the oesophagus. Fibreoptic evaluation of lightwand-guided intubation has revealed a possibility of laryngeal interference and epiglottic distortion. Jaw lift, tongue traction or a combination of both have been used to assist in lightwand-guided intubation. This study fibreoptically evaluates lightwand-guided intubation using jaw lift and combined jaw and tongue traction. Eighty four patients with normal airway undergoing general anaesthesia were studied. This randomised, double blinded, cross over study was done in two phases. First phase - after achieving adequate depth of anaesthesia, a fibrescope was advanced nasally, and lightwand-guided intubation was carried out under direct fibreoptic visualisation with the aid of either jaw lift or combined jaw and tongue traction. Second phase - Extubation followed by reintubation using the other manoeuvre. Interference with laryngeal structures during intubation and position of the epiglottis at the end of intubation were noted. Epiglottic distortion (deviated to one side/infolded into trachea was observed in 6 patients with jaw lift and 17 patients with combined jaw and tongue traction (P=0.003. Laryngeal interference was significantly higher (P=0.012 with combined manoeuvre (30/78 than with jaw lift alone (9/81. Although lightwand-guided intubation can be performed quickly and easily, interference with laryngeal structures and distortion of the epiglottis can occur. Jaw lift manoeuvre causes less laryngeal interference than combined jaw and tongue traction applied by a single operator.

  12. Three-Dimensional Polymeric Mechanical Metamaterials Fabricated by Multibeam Interference Lithography with the Assistance of Plasma Etching.

    Science.gov (United States)

    Kang, Da-Young; Lee, Wooju; Kim, Dongchoul; Moon, Jun Hyuk

    2016-08-23

    The pentamode structure is a type of mechanical metamaterial that displays dramatically different bulk and shear modulus responses. In this study, a face-centered cubic (FCC) polymeric microstructure was fabricated by using SU8 negative-type photoresists and multibeam interference exposure. Isotropic plasma etching is used to control the solid-volume fraction; for the first time, we obtained a structure with the minimum solid-volume fraction as low as 15% that still exhibited high structural integrity. Using this method, we reduced the width of atom-to-atom connections by up to 40 nm. We characterize the effect of the connection area on the anisotropy of the mechanical properties using simulations. Nanoindentation measurements were also conducted to evaluate the energy dissipation by varying the connection area. The Young's/shear modulus ratio is 5 times higher for the etched microstructure than that of the bulk SU8 materials. The use of interference lithography may enable the properties of microscale materials to be engineered for various applications, such as MEMS.

  13. A mechanism-denial study on the Madden-Julian Oscillation with reduced interference from mean state changes

    Science.gov (United States)

    Ma, D.; Kuang, Z.

    2016-03-01

    Mechanism-denial experiments using Superparameterized Community Atmosphere Model are conducted to investigate the importance of extratropical and circumnavigating waves, wind-evaporation feedback, and radiative-convective feedback to the Madden-Julian Oscillation (MJO). A common issue with mechanism-denial studies is the interference from mean state changes when processes are turned off in the model. Here time-invariant forcing and nudging on effective timescales longer than the intraseasonal timescale are implemented to maintain the mean state. The MJO activity remains largely unchanged with suppressed extratropical and circumnavigating waves when the mean state is maintained to be close to that of the control run, suggesting that excitation of MJO by extratropical and circumnavigating waves is not necessary for the existence of MJO in this model. It is also shown that the wind-evaporation feedback slows down eastward propagation of the MJO, and the radiative-convective feedback amplifies the MJO.

  14. Directed networks' different link formation mechanisms causing degree distribution distinction

    Science.gov (United States)

    Behfar, Stefan Kambiz; Turkina, Ekaterina; Cohendet, Patrick; Burger-Helmchen, Thierry

    2016-11-01

    Within undirected networks, scientists have shown much interest in presenting power-law features. For instance, Barabási and Albert (1999) claimed that a common property of many large networks is that vertex connectivity follows scale-free power-law distribution, and in another study Barabási et al. (2002) showed power law evolution in the social network of scientific collaboration. At the same time, Jiang et al. (2011) discussed deviation from power-law distribution; others indicated that size effect (Bagrow et al., 2008), information filtering mechanism (Mossa et al., 2002), and birth and death process (Shi et al., 2005) could account for this deviation. Within directed networks, many authors have considered that outlinks follow a similar mechanism of creation as inlinks' (Faloutsos et al., 1999; Krapivsky et al., 2001; Tanimoto, 2009) with link creation rate being the linear function of node degree, resulting in a power-law shape for both indegree and outdegree distribution. Some other authors have made an assumption that directed networks, such as scientific collaboration or citation, behave as undirected, resulting in a power-law degree distribution accordingly (Barabási et al., 2002). At the same time, we claim (1) Outlinks feature different degree distributions than inlinks; where different link formation mechanisms cause the distribution distinctions, (2) in/outdegree distribution distinction holds for different levels of system decomposition; therefore this distribution distinction is a property of directed networks. First, we emphasize in/outlink formation mechanisms as causal factors for distinction between indegree and outdegree distributions (where this distinction has already been noticed in Barker et al. (2010) and Baxter et al. (2006)) within a sample network of OSS projects as well as Java software corpus as a network. Second, we analyze whether this distribution distinction holds for different levels of system decomposition: open

  15. RNA interference gene therapy in dominant retinitis pigmentosa and cone-rod dystrophy mouse models caused by GCAP1 mutations

    Directory of Open Access Journals (Sweden)

    Li eJiang

    2014-04-01

    Full Text Available RNA interference (RNAi knockdown is an efficacious therapeutic strategy for silencing genes causative for dominant retinal dystrophies. To test this, we used self-complementary (sc AAV2/8 vector to develop an RNAi-based therapy in two dominant retinal degeneration mouse models. The allele-specific model expresses transgenic bovine GCAP1(Y99C establishing a rapid RP-like phenotype, whereas the nonallele-specific model expresses mouse GCAP1(L151F producing a slowly progressing cone/rod dystrophy (CORD. The late onset GCAP1(L151F-CORD mimics the dystrophy observed in human GCAP1-CORD patients. Subretinal injection of scAAV2/8 carrying shRNA expression cassettes specific for bovine or mouse GCAP1 showed strong expression at one week post-injection. In both allele-specific (GCAP1(Y99C-RP and nonallele-specific (GCAP1(L151F-CORD models of dominant retinal dystrophy, RNAi-mediated gene silencing enhanced photoreceptor survival, delayed onset of degeneration and improved visual function. Such results provide a proof of concept toward effective RNAi-based gene therapy mediated by scAAV2/8 for dominant retinal disease based on GCAP1 mutation. Further, nonallele-specific RNAi knockdown of GCAP1 may prove generally applicable toward the rescue of any human GCAP1-based dominant cone-rod dystrophy.

  16. The mechanism by which fish antifreeze proteins cause thermal hysteresis.

    Science.gov (United States)

    Kristiansen, Erlend; Zachariassen, Karl Erik

    2005-12-01

    Antifreeze proteins are characterised by their ability to prevent ice from growing upon cooling below the bulk melting point. This displacement of the freezing temperature of ice is limited and at a sufficiently low temperature a rapid ice growth takes place. The separation of the melting and freezing temperature is usually referred to as thermal hysteresis, and the temperature of ice growth is referred to as the hysteresis freezing point. The hysteresis is supposed to be the result of an adsorption of antifreeze proteins to the crystal surface. This causes the ice to grow as convex surface regions between adjacent adsorbed antifreeze proteins, thus lowering the temperature at which the crystal can visibly expand. The model requires that the antifreeze proteins are irreversibly adsorbed onto the ice surface within the hysteresis gap. This presupposition is apparently in conflict with several characteristic features of the phenomenon; the absence of superheating of ice in the presence of antifreeze proteins, the dependence of the hysteresis activity on the concentration of antifreeze proteins and the different capacities of different types of antifreeze proteins to cause thermal hysteresis at equimolar concentrations. In addition, there are structural obstacles that apparently would preclude irreversible adsorption of the antifreeze proteins to the ice surface; the bond strength necessary for irreversible adsorption and the absence of a clearly defined surface to which the antifreeze proteins may adsorb. This article deals with these apparent conflicts between the prevailing theory and the empirical observations. We first review the mechanism of thermal hysteresis with some modifications: we explain the hysteresis as a result of vapour pressure equilibrium between the ice surface and the ambient fluid fraction within the hysteresis gap due to a pressure build-up within the convex growth zones, and the ice growth as the result of an ice surface nucleation event at

  17. Promoter competition as a mechanism of transcriptional interference mediated by retrotransposons

    OpenAIRE

    Conte, Caroline; Dastugue, Bernard; Vaury, Chantal

    2002-01-01

    Enhancers can function over great distances and interact with almost any kind of promoter, but insulators or promoter competition generally limit their effect to a single gene. We provide in vivo evidence that retroelements may establish promoter competition with their neighboring genes and restrict the range of action of an enhancer. We report that the retroelement Idefix from Drosophila melanogaster inhibits white gene expression in testes by a promoter competition mechanism that does not o...

  18. Robot Vibrations Caused by Torque Ripples in Power Transmission Mechanisms

    OpenAIRE

    小島, 宏行; 田口, 和哉; 辻, 浩明

    1989-01-01

    When an industrial robot with a power transmission mechanism such as a harmonic drive gear is operated, vibrations resulting from the torque ripple of the power transmission mechanism are frequently generated. However, few studies on robot vibration characteristics owing to torque ripples have been reported. In this paper, the vibrations of a horizontal two-link robot are investigated with consideration given to the torque ripple and the nonlinearity of the power transmission mechanism. In th...

  19. MECHANISMS IN ENDOCRINOLOGY: Novel genetic causes of short stature.

    Science.gov (United States)

    Wit, Jan M; Oostdijk, Wilma; Losekoot, Monique; van Duyvenvoorde, Hermine A; Ruivenkamp, Claudia A L; Kant, Sarina G

    2016-04-01

    The fast technological development, particularly single nucleotide polymorphism array, array-comparative genomic hybridization, and whole exome sequencing, has led to the discovery of many novel genetic causes of growth failure. In this review we discuss a selection of these, according to a diagnostic classification centred on the epiphyseal growth plate. We successively discuss disorders in hormone signalling, paracrine factors, matrix molecules, intracellular pathways, and fundamental cellular processes, followed by chromosomal aberrations including copy number variants (CNVs) and imprinting disorders associated with short stature. Many novel causes of GH deficiency (GHD) as part of combined pituitary hormone deficiency have been uncovered. The most frequent genetic causes of isolated GHD are GH1 and GHRHR defects, but several novel causes have recently been found, such as GHSR, RNPC3, and IFT172 mutations. Besides well-defined causes of GH insensitivity (GHR, STAT5B, IGFALS, IGF1 defects), disorders of NFκB signalling, STAT3 and IGF2 have recently been discovered. Heterozygous IGF1R defects are a relatively frequent cause of prenatal and postnatal growth retardation. TRHA mutations cause a syndromic form of short stature with elevated T3/T4 ratio. Disorders of signalling of various paracrine factors (FGFs, BMPs, WNTs, PTHrP/IHH, and CNP/NPR2) or genetic defects affecting cartilage extracellular matrix usually cause disproportionate short stature. Heterozygous NPR2 or SHOX defects may be found in ∼3% of short children, and also rasopathies (e.g., Noonan syndrome) can be found in children without clear syndromic appearance. Numerous other syndromes associated with short stature are caused by genetic defects in fundamental cellular processes, chromosomal abnormalities, CNVs, and imprinting disorders.

  20. The RNA-mediated, asymmetric ring regulatory mechanism of the transcription termination Rho helicase decrypted by time-resolved nucleotide analog interference probing (trNAIP).

    Science.gov (United States)

    Soares, Emilie; Schwartz, Annie; Nollmann, Marcello; Margeat, Emmanuel; Boudvillain, Marc

    2014-08-01

    Rho is a ring-shaped, ATP-dependent RNA helicase/translocase that dissociates transcriptional complexes in bacteria. How RNA recognition is coupled to ATP hydrolysis and translocation in Rho is unclear. Here, we develop and use a new combinatorial approach, called time-resolved Nucleotide Analog Interference Probing (trNAIP), to unmask RNA molecular determinants of catalytic Rho function. We identify a regulatory step in the translocation cycle involving recruitment of the 2'-hydroxyl group of the incoming 3'-RNA nucleotide by a Rho subunit. We propose that this step arises from the intrinsic weakness of one of the subunit interfaces caused by asymmetric, split-ring arrangement of primary RNA tethers around the Rho hexamer. Translocation is at highest stake every seventh nucleotide when the weak interface engages the incoming 3'-RNA nucleotide or breaks, depending on RNA threading constraints in the Rho pore. This substrate-governed, 'test to run' iterative mechanism offers a new perspective on how a ring-translocase may function or be regulated. It also illustrates the interest and versatility of the new trNAIP methodology to unveil the molecular mechanisms of complex RNA-based systems.

  1. Septin 9 interacts with kinesin KIF17 and interferes with the mechanism of NMDA receptor cargo binding and transport.

    Science.gov (United States)

    Bai, Xiaobo; Karasmanis, Eva P; Spiliotis, Elias T

    2016-03-15

    Intracellular transport involves the regulation of microtubule motor interactions with cargo, but the underlying mechanisms are not well understood. Septins are membrane- and microtubule-binding proteins that assemble into filamentous, scaffold-like structures. Septins are implicated in microtubule-dependent transport, but their roles are unknown. Here we describe a novel interaction between KIF17, a kinesin 2 family motor, and septin 9 (SEPT9). We show that SEPT9 associates directly with the C-terminal tail of KIF17 and interacts preferentially with the extended cargo-binding conformation of KIF17. In developing rat hippocampal neurons, SEPT9 partially colocalizes and comigrates with KIF17. We show that SEPT9 interacts with the KIF17 tail domain that associates with mLin-10/Mint1, a cargo adaptor/scaffold protein, which underlies the mechanism of KIF17 binding to the NMDA receptor subunit 2B (NR2B). Significantly, SEPT9 interferes with binding of the PDZ1 domain of mLin-10/Mint1 to KIF17 and thereby down-regulates NR2B transport into the dendrites of hippocampal neurons. Measurements of KIF17 motility in live neurons show that SEPT9 does not affect the microtubule-dependent motility of KIF17. These results provide the first evidence of an interaction between septins and a nonmitotic kinesin and suggest that SEPT9 modulates the interactions of KIF17 with membrane cargo.

  2. Maternal antibodies: clinical significance, mechanism of interference with immune responses, and possible vaccination strategies

    Directory of Open Access Journals (Sweden)

    Stefan eNiewiesk

    2014-09-01

    Full Text Available Neonates have an immature immune system which cannot adequately protect against infectious diseases. Early in life, immune protection is accomplished by maternal antibodies transferred from mother to offspring. However, decaying maternal antibodies inhibit vaccination as is examplified by the inhibition of seroconversion after measles vaccination. This phenomenon has been described in both human and veterinary medicine and is independent of the type of vaccine being used. This review will discuss the use of animal models for vaccine research. I will review clinical solutions for inhibition of vaccination by maternal antibodies, and the testing and development of potentially effective vaccines. These are based on new mechanistic insight about the inhibitory mechanism of maternal antibodies. Maternal antibodies inhibit the generation of antibodies whereas the T cell response is usually unaffected. B cell inhibition is mediated through a cross-link between B-cell receptor (BCR with the Fcg receptor IIB (FcgRIIB by a vaccine-antibody complex. In animal experiments, this inhibition can be partially overcome by injection of a vaccine-specific monoclonal IgM antibody. IgM stimulates the B-cell directly through cross-linking the BCR via complement protein C3d and antigen to the complement receptor 2 (CR2 signaling complex. In addition, it was shown that interferon alpha binds to the CD21 chain of CR2 as well as the interferon receptor and that this dual receptor usage drives B cell responses in the presence of maternal antibodies. In lieu of immunizing the infant the concept of maternal immunization as a strategy to protect neonates has been proposed. This approach would still not solve the question of how to immunize in the presence of maternal antibodies but would defer the time of infection to an age where infection might not have such a detrimental outcome as in neonates. I will review successful examples and potential challenges of implementing

  3. RNA interference of WdFKS1 mRNA expression causes slowed growth, incomplete septation and loss of cell wall integrity in yeast cells of the polymorphic, pathogenic fungus Wangiella (Exophiala) dermatitidis.

    Science.gov (United States)

    Guo, Pengfei; Szaniszlo, Paul J

    2011-11-01

    As one of the main components of the fungal cell wall, β-1,3-glucan provides the mechanical strength to protect fungal protoplasts. The enzyme responsible for the synthesis of β-1,3-glucans in fungi is β-1,3-glucan synthase. Here we report the cloning, sequencing and characterization of the WdFKS1 gene, which in the pathogenic fungus Wangiella dermatitidis encodes the catalytic domain of its β-1, 3-glucan synthase. Because our research suggested that WdFKS1 is a single copy essential gene, we used RNA interference to reduce its expression. Reduction of the WdFKS1 messenger retarded growth and caused the loss of cell wall integrity of yeast cells, but not hyphae or sclerotic cells. We suggest that the WdFKS1 in this polymorphic agent of phaeohyphomycosis is not only required for cell wall construction and maintenance, but also is involved in septum formation.

  4. The Mechanisms of the Ecdysone Pulses that Cause Metamorphosis

    DEFF Research Database (Denmark)

    Møller, Morten Erik

    Maturation in both mammals and insects is caused by pulses of steroid hormones released from glands in response to a brain-derived signal. The timing of this developmental transition is secured by the integration of many developmental cues, such as size, external environment and nutritional...... condition, with hardwired genetic programs. In holometabolous insects, pulses of the steroid hormone ecdysone cause the transition between the larval stages and the initiation of the metamorphosis, which transforms the juvenile larva to a sexually mature adult. Ecdysone is produced in the prothoracic gland...

  5. Upregulated Op18/stathmin activity causes chromosomal instability through a mechanism that evades the spindle assembly checkpoint

    Energy Technology Data Exchange (ETDEWEB)

    Holmfeldt, Per; Sellin, Mikael E. [Department of Molecular Biology, Umea University, SE-901 87 Umea (Sweden); Gullberg, Martin, E-mail: Martin.Gullberg@molbiol.umu.se [Department of Molecular Biology, Umea University, SE-901 87 Umea (Sweden)

    2010-07-15

    Op18/stathmin (Op18) is a microtubule-destabilizing protein that is phosphorylation-inactivated during mitosis and its normal function is to govern tubulin subunit partitioning during interphase. Human tumors frequently overexpress Op18 and a tumor-associated Q18{yields}E mutation has been identified that confers hyperactivity, destabilizes spindle microtubules, and causes mitotic aberrancies, polyploidization, and chromosome loss in K562 leukemia cells. Here we determined whether wild-type and mutant Op18 have the potential to cause chromosomal instability by some means other than interference with spindle assembly, and thereby bypassing the spindle assembly checkpoint. Our approach was based on Op18 derivatives with distinct temporal order of activity during mitosis, conferred either by differential phosphorylation inactivation or by anaphase-specific degradation through fusion with the destruction box of cyclin B1. We present evidence that excessive Op18 activity generates chromosomal instability through interference occurring subsequent to the metaphase-to-anaphase transition, which reduces the fidelity of chromosome segregation to spindle poles during anaphase. Similar to uncorrected merotelic attachment, this mechanism evades detection by the spindle assembly checkpoint and thus provides an additional route to chromosomal instability.

  6. The Mechanisms of the Ecdysone Pulses that Cause Metamorphosis

    DEFF Research Database (Denmark)

    Møller, Morten Erik

    Maturation in both mammals and insects is caused by pulses of steroid hormones released from glands in response to a brain-derived signal. The timing of this developmental transition is secured by the integration of many developmental cues, such as size, external environment and nutritional...... condition, with hardwired genetic programs. In holometabolous insects, pulses of the steroid hormone ecdysone cause the transition between the larval stages and the initiation of the metamorphosis, which transforms the juvenile larva to a sexually mature adult. Ecdysone is produced in the prothoracic gland...... elucidated, many questions of how the system is regulated remain unknown. The first part of the thesis focuses on a genome-wide in-vivo RNAi screen, where 90 % of the protein coding genes in Drosophila were knocked down tissue-specifically in the cells of the PG. 15.2% of the genes led to developmental...

  7. Voltage hysteresis of lithium ion batteries caused by mechanical stress.

    Science.gov (United States)

    Lu, Bo; Song, Yicheng; Zhang, Qinglin; Pan, Jie; Cheng, Yang-Tse; Zhang, Junqian

    2016-02-14

    The crucial role of mechanical stress in voltage hysteresis of lithium ion batteries in charge-discharge cycles is investigated theoretically and experimentally. A modified Butler-Volmer equation of electrochemical kinetics is proposed to account for the influence of mechanical stresses on electrochemical reactions in lithium ion battery electrodes. It is found that the compressive stress in the surface layer of active materials impedes lithium intercalation, and therefore, an extra electrical overpotential is needed to overcome the reaction barrier induced by the stress. The theoretical formulation has produced a linear dependence of the height of voltage hysteresis on the hydrostatic stress difference between lithiation and delithiation, under both open-circuit conditions and galvanostatic operation. Predictions of the electrical overpotential from theoretical equations agree well with the experimental data for thin film silicon electrodes.

  8. Altered cupular mechanics: a cause of peripheral vestibular disorders?

    Science.gov (United States)

    Helling, Kai; Watanabe, Nobuhiro; Jijiwa, Hiroyasu; Mizuno, Yoshio; Watanabe, Satoru; Scherer, Hans

    2002-06-01

    It has taken many decades to arrive at today's concept of cupula mechanics in the stimulation of endolymphatic flows on the hair cells in the ampullae of the semicircular canal. While Steinhausen assumed free swing-door movement of the cupula in the 1930s, Hillman was the first to demonstrate firm cupula attachment to the ampulla wall as a physiological necessity in the 1970s. In contrast to the present clinical concepts of acute peripheral vestibular functional disorders (circulatory disturbances, viral or bacterial infection, altered electrolytes in the endolymph), this study examines the extent to which an impaired attachment mechanism can trigger peripheral vestibular disorders. For this purpose, we used a pigeon model (n = 8), in which mechanical detachment of the cupula from the ampulla wall was achieved by means of a targeted pressure increase in the ampulla of the lateral semicircular canal. In two additional animals the labyrinth was completely destroyed on one side in order to directly compare partial and complete vestibular disorders. In this way partial damage to the lateral semicircular canal ampulla presents a clinical picture whose symptoms are very similar to those of an idiopathic vestibular disorder in humans. Their intensity and course of compensation differ markedly from the symptoms of complete vestibular destruction. Subsequent histological examination revealed that the hair cells remained intact during the experimental detachment of the cupula. Our results thus show that only altered cupula mechanics seem to trigger the clinical picture of a peripheral vestibular disorder. This may result in completely new approaches to differential diagnosis and the therapy of vestibular neuronitis.

  9. Knockdown of RNA Interference Pathway Genes in Western Corn Rootworms (Diabrotica virgifera virgifera Le Conte Demonstrates a Possible Mechanism of Resistance to Lethal dsRNA.

    Directory of Open Access Journals (Sweden)

    Ana María Vélez

    Full Text Available RNA interference (RNAi is being developed as a potential tool for insect pest management. Increased understanding of the RNAi pathway in target insect pests will provide information to use this technology effectively and to inform decisions related to resistant management strategies for RNAi based traits. Dicer 2 (Dcr2, an endonuclease responsible for formation of small interfering RNA's and Argonaute 2 (Ago2, an essential catalytic component of the RNA-induced silencing complex (RISC have both been associated with the RNAi pathway in a number of different insect species including the western corn rootworm, Diabrotica virgifera virgifera (Coleoptera: Chrysomelidae. We identified both genes from a transcriptome library generated from different tissues and developmental stages of the western corn rootworm, an important target pest for transgenic plants expressing dsRNA targeting essential genes. The expression of these genes was suppressed by more than 90% after injecting gene specific dsRNA into adult rootworms. The injected beetles were then fed vATPase A dsRNA which has previously been demonstrated to cause mortality in western corn rootworm adults. The suppression of both RNAi pathway genes resulted in reduced mortality after subsequent exposure to lethal concentrations of vATPase A dsRNA as well as increased vATPase A expression relative to control treatments. Injections with dsRNA for a non-lethal target sequence (Laccase 2 did not affect mortality or expression caused by vATPase A dsRNA indicating that the results observed with Argo and Dicer dsRNA were not caused by simple competition among different dsRNA's. These results confirm that both genes play an important role in the RNAi pathway for western corn rootworms and indicate that selection pressures that potentially affect the expression of these genes may provide a basis for future studies to understand potential mechanisms of resistance.

  10. Adult Scheuermann’s disease as cause of mechanic dorsalgia

    Directory of Open Access Journals (Sweden)

    F.P. Cantatore

    2011-09-01

    Full Text Available Scheuermann’s disease (SD or vertebral osteochondrosis is the most frequent cause of non postural kyphosis and one of more frequent cause of adolescent’s dorsalgia. The criteria for the diagnosis are: more than 5° of wedging of at least three adjacent vertebrae at the apex of the kyphosis; a toracic kyphosis of more than 45° of Cobb’s degree; Schmorl’s nodes and endplates irregularities. In addition to classic SD, there are radiological alterations that remain asintomatic for a long time to reveal in adult age: in that case it speaks of adult Scheuermann’s disease (ASD. We considered the diagnosis of patients came from April 2006 to April 2007 on Day Hospital in our Clinic. ASD was diagnosed, besides, in 10 of these patients. 7 patients had previous diagnosis such as: dorsal Spondiloarthrosis (4 subjects; Osteoporosis with vertebral fractures (3 subjects. All these diagnosis was not confirmed by us. In case of chronic dorsalgia of adult, ASD is rarely considered as differential diagnosis. Besides, the vertebral dorsalgia, even in absence of red flags as fever, astenia, ipersedimetry, functional loss and aching spinal processes to tapping, could hide a serious scene that lead us to be careful in the differential diagnosis, because of similar radiological pictures of the MSA to other pathology as spondylodiscitis, primitive or metastasic spinal tumors, and brittleness vertebral fractures

  11. A review of adaptive mechanisms in cell responses towards oxidative stress caused by dental resin monomers.

    Science.gov (United States)

    Krifka, Stephanie; Spagnuolo, Gianrico; Schmalz, Gottfried; Schweikl, Helmut

    2013-06-01

    Dental composite resins are biomaterials commonly used to aesthetically restore the structure and function of teeth impaired by caries, erosion, or fracture. Residual monomers released from resin restorations as a result of incomplete polymerization processes interact with living oral tissues. Monomers like triethylene glycol dimethacrylate (TEGDMA) or 2-hydroxylethyl methacrylate (HEMA) are cytotoxic via apoptosis, induce genotoxic effects, and delay the cell cycle. Monomers also influence the response of cells of the innate immune system, inhibit specific odontoblast cell functions, or delay the odontogenic differentiation and mineralization processes in pulp-derived cells including stem cells. These observations indicate that resin monomers act as environmental stressors which inevitably disturb regulatory cellular networks through interference with signal transduction pathways. We hypothesize that an understanding of the cellular mechanisms underlying these phenomena will provide a better estimation of the consequences associated with dental therapy using composite materials, and lead to innovative therapeutic strategies and improved materials being used at tissue interfaces within the oral cavity. Current findings strongly suggest that monomers enhance the formation of reactive oxygen species (ROS), which is most likely the cause of biological reactions activated by dental composites and resin monomers. The aim of the present review manuscript is to discuss adaptive cell responses to oxidative stress caused by monomers. The particular significance of a tightly controlled network of non-enzymatic as well as enzymatic antioxidants for the regulation of cellular redox homeostasis and antioxidant defense in monomer-exposed cells will be addressed. The expression of ROS-metabolizing antioxidant enzymes like superoxide dismutase (SOD1), glutathione peroxidase (GPx1/2), and catalase in cells exposed to monomers will be discussed with particular emphasis on the role

  12. Bactericidal Immunity to Salmonella in Africans and Mechanisms Causing Its Failure in HIV Infection.

    Science.gov (United States)

    Goh, Yun Shan; Necchi, Francesca; O'Shaughnessy, Colette M; Micoli, Francesca; Gavini, Massimiliano; Young, Stephen P; Msefula, Chisomo L; Gondwe, Esther N; Mandala, Wilson L; Gordon, Melita A; Saul, Allan J; MacLennan, Calman A

    2016-04-01

    Nontyphoidal strains of Salmonella are a leading cause of death among HIV-infected Africans. Antibody-induced complement-mediated killing protects healthy Africans against Salmonella, but increased levels of anti-lipopolysaccharide (LPS) antibodies in some HIV-infected African adults block this killing. The objective was to understand how these high levels of anti-LPS antibodies interfere with the killing of Salmonella. Sera and affinity-purified antibodies from African HIV-infected adults that failed to kill invasive S. Typhimurium D23580 were compared to sera from HIV-uninfected and HIV-infected subjects with bactericidal activity. The failure of sera from certain HIV-infected subjects to kill Salmonella was found to be due to an inherent inhibitory effect of anti-LPS antibodies. This inhibition was concentration-dependent and strongly associated with IgA and IgG2 anti-LPS antibodies (peffect of high concentrations of anti-LPS antibodies is seen with IgM as well as IgG and IgA. No correlation was found between affinity or avidity, or complement deposition or consumption, and inhibition of killing. IgG and IgM classes of anti-S. Typhimurium LPS antibodies from HIV-infected and HIV-uninfected individuals are bactericidal, while at very high concentrations, anti-LPS antibodies of all classes inhibit in vitro killing of Salmonella. This could be due to a variety of mechanisms relating to the poor ability of IgA and IgG2 to activate complement, and deposition of complement at sites where it cannot insert in the bacterial membrane. Vaccine trials are required to understand the significance of lack of in vitro killing by anti-LPS antibodies from a minority of HIV-infected individuals with impaired immune homeostasis.

  13. [Carbamylation of proteins--mechanism, causes and consequences].

    Science.gov (United States)

    Pieniążek, Anna; Gwoździński, Krzysztof

    2016-05-16

    Carbamylation (carbamoylation) is a post-translational modification resulting from the nonenzymatic reaction between isocyanic acid and free functional groups of proteins, in particular with the free amino groups. This reaction alters structural and functional properties of proteins and results in faster aging of proteins. Urea present in the body can be transformed into cyanate and its more reactive form, isocyanic acid. High concentration of urea is associated with some diseases, especially with chronic renal failure and atherosclerosis. In human tissues, urea and cyanate are in equilibrium in aqueous solutions. Surprisingly, concentration of isocyanate in the body is much lower than it would appear from the kinetic parameters of urea decomposition. The low concentration of isocyanic acid results from its high reactivity and short half-life. In this review we describe the biochemical mechanism of carbamylation of proteins and free amino acids. We summarize the literature data for carbamylation of hemoglobin, lipoproteins, albumin, membrane proteins and erythropoietin in chronic renal failure. In summary, the carbamylation of proteins may have a negative impact on their biological activity and may contribute to the deterioration of patients with chronic renal failure.

  14. Molecular mechanisms by which HERV-K Gag interferes with HIV-1 Gag assembly and particle infectivity.

    Science.gov (United States)

    Monde, Kazuaki; Terasawa, Hiromi; Nakano, Yusuke; Soheilian, Ferri; Nagashima, Kunio; Maeda, Yosuke; Ono, Akira

    2017-04-26

    Human endogenous retroviruses (HERVs), the remnants of ancient retroviral infections, constitute approximately 8% of human genomic DNA. Since HERV-K Gag expression is induced by HIV-1 Tat in T cells, induced HERV-K proteins could affect HIV-1 replication. Indeed, previously we showed that HERV-K Gag and HIV-1 Gag coassemble and that this appears to correlate with the effect of HERV-K Gag expression on HIV-1 particle release and its infectivity. We further showed that coassembly requires both MA and NC domains, which presumably serve as scaffolding for Gag via their abilities to bind membrane and RNA, respectively. Notably, however, despite possessing these abilities, MLV Gag failed to coassemble with HIV-1 Gag and did not affect assembly and infectivity of HIV-1 particles. It is unclear how the specificity of coassembly is determined. Here, we showed that coexpression of HERV-K Gag with HIV-1 Gag changed size and morphology of progeny HIV-1 particles and severely diminished infectivity of such progeny viruses. We further compared HERV-K-MLV chimeric constructs to identify molecular determinants for coassembly specificity and for inhibition of HIV-1 release efficiency and infectivity. We found that the CA N-terminal domain (NTD) of HERV-K Gag is important for the reduction of the HIV-1 release efficiency, whereas both CA-NTD and major homology region of HERV-K Gag contribute to colocalization with HIV-1 Gag. Interestingly, these regions of HERV-K Gag were not required for reduction of progeny HIV-1 infectivity. Our results showed that HERV-K Gag CA is important for reduction of HIV-1 release and infectivity but the different regions within CA are involved in the effects on the HIV-1 release and infectivity. Altogether, these findings revealed that HERV-K Gag interferes the HIV-1 replication by two distinct molecular mechanisms.

  15. RNA interference in Lepidoptera

    DEFF Research Database (Denmark)

    Terenius, Ole; Papanicolaou, Alexie; Garbutt, Jennie S.

    2011-01-01

    Gene silencing through RNA interference (RNAi) has revolutionized the study of gene function, particularly in non-model insects. However, in Lepidoptera (moths and butterflies) RNAi has many times proven to be difficult to achieve. Most of the negative results have been anecdotal and the positive...... is particularly successful in the family Saturniidae and in genes involved in immunity. On the contrary, gene expression in epidermal tissues seems to be most difficult to silence. In addition, gene silencing by feeding dsRNA requires high concentrations for success. Possible causes for the variability of success...... in RNAi experiments in Lepidoptera are discussed. The review also points to a need to further investigate the mechanism of RNAi in lepidopteran insects and its possible connection to the innate immune response. Our general understanding of RNAi in Lepidoptera will be further aided in the future as our...

  16. Quantum Interference in Time-Delayed Nonsequential Double Ionization

    CERN Document Server

    Maxwell, A S

    2015-01-01

    We perform a systematic analysis of quantum interference in nonsequential double ionization focusing on the recollision-excitation with subsequent ionization (RESI) mechanism, employing the strong-field approximation (SFA). We find that interference has a major influence on the shape, localization and symmetry of the correlated electron momentum distributions. In particular, the fourfold symmetry with regard to the parallel momentum components observed in previous SFA studies is broken. Two types of interference are observed and thoroughly analyzed, namely that caused by electron indistinguishability and intra-cycle events, and that stemming from different excitation channels. We find that interference is most prominent around the diagonal and anti-diagonal in the parallel-momentum plane and provide fully analytical expressions for most interference patterns encountered. We also show that this interference can be controlled by an appropriate choice of phase and excited-state geometry. This leads a to myriad o...

  17. Effects and mechanism of downregulation of COX‑2 expression by RNA interference on proliferation and apoptosis of human breast cancer MCF‑7 cells.

    Science.gov (United States)

    Han, Hui; Yang, Sheng; Lin, Shun-Guo; Xu, Chun-Sen; Han, Zhong-Hua

    2014-12-01

    The aim of the present study was to investigate the effects of RNA interference with prostaglandin-endoperoxide synthase 2 (COX‑2) gene on the proliferation and apoptosis of breast cancer MCF‑7 cells, as well as the underlying mechanism. The present study constructed the eukaryotic expression vector of the targeted COX‑2 gene, transfected the MCF‑7 cells and screened the stably expressed clone. Changes in the COX‑2 gene expression in breast cancer MCF‑7 cells prior to and following transfection were examined; the proliferation and apoptosis of MCF‑7 cells were analyzed. Furthermore, changes in the protein levels of survivin, B-cell lymphoma 2 (Bcl‑2) and Bcl-2-associated X (Bax) genes were detected. RNA interference mediated by a lentiviral expression vector significantly decreased the protein expression levels of the COX‑2 gene, and therefore, the proliferation and growth of breast cancer MCF‑7 cells was significantly suppressed and the apoptotic rate increased. Of note, the mRNA and protein expression levels of survivin and Bcl‑2 decreased, while those of Bax increased following COX-2 silencing. RNA interference markedly deactivated the COX‑2 gene, suppressed the proliferation of breast cancer MCF‑7 cells, and, to a certain extent, enhanced the induced spontaneous apoptosis, which is regulated by the Bax gene. These results provided evidence for the potential applications of RNA interference of the targeted COX‑2 gene in gene therapy for the treatment of breast cancer.

  18. Bactericidal Immunity to Salmonella in Africans and Mechanisms Causing Its Failure in HIV Infection.

    Directory of Open Access Journals (Sweden)

    Yun Shan Goh

    2016-04-01

    Full Text Available Nontyphoidal strains of Salmonella are a leading cause of death among HIV-infected Africans. Antibody-induced complement-mediated killing protects healthy Africans against Salmonella, but increased levels of anti-lipopolysaccharide (LPS antibodies in some HIV-infected African adults block this killing. The objective was to understand how these high levels of anti-LPS antibodies interfere with the killing of Salmonella.Sera and affinity-purified antibodies from African HIV-infected adults that failed to kill invasive S. Typhimurium D23580 were compared to sera from HIV-uninfected and HIV-infected subjects with bactericidal activity. The failure of sera from certain HIV-infected subjects to kill Salmonella was found to be due to an inherent inhibitory effect of anti-LPS antibodies. This inhibition was concentration-dependent and strongly associated with IgA and IgG2 anti-LPS antibodies (p<0.0001 for both. IgG anti-LPS antibodies, from sera of HIV-infected individuals that inhibit killing at high concentration, induced killing when diluted. Conversely, IgG, from sera of HIV-uninfected adults that induce killing, inhibited killing when concentrated. IgM anti-LPS antibodies from all subjects also induced Salmonella killing. Finally, the inhibitory effect of high concentrations of anti-LPS antibodies is seen with IgM as well as IgG and IgA. No correlation was found between affinity or avidity, or complement deposition or consumption, and inhibition of killing.IgG and IgM classes of anti-S. Typhimurium LPS antibodies from HIV-infected and HIV-uninfected individuals are bactericidal, while at very high concentrations, anti-LPS antibodies of all classes inhibit in vitro killing of Salmonella. This could be due to a variety of mechanisms relating to the poor ability of IgA and IgG2 to activate complement, and deposition of complement at sites where it cannot insert in the bacterial membrane. Vaccine trials are required to understand the significance of

  19. Bactericidal Immunity to Salmonella in Africans and Mechanisms Causing Its Failure in HIV Infection

    Science.gov (United States)

    Goh, Yun Shan; Necchi, Francesca; O’Shaughnessy, Colette M.; Micoli, Francesca; Gavini, Massimiliano; Young, Stephen P.; Msefula, Chisomo L.; Gondwe, Esther N.; Mandala, Wilson L.; Gordon, Melita A.; Saul, Allan J.; MacLennan, Calman A.

    2016-01-01

    Background Nontyphoidal strains of Salmonella are a leading cause of death among HIV-infected Africans. Antibody-induced complement-mediated killing protects healthy Africans against Salmonella, but increased levels of anti-lipopolysaccharide (LPS) antibodies in some HIV-infected African adults block this killing. The objective was to understand how these high levels of anti-LPS antibodies interfere with the killing of Salmonella. Methodology/Principal Findings Sera and affinity-purified antibodies from African HIV-infected adults that failed to kill invasive S. Typhimurium D23580 were compared to sera from HIV-uninfected and HIV-infected subjects with bactericidal activity. The failure of sera from certain HIV-infected subjects to kill Salmonella was found to be due to an inherent inhibitory effect of anti-LPS antibodies. This inhibition was concentration-dependent and strongly associated with IgA and IgG2 anti-LPS antibodies (p<0.0001 for both). IgG anti-LPS antibodies, from sera of HIV-infected individuals that inhibit killing at high concentration, induced killing when diluted. Conversely, IgG, from sera of HIV-uninfected adults that induce killing, inhibited killing when concentrated. IgM anti-LPS antibodies from all subjects also induced Salmonella killing. Finally, the inhibitory effect of high concentrations of anti-LPS antibodies is seen with IgM as well as IgG and IgA. No correlation was found between affinity or avidity, or complement deposition or consumption, and inhibition of killing. Conclusion/Significance IgG and IgM classes of anti-S. Typhimurium LPS antibodies from HIV-infected and HIV-uninfected individuals are bactericidal, while at very high concentrations, anti-LPS antibodies of all classes inhibit in vitro killing of Salmonella. This could be due to a variety of mechanisms relating to the poor ability of IgA and IgG2 to activate complement, and deposition of complement at sites where it cannot insert in the bacterial membrane. Vaccine trials

  20. First observation of quantum interference in the process phi -> KS KL ->pi+pi-pi+pi-: a test of quantum mechanics and CPT symmetry

    CERN Document Server

    Ambrosino, F; Antonelli, M; Bacci, C; Beltrame, P; Bencivenni, G; Bertolucci, S; Bini, C; Bloise, C; Bocchetta, S; Bocci, V; Bossi, F; Bowring, D; Branchini, P; Caloi, R; Campana, P; Capon, G; Capussela, T; Ceradini, F; Chi, S; Chiefari, G; Ciambrone, P; Conetti, S; De Lucia, E; De Santis, A; De Simone, P; De Zorzi, G; Dell'Agnello, S; Denig, A; Di Domenico, A; Di Donato, C; Di Falco, S; Di Micco, B; Doria, A; Dreucci, M; Felici, G; Ferrari, A; Ferrer, M L; Finocchiaro, G; Fiore, S; Forti, C; Franzini, P; Gatti, C; Gauzzi, P; Giovannella, S; Gorini, E; Graziani, E; Incagli, M; Kluge, W; Kulikov, V; Lacava, F; Lanfranchi, G; Lee-Franzini, J; Leone, D; Martini, M; Massarotti, P; Mei, W; Meola, S; Miscetti, S; Moulson, M; Müller, S; Murtas, F; Napolitano, M; Nguyen, F; Palutan, M; Pasqualucci, E; Passeri, A; Patera, V; Perfetto, F; Pontecorvo, L; Primavera, M; Santangelo, P; Santovetti, E; Saracino, G; Sciascia, B; Sciubba, A; Scuri, F; Sfiligoi, I; Sibidanov, A L; Spadaro, T; Testa, M; Tortora, L; Valente, P; Valeriani, B; Venanzoni, G; Veneziano, Stefano; Ventura, A; Versaci, R; Xu, G

    2006-01-01

    We present the first observation of quantum interference in the process phi -> KS KL ->pi+pi-pi+pi-. This analysis is based on data collected with the KLOE detector at the e^+e^- collider DAFNE in 2001--2002 for an integrated luminosity of about 380pb^-1. Fits to the distribution of Delta t, the difference between the two kaon decay times, allow tests of the validity of quantum mechanics and CPT symmetry. No deviations from the expectations of quantum mechanics and CPT symmetry have been observed. New or improved limits on various decoherence and CPT violation parameters have been obtained

  1. Construction accidents: identification of the main associations between causes, mechanisms and stages of the construction process.

    Science.gov (United States)

    Carrillo-Castrillo, Jesús A; Trillo-Cabello, Antonio F; Rubio-Romero, Juan C

    2017-06-01

    To identify the most frequent causes of accidents in the construction sector in order to help safety practitioners in the task of prioritizing preventive actions depending on the stage of construction. Official accident investigation reports are analysed. A causation pattern is identified with the proportion of causes in each of the different possible groups of causes. Significant associations of the types of causes with accident mechanisms and construction stages have been identified. Significant differences have been found in accident causation depending on the mechanism of the accident and the construction stage ongoing. These results should be used to prioritize preventive actions to combat the most likely causes for each accident mechanism and construction stage.

  2. Development, Integration, and Testing of a Nano-Satellite Coupling Mechanism Using Shape Memory Alloy for an Interference Joint

    Science.gov (United States)

    2012-12-01

    R, measured in Ohms) Density (g/cm3) Density (lb/in3) Tensile Yield Strength (Mpa) Tensile Yield Strength (x 106 psi) Melting Point (Deg...separation testing (not fresh unused NiTi ring samples) were measured and then matched to the six AL 7075 -T6 bushings selected to have an interference...on the bottom of the AL 7075 -T6 bushing and on top of the PC washer (Figure 45). Measurements were taken using the OMEGA HH147U data logger

  3. Slow Pain Generation Model Caused by Mechanical Stimulus Based on the Laminated Structure of Skin

    Science.gov (United States)

    Matsunaga, Nobutomo; Akayama, Seiko; Kawaji, Shigeyasu

    For design of the autonomous robot, action learning ability based on the subjective feeling pain is an important issue. In our previous researches, artificial superficial pain model caused by impact had been studied and the transmission mechanism focused on the input-output relations was proposed. However, the generation mechanism of the pain has not been considered yet. In this paper, the pain model of slow pain considering the skin dynamics is proposed. It is clarified from the FEM simulations that the strain energy density (SED) caused around the layer is related to the subjective pain level. From the experimental pain caused by quasi-static motion, the proposed pain model is evaluated.

  4. Progress in Molecular Mechanism of RNA Interference%RNA干涉分子机制研究进展

    Institute of Scientific and Technical Information of China (English)

    孙建国; 廖荣霞; 陈正堂

    2002-01-01

    RNA干涉(RNA interference,RNAi)是生物体内的一种通过双链RNA(dsRNA)来抵抗病毒入侵和抑制转座子活动的自然机制.双链RNA与同源mRNA互补结合而使特定基因失活,这一过程已经在包括拟南芥、线虫和真菌等多种模式生物中得到揭示.近来研究表明,21~25 nt的小干涉RNA(small interference RNA, siRNA)可介导哺乳动物细胞特异性基因沉默.RNAi具有高效性和高度特异性,可能成为关闭基因的新技术而在基因功能研究和疾病基因治疗中发挥重要作用.

  5. Multilocus half-tetrad analysis and centromere mapping in citrus: evidence of SDR mechanism for 2n megagametophyte production and partial chiasma interference in mandarin cv 'Fortune'.

    Science.gov (United States)

    Cuenca, J; Froelicher, Y; Aleza, P; Juárez, J; Navarro, L; Ollitrault, P

    2011-10-01

    The genetic structure of 2n gametes and, particularly, the parental heterozygosity restitution at each locus depends on the meiotic process by which they originated, with first-division restitution and second-division restitution (SDR) being the two major mechanisms. The origin of 2n gametes in citrus is still controversial, although sexual polyploidisation is widely used for triploid seedless cultivar development. In this study, we report the analysis of 2n gametes of mandarin cv 'Fortune' by genotyping 171 triploid hybrids with 35 simple sequence repeat markers. The microsatellite DNA allele counting-peak ratios method for allele-dosage evaluation proved highly efficient in segregating triploid progenies and allowed half-tetrad analysis (HTA) by inferring the 2n gamete allelic configuration. All 2n gametes arose from the female genitor. The observed maternal heterozygosity restitution varied between 10 and 82%, depending on the locus, thus SDR appears to be the mechanism underlying 2n gamete production in mandarin cv 'Fortune'. A new method to locate the centromere, based on the best fit between observed heterozygosity restitution within a linkage group and theoretical functions under either partial or no chiasmata interference hypotheses was successfully applied to linkage group II. The maximum value of heterozygosity restitution and the pattern of restitution along this linkage group would suggest there is partial chiasma interference. The implications of such a restitution mechanism for citrus breeding are discussed.

  6. Interference in motor learning - is motor interference sensory?

    DEFF Research Database (Denmark)

    Jensen, Jesper Lundbye; Petersen, Tue Hvass; Rothwell, John C

    mechanisms determine whether or not interference occurs. We hypothesised that interference requires the same neural circuits to be engaged in the two tasks and provoke competing processes of synaptic plasticity. To test this, subjects learned a ballistic ankle plantarflexion task. Early motor memory...

  7. Toponymic interferences

    Directory of Open Access Journals (Sweden)

    Marius Ilie Oros

    1985-12-01

    Full Text Available The study of linguistic interferences has been greatly extended lately. It comprises all language sections. In onomastics great attention was paid to to the study of macrotoponyms of foreign origin. I would like to mention in this respect the research concerning the toponyms of Slavic origin in Romania and Greece, the toponyms of Romance origin in Yugoslavia etc. The studies referring to the interferences in microtoponymy are more rare. These call for the collecting of all microtoponyms through inquiries made in plaees inhabited by mixed populetion from the ethnic point of view. The microtoponymy of these places off ers a very interesting material as far as the interactiong the reciprocal in.fluences of two or more toponymic systems is concerned.

  8. Phenanthrene causes ocular developmental toxicity in zebrafish embryos and the possible mechanisms involved

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Lixing [State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiamen 361005 (China); Wang, Chonggang [State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiamen 361005 (China); State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen (China); Zhang, Youyu; Wu, Meifang [State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiamen 361005 (China); Zuo, Zhenghong, E-mail: zuozhenghong@xmu.edu.cn [State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiamen 361005 (China); State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen (China)

    2013-10-15

    Highlights: • Phe exposure caused obvious morphological changes in the retina. • Phe exposure caused apoptosis and reduction of cell proliferation in the retina. • Phe causes ocular toxicity might be via the AhR/Zeb1/Mitf/Pax6 signaling pathway. • AhR is a repressor of Zeb1. -- Abstract: Recent studies show that polycyclic aromatic hydrocarbons (PAHs) may be a candidate cause of developmental defects of the retina, but the mechanism is still unclear. We evaluated the mechanism(s) underlying PAH-induced retinal development defects due to exposure to environmental concentrations of Phenanthrene (Phe) in zebrafish. We found that exposure to environmental concentrations of Phe caused obvious morphological changes, developmental retardation, apoptosis, and reduction of cell proliferation in the retina. Our results indicated that Phe could cause visual system developmental defects. Phe exposure up-regulated aryl hydrocarbon receptor (AhR) and microphthalmia-associated transcription factor (Mtif) expression, and down-regulated zinc finger E-box binding homeobox 1 (Zeb1) and paired box 6 (Pax6). Moreover, we demonstrated that AhR was a repressor of Zeb1. We propose that Phe's ocular toxicity is mediated by up-regulating AhR, which then down-regulates Zeb1, in turn inducing Mitf expression while inhibiting Pax6 expression.

  9. Interference Impacts Working Memory in Mild Cognitive Impairment

    Science.gov (United States)

    Aurtenetxe, Sara; García-Pacios, Javier; del Río, David; López, María E.; Pineda-Pardo, José A.; Marcos, Alberto; Delgado Losada, Maria L.; López-Frutos, José M.; Maestú, Fernando

    2016-01-01

    Mild cognitive impairment (MCI) is considered a transitional stage between healthy aging and dementia, specifically Alzheimer's disease (AD). The most common cognitive impairment of MCI includes episodic memory loss and difficulties in working memory (WM). Interference can deplete WM, and an optimal WM performance requires an effective control of attentional resources between the memoranda and the incoming stimuli. Difficulties in handling interference lead to forgetting. However, the interplay between interference and WM in MCI is not well-understood and needs further investigation. The current study investigated the effect of interference during a WM task in 20 MCIs and 20 healthy elder volunteers. Participants performed a delayed match-to-sample paradigm which consisted in two interference conditions, distraction and interruption, and one control condition without any interference. Results evidenced a disproportionate impact of interference on the WM performance of MCIs, mainly in the presence of interruption. These findings demonstrate that interference, and more precisely interruption, is an important proxy for memory-related deficits in MCI. Thus, the current findings reveal novel evidence regarding the causes of WM forgetting in MCI patients, associated with difficulties in the mechanisms of attentional control. PMID:27790082

  10. Interference impacts working memory in mild cognitive impairment

    Directory of Open Access Journals (Sweden)

    Sara Aurtenetxe

    2016-10-01

    Full Text Available Mild cognitive impairment (MCI is considered a transitional stage between healthy aging and dementia, specifically Alzheimer’s disease (AD. The most common cognitive impairment of MCI includes episodic memory loss and difficulties in working memory (WM. Interference can deplete WM, and an optimal WM performance requires an effective control of attentional resources between the memoranda and the incoming stimuli. Difficulties in handling interference lead to forgetting. However, the interplay between interference and WM in MCI is not well understood and needs further investigation. The current study investigated the effect of interference during a WM task in 20 MCIs and 20 healthy elder volunteers. Participants performed a delayed match-to-sample paradigm which consisted in two interference conditions, distraction and interruption, and one control condition without any interference. Results evidenced a disproportionate impact of interference on the WM performance of MCIs, mainly in the presence of interruption. These findings demonstrate that interference, and more precisely interruption, is an important proxy for memory-related deficits in MCI. Thus the current findings reveal novel evidence regarding the causes of WM forgetting in MCI patients, associated with difficulties in the mechanisms of attentional control.

  11. Fabrication and evaluation of thin layer PVDF composites using MWCNT reinforcement: Mechanical, electrical and enhanced electromagnetic interference shielding properties

    Directory of Open Access Journals (Sweden)

    B. V. Bhaskara Rao

    2016-06-01

    Full Text Available Radar X-band electromagnetic interference shielding (EMS is one of the prime requirements for any air vehicle coating; with limitations on the balance between strength and thickness of the EMS material. Nanocomposite of multiwalled-carbon-nanotubes (MWCNT has been homogeneously integrated (0 – 9 wt% with polymer, poly (vinylidene fluoride, PVDF to yield 300 micron film. The PVDF + 9 wt% MWCNT sample of density 1.41 g/cm3 show specific shielding effectiveness (SSE of 17.7 dB/(g/cm3 (99.6% EMS, with maintained hardness and improved conductivity. With multilayer stacking (900 microns of these films of density 1.37 g/cm3, the sample showed increase in SSE to 23.3 dB/(g/cm3 (99.93% EMS. Uniform dispersion of MWCNTs in the PVDF matrix gives rise to increased conductivity in the sample beyond 5 wt% MWCNT reinforcement. The results are correlated to the hardness, reflection loss, absorption loss, percolation threshold, permittivity and the conductivity data. An extremely thin film with maximum EMS property is hence proposed.

  12. Nicotine-induced upregulation of native neuronal nicotinic receptors is caused by multiple mechanisms.

    Science.gov (United States)

    Govind, Anitha P; Walsh, Heather; Green, William N

    2012-02-08

    Nicotine causes changes in brain nicotinic acetylcholine receptors (nAChRs) during smoking that initiate addiction. Nicotine-induced upregulation is the long-lasting increase in nAChR radioligand binding sites in brain resulting from exposure. The mechanisms causing upregulation are not established. Many different mechanisms have been reported with the assumption that there is a single underlying cause. Using live rat cortical neurons, we examined for the first time how exposure and withdrawal of nicotine shape the kinetics of native α4β2-containing nAChR upregulation in real time. Upregulation kinetics demonstrates that at least two different mechanisms underlie this phenomenon. First, a transient upregulation occurs that rapidly reverses, faster than nAChR degradation, and corresponds to nAChR conformational changes as assayed by conformational-dependent, subunit-specific antibodies. Second, a long-lasting process occurs correlating with increases in nAChR numbers caused by decreased proteasomal subunit degradation. Previous radioligand binding measurements to brain tissue have measured the second process and largely missed the first. We conclude that nicotine-induced upregulation is composed of multiple processes occurring at different rates with different underlying causes.

  13. Drug Resistance Mechanisms in Bacteria Causing Sexually Transmitted Diseases and Associated with Vaginosis.

    Science.gov (United States)

    Shaskolskiy, Boris; Dementieva, Ekaterina; Leinsoo, Arvo; Runina, Anastassia; Vorobyev, Denis; Plakhova, Xenia; Kubanov, Alexey; Deryabin, Dmitrii; Gryadunov, Dmitry

    2016-01-01

    Here, we review sexually transmitted diseases (STDs) caused by pathogenic bacteria and vaginal infections which result from an overgrowth of opportunistic bacterial microflora. First, we describe the STDs, the corresponding pathogens and the antimicrobials used for their treatment. In addition to the well-known diseases caused by single pathogens (i.e., syphilis, gonococcal infections, and chlamydiosis), we consider polymicrobial reproductive tract infections (especially those that are difficult to effectively clinically manage). Then, we summarize the biochemical mechanisms that lead to antimicrobial resistance and the most recent data on the emergence of drug resistance in STD pathogens and bacteria associated with vaginosis. A large amount of research performed in the last 10-15 years has shed light on the enormous diversity of mechanisms of resistance developed by bacteria. A detailed understanding of the mechanisms of antimicrobials action and the emergence of resistance is necessary to modify existing drugs and to develop new ones directed against new targets.

  14. Ultrasonic Phased Array Assessment of the Interference Fit and Leak Path of the North Anna Unit 2 Control Rod Drive Mechanism Nozzle 63 with Destructive Validation

    Energy Technology Data Exchange (ETDEWEB)

    Crawford, Susan L.; Cinson, Anthony D.; MacFarlan, Paul J.; Hanson, Brady D.; Mathews, Royce

    2012-08-01

    The objective of this investigation was to evaluate the efficacy of ultrasonic testing (UT) for primary water leak path assessments of reactor pressure vessel (RPV) upper head penetrations. Operating reactors have experienced leakage when stress corrosion cracking of nickel-based alloy penetrations allowed primary water into the annulus of the interference fit between the penetration and the low-alloy steel RPV head. In this investigation, UT leak path data were acquired for an Alloy 600 control rod drive mechanism nozzle penetration, referred to as Nozzle 63, which was removed from the North Anna Unit 2 reactor when the RPV head was replaced in 2002. In-service inspection prior to the head replacement indicated that Nozzle 63 had a probable leakage path through the interference fit region. Nozzle 63 was examined using a phased-array UT probe with a 5.0-MHz, eight-element annular array. Immersion data were acquired from the nozzle inner diameter surface. The UT data were interpreted by comparing to responses measured on a mockup penetration with known features. Following acquisition of the UT data, Nozzle 63 was destructively examined to determine if the features identified in the UT examination, including leakage paths and crystalline boric acid deposits, could be visually confirmed. Additional measurements of boric acid deposit thickness and low-alloy steel wastage were made to assess how these factors affect the UT response. The implications of these findings for interpreting UT leak path data are described.

  15. RNA Interference: A New Mechanism by Which FMRP Acts in the Normal Brain? What Can Drosophila Teach Us?

    Science.gov (United States)

    Siomi, Haruhiko; Ishizuka, Akira; Siomi, Mikiko C.

    2004-01-01

    Fragile X syndrome is the most common heritable form of mental retardation caused by loss-of-function mutations in the "FMR1" gene. The "FMR1" gene encodes an RNA-binding protein that associates with translating ribosomes and acts as a negative translational regulator. Recent work in "Drosophila melanogaster" has shown that the fly homolog of…

  16. Lamin A/C deficiency causes defective nuclear mechanics and mechanotransduction.

    Science.gov (United States)

    Lammerding, Jan; Schulze, P Christian; Takahashi, Tomosaburo; Kozlov, Serguei; Sullivan, Teresa; Kamm, Roger D; Stewart, Colin L; Lee, Richard T

    2004-02-01

    Mutations in the lamin A/C gene (LMNA) cause a variety of human diseases including Emery-Dreifuss muscular dystrophy, dilated cardiomyopathy, and Hutchinson-Gilford progeria syndrome. The tissue-specific effects of lamin mutations are unclear, in part because the function of lamin A/C is incompletely defined, but the many muscle-specific phenotypes suggest that defective lamin A/C could increase cellular mechanical sensitivity. To investigate the role of lamin A/C in mechanotransduction, we subjected lamin A/C-deficient mouse embryo fibroblasts to mechanical strain and measured nuclear mechanical properties and strain-induced signaling. We found that Lmna-/- cells have increased nuclear deformation, defective mechanotransduction, and impaired viability under mechanical strain. NF-kappaB-regulated transcription in response to mechanical or cytokine stimulation was attenuated in Lmna-/- cells despite increased transcription factor binding. Lamin A/C deficiency is thus associated with both defective nuclear mechanics and impaired mechanically activated gene transcription. These findings suggest that the tissue-specific effects of lamin A/C mutations observed in the laminopathies may arise from varying degrees of impaired nuclear mechanics and transcriptional activation.

  17. Interference of processing variables on the mechanical behavior of nano composites HDPE/clay; Interferencia das variaveis de processamento no comportamento mecanico de nanocompositos PEAD/argila

    Energy Technology Data Exchange (ETDEWEB)

    Barbosa, R. [Universidade Federal do Piaui, Teresina, PI (Brazil); Souza, D.D.; Nobrega, K.C.; Araujo, E.M.; Melo, T.J. [Universidade Federal de Campina Grande - UAEMa Campina Grande, PB (Brazil)

    2010-07-01

    Nano composites were processed using the technique of melt intercalation, starting from a concentrated polar compatibilizer / organo clay (PE-g-MA / organo clay) prepared in an internal mixer. The concentrate was incorporated into the matrix of PEAD by two methods: (I) twin screw contrarrotational extruder and (II) twin screw corrotational extruder, using two thread profiles (ROS and 2KB90), after extrusion, the specimens of the extruded composites were injection molded. The diffraction of X-ray was used to analyze the degree of expansion of the clays prepared, and the degree of exfoliation of nano composites developed. The interference of processing variables on mechanical properties was studied by the behavior of the modulus and tensile strength of nano composite systems. Observed similar behavior in the use of thread (or 2KB90 ROS) of the nano composites, with a reduction in modulus and tensile strength. (author)

  18. Body fatness as a cause of cancer: epidemiologic clues to biologic mechanisms.

    Science.gov (United States)

    Byers, Tim; Sedjo, Rebecca L

    2015-06-01

    Carrying excess body fat is a leading cause of cancer. Epidemiologic evidence gives strong clues about the mechanisms that link excess adiposity to risk for several cancer sites. For postmenopausal breast cancer and endometrial cancer, the hyper-estrogenic state that is induced by excess body fatness is the likely cause. For esophageal cancer and gallbladder cancer, chronic local inflammation induced by acid reflux and gallstones is the likely cause, and for liver cancer, local inflammation induced by hepatic fatty infiltration is the likely cause. However, for several other cancers known to be associated with excess adiposity, including cancers of the colon, pancreas, ovary, kidney, and prostate, specific causes are not known. Possible candidates include elevated systemic or local tissue inflammation induced by adiposity and effects of the elevated levels of leptin, insulin, IGFs, and depressed immune function that are seen with excess adiposity. There is growing evidence that intentional weight loss not only reduces circulating levels of cancer-associated factors but that it also reduces cancer incidence and recurrence. Better research is needed to understand the mechanisms that link excess body fat to cancer risk as well as to understand the amount of weight loss needed for substantial cancer risk reduction. Finally, as we develop better understanding of the mediators of the effects of excess body fatness on cancer risk, we should identify pharmacologic interventions that target those mediators so that they can be used to complement weight loss in order to reduce cancer risk. © 2015 Society for Endocrinology.

  19. Common Interferences in Drug Testing.

    Science.gov (United States)

    Smith, Michael P; Bluth, Martin H

    2016-12-01

    Interferences relating to laboratory toxicology testing refer to results which differ from their true value and are often encountered in the setting of a drug screen compared with confirmatory testing. Such interferences fall into two general categories; those that cause false positive results (when a drug screen is positive but confirmatory testing is negative) and those that cause false negative results (when a drug screen is negative when in reality the sample donor has ingested the tested substance). Such interferences can result from differences in laboratory testing methodology, reagent and analyte cross reactivity, limits of analyte detection, instrument resolution, reporting cutoff, sample processing, tissue type and sample adulteration among others. Awareness of the possible causes of such interferences are integral to proper laboratory result interpretation and patient management. Copyright © 2016 Elsevier Inc. All rights reserved.

  20. Mechanisms by which nutritional disorders cause reduced bone mass in adults.

    Science.gov (United States)

    Miller, Karen K

    2003-03-01

    Nutritional disorders that cause bone loss in adults include disordered eating behaviors (female athlete triad and anorexia nervosa), gastrointestinal diseases (celiac sprue, inflammatory bowel disease, and other malabsorption syndromes), alcoholism, and hypervitaminosis A. These disorders exert their effects on bone through a number of mechanisms, including estrogen deficiency. Deficiencies of anabolic hormones may also be important, including insulin-like growth factor I (IGF-I), a nutritionally regulated bone trophic factor. In addition, low weight itself is a risk factor for bone loss and decreased bone formation. Reduced calcium and vitamin D availability, with resultant secondary hyperparathyroidism, is another important mechanism of bone loss in nutritional disorders. This review discusses nutritional causes of reduced bone mass in adults and how nutritional disorders exert deleterious effects on the skeleton.

  1. Age-related differences in mechanism, cause, and location of trauma deaths

    DEFF Research Database (Denmark)

    Meisler, Rikke; Thomsen, Annemarie Bondegaard; Theilade, Peter

    2011-01-01

    BACKGROUND: Trauma death has traditionally been described as primarily occurring in young men exposed to penetrating trauma or road traffic accidents. The epidemiology of trauma fatalities in Europe may change as a result of the increasing proportion of elderly patients. The goal of this study...... was to describe age-related differences in trauma type, mechanism, cause and location of death in a well-defined European region. METHODS: We prospectively registered all trauma patients and severe burn patients in eastern Denmark over 12 consecutive months. We analyzed all trauma fatalities in our region...... regarding the trauma type, mechanism, cause and location of death. RESULTS: A total of 2923 patients were registered, of which 292 (9.9%) died within 30 days. Mortality increased with age, with a mortality of 46.1% in patients older than 80 years old. Blunt trauma was the most frequent trauma type at all...

  2. Interference and Mechanism of Dill Seed Essential Oil and Contribution of Carvone and Limonene in Preventing Sclerotinia Rot of Rapeseed.

    Science.gov (United States)

    Ma, Bingxin; Ban, Xiaoquan; Huang, Bo; He, Jingsheng; Tian, Jun; Zeng, Hong; Chen, Yuxin; Wang, Youwei

    2015-01-01

    This study aimed to evaluate the inhibitory effects of dill (Anethum graveolens L.) seed essential oil against Sclerotinia sclerotiorum and its mechanism of action. The antifungal activities of the two main constituents, namely carvone and limonene, were also measured. Mycelial growth and sclerotial germination were thoroughly inhibited by dill seed essential oil at the 1.00 μL/mL under contact condition and 0.125μL/mL air under vapor condition. Carvone also contributed more than limonene in inhibiting the growth of S. sclerotiorum. Carvone and limonene synergistically inhibited the growth of the fungus. In vivo experiments, the essential oil remarkably suppressed S. sclerotiorum, and considerable morphological alterations were observed in the hyphae and sclerotia. Inhibition of ergosterol synthesis, malate dehydrogenase, succinate dehydrogenase activities, and external medium acidification were investigated to elucidate the antifungal mechanism of the essential oil. The seed essential oil of A. graveolens can be extensively used in agriculture for preventing the oilseed crops fungal disease.

  3. Interference and Mechanism of Dill Seed Essential Oil and Contribution of Carvone and Limonene in Preventing Sclerotinia Rot of Rapeseed.

    Directory of Open Access Journals (Sweden)

    Bingxin Ma

    Full Text Available This study aimed to evaluate the inhibitory effects of dill (Anethum graveolens L. seed essential oil against Sclerotinia sclerotiorum and its mechanism of action. The antifungal activities of the two main constituents, namely carvone and limonene, were also measured. Mycelial growth and sclerotial germination were thoroughly inhibited by dill seed essential oil at the 1.00 μL/mL under contact condition and 0.125μL/mL air under vapor condition. Carvone also contributed more than limonene in inhibiting the growth of S. sclerotiorum. Carvone and limonene synergistically inhibited the growth of the fungus. In vivo experiments, the essential oil remarkably suppressed S. sclerotiorum, and considerable morphological alterations were observed in the hyphae and sclerotia. Inhibition of ergosterol synthesis, malate dehydrogenase, succinate dehydrogenase activities, and external medium acidification were investigated to elucidate the antifungal mechanism of the essential oil. The seed essential oil of A. graveolens can be extensively used in agriculture for preventing the oilseed crops fungal disease.

  4. On the mechanisms of interference between mobile phones and pacemakers: parasitic demodulation of GSM signal by the sensing amplifier

    Science.gov (United States)

    Barbaro, V.; Bartolini, P.; Calcagnini, G.; Censi, F.; Beard, B.; Ruggera, P.; Witters, D.

    2003-06-01

    The aim of this study was to investigate the mechanisms by which the radiated radiofrequency (RF) GSM (global system for mobile communication) signal may affect pacemaker (PM) function. We measured the signal at the output of the sensing amplifier of PMs with various configurations of low-pass filters. We used three versions of the same PM model: one with a block capacitor which short circuits high-frequency signals; one with a ceramic feedthrough capacitor, a hermetically sealed mechanism connecting the internal electronics to the external connection block, and one with both. The PMs had been modified to have an electrical shielded connection to the output of the sensing amplifier. For each PM, the output of the sensing amplifier was monitored under exposure to modulated and non-modulated RF signals, and to GSM signals (900 and 1800 MHz). Non-modulated RF signals did not alter the response of the PM sensing amplifier. Modulated RF signals showed that the block capacitor did not succeed in short circuiting the RF signal, which is somehow demodulated by the PM internal non-linear circuit elements. Such a demodulation phenomenon poses a critical problem because digital cellular phones use extremely low-frequency modulation (as low as 2 Hz), which can be mistaken for normal heartbeat.

  5. Mechanical overloading causes mitochondrial superoxide and SOD2 imbalance in chondrocytes resulting in cartilage degeneration.

    Science.gov (United States)

    Koike, Masato; Nojiri, Hidetoshi; Ozawa, Yusuke; Watanabe, Kenji; Muramatsu, Yuta; Kaneko, Haruka; Morikawa, Daichi; Kobayashi, Keiji; Saita, Yoshitomo; Sasho, Takahisa; Shirasawa, Takuji; Yokote, Koutaro; Kaneko, Kazuo; Shimizu, Takahiko

    2015-06-25

    Mechanical stress and aging are major risk factors of cartilage degeneration. Human studies have previously reported that oxidative damage increased, while SOD2 protein was reciprocally downregulated in osteoarthritic degenerated cartilage. However, it remains unclear whether mitochondrial superoxide imbalance in chondrocytes causes cartilage degeneration. We herein demonstrate that mechanical loading promoted mitochondrial superoxide generation and selective Sod2 downregulation in chondrocytes in vivo and that mitochondrial superoxide inducer also downregulated Sod2 expression in chondrocytes in vitro. A genetically manipulated model revealed that Sod2 deficiency in chondrocytes also resulted in mitochondrial superoxide overproduction and dysfunction, thus leading to cartilage degeneration. Intra-articular injection of a permeable antioxidant effectively suppressed the mechanical loading-induced mitochondrial superoxide generation and cartilage degeneration in mice. Our findings demonstrate that mitochondrial superoxide plays a pivotal role in the development and progression of osteoarthritis, and the mitochondrial superoxide balance may therefore be a promising target for the treatment of cartilage degeneration.

  6. Downlink Interference Alignment

    CERN Document Server

    Suh, Changho; Tse, David

    2010-01-01

    We develop an interference alignment (IA) technique for a downlink cellular system. In the uplink, IA schemes need channel-state-information exchange across base-stations of different cells, but our downlink IA technique requires feedback only within a cell. As a result, the proposed scheme can be implemented with a few changes to an existing cellular system where the feedback mechanism (within a cell) is already being considered for supporting multi-user MIMO. Not only is our proposed scheme implementable with little effort, it can in fact provide substantial gain especially when interference from a dominant interferer (base-station) is significantly stronger than the remaining interference: it is shown that in the two-isolated cell layout, our scheme provides four-fold gain in throughput performance over a standard multi-user MIMO technique. We show through simulations that our technique provides respectable gain under more realistic scenarios: it gives approximately 55% and 20% gain for a linear cell layou...

  7. Assessment of Electromagnetic Interference with Active Cardiovascular Implantable Electronic Devices (CIEDs Caused by the Qi A13 Design Wireless Charging Board

    Directory of Open Access Journals (Sweden)

    Tobias Seckler

    2015-05-01

    Full Text Available Electromagnetic interference is a concern for people wearing cardiovascular implantable electronic devices (CIEDs. The aim of this study was to assess the electromagnetic compatibility between CIEDs and the magnetic field of a common wireless charging technology. To do so the voltage induced in CIEDs by Qi A13 design magnetic fields were measured and compared with the performance limits set by ISO 14117. In order to carry this out a measuring circuit was developed which can be connected with unipolar or bipolar pacemaker leads. The measuring system was positioned at the four most common implantation sites in a torso phantom filled with physiological saline solution. The phantom was exposed by using Helmholtz coils from 5 µT to 27 µT with 111 kHz sine‑bursts or by using a Qi A13 design wireless charging board (Qi‑A13‑Board in two operating modes “power transfer” and “pinging”. With the Helmholtz coils the lowest magnetic flux density at which the performance limit was exceeded is 11 µT. With the Qi‑A13‑Board in power transfer mode 10.8% and in pinging mode 45.7% (2.2% at 10 cm distance of the performance limit were reached at maximum. In neither of the scrutinized cases, did the voltage induced by the Qi‑A13‑Board exceed the performance limits.

  8. 人为干扰机制下的MIMO系统安全容量研究%Research on secrecy capacity of MIMO system in artificial interference mechanism

    Institute of Scientific and Technical Information of China (English)

    朱耀; 朱义君; 张水莲; 程增霞

    2012-01-01

    In MIMO wiretap channel, for the problem that the secrecy capacity equals to zero while the channel of illegitimate receiver is not the degraded of the channel of legitimate receiver, two specific design algorithms which are orthogonal and null space methods of the artificial interference which only jam the illegitimate receiver are proposed to produce a positive secrecy capacity. In addition, for the constraint of message signal power and the total transmitted power, two kinds of secrecy capacity expression are presented respectively. Simulation result shows that this artificial interference mechanism can improve the secrecy capacity effectively, even though the channel of illegitimate receiver is not the degraded of the channel of legitimate receiver, it still produces a positive secrecy capacity.%在MIMO系统窃听信道中,针对当非法接收者的信道与合法接收者的信道相比是非退化信道时,安全容量为零的问题,提出两种具体的仅仅对非法接收者产生影响的人为干扰算法——零空间法和正交法,从而产生正的安全容量,并且分别给出了发射者消息信号功率受限和发射总功率受限两种情况下的安全容量表达式.仿真结果表明,人为干扰机制能够有效地改善和提高MIMO系统的安全容量,即使非法信道是非退化的信道,仍然能够产生正的安全容量.

  9. Sleep can reduce proactive interference.

    Science.gov (United States)

    Abel, Magdalena; Bäuml, Karl-Heinz T

    2014-01-01

    Sleep has repeatedly been connected to processes of memory consolidation. While extensive research indeed documents beneficial effects of sleep on memory, little is yet known about the role of sleep for interference effects in episodic memory. Although two prior studies reported sleep to reduce retroactive interference, no sleep effect has previously been found for proactive interference. Here we applied a study format differing from that employed by the prior studies to induce a high degree of proactive interference, and asked participants to encode a single list or two interfering lists of paired associates via pure study cycles. Testing occurred after 12 hours of diurnal wakefulness or nocturnal sleep. Consistent with the prior work, we found sleep in comparison to wake did not affect memory for the single list, but reduced retroactive interference. In addition we found sleep reduced proactive interference, and reduced retroactive and proactive interference to the same extent. The finding is consistent with the view that arising benefits of sleep are caused by the reactivation of memory contents during sleep, which has been suggested to strengthen and stabilise memories. Such stabilisation may make memories less susceptible to competition from interfering memories at test and thus reduce interference effects.

  10. Fluvastatin interferes with hepatitis C virus replication via microtubule bundling and a doublecortin-like kinase-mediated mechanism.

    Directory of Open Access Journals (Sweden)

    Naushad Ali

    Full Text Available Hepatitis C virus (HCV-induced alterations in lipid metabolism and cellular protein expression contribute to viral pathogenesis. The mechanism of pleiotropic actions of cholesterol-lowering drugs, statins, against HCV and multiple cancers are not well understood. We investigated effects of fluvastatin (FLV on microtubule-associated and cancer stem cell marker (CSC, doublecortin-like kinase 1 (DCLK1 during HCV-induced hepatocarcinogenesis. HCV replication models, cancer cell lines and normal human hepatocytes were used to investigate the antiviral and antitumor effects of statins. FLV treatment resulted in induction of microtubule bundling, cell-cycle arrest and alterations in cellular DCLK1 distribution in HCV-expressing hepatoma cells. These events adversely affected the survival of liver-derived tumor cells without affecting normal human hepatocytes. FLV downregulated HCV replication in cell culture where the ATP pool and cell viability were not compromised. Pravastatin did not exhibit these effects on HCV replication, microtubules and cancer cells. The levels of miR-122 that regulates liver homeostasis and provides HCV genomic stability remained at steady state whereas DCLK1 mRNA levels were considerably reduced during FLV treatment. We further demonstrated that HCV replication was increased with DCLK1 overexpression. In conclusion, unique effects of FLV on microtubules and their binding partner DCLK1 are likely to contribute to its anti-HCV and antitumor activities in addition to its known inhibitory effects on 3-hydroxy-3-methylglutary-CoA reductase (HMGCR.

  11. Developing a highly reliable cae analysis model of the mechanisms that cause bolt loosening in automobiles

    Directory of Open Access Journals (Sweden)

    Ken Hashimoto

    2014-10-01

    Full Text Available In this study, we developed a highly reliable CAE analysis model of the mechanisms that cause loosening of bolt fasteners, which has been a bottleneck in automobile development and design, using a technical element model for highly accurate CAE that we had previously developed, and verified its validity. Specifically, drawing on knowledge gained from our clarification of the mechanisms that cause loosening of bolt fasteners using actual machine tests, we conducted an accelerated bench test consisting of a threedimensional vibration load test of the loosening of bolt fasteners used in mounts and rear suspension arms, where interviews with personnel at an automaker indicated loosening was most pronounced, and reproduced actual machine tests with CAE analysis based on a technical element model for highly accurate CAE analysis. Based on these results, we were able to reproduce dynamic behavior in which larger screw pitches (lead angles lead to greater non-uniformity of surface pressure, particularly around the nut seating surface, causing loosening to occur in areas with the lowest surface pressure. Furthermore, we implemented highly accurate CAE analysis with no error (gap compared to actual machine tests.

  12. Fracture mechanism of TiAl intermetallics caused by hydride and atomic hydrogen

    Institute of Scientific and Technical Information of China (English)

    高克玮; 王燕斌; 林志; 乔利杰; 褚武扬

    1999-01-01

    Hydrogen embrittlement (HE) of TiAl intermetallics was studied at room temperature. The results showed that there were two forms of HE in TiAl intermetallics, i.e. hydride HE and atomic HE. Most of hydrogen in TiAl intermetallics was transformed into hydrides at room temperature. The hydride exists as (TiAl)Hx for a low hydrogen concentration while it exists in several forms for a higher hydrogen concentration. Stress intensity factor KIC decreased with increase in hydride concentration. KIC decreased further when TiAl intermetallics were charged cathodically with hydrogen in 1 mol/L H2SO4 solution. Stress intensity factor during hydrogen charging KIH was about 50% KIC. 20% of the decrease was caused by hydrides while 30% was caused by atomic hydrogen. Mechanism of HE caused hydrides was the same as any other second phase in nature. Delayed fracture caused by atomic hydrogen resulted from hydrogen induced local plastic deformation.

  13. Candida Infections, Causes, Targets, and Resistance Mechanisms: Traditional and Alternative Antifungal Agents

    Directory of Open Access Journals (Sweden)

    Claudia Spampinato

    2013-01-01

    Full Text Available The genus Candida includes about 200 different species, but only a few species are human opportunistic pathogens and cause infections when the host becomes debilitated or immunocompromised. Candida infections can be superficial or invasive. Superficial infections often affect the skin or mucous membranes and can be treated successfully with topical antifungal drugs. However, invasive fungal infections are often life-threatening, probably due to inefficient diagnostic methods and inappropriate initial antifungal therapies. Here, we briefly review our current knowledge of pathogenic species of the genus Candida and yeast infection causes and then focus on current antifungal drugs and resistance mechanisms. An overview of new therapeutic alternatives for the treatment of Candida infections is also provided.

  14. Mechanisms of cadmium-caused eye hypoplasia and hypopigmentation in zebrafish embryos

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Ting, E-mail: zting@webmail.hzau.edu.cn; Zhou, Xin-Ying, E-mail: 290356082@qq.com; Ma, Xu-Fa, E-mail: xufama@mail.hzau.edu.cn; Liu, Jing-Xia, E-mail: ichliu@mail.hzau.edu.cn

    2015-10-15

    Highlights: Using high-throughput in situ hybridization screening, we found that genes labeling the neural crest and its derivative pigment cells were sensitive to cadmium toxicity during zebrafish organogenesis, which might contribute to the molecular mechanisms underlying the phenotype defects of head and eye hypoplasia and hypopigmentation in cadmium-exposed embryos. Based on neural crest markers, we identified the doses and times of cadmium exposure that cause damage to the zebrafish organogenesis, and we also found that compounds BIO or RA could neutralize the toxic effects of cadmium. - Abstract: Cadmium-caused head and eye hypoplasia and hypopigmentation has been recognized for a long time, but knowledge of the underlying mechanisms is limited. In this study, we found that high mortality occurred in exposed embryos after 24 hpf, when cadmium (Cd) dosage was above 17.8 μM. Using high-throughput in situ hybridization screening, we found that genes labelling the neural crest and its derivative pigment cells exhibited obviously reduced expression in Cd-exposed embryos from 24 hpf, 2 days earlier than head and eye hypoplasia and hypopigmentation occurred. Moreover, based on expression of crestin, a neural crest marker, we found that embryos before the gastrula stage were more sensitive to cadmium toxicity and that damage caused by Cd on embryogenesis was dosage dependent. In addition, by phenotype observation and detection of neural crest and pigment cell markers, we found that BIO and retinoic acid (RA) could neutralize the toxic effects of Cd on zebrafish embryogenesis. In this study, we first determined that Cd blocked the formation of the neural crest and inhibited specification of pigment cells, which might contribute to the molecular mechanisms underlying the phenotype defects of head and eye hypoplasia and hypopigmentation in Cd-exposed embryos. Moreover, we found that compounds BIO or RA could neutralize the toxic effects of Cd.

  15. Discussion on Mechanism of Breech-Blow Caused by Propellant Charge

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    From the view point of launch safety caused by fracture of propellant charge, this paper points out that the safety criterion of pressure wave is inadequate to evaluate the launch safety of propellant charge based on the initial negative differential pressure and sensitivity tests. Generally, the maximum barrel pressure does not depend upon the intensity of pressure wave correspondingly. The pressure wave intensity can not describe the fracture degree of propellant charge in chamber and reflect the mechanical environment of propellant charge fracturing exactly and wholly. The evaluation criterion for launch safety of propellant charge should be built on the basis of depicting the fracture degree of propellant bed.

  16. Interference of a Narrowband Biphoton with Double Electromagnetically Induced Transparency in an N-Type System

    Institute of Scientific and Technical Information of China (English)

    CHEN Peng; QIAN Jun; CHEN Dong-Yuan; HU Zheng-Feng; WANG Yu-Zhu

    2012-01-01

    We predict the possibility of the interference of narrow-hand biphotons generated by spontaneous four-wave mixing with double electromagnetically induced transparency configuration in cold atoms. In an N-type four-level system, an auxiliary optical field Ωm can create double transparency windows for anti-Stokes photons. When the slow light effects in the double transparency windows are very strong, two four-wave mixing channels could exist due to the splitting of the phase matching condition. The biphoton generated from the two four-wave mixing channels can cause interference and shows Rabi oscillations in two-photon correlation. This interference mechanism will complement the understanding of interference at the two-photon level.%We predict the possibility of the interference of narrow-band biphotons generated by spontaneous four-wave mixing with double electromagnetically induced transparency configuration in cold atoms.In an N-type fourlevel system,an auxiliary optical field Ωm can create double transparency windows for anti-Stokes photons.When the slow light effects in the double transparency windows are very strong,two four-wave mixing channels could exist due to the splitting of the phase matching condition.The biphoton generated from the two four-wave mixing channels can cause interference and shows Rabi oscillations in two-photon correlation.This interference mechanism will complement the understanding of interference at the two-photon level.

  17. REM sleep rescues learning from interference.

    Science.gov (United States)

    McDevitt, Elizabeth A; Duggan, Katherine A; Mednick, Sara C

    2015-07-01

    Classical human memory studies investigating the acquisition of temporally-linked events have found that the memories for two events will interfere with each other and cause forgetting (i.e., interference; Wixted, 2004). Importantly, sleep helps consolidate memories and protect them from subsequent interference (Ellenbogen, Hulbert, Stickgold, Dinges, & Thompson-Schill, 2006). We asked whether sleep can also repair memories that have already been damaged by interference. Using a perceptual learning paradigm, we induced interference either before or after a consolidation period. We varied brain states during consolidation by comparing active wake, quiet wake, and naps with either non-rapid eye movement sleep (NREM), or both NREM and REM sleep. When interference occurred after consolidation, sleep and wake both produced learning. However, interference prior to consolidation impaired memory, with retroactive interference showing more disruption than proactive interference. Sleep rescued learning damaged by interference. Critically, only naps that contained REM sleep were able to rescue learning that was highly disrupted by retroactive interference. Furthermore, the magnitude of rescued learning was correlated with the amount of REM sleep. We demonstrate the first evidence of a process by which the brain can rescue and consolidate memories damaged by interference, and that this process requires REM sleep. We explain these results within a theoretical model that considers how interference during encoding interacts with consolidation processes to predict which memories are retained or lost.

  18. Identifying the causes of differences in ozone production from the CB05 and CBMIV chemical mechanisms

    Directory of Open Access Journals (Sweden)

    R. D. Saylor

    2012-02-01

    Full Text Available An investigation was conducted to identify the mechanistic differences between two versions of the carbon bond gas-phase chemical mechanism (CB05 and CBMIV which consistently lead to larger ground-level ozone concentrations being produced in the CB05 version of the National Air Quality Forecasting Capability (NAQFC modeling system even though the two parallel forecast systems utilize the same meteorology and base emissions and similar initial and boundary conditions. Box models of each of the mechanisms as they are implemented in the NAQFC were created and a set of 12 sensitivity simulations was designed. The sensitivity simulations independently probed the conceptual mechanistic differences between CB05 and CBMIV and were exercised over a 45-scenario simulation suite designed to emulate the wide range of chemical regimes encountered in a continental-scale atmospheric chemistry model. Results of the sensitivity simulations indicate that two sets of reactions that were included in the CB05 mechanism, but which were absent from the CBMIV mechanism, are the primary causes of the greater ozone production in the CB05 version of the NAQFC. One set of reactions recycles the higher organic peroxide species of CB05 (ROOH, resulting in additional photochemically reactive products that act to produce additional ozone in some chemical regimes. The other set of reactions recycles reactive nitrogen from less reactive forms back to NO2, increasing the effective NOx concentration of the system. In particular, the organic nitrate species (NTR, which was a terminal product for reactive nitrogen in the CBMIV mechanism, acts as a reservoir species in CB05 to redistribute NOx from major source areas to potentially NOx-sensitive areas where additional ozone may be produced in areas remote from direct NOx sources.

  19. Identifying the causes of differences in ozone production from the CB05 and CBMIV chemical mechanisms

    Directory of Open Access Journals (Sweden)

    R. D. Saylor

    2011-10-01

    Full Text Available An investigation was conducted to identify the mechanistic differences between two versions of the carbon bond gas-phase chemical mechanism (CB05 and CBMIV which consistently lead to larger ground-level ozone concentrations being produced in the CB05 version of the National Air Quality Forecasting Capability (NAQFC modeling system even though the two parallel forecast systems utilize the same meteorology and base emissions and similar initial and boundary conditions. Box models of each of the mechanisms as they are implemented in the NAQFC were created and a set of 12 sensitivity simulations was designed. The sensitivity simulations independently probed the conceptual mechanistic differences between CB05 and CBMIV and were exercised over a 45-scenario simulation suite designed to emulate the wide range of chemical regimes encountered in a continental-scale atmospheric chemistry model. Results of the sensitivity simulations indicate that two sets of reactions that were included in the CB05 mechanism, but which were absent from the CBMIV mechanism, are the primary causes of the greater ozone production in the CB05 version of the NAQFC. One set of reactions recycles the higher organic peroxide species of CB05 (ROOH, resulting in additional photochemically reactive products that act to produce additional ozone in some chemical regimes. The other set of reactions recycles reactive nitrogen from less reactive forms back to NO2, increasing the effective NOx concentration of the system. In particular, the organic nitrate species (NTR, which was a terminal product for reactive nitrogen in the CBMIV mechanism, acts as a reservoir species in CB05 to redistribute NOx from major source areas to potentially NOx-sensitive areas where additional ozone may be produced in areas remote from direct NOx sources.

  20. RNA interference and its application in plants

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    RNA interference (RNAi), a process that inhibits gene expression by the double-stranded RNA (dsRNA), causes the deg-radation of target messenger RNA molecules. RNAi exists in almost all organisms. We review the recent history of RNAi studies,RNAi molecular mechanisms, characteristics and RNAi applications in higher plants. At the same time, the prospect of RNAi appli-cations in functional genomics and genetic improvement of higher plants and possible future problems and possibilities are also dis-cussed.

  1. PHYSIOLOGICAL QUALITY OF SOYBEAN SEEDS UNDER MECHANICAL INJURIES CAUSED BY COMBINES

    Directory of Open Access Journals (Sweden)

    FÁBIO PALCZEWSKI PACHECO

    2015-01-01

    Full Text Available The mechanical harvesting causes injuries on seeds and may affect their quality. Different threshing mechanisms and their adjustments may also affect the intensity of impacts that machines cause on seeds. So, this study aimed at diagnosing and evaluating the effect of two combines: the first one with a threshing system of axial flow and the other one with a threshing system of tangential flow, under adjustments of concave opening (10 mm, 30 mm and 10 mm for a combine with axial flow and 3.0 mm, 15 mm and 3.0 mm for a combine with tangential flow and three cylinder rotations on the quality of soybean seeds harvested at two moisture contents. Soybean seeds of cultivar 'ND 4910' were harvested at 16.6% moisture (mid - morning and 13.7% moisture in the afternoon. The seeds quality was evaluated by germination tests, germination speed index (GSI, germination rate, moisture content, percentage of purity and vigor by tetrazolium test. Despite the combine, the results showed that the mechanical injury has most reduced seeds quality, at 16.6% moisture content, concave opening of 30 mm (axial and 10 mm (tangential and cylinder rotation of 1100 rpm (axial and 1000 (tangential, both with the highest rotations used. The combine with tangential flow had the highest degree of seeds purity. When seeds moisture content at harvest was close to 13.7%, there was the highest seed injury, while, at 16.6%, there was the highest number of crushed soybeans, regardless the combine adjustment.

  2. Efficacy and possible mechanisms of perillaldehyde in control of Aspergillus niger causing grape decay.

    Science.gov (United States)

    Tian, Jun; Wang, Yanzhen; Zeng, Hong; Li, Zongyun; Zhang, Peng; Tessema, Akalate; Peng, Xue

    2015-06-02

    A variety of plant products have been recognized for their antifungal activity and recently have attracted food industry attention for their efficacy in controlling postharvest fungal decay of fruits. The antifungal activity of perillaldehyde (PAE) was evaluated against Aspergillus niger, a known cause of grape spoilage, and possible mechanisms were explored. PAE showed notable antifungal activity against A. niger, with a minimum inhibitory concentration (MIC) and a minimum fungicidal concentration (MFC) of 0.25 and 1 μl/ml, respectively. The accumulation of mycelial biomass was also inhibited by PAE in a dose-dependent manner, completely inhibiting mycelial growth at 1 μl/ml. In vivo data confirmed that the vapour treatment of grapes with various concentrations of PAE markedly improved control of A. niger and suppressed natural decay. Concentrations of PAE of 0.075 μl/ml air showed the greatest inhibition of fungal growth compared to the controls. Further experiments indicated that PAE activated a membrane-active mechanism that inhibits ergosterol synthesis, increases membrane permeability (as evidenced by extracellular pH and conductivity measurements), and disrupts membrane integrity, leading to cell death. Our findings suggest that this membrane-active mechanism makes PAE a promising potential antifungal agent for postharvest control of grape spoilage.

  3. Focal mechanism caused by fracture or burst of a coal pillar

    Institute of Scientific and Technical Information of China (English)

    CAO An-ye; DOU Lin-ming; CHEN Guo-xiang; GONG Si-yuan; WANG Yu-gang; LI Zhi-hua

    2008-01-01

    As a regional, real-time and dynamic method, microseismic monitoring technology is quite an appropriate technology for forecasting geological hazards, such as rock bursts, mine tremors, coal and gas outbursts and can even be used to prevent or at least reduce these disasters. The study of the focal mechanisms of different seismic sources is the prerequisite and basis for forecasting rock burst by microseismic monitoring technology. Based on the analysis on the mechanism and fracture course of coal pillars where rock bursts occur mostly, the equivalent point source model of the seismicity caused by a coal pillar was created. Given the model, the seismic displacement equation of a coal pillar was analyzed and the seismic mechanism was pointed out by seismic wave theory. The course of the fracture of the coal pillar was simulated closely in the laboratory and the equivalent microseismic signals of the fractures of the coal pillar were acquired using a TDS-6 experimental system. The results show that, by the pressure and friction of a medium near the seismic source, both a compression wave and a shear wave will be emitted and shear fracture will be induced at the moment of breakage. The results can be used to provide an academic basis to forecast and prevent rock bursts or tremors in a coal pillar.

  4. Nonoclusive thrombosis of mechanical mitral valve prosthesis caused by inadequate treatment of anticoagulant therapy resistance

    Directory of Open Access Journals (Sweden)

    Ivanović Branislava

    2008-01-01

    Full Text Available Background. Oral anticoagulants have been used in the prevention of thromboembolic complications for over six decades. A rare, but possible problem in the application of these medications could be resistance to them. Case report. We presented a patient with nonocclusive thrombosis of the mechanical mitral prosthesis due to inadequately treated resistance to peroral anticoagulant therapy. Resistance to oral anticoagulant medications was proven by an increased dosage of warfarin up to 20 mg and, after that, acenokumarol to 15 mg over ten days which did not lead to an increase in the international normalized ratio (INR value over 1.2. On the basis of information that she did not take food rich in vitamin K or medications which could reduce effects of oral anticoagulants, and that she did not have additional illnesses and conditions that could cause an inadequate response to anticoagulant therapy, it was circumstantially concluded that this was a hereditary form of resistance. Because of the existing mechanical prosthetics on the mitral position, low molecular heparin has been introduced into the therapy. The patient reduced it on her own initiative, leading to nonocclusive valvular thrombosis. Conclusion. When associated complications like absolute arrhithmia does not exist, the finding of resistance to oral anticoagulant agents is an indication for the replacement of a mechanical prosthetic with a biological one which has been done in this patients.

  5. Rapid and reversible impairments of short- and long-term social recognition memory are caused by acute isolation of adult rats via distinct mechanisms.

    Science.gov (United States)

    Shahar-Gold, Hadar; Gur, Rotem; Wagner, Shlomo

    2013-01-01

    Mammalian social organizations require the ability to recognize and remember individual conspecifics. This social recognition memory (SRM) can be examined in rodents using their innate tendency to investigate novel conspecifics more persistently than familiar ones. Here we used the SRM paradigm to examine the influence of housing conditions on the social memory of adult rats. We found that acute social isolation caused within few days a significant impairment in acquisition of short-term SRM of male and female rats. Moreover, SRM consolidation into long-term memory was blocked following only one day of social isolation. Both impairments were reversible, but with different time courses. Furthermore, only the impairment in SRM consolidation was reversed by systemic administration of arginine-vasopressin (AVP). In contrast to SRM, object recognition memory was not affected by social isolation. We conclude that acute social isolation rapidly induces reversible changes in the brain neuronal and molecular mechanisms underlying SRM, which hamper its acquisition and completely block its consolidation. These changes occur via distinct, AVP sensitive and insensitive mechanisms. Thus, acute social isolation of rats swiftly causes changes in their brain and interferes with their normal social behavior.

  6. RNA interference-mediated repression of SmCPS (copalyldiphosphate synthase) expression in hairy roots of Salvia miltiorrhiza causes a decrease of tanshinones and sheds light on the functional role of SmCPS.

    Science.gov (United States)

    Cheng, Qiqing; Su, Ping; Hu, Yating; He, Yunfei; Gao, Wei; Huang, Luqi

    2014-02-01

    Tanshinones are a group of bioactive abietane-type norditerpenoid quinone compounds in Salvia miltiorrhiza. Copalyldiphosphate synthase of S. miltiorrhiza (SmCPS) is the first key enzyme in tanshinone biosynthesis from the universal diterpene precursor geranylgeranyl diphosphate. Hairy roots of S. miltiorrhiza were transformed with Agrobacterium rhizogenes carrying an RNA interference (RNAi) construct designed to silence SmCPS, and we examined the resulting SmCPS expression and tanshinone accumulation. In SmCPS–RNAi hairy roots, the transcript level of SmCPS was reduced to 26 % while the dihydrotanshinone I and cryptotanshinone levels were decreased by 53 and 38 % compared to those of the vector control hairy roots; tanshinone IIA was not detected. Therefore, the decreased expression of SmCPS caused a decrease in tanshinone levels which verifies that SmCPS is a key enzyme for tanshinone biosynthesis in S. miltiorrhiza.

  7. Interference Phenomena in Quantum Information

    CERN Document Server

    Stefanak, Martin

    2010-01-01

    One of the key features of quantum mechanics is the interference of probability amplitudes. The reason for the appearance of interference is mathematically very simple. It is the linear structure of the Hilbert space which is used for the description of quantum systems. In terms of physics we usually talk about the superposition principle valid for individual and composed quantum objects. So, while the source of interference is understandable it leads in fact to many counter-intuitive physical phenomena which puzzle physicists for almost hundred years. The present thesis studies interference in two seemingly disjoint fields of physics. However, both have strong links to quantum information processing and hence are related. In the first part we study the intriguing properties of quantum walks. In the second part we analyze a sophisticated application of wave packet dynamics in atoms and molecules for factorization of integers. The main body of the thesis is based on the original contributions listed separately...

  8. Human Hemorrhagic Fever Causing Arenaviruses: Molecular Mechanisms Contributing to Virus Virulence and Disease Pathogenesis

    Directory of Open Access Journals (Sweden)

    Junjie Shao

    2015-05-01

    Full Text Available Arenaviruses include multiple human pathogens ranging from the low-risk lymphocytic choriomeningitis virus (LCMV to highly virulent hemorrhagic fever (HF causing viruses such as Lassa (LASV, Junin (JUNV, Machupo (MACV, Lujo (LUJV, Sabia (SABV, Guanarito (GTOV, and Chapare (CHPV, for which there are limited preventative and therapeutic measures. Why some arenaviruses can cause virulent human infections while others cannot, even though they are isolated from the same rodent hosts, is an enigma. Recent studies have revealed several potential pathogenic mechanisms of arenaviruses, including factors that increase viral replication capacity and suppress host innate immunity, which leads to high viremia and generalized immune suppression as the hallmarks of severe and lethal arenaviral HF diseases. This review summarizes current knowledge of the roles of each of the four viral proteins and some known cellular factors in the pathogenesis of arenaviral HF as well as of some human primary cell-culture and animal models that lend themselves to studying arenavirus-induced HF disease pathogenesis. Knowledge gained from these studies can be applied towards the development of novel therapeutics and vaccines against these deadly human pathogens.

  9. Mitigation Effect of Proanthocyanidin on Secondary Heart Injury in Rats Caused by Mechanical Trauma

    Science.gov (United States)

    Ma, Shuo; Chen, Chong; Cao, Tingting; Bi, Yue; Zhou, Jicheng; Li, Xintao; Yu, Deqin; Li, Shuzhuang

    2017-01-01

    Multiple organ dysfunctional syndrome secondary to mechanical trauma (MT) has attracted considerable research attention. The heart is one of the most important organs of the body, and secondary cardiac insufficiency caused by MT seriously affects the quality of life. This study aims to investigate whether proanthocyanidin can alleviate myocardial injury and improve heart function in the process of MT leading to secondary cardiac insufficiency. Noble-Collip drum wasused to prepare MT model in rats. And myocardial apoptosis index was calculated after TUNEL staining. Ventricular intubation was employed to detect heart function. Changes in myocardial ultrastructure were observed using an electron microscope. ELISA was used to detect the content of TNF-α and reactive oxygen species generated from monocytes and cardiomyocytes. The changes in Ca2+ concentration in cardiomyocyte were observed by confocal microscope. Compared with trauma group, the administration group had a decreased apoptosis index of cardiomyocytes, and increased ±dp/dtmax. Meanwhile, proanthocyanidin can inhibit monocytes’ TNF-α production, and reduce plasma TNF-α concentration. Moreover, proanthocyanidin can attenuate the excessive oxidative stress reaction of cardiomyocyte, and inhibit calcium overload in cardiomyocytes. In conclusion, proanthocyanidin can effectively ease myocardial damage and improve cardiac function, through anti-inflammatory and antioxidant effects in secondary cardiac insufficiency caused by MT. PMID:28294148

  10. Variation in the Displacement of Base Isolation System Caused by an Uncertainty of Mechanical Properties

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Junghan; Kim, Minkyu; Choi, Inkil [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2013-05-15

    In this study, the variations of the displacement response of a simplified isolation system were evaluated. The variation of a horizontal translation displacement and the eccentricity of a system stiffness caused by the uncertainty of mechanical property of isolators are quantitatively calculated. These procedures can be used to estimate the probabilistic distribution of the responses of an isolation system efficiently. A performance-based approach was introduced in the seismic design criteria of nuclear power plants such as the ASCE 43-05. In this approach, a risk-based concept considering the probability of unacceptable performance was suggested. Therefore, it is indispensable that design variables are regarded as stochastic variables and their distributions should be estimated. In the design of a base isolation system, the displacement response of an isolator induced by an earthquake event is most important design variable. The displacement response is affected by mechanical properties of an isolator as well as an input ground motion. In this study, the several contribution factors to the displacement response of an isolation system using elastomeric lead rubber bearings (LRB) were evaluated by the simplified analysis methods.

  11. Low-frequency variability of surface air temperature over the Barents Sea: causes and mechanisms

    Science.gov (United States)

    van der Linden, Eveline C.; Bintanja, Richard; Hazeleger, Wilco; Graversen, Rune G.

    2016-08-01

    The predominant decadal to multidecadal variability in the Arctic region is a feature that is not yet well-understood. It is shown that the Barents Sea is a key region for Arctic-wide variability. This is an important topic because low-frequency changes in the ocean might lead to large variations in the sea-ice cover, which then cause massive changes in the ocean-atmosphere heat exchanges. Here we describe the mechanism driving surface temperatures and heat fluxes in the Barents Sea based primarily on analyzes of one global coupled climate model. It is found that the ocean drives the low-frequency changes in surface temperature, whereas the atmosphere compensates the oceanic transport anomalies. The seasonal dependence and the role of individual components of the ocean-atmosphere energy budget are analyzed in detail, showing that seasonally-varying climate mechanisms play an important role. Herein, sea ice is governing the seasonal response, by acting as a lid that opens and closes during warm and cold periods, respectively, thereby modulating the surface heat fluxes.

  12. The Mechanism of Russian Nanoindustry Development Caused by Globalization: Methods and Tools

    Directory of Open Access Journals (Sweden)

    Avtonomova Oksana Alekseevna

    2015-05-01

    Full Text Available Establishing the effective mechanism of the Russian nanoindustry functioning by means of globalization benefits is one of the most important factors of raising the national economy competitiveness in the context of transition to a new technological way. Nanotechnologies is one of the key factors of this new way. The mechanism of nanoindustrial development of the Russian Federation caused by globalization is characterized in the article as a way of task-oriented implementation and management of the global nanotechnology industry development on the basis of cooperation of entities at different levels of the global economic system using the appropriate methods, tools, resources and communication channels, factors and capitals. The mechanism aims at adjusting the described contradictions faced by Russian entities in their business activities in the sphere of production, consumption and promotion of nanotechnologies, nanogoods and nanoservices. Within the framework of a theoretical research the author proposes the classification of methods and tools for the development of the Russian nanoindustry through the international cooperation by the criteria of economic functions: planning, institution, organization, management, investment, finance, information, analysis, control – all aimed at promoting the unification of concepts and actions of collaborating entities in the sphere of nanotechnology. The developed methodology of the international nanoindustrial interaction of Russian entities includes the result-oriented, institutional, organizational, budgetary, investment, tax, informative, and administrative methods, as well as analysis, audit, accounting and evaluation. Besides, the article proves the feasibility of marketing tools application in the sphere of nanoindustrial cooperation aimed at developing a more efficient strategy of promoting products with nanofeatures to the global market.

  13. Channel catfish reovirus (CRV) inhibits replication of channel catfish herpesvirus (CCV) by two distinct mechanisms: viral interference and induction of an anti-viral factor.

    Science.gov (United States)

    Chinchar, V G; Logue, O; Antao, A; Chinchar, G D

    1998-06-19

    Catfish reovirus (CRV), a double stranded RNA virus, inhibited channel catfish herpes-virus (CCV) replication by 2 different mechanisms: (1) directly as a consequence of its own replication, and (2) indirectly due to the induction of an anti-viral factor. In the former, prior infection with CRV significantly reduced subsequent CCV protein synthesis and virus yield. CRV mediated-interference was greatest when CRV infection preceded CCV infection by 16 h, and was least when cell cultures were simultaneously infected with both viruses. in the latter case, the infection of channel catfish ovary (CCO) cultures with UV-inactivated CRV resulted in the synthesis (or release) of an anti-viral factor. Cells producing the factor were protected from CCV infection, as were cells which had been treated with spent culture medium containing anti-viral activity. Interestingly an anti-viral activity was constitutively present in long-term cultures of catfish T-cells and macrophages. Whether this factor and the one induced by UV-inactivated CRV are identical is not known, but analogy to mammalian systems suggests that the former may be similar to type II interferon, whereas the latter may be the piscine equivalent of type I interferon. These results suggest that UV-inactivated CRV may prove useful in the induction and characterization of interferon-like anti-viral proteins in the channel catfish and that long-term cultures of catfish T-cells and monocytes may serve as a ready source of additional anti-viral factors.

  14. On Uplink Interference Scenarios in Two-Tier Macro and Femto Co-Existing UMTS Networks

    Directory of Open Access Journals (Sweden)

    Zhenning Shi

    2010-01-01

    Full Text Available A two-tier UMTS network is considered where a large number of randomly deployed Wideband Code Division Multiple Access (WCDMA femtocells are laid under macrocells where the spectrum is shared. The cochannel interference between the cells may be a potential limiting factor for the system. We study the uplink of this hybrid network and identify the critical scenarios that give rise to substantial interference. The mechanism for generating the interference is analyzed and guidelines for interference mitigation are provided. The impacts of the cross-tier interference especially caused by increased numbers of users and higher data rates are evaluated in the multicell simulation environment in terms of the noise rise at the base stations, the cell throughput, and the user transmit power consumption.

  15. On Uplink Interference Scenarios in Two-Tier Macro and Femto Co-Existing UMTS Networks

    Directory of Open Access Journals (Sweden)

    Shi Zhenning

    2010-01-01

    Full Text Available A two-tier UMTS network is considered where a large number of randomly deployed Wideband Code Division Multiple Access (WCDMA femtocells are laid under macrocells where the spectrum is shared. The cochannel interference between the cells may be a potential limiting factor for the system. We study the uplink of this hybrid network and identify the critical scenarios that give rise to substantial interference. The mechanism for generating the interference is analyzed and guidelines for interference mitigation are provided. The impacts of the cross-tier interference especially caused by increased numbers of users and higher data rates are evaluated in the multicell simulation environment in terms of the noise rise at the base stations, the cell throughput, and the user transmit power consumption.

  16. "Quantum Interference with Slits" Revisited

    CERN Document Server

    Rothman, Tony

    2010-01-01

    Marcella [arXiv:quant-ph/0703126] has presented a straightforward technique employing the Dirac formalism to calculate single- and double-slit interference patterns. He claims that no reference is made to classical optics or scattering theory and that his method therefore provides a purely quantum mechanical description of these experiments. He also presents his calculation as if no approximations are employed. We show that he implicitly makes the same approximations found in classical treatments of interference and that no new physics has been introduced. At the same time, some of the quantum mechanical arguments Marcella gives are, at best, misleading.

  17. Native-Language Phonological Interference in Early Hakka-Mandarin Bilinguals' Visual Recognition of Chinese Two-Character Compounds: Evidence from the Semantic-Relatedness Decision Task

    Science.gov (United States)

    Wu, Shiyu; Ma, Zheng

    2017-01-01

    Previous research has indicated that, in viewing a visual word, the activated phonological representation in turn activates its homophone, causing semantic interference. Using this mechanism of phonological mediation, this study investigated native-language phonological interference in visual recognition of Chinese two-character compounds by early…

  18. Native-Language Phonological Interference in Early Hakka-Mandarin Bilinguals' Visual Recognition of Chinese Two-Character Compounds: Evidence from the Semantic-Relatedness Decision Task

    Science.gov (United States)

    Wu, Shiyu; Ma, Zheng

    2017-01-01

    Previous research has indicated that, in viewing a visual word, the activated phonological representation in turn activates its homophone, causing semantic interference. Using this mechanism of phonological mediation, this study investigated native-language phonological interference in visual recognition of Chinese two-character compounds by early…

  19. IETS and quantum interference

    DEFF Research Database (Denmark)

    Jørgensen, Jacob Lykkebo; Gagliardi, Alessio; Pecchia, Alessandro

    2014-01-01

    Destructive quantum interference in single molecule electronics is an intriguing phenomenon; however, distinguishing quantum interference effects from generically low transmission is not trivial. In this paper, we discuss how quantum interference effects in the transmission lead to either low...... suppressed when quantum interference effects dominate. That is, we expand the understanding of propensity rules in inelastic electron tunneling spectroscopy to molecules with destructive quantum interference....

  20. Molecular Mechanisms of RNA Interference and its Use in Melanoma%RNA干扰分子机制的研究进展及其在黑素瘤中的应用

    Institute of Scientific and Technical Information of China (English)

    张娜; 钱悦

    2011-01-01

    RNA干扰是一种由外源性或内源性双链RNA分子阻断或者降低同源基因表达的现象,是目前生物分子学研究的热点之一.近年来RNA干扰分子机制的研究从转录后水平逐渐深入到转录水平、翻译水平,取得了飞速的发展.由于RNA干扰作用的靶向性,为肿瘤的治疗带来了新的希望,现从RNA干扰的分子学机制及其在黑素瘤中的研究予以简要综述.%RNA interference, one of molecular biology research hotspots, is a natural pathway through which the endogenous or exogenous double-strand RNA selectively suppresses or down-regulate the homologous gene. Recently, the research on molecular mechanisms of RNA interference has been in rapid development, from post-transcriptional level to transcriptional and translational levels. The specificity of RNA interference brings a new hope for cancer treatment. This article reviews the molecular mechanisms of RNA interference and its use in melanoma.

  1. Simulation study of the mechanisms underlying outbreaks of clinical disease caused by Actinobacillus pleuropneumoniae in finishing pigs

    NARCIS (Netherlands)

    Klinkenberg, D|info:eu-repo/dai/nl/248331485; Tobias, T J|info:eu-repo/dai/nl/323926789; Bouma, A|info:eu-repo/dai/nl/156999080; van Leengoed, L A M G|info:eu-repo/dai/nl/073994979; Stegeman, J A|info:eu-repo/dai/nl/137144040

    2014-01-01

    Actinobacillus pleuropneumoniae is a major cause of respiratory disease in pigs. Many farms are endemically infected without apparent disease, but occasionally severe outbreaks of pleuropneumonia occur. To prevent and control these outbreaks without antibiotics, the underlying mechanisms of these

  2. Microscopic degradation mechanism of polyimide film caused by surface discharge under bipolar continuous square impulse voltage

    Science.gov (United States)

    Luo, Yang; Wu, Guang-Ning; Liu, Ji-Wu; Peng, Jia; Gao, Guo-Qiang; Zhu, Guang-Ya; Wang, Peng; Cao, Kai-Jiang

    2014-02-01

    Polyimide (PI) film is an important type of insulating material used in inverter-fed motors. Partial discharge (PD) under a sequence of high-frequency square impulses is one of the key factors that lead to premature failures in insulation systems of inverter-fed motors. In order to explore the damage mechanism of PI film caused by discharge, an aging system of surface discharge under bipolar continuous square impulse voltage (BCSIV) is designed based on the ASTM 2275 01 standard and the electrical aging tests of PI film samples are performed above the partial discharge inception voltage (PDIV). The chemical bonds of PI polymer chains are analyzed through Fourier transform infrared spectroscopy (FTIR) and the dielectric properties of unaged and aged PI samples are investigated by LCR testers HIOKI 3532-50. Finally, the micro-morphology and micro-structure changes of PI film samples are observed through scanning electron microscopy (SEM). The results show that the physical and chemical effects of discharge cut off the chemical bonds of PI polymer chains. The fractures of ether bond (C—O—C) and imide ring (C—N—C) on the backbone of a PI polymer chain leads to the decrease of molecular weight, which results in the degradation of PI polymers and the generation of new chemical groups and materials, like carboxylic acid, ketone, aldehydes, etc. The variation of microscopic structure of PI polymers can change the orientation ability of polarizable units when the samples are under an AC electric field, which would cause the dielectric constant ɛ to increase and dielectric loss tan δ to decrease. The SEM images show that the degradation path of PI film is initiated from the surface and then gradually extends to the interior with continuous aging. The injection charge could result in the PI macromolecular chain degradation and increase the trap density in the PI polymer bulk.

  3. An Investigation of the Mechanism of Traumatic Brain Injury Caused by Blast in the Open Field

    Science.gov (United States)

    Feng, Ke

    Blast-induced traumatic brain injury (bTBI) is a signature wound of modern warfare. The current incomplete understanding of its injury mechanism impedes the development of strategies for effective protection of bTBI. Despite a considerable amount of experimental animal studies focused on the evaluation of brain neurotrauma caused by blast exposure, there is very limited knowledge on the biomechanical responses of the gyrenecephalic brain subjected to primary free-field blast waves imposed in vivo, and the correlation analysis between the biomechanical responses and its injury outcomes. Such information is crucial to the development of injury criteria of bTBI. This study aims to evaluate the external and internal mechanical responses of the brain against different levels of blast loading with Yucatan swine in free field, and to conduct correlational studies with brain tissue damage. To better understand primary bTBI, we have implemented an open field experimental model to apply controlled shock waves on swine head. The applied pressure levels of shock waves were predicted by finite element modeling and verified with calibrated testing. Biomechanical responses of primary blasts such as intracranial pressure (ICP), head kinetics, strain rate of skull, were measured in vivo during the blasts. A positive correlation between incident overpressure (IOP) and its corresponding biomechanical responses of the brain was observed. A parallel group of non-instrumented animals were used to collect injury data 72 hours post experiment. Cellular responses governed by primary blasts, such as neuronal degeneration and apoptosis were studied via immunohistochemistry. Representative fluorescent-stained images were examined under microscope. A positive correlation was found between the amount of degenerative neurons and the blast level. Significant elevation of apoptosis was found in the high-level blast. Comparisons between brains with varies ICP readings demonstrate differences of the

  4. Damage Mechanism in Counter Pairs Caused by Bionic Non-smoothed Surface

    Directory of Open Access Journals (Sweden)

    ZHANG Zhan-hui

    2016-08-01

    Full Text Available Four biomimetic non-smoothed surface specimens with different shapes were prepared by laser processing. Tests were conducted on MMU-5G wear and abrasion test machine to study the influencing rule of non-smoothed surfaces on counter pairs. The results show that the mass loss of the friction pair matching with the non-smoothed units is much greater than the ones matching with the smooth specimens. The pairs matching with different non-smoothed units suffer differently. The non-smoothed surface protruding zone exerts micro cutting on counter pairs. The striation causes the greatest mass loss of the pairs than the other non-smoothed units, which almost doubles the damage of the grid ones suffering the least. The difference in pairs damage is attributed to the different mechanism of undertaking the load in the process of wear. The damage can be alleviated effectively by changing the shapes of the units without increasing or decreasing the area ratio of the non-smoothed units.

  5. Heavy metal toxicity as a kill mechanism in impact caused mass extinctions

    Science.gov (United States)

    Wdowiak, T. J.; Davenport, S. A.; Jones, D. D.; Wdowiak, P.

    1988-01-01

    Heavy metals that are known to be toxic exist in carbonaceous chrondrites at abundances considerably in excess to that of the terrestrial crust. An impactor of relatively undifferentiated cosmic matter would inject into the terrestrial environment large quantities of toxic elements. The abundances of toxic metals found in the Allende CV carbonaceous chondrite and the ratio of meteoritic abundance to crustal abundance are: Cr, 3630 PPM, 30X; Co, 662 PPM, 23X; ni, 13300 PPm, 134X; se, 8.2 PPM, 164X; Os, 0.828 PPM, 166X. The resulting areal density for global dispersal of impactor derived heavy metals and their dilution with terrestrial ejecta are important factors in the determination of the significance of impactor heavy metal toxicity as a kill mechanism in impact caused mass extinctions. A 10 km-diameter asteroid having a density of 3 gram per cu cm would yield a global areal density of impact dispersed chondritic material of 3 kg per square meter. The present areal density of living matter on the terrestrial land surface is 1 kg per square meter. Dilution of impactor material with terrestrial ejecta is determined by energetics, with the mass of ejecta estimated to be in the range of 10 to 100 times that of the mass of the impactor. Because a pelagic impact would be the most likely case, the result would be a heavy metal rainout.

  6. Power as the Cause of Motion and a New Foundation of Classical Mechanics

    Directory of Open Access Journals (Sweden)

    Harokopos E.

    2005-07-01

    Full Text Available Laws of motion are derived based on power rather than on force. I show how power extends the law of inertia to include curvilinear motion and I also show that the law of action-reaction can be expressed in terms of the mutual time rate of change of kinetic energies instead of mutual forces. I then compare the laws of motion based on power to Newton’s Laws of Motion and I investigate the relation of power to Leibniz’s notion of vis viva. I also discuss briefly how the metaphysics of power as the cause of motion can be grounded in a modern version of occasionalism for the purpose of establishing an alternative foundation of mechanics. The laws of motion derived in this paper along with the metaphysical foundation proposed come in defense of the hypotheses that time emerges as an ordered progression of now and that gravitation is the effect of energy transfer between an unobservable substance and all matter in the Universe.

  7. Clostridium difficile Toxin B causes epithelial cell necrosis through an autoprocessing-independent mechanism.

    Directory of Open Access Journals (Sweden)

    Nicole M Chumbler

    Full Text Available Clostridium difficile is the most common cause of antibiotic-associated nosocomial infection in the United States. C. difficile secretes two homologous toxins, TcdA and TcdB, which are responsible for the symptoms of C. difficile associated disease. The mechanism of toxin action includes an autoprocessing event where a cysteine protease domain (CPD releases a glucosyltransferase domain (GTD into the cytosol. The GTD acts to modify and inactivate Rho-family GTPases. The presumed importance of autoprocessing in toxicity, and the apparent specificity of the CPD active site make it, potentially, an attractive target for small molecule drug discovery. In the course of exploring this potential, we have discovered that both wild-type TcdB and TcdB mutants with impaired autoprocessing or glucosyltransferase activities are able to induce rapid, necrotic cell death in HeLa and Caco-2 epithelial cell lines. The concentrations required to induce this phenotype correlate with pathology in a porcine colonic explant model of epithelial damage. We conclude that autoprocessing and GTD release is not required for epithelial cell necrosis and that targeting the autoprocessing activity of TcdB for the development of novel therapeutics will not prevent the colonic tissue damage that occurs in C. difficile - associated disease.

  8. Opportunistic Interference Alignment in MIMO Interference Channels

    CERN Document Server

    Perlaza, Samir Medina; Lasaulce, Samson; Chaufray, Jean Marie

    2008-01-01

    We present two interference alignment techniques such that an opportunistic point-to-point multiple input multiple output (MIMO) link can reuse, without generating any additional interference, the same frequency band of a similar pre-existing primary link. In this scenario, we exploit the fact that under power constraints, although each radio maximizes independently its rate by water-filling on their channel transfer matrix singular values, frequently, not all of them are used. Therefore, by aligning the interference of the opportunistic radio it is possible to transmit at a significant rate while insuring zero-interference on the pre-existing link. We propose a linear pre-coder for a perfect interference alignment and a power allocation scheme which maximizes the individual data rate of the secondary link. Our numerical results show that significant data rates are achieved even for a reduced number of antennas.

  9. "Quantum Interference with Slits" Revisited

    Science.gov (United States)

    Rothman, Tony; Boughn, Stephen

    2011-01-01

    Marcella has presented a straightforward technique employing the Dirac formalism to calculate single- and double-slit interference patterns. He claims that no reference is made to classical optics or scattering theory and that his method therefore provides a purely quantum mechanical description of these experiments. He also presents his…

  10. "Quantum Interference with Slits" Revisited

    Science.gov (United States)

    Rothman, Tony; Boughn, Stephen

    2011-01-01

    Marcella has presented a straightforward technique employing the Dirac formalism to calculate single- and double-slit interference patterns. He claims that no reference is made to classical optics or scattering theory and that his method therefore provides a purely quantum mechanical description of these experiments. He also presents his…

  11. [Effect of RNA Interference-silenced TAK1 on Kasumi-1 cell Proliferation Inhibition Induced by As2O3 and Its Mechanism].

    Science.gov (United States)

    Liu, Sha; Yuan, Fang-Fang; Mi, Rui-Hua; Wang, Xiao-Jiao; Fan, Rui-Hua; Wei, Xu-Dong

    2017-04-01

    To explore the effect of transforming growth factor-β activated kinase-1(TAK1) gene silenced by RNA interference on proliferation inhibition of Kasumi-1 cells induced by As2O3 and its mechanism. The experiments were divided into 4 groups, including control group(Kasumi-1 cells treated with non-specific siRNA), TAK1 specific siRNA treated group (Kasumi 1 treated with TAK specific siRNA), As2O3 treated group (Kasumi 1 cells treated with As2O3) and combined treated group (Kasumi 1 cells treated with TAK1 specific siRNA plus As2O3). The proliferation inhibition rate of Kasami 1 cells was detected by CCK-8 method, the apoptotic rate of cells was detected by flow eytometry, the expressions of TAK1, phosphorylated c-Jun N-terminal kinase(p-JNK) and apoptosis-related proteins were detected by Western blot. As2O3 could inhibit Kasumi-1 cell proliferation in a dose-dependent manner between 0.5 to 20 µmol/L with IC50 of (3.79±0.36) µmol/L at 24 h, and also inhibit Kasumi-1 cell proliferation in a dose-dependent manner between 0.5 to 10 µmol/L with IC50 of (2.38±0.17) µmol/L at 48 h, but then the inhibitory effect reached plateau. After treating Kasumi-1 cells with TAK1 siRNA and 3.5 µmol/L As2O3 for 24 h, the proliferation inhibition rate was (10.86±1.64)% and (49.80±2.19)%, meanwhile the apoptosis rate was (8.47±0.75)% and (24.78±2.14)%, all significantly higher than those in control group (PKasumi-1 cells were treated with TAK1 specific siRNA plus As2O3 for 24 h, protein expression levels were all significantly greater than that in the single-treated groups (PKasumi-1 cell proliferation which probably relates with the inducing apoptosis via the JNK and mitochondrial pathway. Meanwhile, TAK1 silencing enhances the inhibitory effect of As2O3 on Kasumi-1 cell proliferation.

  12. 47 CFR 27.64 - Protection from interference.

    Science.gov (United States)

    2010-10-01

    ... MISCELLANEOUS WIRELESS COMMUNICATIONS SERVICES Technical Standards § 27.64 Protection from interference. Wireless Communications Service (WCS) stations operating in full accordance with applicable FCC rules and... provided against interference caused by tropospheric and ionospheric propagation of signals....

  13. Simulation study of the mechanisms underlying outbreaks of clinical disease caused by Actinobacillus pleuropneumoniae in finishing pigs.

    Science.gov (United States)

    Klinkenberg, D; Tobias, T J; Bouma, A; van Leengoed, L A M G; Stegeman, J A

    2014-10-01

    Actinobacillus pleuropneumoniae is a major cause of respiratory disease in pigs. Many farms are endemically infected without apparent disease, but occasionally severe outbreaks of pleuropneumonia occur. To prevent and control these outbreaks without antibiotics, the underlying mechanisms of these outbreaks need to be understood. Outbreaks are probably initiated by a trigger (common risk factor) changing the host-pathogen interaction, but it is unclear whether this trigger causes all cases directly (trigger mechanism), or whether the first case starts a transmission chain inducing disease in the infected contacts (transmission mechanism). The aim of this study was to identify conditions under which these mechanisms could cause A. pleuropneumoniae outbreaks, and to assess means for prevention and control. Outbreaks were first characterised by data from a literature review, defining an average outbreak at 12 weeks of age, affecting 50% of animals within 4 days. Simple mathematical models describing the two mechanisms can reproduce average outbreaks, with two observations supporting the trigger mechanism: (1) disease should be transmitted 50 times faster than supported by literature if there is a transmission chain; and (2) the trigger mechanism is consistent with the absence of reported outbreaks in young pigs as they have not yet been colonised by the bacterium. In conclusion, outbreaks of A. pleuropneumoniae on endemic farms are most likely caused by a trigger inducing pneumonia in already infected pigs, but more evidence is needed to identify optimum preventive interventions. Copyright © 2014 Elsevier Ltd. All rights reserved.

  14. Scientific networking to address the causes, timing, emplacement mechanisms, and consequences of the Messinian Salinity Crisis

    Science.gov (United States)

    Camerlenghi, Angelo; Lofi, Johanna; Aloisi, Vanni; Flecker, Rachel

    2017-04-01

    The origin of the Mediterranean salt giant is linked to an extraordinary event in the geological history of the Mediterranean region, commonly referred to as the Messinian Salinity Crisis (MSC). After 45 years of intense yet disunited research efforts, the international scientific community at large faces a unique opportunity to access the deep and marginal basins Messinian depositional successions in the Mediterranean through scientific drilling, namely through the Integrated Ocean Discovery Program (IODP) and the International Continental Drilling Program (ICDP). Scientific activity to promote scientific drilling offshore and onshore is in progress under the broad umbrella of the Uncovering a Salt Giant' IODP Multi-Platform Drilling proposal, that has generated the Deep-Sea Records of the Messinian Salinity Crisis (DREAM) site-specific pre-proposal for riserless drilling on Messinian marginal basins and the related ICDP-IODP amphibious initiative Investigating Miocene Mediterranean- Atlantic gateway exchange (IMMAGE). Scientific networking has begun to establish a broad cross-disciplinary research community embracing geology, geophysics, geochemistry, microbiology, and paleoclimatology. Formal networking activities represent an opportunity for the scientific community to share objectives, data, expertise and tools with industry since there is considerable interest in oil and gas exploration, and consequent hazards, targeting the Mediterranean's deep salt deposits. With the acronym MEDSALT, we have established two networks working in close cooperation: (1) COST Action CA15103 Uncovering the Mediterranean salt giant (MEDSALT) (https://medsalt.eu/) is a 4-year long network established in May 2016 comprising scientific institutions from 28 states. This COST Action will provide an opportunity to develop further our knowledge of salt rock formation addressing four overarching scientific questions: a) What are the causes, timing and emplacement mechanisms of the

  15. Memory Interference as a Determinant of Language Comprehension.

    Science.gov (United States)

    Van Dyke, Julie A; Johns, Clinton L

    2012-04-01

    The parameters of the human memory system constrain the operation of language comprehension processes. In the memory literature, both decay and interference have been proposed as causes of forgetting; however, while there is a long history of research establishing the nature of interference effects in memory, the effects of decay are much more poorly supported. Nevertheless, research investigating the limitations of the human sentence processing mechanism typically focus on decay-based explanations, emphasizing the role of capacity, while the role of interference has received comparatively little attention. This paper reviews both accounts of difficulty in language comprehension by drawing direct connections to research in the memory domain. Capacity-based accounts are found to be untenable, diverging substantially from what is known about the operation of the human memory system. In contrast, recent research investigating comprehension difficulty using a retrieval-interference paradigm is shown to be wholly consistent with both behavioral and neuropsychological memory phenomena. The implications of adopting a retrieval-interference approach to investigating individual variation in language comprehension are discussed.

  16. Mechanisms causing variation in sexual size dimorphism in three sympatric, congeneric lizards.

    Science.gov (United States)

    Manicom, Carryn; Alford, Ross; Schoener, Thomas W; Schwarzkopf, Lin

    2014-06-01

    Sexual differences in adult body size (sexual size dimorphism, or SSD) ultimately can be favored by selection because larger males are more likely to be successful competitors for females, because larger females bear larger clutches, or because intersexual size differences reduce resource competition. Natural selection during juvenile development can influence sexual dimorphism of adults, and selection on adults and juveniles may differ. Studies that address the relative contributions of adult body shape dimorphism and sexually dimorphic patterns of growth and maturity are particularly useful in understanding the evolution of size dimorphism, yet they are rare. We investigated three sympatric, congeneric lizard species with different degrees and directions of adult sexual dimorphism and compared their growth patterns, survival probabilities, and intersexual trophic niche differences. Different mechanisms, even within these closely related, sympatric species, acted on juvenile lizards to produce species differences in adult SSD. Both degree and direction of dimorphism resulted from differences between the sexes in either the duration of growth or the rate of growth, but not from differences in rates of survival or selection on juvenile growth rate. Species- and sex-specific trade-offs in the allocation of energy to growth and reproduction, as well as differential timing of maturation, thus caused the growth patterns of the sexes to diverge, producing SSD. The differences that we observed in the direction of SSD among these species is consistent with their different social systems, suggesting that differential selection on adult body size has been responsible for the observed species-specific differences in juvenile growth rates and maturational timing.

  17. Mechanism and treatment principle for cerebral vessel spasm caused by concussion

    Institute of Scientific and Technical Information of China (English)

    肖兴义; 郭新红; 王德文; 薛关生

    2002-01-01

    Objective: To discuss the mechanism of cerebral vessel spasm caused by concussion and the effect of Nimodipine on concussion. Methods: A total of 224 patients who were treated from March 1995 to October 1999 were divided into two groups randomly, ie, Nimodipine group (113 cases) and control group (111 cases). Middle cerebral artery (MCA), basilar artery (BA) and the average peak forward velocity of cerebral blood flow were observed by color three-dimensional transcranial Doppler (3D-TCD) within 24 hours after admission and at the end of 3-6 days of treatment. Cerebral blood flow changes, characteristics and treatment effect were analyzed and determined by clinical main symptom disappearance rate. Results: In concussion, cerebral blood flow was divided into 3 phases: cerebral blood flow low infusion dilation phase, cerebral blood vessel spasm phase and cerebral blood flow recovery phase. In the Nimodipine group, clinical main symptom disappearance rate was higher than that in the control group in the cerebral spasm and recovery phases with a significant difference (P<0.01).  Conclusions: Cerebral vessel spasm, hypoxia and ischemia lesion are the main pathological changes. Whether cerebral dysfunction is reversible or not is mainly determined by spasm time of cerebral blood vessel. Nimodipine has a good effect on releasing spasm and diminishing the cerebral blood flow velocity. It not only improves curative effect on concussion, but also reduces and prevents concussion sequelae. Hence, concussion patients who have cerebral spasm confirmed by 3D-TCD should be given Nimodipine routinely and early.

  18. Sorbitol-based osmotic diarrhea: Possible causes and mechanism of prevention investigated in rats

    Institute of Scientific and Technical Information of China (English)

    Md Shahidul Islam; Ei Sakaguchi

    2006-01-01

    AIM: To study the possible causes of sorbitol (S)-based diarrhea and its mechanism of reduction by rice gruel (RG)in cecectomized rats.METHODS: S was dissolved either in distilled water or in RG (50 g/L) and ingested as a single oral dose (1.2 g/kg body mass, containing 0.5 g/L phenol red as a recovery marker) by S (control) and S + RG groups (n = 7),respectively. This dose is over the laxative dose for humans. Animals were sacrificed exactly 1 h after dose ingestion, without any access to drinking water. The whole gastro-intestinal tract was divided into seven segments and sampled to analyze the S and marker remaining in its contents.RESULTS: Gastric-emptying and intestinal transit were comparatively slower in the S + RG group. Also, the S absorption index in the 3rd and last quarter of the small intestine (24.85 ± 18.88% vs 0.0 ± 0.0% and 39.09 ± 32.75% vs 0.0 ± 0.0%, respectively, P < 0.05) was significantly higher in the S + RG group than in the control group. The S absorption index and the intestinal fluid volume are inversely related to each other.CONCLUSION: The intestinal mai-absorption of S is the main reason for S-based osmotic diarrhea. Where RG enhanced the absorption of S through passive diffusion, the degree of diarrhea was reduced in cecectomized rats.

  19. Graphene quantum interference photodetector.

    Science.gov (United States)

    Alam, Mahbub; Voss, Paul L

    2015-01-01

    In this work, a graphene quantum interference (QI) photodetector was simulated in two regimes of operation. The structure consists of a graphene nanoribbon, Mach-Zehnder interferometer (MZI), which exhibits a strongly resonant transmission of electrons of specific energies. In the first regime of operation (that of a linear photodetector), low intensity light couples two resonant energy levels, resulting in scattering and differential transmission of current with an external quantum efficiency of up to 5.2%. In the second regime of operation, full current switching is caused by the phase decoherence of the current due to a strong photon flux in one or both of the interferometer arms in the same MZI structure. Graphene QI photodetectors have several distinct advantages: they are of very small size, they do not require p- and n-doped regions, and they exhibit a high external quantum efficiency.

  20. Graphene quantum interference photodetector

    Directory of Open Access Journals (Sweden)

    Mahbub Alam

    2015-03-01

    Full Text Available In this work, a graphene quantum interference (QI photodetector was simulated in two regimes of operation. The structure consists of a graphene nanoribbon, Mach–Zehnder interferometer (MZI, which exhibits a strongly resonant transmission of electrons of specific energies. In the first regime of operation (that of a linear photodetector, low intensity light couples two resonant energy levels, resulting in scattering and differential transmission of current with an external quantum efficiency of up to 5.2%. In the second regime of operation, full current switching is caused by the phase decoherence of the current due to a strong photon flux in one or both of the interferometer arms in the same MZI structure. Graphene QI photodetectors have several distinct advantages: they are of very small size, they do not require p- and n-doped regions, and they exhibit a high external quantum efficiency.

  1. A putative RNA-interference-based immune system in prokaryotes: computational analysis of the predicted enzymatic machinery, functional analogies with eukaryotic RNAi, and hypothetical mechanisms of action

    Directory of Open Access Journals (Sweden)

    Wolf Yuri I

    2006-03-01

    Full Text Available Abstract Background All archaeal and many bacterial genomes contain Clustered Regularly Interspaced Short Palindrome Repeats (CRISPR and variable arrays of the CRISPR-associated (cas genes that have been previously implicated in a novel form of DNA repair on the basis of comparative analysis of their protein product sequences. However, the proximity of CRISPR and cas genes strongly suggests that they have related functions which is hard to reconcile with the repair hypothesis. Results The protein sequences of the numerous cas gene products were classified into ~25 distinct protein families; several new functional and structural predictions are described. Comparative-genomic analysis of CRISPR and cas genes leads to the hypothesis that the CRISPR-Cas system (CASS is a mechanism of defense against invading phages and plasmids that functions analogously to the eukaryotic RNA interference (RNAi systems. Specific functional analogies are drawn between several components of CASS and proteins involved in eukaryotic RNAi, including the double-stranded RNA-specific helicase-nuclease (dicer, the endonuclease cleaving target mRNAs (slicer, and the RNA-dependent RNA polymerase. However, none of the CASS components is orthologous to its apparent eukaryotic functional counterpart. It is proposed that unique inserts of CRISPR, some of which are homologous to fragments of bacteriophage and plasmid genes, function as prokaryotic siRNAs (psiRNA, by base-pairing with the target mRNAs and promoting their degradation or translation shutdown. Specific hypothetical schemes are developed for the functioning of the predicted prokaryotic siRNA system and for the formation of new CRISPR units with unique inserts encoding psiRNA conferring immunity to the respective newly encountered phages or plasmids. The unique inserts in CRISPR show virtually no similarity even between closely related bacterial strains which suggests their rapid turnover, on evolutionary scale

  2. Germline Defects Caused by Smed-boule RNA-Interference Reveal That Egg Capsule Deposition Occurs Independently of Fertilization, Ovulation, Mating, or the Presence of Gametes in Planarian Flatworms.

    Directory of Open Access Journals (Sweden)

    Jessica Kathryne Steiner

    2016-05-01

    Full Text Available Few animals are known to lay eggs in the absence of ovulation or copulation, as it is presumably energetically wasteful and subjected to negative selection. Characterization of Smed-boule, a member of the DAZ family of germline RNA-binding proteins, revealed that egg capsule (or capsule production and deposition occurs independently of the presence of gametes in the planarian flatworm Schmidtea mediterranea. Reduction of Smed-boule expression by RNA-interference (RNAi causes ablation of spermatogonial stem cells and the inability of ovarian germline stem cells to undergo oogenesis. Although animals subjected to Smed-boule RNAi lose their gametes and become sterile, they continue to lay egg capsules. Production of sterile capsules is even observed in virgin Smed-boule(RNAi and control planarians maintained in complete isolation, demonstrating that egg production in S. mediterranea occurs independently of ovulation, fertilization, or mating. Evidence suggests that this is a conserved feature amongst Platyhelminthes, and therefore relevant to the pathology and dissemination of parasitic flatworms. These findings demonstrate that Smed-boule functions at different stages during male and female germline stem cell development, and also demonstrate that egg capsule production by planarian flatworms occurs independently of signals produced by mating or ova.

  3. Germline Defects Caused by Smed-boule RNA-Interference Reveal That Egg Capsule Deposition Occurs Independently of Fertilization, Ovulation, Mating, or the Presence of Gametes in Planarian Flatworms.

    Science.gov (United States)

    Steiner, Jessica Kathryne; Tasaki, Junichi; Rouhana, Labib

    2016-05-01

    Few animals are known to lay eggs in the absence of ovulation or copulation, as it is presumably energetically wasteful and subjected to negative selection. Characterization of Smed-boule, a member of the DAZ family of germline RNA-binding proteins, revealed that egg capsule (or capsule) production and deposition occurs independently of the presence of gametes in the planarian flatworm Schmidtea mediterranea. Reduction of Smed-boule expression by RNA-interference (RNAi) causes ablation of spermatogonial stem cells and the inability of ovarian germline stem cells to undergo oogenesis. Although animals subjected to Smed-boule RNAi lose their gametes and become sterile, they continue to lay egg capsules. Production of sterile capsules is even observed in virgin Smed-boule(RNAi) and control planarians maintained in complete isolation, demonstrating that egg production in S. mediterranea occurs independently of ovulation, fertilization, or mating. Evidence suggests that this is a conserved feature amongst Platyhelminthes, and therefore relevant to the pathology and dissemination of parasitic flatworms. These findings demonstrate that Smed-boule functions at different stages during male and female germline stem cell development, and also demonstrate that egg capsule production by planarian flatworms occurs independently of signals produced by mating or ova.

  4. Whirling waves in Interference experiments

    Science.gov (United States)

    Sinha, Urbasi; Sawant, Rahul; Samuel, Joseph; Sinha, Aninda; Sinha, Supurna

    2014-03-01

    In a double slit interference experiment, the wave function at the screen with both slits open is not exactly the sum of the wave functions with the slits individually open one at a time. The three scenarios represent three different boundary conditions and as such, the superposition principle should not be applicable. However, most well- known text books in quantum mechanics implicitly and/or explicitly use this assumption, the wave function hypothesis, which is only approximately true. In our present study, we have used the Feynman path integral formalism to quantify contributions from non-classical paths in interference experiments which provide a measurable deviation from the wave function hypothesis. A direct experimental demonstration for the existence of these non-classical paths is hard. We find that contributions from such paths can be significant and we propose simple three-slit interference experiments to directly confirm their existence. I will also describe some ongoing experimental efforts towards testing our theoretical findings.

  5. Admission Control and Interference Management in Dynamic Spectrum Access Networks

    Directory of Open Access Journals (Sweden)

    Jorge Martinez-Bauset

    2010-01-01

    Full Text Available We study two important aspects to make dynamic spectrum access work in practice: the admission policy of secondary users (SUs to achieve a certain degree of quality of service and the management of the interference caused by SUs to primary users (PUs. In order to limit the forced termination probability of SUs, we evaluate the Fractional Guard Channel reservation scheme to give priority to spectrum handovers over new arrivals. We show that, contrary to what has been proposed, the throughput of SUs cannot be maximized by configuring the reservation parameter. We also study the interference caused by SUs to PUs. We propose and evaluate different mechanisms to reduce the interference, which are based on simple spectrum access algorithms for both PUs and SUs and channel repacking algorithms for SUs. Numerical results show that the reduction can be of one order of magnitude or more with respect to the random access case. Finally, we propose an adaptive admission control scheme that is able to limit simultaneously the forced termination probability of SUs and what we define as the probability of interference. Our scheme does not require any configuration parameters beyond the probability objectives. Besides, it is simple to implement and it can operate with any arrival process and distribution of the session duration.

  6. Mechanisms of Subsurface Drip Irrigation-Mediated Suppression of Lettuce Drop Caused by Sclerotinia minor.

    Science.gov (United States)

    Bell, A A; Liu, L; Reidy, B; Davis, R M; Subbarao, K V

    1998-03-01

    ABSTRACT Subsurface drip irrigation and associated mandatory minimum tillage practices significantly reduced the incidence of lettuce drop (Sclerotinia minor) and the severity of corky root on lettuce compared with furrow irrigation and conventional tillage. Three possible mechanisms for the drip irrigation-mediated disease suppression were examined in this study: qualitative and quantitative differences in the soil microflora under furrow and subsurface drip irrigation; their antagonism and potential bio-control effects on S. minor; and the physical distribution of soil moisture and temperature relative to the two irrigation methods. To determine if the suppressive effects under subsurface drip irrigation were related to changes in soil microflora, soils were assayed for actinomycetes, bacteria, and fungi during the spring and fall seasons. The effects of the irrigation methods on microbial populations were nearly identical during both seasons. In the spring season, the total number of fungal colonies recovered on potato dextrose agar amended with rose Bengal generally was greater in soils under drip irrigation than under furrow irrigation, but no such differences were observed during the fall. Numbers of actinomycetes and bacteria were not significantly different between irrigation methods during either season. No interaction between sampling time and irrigation methods was observed for any of the microbial populations during both seasons. Thus, the significant effect of sampling time observed for actinomycete and bacterial populations during the spring was most likely not caused by the irrigation treatments. There were also no qualitative differences in the three groups of soil microflora between the irrigation treatments. Even though some fungal, actinomycete, and bacterial isolates suppressed mycelial growth of S. minor in in vitro assays, the isolates came from both subsurface drip- and furrow-irrigated soils. In in planta assays, selected isolates failed to

  7. Population genetic analysis of the intertidal limpet Lottia scabra and inference of the causes and mechanisms of range limits

    OpenAIRE

    Lehman, Joan

    2010-01-01

    Range limits have been described for many species, and the interest in range limits has increased in the wake of climate change, but few researchers attempt to document the causes and mechanisms of these limits and empirical tests of range limit theory remain sparse. Three principle mechanisms have been proposed to limit species’ range in models incorporating environmental heterogeneity and evolution: genetic impoverishment, migration load, or a physical barrier to dispersal. O...

  8. Drug Resistance Mechanisms in Bacteria Causing Sexually Transmitted Diseases and Associated with Vaginosis

    OpenAIRE

    Shaskolskiy, Boris; Dementieva, Ekaterina; Leinsoo, Arvo; Runina, Anastassia; Vorobyev, Denis; Plakhova, Xenia; Kubanov, Alexey; Deryabin, Dmitrii; Gryadunov, Dmitry

    2016-01-01

    Here, we review sexually transmitted diseases (STDs) caused by pathogenic bacteria and vaginal infections which result from an overgrowth of opportunistic bacterial microflora. First, we describe the STDs, the corresponding pathogens and the antimicrobials used for their treatment. In addition to the well-known diseases caused by single pathogens (i.e., syphilis, gonococcal infections, and chlamydiosis), we consider polymicrobial reproductive tract infections (especially those that are diffic...

  9. Non-Invasive Mechanic Ventilation Using in Flail Chest, Caused By Blunt Chest Trauma

    Directory of Open Access Journals (Sweden)

    Serdar Onat

    2008-01-01

    Full Text Available A 75-year-old woman admitted our faculty emergency room with shortness of breath, and chest pain after traffic accident’s second hour. She was diagnosed as bilateral multipl rib fractures, left clavicula fracture, and left flail chest by phsical and radiological examinations. She was transfered to Chest Surgery Depatment’s intensive care unit. The patient was undergone non-invasive mask mechanic ventilation support, because of the decreasing of blood oxygen saturation and increasing of arteriel blood partial carbondioxide pressure. The treatment of non-invasive mechanic ventilation was succesfull for ventilation support. With this report, we would like to attentioned that non-invasive mechanic ventilation for blunt chest trauma patients could be used succesfully and could be used instead of endotracheal invasive mechanic ventilation.

  10. The toxicity of oxidised DWCNTs to the aquatic organisms, and related causing mechanisms

    CSIR Research Space (South Africa)

    Lukhele, LP

    2013-08-01

    Full Text Available earlier reported for the three aquatic organisms in earlier scientific reports. Finally, the paper discusses the linkage between the toxicity mechanisms and the physicochemical properties of DWCNTs, namely: agglomeration state, surface chemistry...

  11. Autism spectrum disorder causes, mechanisms, and treatments: focus on neuronal synapses

    Directory of Open Access Journals (Sweden)

    Hyejung eWon

    2013-08-01

    Full Text Available Autism spectrum disorder (ASD is a group of developmental disabilities characterized by impairments in social interaction and communication and restricted and repetitive inter-ests/behaviors. Advances in human genomics have identified a large number of genetic varia-tions associated with ASD. These associations are being rapidly verified by a growing number of studies using a variety of approaches, including mouse genetics. These studies have also identified key mechanisms underlying the pathogenesis of ASD, many of which involve synaptic dysfunctions, and have investigated novel, mechanism-based therapeutic strategies. This review will try to integrate these three key aspects of ASD research: human genetics, animal models, and potential treatments. Continued efforts in this direction should ultimately reveal core mechanisms that account for a larger fraction of ASD cases and identify neural mechanisms associated with specific ASD symptoms, providing important clues to efficient ASD treatment.

  12. The mechanism of “killer turn” causing residual laxity after transtibial posterior cruciate ligament reconstruction

    Directory of Open Access Journals (Sweden)

    Yue Li

    2016-01-01

    Conclusion: The mechanism of “killer turn” compromising posterior stability was that the repetitive friction between graft and tunnel inlet not only attenuated the graft, but also enlarged the tunnel inlet, leading to the displacement of the graft.

  13. Coronary Emboli in a Young Patient with Mechanical Aortic Valve: A Rare Cause of Acute Myocardial Infarction

    Directory of Open Access Journals (Sweden)

    Arash Gholoobi

    2016-03-01

    Full Text Available Coronary artery embolism is an uncommon cause of Acute Myocardial Infarction (AMI. Herein, we reported a 24-year-old male who was admitted with acute infero-posterior myocardial infarction and cerebral Transient Ischemic Attack (TIA. He had undergone mechanical Aortic Valve Replacement (AVR surgery 6 years ago. Surprisingly, the patient had decided to stop taking his medication (warfarin 20 days earlier without any medical advice. Coronary angiography revealed a thrombus located at the distal part of the left circumflex artery. Discontinuation of anticoagulant therapy in the presence of mechanical valve prosthesis, clinical evidence of coincidental TIA, and lack of atherosclerotic risk factors were highly suggestive of coronary thromboembolism as the cause of AMI. Overall, this case report emphasized the necessity of continuous education in patients with mechanical heart valves to prevent such undesired events.

  14. Tidal mechanism as an impossible cause of the observed secular increase of the astronomical unit

    CERN Document Server

    Itoh, Yousuke

    2009-01-01

    Krasinsky and Brumberg (2004 Celest. Mech. Dyn. Astron., 90, 267) reported a secular increase of the astronomical unit (AU) of 15 meters per century. Recently, Miura et al. (2009, PASJ, 61) proposed that a possible angular momentum transfer from the rotation of the Sun to the orbital motion of the solar system planets may explain the observed increase of the AU. They assumed that the tidal effect between the planets and the Sun is the cause of this transfer. Here we claim that tidal effect cannot be a cause of this type of the transfer to explain the increase of the AU.

  15. Multilocus half-tetrad analysis and centromere mapping in citrus: evidence of SDR mechanism for 2n megagametophyte production and partial chiasma interference in mandarin cv ‘Fortune'

    Science.gov (United States)

    Cuenca, J; Froelicher, Y; Aleza, P; Juárez, J; Navarro, L; Ollitrault, P

    2011-01-01

    The genetic structure of 2n gametes and, particularly, the parental heterozygosity restitution at each locus depends on the meiotic process by which they originated, with first-division restitution and second-division restitution (SDR) being the two major mechanisms. The origin of 2n gametes in citrus is still controversial, although sexual polyploidisation is widely used for triploid seedless cultivar development. In this study, we report the analysis of 2n gametes of mandarin cv ‘Fortune' by genotyping 171 triploid hybrids with 35 simple sequence repeat markers. The microsatellite DNA allele counting-peak ratios method for allele-dosage evaluation proved highly efficient in segregating triploid progenies and allowed half-tetrad analysis (HTA) by inferring the 2n gamete allelic configuration. All 2n gametes arose from the female genitor. The observed maternal heterozygosity restitution varied between 10 and 82%, depending on the locus, thus SDR appears to be the mechanism underlying 2n gamete production in mandarin cv ‘Fortune'. A new method to locate the centromere, based on the best fit between observed heterozygosity restitution within a linkage group and theoretical functions under either partial or no chiasmata interference hypotheses was successfully applied to linkage group II. The maximum value of heterozygosity restitution and the pattern of restitution along this linkage group would suggest there is partial chiasma interference. The implications of such a restitution mechanism for citrus breeding are discussed. PMID:21587302

  16. Interference with the host haemostatic system by schistosomes.

    Directory of Open Access Journals (Sweden)

    Mirjam M Mebius

    Full Text Available Schistosomes, parasitic flatworms that cause the tropical disease schistosomiasis, are still a threat. They are responsible for 200 million infections worldwide and an estimated 280,000 deaths annually in sub-Saharan Africa alone. The adult parasites reside as pairs in the mesenteric or perivesicular veins of their human host, where they can survive for up to 30 years. The parasite is a potential activator of blood coagulation according to Virchow's triad, because it is expected to alter blood flow and endothelial function, leading to hypercoagulability. In contrast, hepatosplenic schistosomiasis patients are in a hypocoagulable and hyperfibrinolytic state, indicating that schistosomes interfere with the haemostatic system of their host. In this review, the interactions of schistosomes with primary haemostasis, secondary haemostasis, fibrinolysis, and the vascular tone will be discussed to provide insight into the reduction in coagulation observed in schistosomiasis patients. Interference with the haemostatic system by pathogens is a common mechanism and has been described for other parasitic worms, bacteria, and fungi as a mechanism to support survival and spread or enhance virulence. Insight into the mechanisms used by schistosomes to interfere with the haemostatic system will provide important insight into the maintenance of the parasitic life cycle within the host. This knowledge may reveal new potential anti-schistosome drug and vaccine targets. In addition, some of the survival mechanisms employed by schistosomes might be used by other pathogens, and therefore, these mechanisms that interfere with host haemostasis might be a broad target for drug development against blood-dwelling pathogens. Also, schistosome antithrombotic or thrombolytic molecules could form potential new drugs in the treatment of haemostatic disorders.

  17. Interconnections between cell wall polymers, wall mechanics, and cortical microtubules: Teasing out causes and consequences.

    Science.gov (United States)

    Xiao, Chaowen; Anderson, Charles T

    2016-09-01

    In plants, cell wall components including cellulose, hemicelluloses, and pectins interact with each other to form complex extracellular network structures that control cell growth and maintain cell shape. However, it is still not clear exactly how different wall polymers interact, how the conformations and interactions of cell wall polymers relate to wall mechanics, and how these factors impinge on intracellular structures such as the cortical microtubule cytoskeleton. Here, based on studies of Arabidopsis thaliana xxt1 xxt2 mutants, which lack detectable xyloglucan in their walls and display aberrant wall mechanics, altered cellulose patterning and biosynthesis, and reduced cortical microtubule stability, we discuss the potential relationships between cell wall biosynthesis, wall mechanics, and cytoskeletal dynamics in an effort to better understand their roles in controlling plant growth and morphogenesis.

  18. Soil bulk density changes caused by mechanized harvesting: A case study in central Appalachia

    Science.gov (United States)

    Jingxin Wang; Chris B. LeDoux; Pam Edwards; Mark Jones; Mark Jones

    2005-01-01

    A mechanized harvesting system consisting of a feller-buncher and a grapple skidder was examined to quantify soil bulk density changes in a central Appalachian hardwood forest site. Soil bulk density was measured using a nuclear gauge pre-harvest and post-harvest systematically across the harvest unit and on transects across skid trails. Bulk density also was measured...

  19. Conducted interference, challenges and interference cases

    NARCIS (Netherlands)

    Leferink, Frank Bernardus Johannes

    2015-01-01

    Conducted interference has become increasingly problematic in the past few years, especially within the 2-150 kHz band. The high penetration of non-linear loads, combined with distributed generation, will influence the voltage profile, i.e. the power quality. New technologies will introduce new type

  20. Conducted interference, challenges and interference cases

    NARCIS (Netherlands)

    Leferink, Frank Bernardus Johannes

    2015-01-01

    Conducted interference has become increasingly problematic in the past few years, especially within the 2-150 kHz band. The high penetration of non-linear loads, combined with distributed generation, will influence the voltage profile, i.e. the power quality. New technologies will introduce new

  1. Novel Mechanism to Defend DDoS Attacks Caused by Spam

    CERN Document Server

    Nagamalai, Dhinaharan; Lee, Jae-Kwang

    2010-01-01

    Corporate mail services are designed to perform better than public mail services. Fast mail delivery, large size file transfer as an attachments, high level spam and virus protection, commercial advertisement free environment are some of the advantages worth to mention. But these mail services are frequent target of hackers and spammers. Distributed Denial of service attacks are becoming more common and sophisticated. The researchers have proposed various solutions to the DDOS attacks. Can we stop these kinds of attacks with available technology? These days the DDoS attack through spam has increased and disturbed the mail services of various organizations. Spam penetrates through all the filters to establish DDoS attacks, which causes serious problems to users and the data. In this paper we propose a novel approach to defend DDoS attack caused by spam mails. This approach is a combination of fine tuning of source filters, content filters, strictly implementing mail policies,educating user, network monitoring ...

  2. Mechanism and preclinical prevention of increased breast cancer risk caused by pregnancy.

    Science.gov (United States)

    Haricharan, Svasti; Dong, Jie; Hein, Sarah; Reddy, Jay P; Du, Zhijun; Toneff, Michael; Holloway, Kimberly; Hilsenbeck, Susan G; Huang, Shixia; Atkinson, Rachel; Woodward, Wendy; Jindal, Sonali; Borges, Virginia F; Gutierrez, Carolina; Zhang, Hong; Schedin, Pepper J; Osborne, C Kent; Tweardy, David J; Li, Yi

    2013-12-31

    While a first pregnancy before age 22 lowers breast cancer risk, a pregnancy after age 35 significantly increases life-long breast cancer risk. Pregnancy causes several changes to the normal breast that raise barriers to transformation, but how pregnancy can also increase cancer risk remains unclear. We show in mice that pregnancy has different effects on the few early lesions that have already developed in the otherwise normal breast-it causes apoptosis evasion and accelerated progression to cancer. The apoptosis evasion is due to the normally tightly controlled STAT5 signaling going astray-these precancerous cells activate STAT5 in response to pregnancy/lactation hormones and maintain STAT5 activation even during involution, thus preventing the apoptosis normally initiated by oncoprotein and involution. Short-term anti-STAT5 treatment of lactation-completed mice bearing early lesions eliminates the increased risk after a pregnancy. This chemoprevention strategy has important implications for preventing increased human breast cancer risk caused by pregnancy. DOI: http://dx.doi.org/10.7554/eLife.00996.001.

  3. Phonon-Mediated Nonclassical Interference in Diamond

    Science.gov (United States)

    England, Duncan G.; Fisher, Kent A. G.; MacLean, Jean-Philippe W.; Bustard, Philip J.; Heshami, Khabat; Resch, Kevin J.; Sussman, Benjamin J.

    2016-08-01

    Quantum interference of single photons is a fundamental aspect of many photonic quantum processing and communication protocols. Interference requires that the multiple pathways through an interferometer be temporally indistinguishable to within the coherence time of the photon. In this Letter, we use a diamond quantum memory to demonstrate interference between quantum pathways, initially temporally separated by many multiples of the optical coherence time. The quantum memory can be viewed as a light-matter beam splitter, mapping a THz-bandwidth single photon to a variable superposition of the output optical mode and stored phononic mode. Because the memory acts both as a beam splitter and as a buffer, the relevant coherence time for interference is not that of the photon, but rather that of the memory. We use this mechanism to demonstrate nonclassical single-photon and two-photon interference between quantum pathways initially separated by several picoseconds, even though the duration of the photons themselves is just ˜250 fs .

  4. Dark Matter Interference

    DEFF Research Database (Denmark)

    Del Nobile, Eugenio; Kouvaris, Christoforos; Sannino, Francesco

    2012-01-01

    We study different patterns of interference in WIMP-nuclei elastic scattering that can accommodate the DAMA and CoGeNT experiments via an isospin violating ratio $f_n/f_p=-0.71$. We study interference between the following pairs of mediators: Z and Z', Z' and Higgs, and two Higgs fields. We show ...

  5. Changes in permeability caused by transient stresses: field observations, experiments, and mechanisms

    Science.gov (United States)

    Manga, Michael; Beresnev, Igor; Brodsky, Emily E.; Elkhoury, Jean E.; Elsworth, Derek; Ingebritsen, Steve E.; Mays, David C.; Wang, Chi-yuen

    2012-01-01

    Oscillations in stress, such as those created by earthquakes, can increase permeability and fluid mobility in geologic media. In natural systems, strain amplitudes as small as 10–6 can increase discharge in streams and springs, change the water level in wells, and enhance production from petroleum reservoirs. Enhanced permeability typically recovers to prestimulated values over a period of months to years. Mechanisms that can change permeability at such small stresses include unblocking pores, either by breaking up permeability-limiting colloidal deposits or by mobilizing droplets and bubbles trapped in pores by capillary forces. The recovery time over which permeability returns to the prestimulated value is governed by the time to reblock pores, or for geochemical processes to seal pores. Monitoring permeability in geothermal systems where there is abundant seismicity, and the response of flow to local and regional earthquakes, would help test some of the proposed mechanisms and identify controls on permeability and its evolution.

  6. How does interference fall?

    CERN Document Server

    Orlando, Patrick J; Modi, Kavan

    2016-01-01

    We study how single- and double-slit interference patterns fall in the presence of gravity. First, we demonstrate that universality of free fall still holds in this case, i.e., interference patterns fall just like classical objects. Next, we explore lowest order relativistic effects in the Newtonian regime by employing a recent quantum formalism which treats mass as an operator. This leads to interactions between non-degenerate internal degrees of freedom (like spin in an external magnetic field) and external degrees of freedom (like position). Based on these effects, we present an unusual phenomenon, in which a falling double slit interference pattern periodically decoheres and recoheres. The oscillations in the visibility of this interference occur due to correlations built up between spin and position. Finally, we connect the interference visibility revivals with non-Markovian quantum dynamics.

  7. Models of intracellular mechanisms of plant bioelectrical potentials caused by combined stimulation

    Directory of Open Access Journals (Sweden)

    D. V. Chernetchenko

    2014-10-01

    Full Text Available This paper deals with bioelectrical potentials of the plants recorded during different types of stimuli and combined stimulus as well. All registrations were observed on the leaves of the corn. We used different stimuli, such as cold, heat, photo- and electrical stimulation, and certain combination of this stimuli. Hardware and software system for automated recording of bioelectrical potentials has been successfully used in this work. We proposed the universal pattern of bioelectrical potentials’ recording which allowed to detect the response of the biological object to different stimuli and various combinations of these stimuli. This pattern can be used for the deeper understanding of biological mechanisms of electrical potentials’ generation in cells and discovering of processes of accommodation of whole organisms to these stimuli. Integrated system of recording and biometrical processing was used for analysis of corn leaves electrical responses to the thermal stimuli. The dynamics of these potentials was studied, with the quantitative analysis of the potential level stabilization.We calculated the ratio of amplitude of response potentials to the first response amplitude. Mathematical models of the plant cell were used for studying of intracellular mechanisms of biopotentials gereration. As a result of modeling, we revealed that electrical response of the cells was based on selectiveconductivity of cell membrane for Н+ and Ca2+ ions. Therefore, we showed the biophysical relation of plant potentials to underlying intracellular biophysical mechanisms during thermal and combined stimulation.

  8. Evidence of an emerging levee failure mechanism causing disastrous floods in Italy

    Science.gov (United States)

    Orlandini, Stefano; Moretti, Giovanni; Albertson, John

    2017-04-01

    A levee failure occurred along the Secchia River, Northern Italy, on January 19, 2014, resulting in flood damage in excess of 500 Million. In response to this failure, immediate surveillance of other levees in the region led to the identification of a second breach developing on the neighboring Panaro River, where rapid mitigation efforts were successful in averting a full levee failure. The paired breach events that occurred along the Secchia and Panaro Rivers provided an excellent window on an emerging levee failure mechanism. In the Secchia River, by combining the information content of photographs taken from helicopters in the early stage of breach development and 10-cm resolution aerial photographs taken in 2010 and 2012, animal burrows were found to exist in the precise levee location where the breach originated. In the Panaro River, internal erosion was observed to occur at a location where a crested porcupine den was known to exist and this erosion led to the collapse of the levee top. This paper uses detailed numerical modeling of rainfall, river flow, and variably saturated flow in the levee to explore the hydraulic and geotechnical mechanisms that were triggered along the Secchia and Panaro Rivers by activities of burrowing animals leading to levee failures. As habitats become more fragmented and constrained along river corridors it is possible that this failure mechanism could become more prevalent and, therefore, will demand greater attention in both the design and maintenance of earthen hydraulic structures as well as in wildlife management.

  9. Shape-Memory-Alloy Release Mechanism

    Science.gov (United States)

    Mckinnis, Darin

    1993-01-01

    Release-nut mechanism activated by electric current applied to shape-memory alloy. Separates attached objects quickly by remote control. Does not create hazard or cause damage. Shape-memory release-nut mechanism unaffected by moisture or vacuum. Requires sustained current lasting 5 seconds or longer, and insensitive to electromagnetic interference. Mechanism can be reused.

  10. The complexity of biomechanics causing primary blast-induced traumatic brain injury: a review of potential mechanisms.

    Directory of Open Access Journals (Sweden)

    Amy eCourtney

    2015-10-01

    Full Text Available Primary blast induced traumatic brain injury (bTBI is a prevalent battlefield injury in recent conflicts, yet biomechanical mechanisms of bTBI remain unclear. Elucidating specific biomechanical mechanisms is essential to developing animal models for testing candidate therapies and for improving protective equipment. Three hypothetical mechanisms of primary bTBI have received the most attention. Because translational and rotational head accelerations are primary contributors to TBI from non-penetrating blunt force head trauma, the acceleration hypothesis suggests that blast-induced head accelerations may cause bTBI. The hypothesis of direct cranial transmission suggests that a pressure transient traverses the skull into the brain and directly injures brain tissue. The thoracic hypothesis of bTBI suggests that some combination of a pressure transient reaching the brain via the thorax and a vagally mediated reflex result in bTBI. These three mechanisms may not be mutually exclusive, and quantifying exposure thresholds (for blasts of a given duration is essential for determining which mechanisms may be contributing for a level of blast exposure. Progress has been hindered by experimental designs which do not effectively expose animal models to a single mechanism and by over-reliance on poorly validated computational models. The path forward should be predictive validation of computational models by quantitative confirmation with blast experiments in animal models, human cadavers, and biofidelic human surrogates over a range of relevant blast magnitudes and durations coupled with experimental designs which isolate a single injury mechanism.

  11. Can We Falsify the Consciousness-Causes-Collapse Hypothesis in Quantum Mechanics?

    Science.gov (United States)

    de Barros, J. Acacio; Oas, Gary

    2017-06-01

    In this paper we examine some proposals to disprove the hypothesis that the interaction between mind and matter causes the collapse of the wave function, showing that such proposals are fundamentally flawed. We then describe a general experimental setup retaining the key features of the ones examined, and show that even a more general case is inadequate to disprove the mind-matter collapse hypothesis. Finally, we use our setup provided to argue that, under some reasonable assumptions about consciousness, such hypothesis is unfalsifiable.

  12. Peritoneal Adhesions as a Cause of Mechanical Small Bowel Obstruction Based on Own Experience

    Directory of Open Access Journals (Sweden)

    Morawski Bartłomiej

    2015-02-01

    Full Text Available Bowel obstruction is a condition which has been known for many years. As time goes by, the problem is still often encountered at surgical emergency rooms. More than 20% of emergency surgical interventions are performed because of symptoms of digestive tract obstruction with the disease mostly situated in the small bowel. Rates of causative factors of the disease have changed over recent years and there have been increasingly more cases of small bowel obstruction caused by peritoneal adhesions, i.e., adhesive small bowel obstruction (ASBO.

  13. Inter-WBAN Coexistence and Interference Mitigation

    Institute of Scientific and Technical Information of China (English)

    Bin Liu; Xiaosong Zhao; Lei Zou; Chang Wen Chen

    2015-01-01

    With promising applications in e⁃health and entertainment, wireless body area networks (WBANs) have attracted the in⁃terest of both academia and industry. If WBANs are densely deployed within a small area, serious problems may arise be⁃tween the WBANs. In this paper, we discuss issues related to the coexistence of WBANs and investigate the main fac⁃tors that cause inter⁃WBAN interference. We survey inter⁃WBAN interference mitigation strategies and track recent re⁃search developments. We also discuss unresolved issues re⁃lated to inter⁃WBAN interference mitigation and propose fu⁃ture research directions.

  14. A CFD Study on the Mechanisms Which Cause Cavitation in Positive Displacement Reciprocating Pumps

    Institute of Scientific and Technical Information of China (English)

    Aldo Iannetti; Matthew T. Stickland; William M. Dempster

    2015-01-01

    A transient multiphase CFD (computational fluid dynamics) model was set up to investigate the main causes which lead to cavitation in PD (positive displacement) reciprocating pumps. Many authors agree on distinguishing two different types of cavitation affecting PD pumps: flow induced cavitation and cavitation due to expansion. The flow induced cavitation affects the zones of high fluid velocity and consequent low static pressure e.g. the valve-seat volume gap while the cavitation due to expansion can be detected in zones where the decompression effects are important e.g. in the vicinity of the plunger. This second factor is a distinctive feature of PD pumps since other devices such as centrifugal pumps are only affected by the flow induced type. Unlike what has been published in the technical literature to date, where analysis of positive displacement pumps are based exclusively on experimental or analytic methods, the work presented in this paper is based entirely on a CFD approach, it discusses the appearance and the dynamics of these two phenomena throughout an entire pumping cycle pointing out the potential of CFD techniques in studying the causes of cavitation and assessing the consequent loss of performance in positive displacement pumps.

  15. Mechanical analysis of congestive heart failure caused by bundle branch block based on an electromechanical canine heart model

    Energy Technology Data Exchange (ETDEWEB)

    Dou Jianhong; Xia Ling; Zhang Yu; Shou Guofa [Department of Biomedical Engineering, Zhejiang University, Hangzhou 310027 (China); Wei Qing; Liu Feng; Crozier, Stuart [School of Information Technology and Electrical Engineering, University of Queensland, St Lucia, Brisbane, Queensland 4072 (Australia)], E-mail: xialing@zju.edu.cn

    2009-01-21

    Asynchronous electrical activation, induced by bundle branch block (BBB), can cause reduced ventricular function. However, the effects of BBB on the mechanical function of heart are difficult to assess experimentally. Many heart models have been developed to investigate cardiac properties during BBB but have mainly focused on the electrophysiological properties. To date, the mechanical function of BBB has not been well investigated. Based on a three-dimensional electromechanical canine heart model, the mechanical properties of complete left and right bundle branch block (LBBB and RBBB) were simulated. The anatomical model as well as the fiber orientations of a dog heart was reconstructed from magnetic resonance imaging (MRI) and diffusion tensor MRI (DT-MRI). Using the solutions of reaction-diffusion equations and with a strategy of parallel computation, the asynchronous excitation propagation and intraventricular conduction in BBB was simulated. The mechanics of myocardial tissues were computed with time-, sarcomere length-dependent uniaxial active stress initiated at the time of depolarization. The quantification of mechanical intra- and interventricular asynchrony of BBB was then investigated using the finite-element method with an eight-node isoparametric element. The simulation results show that (1) there exists inter- and intraventricular systolic dyssynchrony during BBB; (2) RBBB may have more mechanical synchrony and better systolic function of the left ventricle (LV) than LBBB; (3) the ventricles always move toward the early-activated ventricle; and (4) the septum experiences higher stress than left and right ventricular free walls in BBB. The simulation results validate clinical and experimental recordings of heart deformation and provide regional quantitative estimates of ventricular wall strain and stress. The present work suggests that an electromechanical heart model, incorporating real geometry and fiber orientations, may be helpful for better

  16. Mechanical analysis of congestive heart failure caused by bundle branch block based on an electromechanical canine heart model

    Science.gov (United States)

    Dou, Jianhong; Xia, Ling; Zhang, Yu; Shou, Guofa; Wei, Qing; Liu, Feng; Crozier, Stuart

    2009-01-01

    Asynchronous electrical activation, induced by bundle branch block (BBB), can cause reduced ventricular function. However, the effects of BBB on the mechanical function of heart are difficult to assess experimentally. Many heart models have been developed to investigate cardiac properties during BBB but have mainly focused on the electrophysiological properties. To date, the mechanical function of BBB has not been well investigated. Based on a three-dimensional electromechanical canine heart model, the mechanical properties of complete left and right bundle branch block (LBBB and RBBB) were simulated. The anatomical model as well as the fiber orientations of a dog heart was reconstructed from magnetic resonance imaging (MRI) and diffusion tensor MRI (DT-MRI). Using the solutions of reaction-diffusion equations and with a strategy of parallel computation, the asynchronous excitation propagation and intraventricular conduction in BBB was simulated. The mechanics of myocardial tissues were computed with time-, sarcomere length-dependent uniaxial active stress initiated at the time of depolarization. The quantification of mechanical intra- and interventricular asynchrony of BBB was then investigated using the finite-element method with an eight-node isoparametric element. The simulation results show that (1) there exists inter- and intraventricular systolic dyssynchrony during BBB; (2) RBBB may have more mechanical synchrony and better systolic function of the left ventricle (LV) than LBBB; (3) the ventricles always move toward the early-activated ventricle; and (4) the septum experiences higher stress than left and right ventricular free walls in BBB. The simulation results validate clinical and experimental recordings of heart deformation and provide regional quantitative estimates of ventricular wall strain and stress. The present work suggests that an electromechanical heart model, incorporating real geometry and fiber orientations, may be helpful for better

  17. The RNA interference revolution

    Directory of Open Access Journals (Sweden)

    G. Lenz

    2005-12-01

    Full Text Available The discovery of double-stranded RNA-mediated gene silencing has rapidly led to its use as a method of choice for blocking a gene, and has turned it into one of the most discussed topics in cell biology. Although still in its infancy, the field of RNA interference has already produced a vast array of results, mainly in Caenorhabditis elegans, but recently also in mammalian systems. Micro-RNAs are short hairpins of RNA capable of blocking translation, which are transcribed from genomic DNA and are implicated in several aspects from development to cell signaling. The present review discusses the main methods used for gene silencing in cell culture and animal models, including the selection of target sequences, delivery methods and strategies for a successful silencing. Expected developments are briefly discussed, ranging from reverse genetics to therapeutics. Thus, the development of the new paradigm of RNA-mediated gene silencing has produced two important advances: knowledge of a basic cellular mechanism present in the majority of eukaryotic cells and access to a potent and specific new method for gene silencing.

  18. Life-Threatening and Suspicious Lesions Caused by Mechanical Cardiopulmonary Resuscitation

    DEFF Research Database (Denmark)

    Milling, Louise; Leth, Peter Mygind; Astrup, Birgitte Schmidt

    2017-01-01

    Chest compression devices for mechanical cardiopulmonary resuscitation (CPR) have become more common. Here, we report the case of a young woman who attempted resuscitated with LUCAS™2 after she was found unconscious at home. At autopsy, we found extensive intramuscular hemorrhages in posterior neck...... be attributed to automatic compression decompression CPR with LUCAS™2.The injuries may have been lethal had the patient survived. For the forensic pathologists, it is important to remain updated on developments in treatment techniques to avoid pitfalls when interpreting injury.Larger studies, prospective...... or retrospective, may be able to qualify the possible risks of automatic compression decompression CPR even further....

  19. Meckel’s diverticulitis causing small bowel obstruction by a novel mechanism

    Directory of Open Access Journals (Sweden)

    Vishalkumar G. Shelat

    2011-07-01

    Full Text Available Meckel’s diverticulum occurs in 2% of the general population and majority of patients remain asymptomatic. Gastrointestinal bleeding is the most common presentation in the paediatric population. While asymptomatic and incidentally found Meckel’s diverticulum may be left alone, surgery is essential for treating a symptomatic patient. Despite advances in imaging and technology, pre-operative diagnosis is often difficult. We present a first report of an unusual mechanism of small bowel obstruction due to Meckel’s diverticulitis in a paediatric patient. The diagnosis was only apparent at laparotomy.

  20. Biomechanical walking mechanisms underlying the metabolic reduction caused by an autonomous exoskeleton.

    Science.gov (United States)

    Mooney, Luke M; Herr, Hugh M

    2016-01-28

    Ankle exoskeletons can now reduce the metabolic cost of walking in humans without leg disability, but the biomechanical mechanisms that underlie this augmentation are not fully understood. In this study, we analyze the energetics and lower limb mechanics of human study participants walking with and without an active autonomous ankle exoskeleton previously shown to reduce the metabolic cost of walking. We measured the metabolic, kinetic and kinematic effects of wearing a battery powered bilateral ankle exoskeleton. Six participants walked on a level treadmill at 1.4 m/s under three conditions: exoskeleton not worn, exoskeleton worn in a powered-on state, and exoskeleton worn in a powered-off state. Metabolic rates were measured with a portable pulmonary gas exchange unit, body marker positions with a motion capture system, and ground reaction forces with a force-plate instrumented treadmill. Inverse dynamics were then used to estimate ankle, knee and hip torques and mechanical powers. The active ankle exoskeleton provided a mean positive power of 0.105 ± 0.008 W/kg per leg during the push-off region of stance phase. The net metabolic cost of walking with the active exoskeleton (3.28 ± 0.10 W/kg) was an 11 ± 4 % (p = 0.019) reduction compared to the cost of walking without the exoskeleton (3.71 ± 0.14 W/kg). Wearing the ankle exoskeleton significantly reduced the mean positive power of the ankle joint by 0.033 ± 0.006 W/kg (p = 0.007), the knee joint by 0.042 ± 0.015 W/kg (p = 0.020), and the hip joint by 0.034 ± 0.009 W/kg (p = 0.006). This study shows that the ankle exoskeleton does not exclusively reduce positive mechanical power at the ankle joint, but also mitigates positive power at the knee and hip. Furthermore, the active ankle exoskeleton did not simply replace biological ankle function in walking, but rather augmented the total (biological + exoskeletal) ankle moment and power. This study

  1. Experimental Investigation of the Root Cause Mechanism and Effectiveness of Mitigating Actions for Axial Offset Anomaly in Pressurized Water Reactors

    Energy Technology Data Exchange (ETDEWEB)

    Said Abdel-Khalik

    2005-07-02

    Axial offset anomaly (AOA) in pressurized water reactors refers to the presence of a significantly larger measured negative axial offset deviation than predicted by core design calculations. The neutron flux depression in the upper half of high-power rods experiencing significant subcooled boiling is believed to be caused by the concentration of boron species within the crud layer formed on the cladding surface. Recent investigations of the root-cause mechanism for AOA [1,2] suggest that boron build-up on the fuel is caused by precipitation of lithium metaborate (LiBO2) within the crud in regions of subcooled boiling. Indirect evidence in support of this hypothesis was inferred from operating experience at Callaway, where lithium return and hide-out were, respectively, observed following power reductions and power increases when AOA was present. However, direct evidence of lithium metaborate precipitation within the crud has, heretofore, not been shown because of its retrograde solubility. To this end, this investigation has been undertaken in order to directly verify or refute the proposed root-cause mechanism of AOA, and examine the effectiveness of possible mitigating actions to limit its impact in high power PWR cores.

  2. Mechanisms and Feedbacks Causing Changes in Upper Stratospheric Ozone in the 21st Century

    Science.gov (United States)

    Oman, Luke; Waugh, D. W.; Kawa, S. R.; Stolarski, R. S.; Douglass, A. R.; Newman, P. A.

    2009-01-01

    Stratospheric ozone is expected to increase during the 21st century as the abundance of halogenated ozone-depleting substances decrease to 1960 values. However, climate change will likely alter this "recovery" of stratospheric ozone by changing stratospheric temperatures, circulation, and abundance of reactive chemical species. Here we quantity the contribution of different mechanisms to changes in upper stratospheric ozone from 1960 to 2100 in the Goddard Earth Observing System Chemistry-Climate Model (GEOS CCM), using multiple linear regression analysis applied to simulations using either Alb or A2 greenhouse gas (GHG) scenarios. In both these scenarios upper stratospheric ozone has a secular increase over the 21st century. For the simulation using the Alb GHG scenario, this increase is determined by the decrease in halogen amounts and the greenhouse gas induced cooling, with roughly equal contributions from each mechanism. There is a larger cooling in the simulation using the A2 GHG scenario, but also enhanced loss from higher NOy and HOx concentrations, which nearly offsets the increase due to cooler temperatures. The resulting ozone evolutions are similar in the A2 and Alb simulations. The response of ozone due to feedbacks from temperature and HOx changes, related to changing halogen concentrations, are also quantified using simulations with fixed halogen concentrations.

  3. MECHANISMS IN ENDOCRINOLOGY: Aberrations of the X chromosome as cause of male infertility.

    Science.gov (United States)

    Röpke, Albrecht; Tüttelmann, Frank

    2017-06-13

    Male infertility is most commonly caused by spermatogenetic failure, clinically noted as oligo- or azoospermia. Today, in approximately 20% of azoospermic patients, a causal genetic defect can be identified. The most frequent genetic causes of azoospermia (or severe oligozoospermia) are Klinefelter syndrome (47,XXY), structural chromosomal abnormalities and Y-chromosomal microdeletions. Consistently with Ohno's law, the human X chromosome is the most stable of all the chromosomes, but contrary to Ohno's law, the X chromosome is loaded with regions of acquired, rapidly evolving genes, which are of special interest because they are predominantly expressed in the testis. Therefore, it is not surprising that the X chromosome, considered as the female counterpart of the male associated Y chromosome, may actually play an essential role in male infertility and sperm production. This is supported by the recent description of a significantly increased CNV burden on both sex chromosomes in infertile men and point mutations in X-chromosomal genes responsible for male infertility. Thus, the X chromosome seems to be frequently affected in infertile male patients. Four principal X-chromosomal aberrations have been identified so far: 1) aneuploidy of the X chromosome as found in Klinefelter syndrome (47,XXY or mosaicism for additional X chromosomes). 2) Translocations involving the X chromosome, e.g. nonsyndromic 46,XX testicular disorders of sex development (XX-male syndrome) or X-autosome translocations. 3) Copy Number Variations (CNVs) affecting the X chromosome. 4) Point mutations disrupting X-chromosomal genes. All of these are reviewed herein and assessed concerning their importance for the clinical routine diagnostic workup of the infertile male as well as their potential to shape research on spermatogenic failure in the next years.

  4. Mechanisms governing the direct removal of wastes from the Waste Isolation Pilot Plant repository caused by exploratory drilling

    Energy Technology Data Exchange (ETDEWEB)

    Berglund, J.W. [New Mexico Engineering Research Inst., Albuquerque, NM (United States)

    1992-12-01

    Two processes are identified that can influence the quantity of wastes brought to the ground surface when a waste disposal room of the Waste Isolation Pilot Plant is inadvertently penetrated by an exploratory borehole. The first mechanism is due to the erosion of the borehole wall adjacent to the waste caused by the flowing drilling fluid (mud); a quantitative computational model based upon the flow characteristics of the drilling fluid (laminar or turbulent) and other drilling parameters is developed and example results shown. The second mechanism concerns the motion of the waste and borehole spall caused by the flow of waste-generated gas to the borehole. Some of the available literature concerning this process is discussed, and a number of elastic and elastic-plastic finite-difference and finite-element calculations are described that confirm the potential importance of this process in directly removing wastes from the repository to the ground surface. Based upon the amount of analysis performed to date, it is concluded that it is not unreasonable to expect that volumes of waste several times greater than that resulting from direct cutting of a gauge borehole could eventually reach the ground surface. No definitive quantitative model for waste removal as a result of the second mechanism is presented; it is concluded that decomposed waste constitutive data must be developed and additional experiments performed to assess further the full significance of this latter mechanism.

  5. Forming Mechanism and Correction of CT Image Artifacts Caused by the Errors of Three System Parameters

    Directory of Open Access Journals (Sweden)

    Ming Chen

    2013-01-01

    Full Text Available We know that three system parameters, a center of X-ray source, an isocenter, and a center of linear detectors, are very difficult to be calibrated in industrial CT system. So there are often the offset of an isocenter and the deflection of linear detectors. When still using the FBP (filtered backprojection algorithm under this condition, CT image artifacts will happen and then can seriously affect test results. In this paper, we give the appearances and forming mechanism of these artifacts and propose the reconstruction algorithm including a deflection angle of linear detectors. The numerical experiments with simulated data have validated that our propose algorithm can correct CT images artifacts without data rebinning.

  6. Prelamin A causes progeria through cell-extrinsic mechanisms and prevents cancer invasion

    Science.gov (United States)

    de la Rosa, Jorge; Freije, José M. P.; Cabanillas, Rubén; Osorio, Fernando G.; Fraga, Mario F.; Fernández-García, M. Soledad; Rad, Roland; Fanjul, Víctor; Ugalde, Alejandro P.; Liang, Qi; Prosser, Haydn M.; Bradley, Allan; Cadiñanos, Juan; López-Otín, Carlos

    2013-01-01

    Defining the relationship between ageing and cancer is a crucial but challenging task. Mice deficient in Zmpste24, a metalloproteinase mutated in human progeria and involved in nuclear prelamin A maturation, recapitulate multiple features of ageing. However, their short lifespan and serious cell-intrinsic and cell-extrinsic alterations restrict the application and interpretation of carcinogenesis protocols. Here we present Zmpste24 mosaic mice that lack these limitations. Zmpste24 mosaic mice develop normally and keep similar proportions of Zmpste24-deficient (prelamin A accumulating) and Zmpste24-proficient (mature lamin A containing) cells throughout life, revealing that cell-extrinsic mechanisms are preeminent for progeria development. Moreover, prelamin A accumulation does not impair tumour initiation and growth, but it decreases the incidence of infiltrating oral carcinomas. Accordingly, silencing of ZMPSTE24 reduces human cancer cell invasiveness. Our results support the potential of cell-based and systemic therapies for progeria and highlight ZMPSTE24 as a new anticancer target. PMID:23917225

  7. Prelamin A causes progeria through cell-extrinsic mechanisms and prevents cancer invasion.

    Science.gov (United States)

    de la Rosa, Jorge; Freije, José M P; Cabanillas, Rubén; Osorio, Fernando G; Fraga, Mario F; Fernández-García, M Soledad; Rad, Roland; Fanjul, Víctor; Ugalde, Alejandro P; Liang, Qi; Prosser, Haydn M; Bradley, Allan; Cadiñanos, Juan; López-Otín, Carlos

    2013-01-01

    Defining the relationship between ageing and cancer is a crucial but challenging task. Mice deficient in Zmpste24, a metalloproteinase mutated in human progeria and involved in nuclear prelamin A maturation, recapitulate multiple features of ageing. However, their short lifespan and serious cell-intrinsic and cell-extrinsic alterations restrict the application and interpretation of carcinogenesis protocols. Here we present Zmpste24 mosaic mice that lack these limitations. Zmpste24 mosaic mice develop normally and keep similar proportions of Zmpste24-deficient (prelamin A-accumulating) and Zmpste24-proficient (mature lamin A-containing) cells throughout life, revealing that cell-extrinsic mechanisms are preeminent for progeria development. Moreover, prelamin A accumulation does not impair tumour initiation and growth, but it decreases the incidence of infiltrating oral carcinomas. Accordingly, silencing of ZMPSTE24 reduces human cancer cell invasiveness. Our results support the potential of cell-based and systemic therapies for progeria and highlight ZMPSTE24 as a new anticancer target.

  8. Systematization of the Mechanism by Which Plasma Irradiation Causes Cell Growth and Tumor Cell Death

    Science.gov (United States)

    Shimizu, Nobuyuki

    2015-09-01

    New methods and technologies have improved minimally invasive surgical treatment and saved numerous patients. Recently, plasma irradiation has been demonstrated that might be useful in medical field and the plasma irradiation device is expected to become practically applicable. Mild plasma coagulator showed some advantages such as hemostasis and adhesion reduction in experimental animal model, but the mechanism of plasma irradiation remains unclear. Our study group aim to clarify the mechanism of plasma irradiation effects, mainly focusing on oxidative stress using cultured cell lines and small animal model. First, a study using cultured cell lines showed that the culture medium that was activated by plasma irradiation (we called this kind of medium as ``PAM'' -plasma activated medium-) induced tumor cell death. Although this effect was mainly found to be due to hydrogen peroxide, the remaining portion was considered as the specific effect of the plasma irradiation and we are now studying focusing on this effect. Second, we established a mouse intra-peritoneal adhesion model and checked biological reaction that occurred in the adhesion part. Histopathological study showed inflammatory cells infiltration into adhesion part and the expression of PTX3 that might involve tissue repair around adhesion part. We also confirmed that cytokines IL-6 and IL-10 might be useful as a marker of adhesion formation in this model. Applying ``PAM'' or mild plasma irradiation in this model, we examine the effects of plasma on inflamed cells. The samples in these experiments would be applied to targeted proteomics analysis, and we aim to demonstrate the systematization of the cell's reaction by plasma irradiation.

  9. [The regulation mechanism of protein kinase Cδ on arsenic liver injury caused by coal-burning].

    Science.gov (United States)

    Hu, Yong; Zhang, Ai-hua; Yao, Mao-lin; Tang, Xu-dong; Huang, Xiao-xin

    2013-09-01

    To investigate the effects of mRNA transcriptional and protein expressions of protein kinase Cδ (PKCδ) on the development of arsenic liver injury caused by coal-burning. Population study:133 arsenic exposures were selected as arsenic exposure groups including the ward non-patient group (25 cases) , no obvious hepatopathy group (38 cases) , mild (43 cases) and moderate to severe hepatopathy group (27 cases) from the area with endemic arsenism in Guizhou province. Another 34 healthy residents were selected as the control group in non-arsenic pollution village. The urine and peripheral blood were collected from the subjects. The arsenic contents in urine and mRNA expressions of PKCδ in peripheral blood were detected. Animal experiment study:thirty wistar rats were randomly by random number table divided into control group, drinking water arsenic poisoning group and coal-burning arsenic poisoning group (i.e., low, medium and high arsenic contaminated grain group) by random number table method, including 6 rats in each group. The control group was fed normally for 3 months, drinking water arsenic poisoning group and coal-burning arsenic poisoning groups were fed respectively with 10 mg/kg As2O3 solution and different concentrations (25, 50 and 100 mg/kg) of arsenic-containing feed which was persisted 3 months. The arsenic contents in urine, mRNA expression levels of PKCδ in peripheral blood and liver tissue and the protein expression levels of phosphorylated protein kinase Cδ(pPKCδ) in liver tissue were detected. The median(quartile) of arsenic contents in urine were 25.58 (18.62-40.73), 56.66 (38.93-76.77), 64.90 (39.55- 98.37) and 75.47 (41.30-109.70) µg/g Cr respectively for the non-patient group, no obvious hepatopathy group, mild and moderate to severe hepatopathy group. The levels were higher than that in the control group (23.34 (17.84-37.45) µg/g Cr) (P arsenic contents in rat urine were 2223.61 (472.98-3976.73), 701.16 (194.01-1300.27), 1060.94 (246

  10. Recovery of dynamic interference

    CERN Document Server

    Baghery, Mehrdad; Rost, Jan M

    2016-01-01

    We develop general quantitative criteria for dynamic interference, a manifestation of double-slit interference in time which should be realizable with brilliant state-of-the-art high-frequency laser sources. Our analysis reveals that the observation of dynamic interference hinges upon maximizing the difference between the dynamic polarization of the initial bound and the final continuum state of the electron during the light pulse, while keeping depletion of the initial state small. Confirmed by numerical results, we predict that this is impossible for the hydrogen ground-state but feasible with excited states explicitly exemplified with the hydrogen 2p-state.

  11. Group Based Interference Alignment

    CERN Document Server

    Ma, Yanjun; Chen, Rui; Yao, Junliang

    2010-01-01

    in $K$-user single-input single-output (SISO) frequency selective fading interference channels, it is shown that the achievable multiplexing gain is almost surely $K/2$ by using interference alignment (IA). However when the signaling dimensions is limited, allocating all the resource to all the users simultaneously is not optimal. According to this problem, a group based interference alignment (GIA) scheme is proposed and a search algorithm is designed to get the group patterns and the resource allocation among them. Analysis results show that our proposed scheme achieves a higher multiplexing gain when the resource is limited.

  12. RNAi的作用机制及其在口腔医学领域的研究进展%Mechanism and application of RNA interference in stomatology

    Institute of Scientific and Technical Information of China (English)

    葛奕辰; 陆文昕; 李燕

    2016-01-01

    RNA干扰是由双链RNA诱发的使特定序列基因沉默的现象,存在小干扰RNA( siRNA)和微小RNA ( miRNA)两种不同的途径,主要有转录水平基因沉默,转录后水平基因沉默和翻译水平基因沉默三种机制,具有高效性和高特异性的特点。本文就RNAi的途径、技术路线及RNA干扰在牙齿发育、唇腭裂研究、牙周组织和口腔肿瘤中的研究进展作一综述。%RNA interference ( RNAi) is a sequence-specific gene silencing phenomena mediated by double-stranded RNA which in-volves siRNA (Small interfering RNA) and miRNA (Micro RNA), and it could block gene expression at the level of transcription, post-transcription and translation, with high efficiency and specificity. This review summarized the pathway and technical route, and the application of RNAi in maxillofacial development, cheilopalatognathus researches, periodontal tissue development and oral tumor researches in stomatology.

  13. Biocontrol mechanisms of Trichoderma harzianum against soybean charcoal rot caused by Macrophomina phaseolina

    Directory of Open Access Journals (Sweden)

    Khaledi Nima

    2016-01-01

    Full Text Available Throughout the world, charcoal rot, caused by Macrophomina phaseolina, is one of the most destructive and widespread diseases of crop plants such as soybean. In this study, the biological control capability of 11 Trichoderma spp. isolates against M. phaseolina was investigated using screening tests. Among all the tested Trichoderma spp. isolates, inhibition varied from 20.22 to 58.67% in dual culture tests. Dual culture, volatile and non-volatile tests revealed that two isolates of Trichoderma harzianum (including the isolates T7 and T14 best inhibited the growth of M. phaseolina in vitro. Therefore, these isolates were selected for biocontrol of M. phaseolina in vivo. The results of greenhouse experiments revealed that disease severity in the seed treatment with T. harzianum isolates was significantly lower than that of the soil treatment. In most of the cases, though, soil treatment with T. harzianum resulted in higher plant growth parameters, such as root and shoot weight. The effects of T. harzianum isolates on the activity of peroxidase enzyme and phenolic contents of the soybean root in the presence and absence of M. phaseolina were determined in greenhouse conditions. Our results suggested that a part of the inhibitory effect of T. harzianum isolates on soybean charcoal rot might be related to the indirect influence on M. phaseolina. Plant defense responses were activated as an elicitor in addition to the direct effect on the pathogen growth.

  14. Insight into the mechanism of reproductive dysfunction caused by neonicotinoid pesticides.

    Science.gov (United States)

    Hoshi, Nobuhiko; Hirano, Tetsushi; Omotehara, Takuya; Tokumoto, Junko; Umemura, Yuria; Mantani, Youhei; Tanida, Takashi; Warita, Katsuhiko; Tabuchi, Yoshiaki; Yokoyama, Toshifumi; Kitagawa, Hiroshi

    2014-01-01

    Neonicotinoids, which were developed in the 1990 s as an insecticide having selective toxicity, were later found to cause reproductive abnormalities in experimental animals. In Japan there is an attempt to preserve endangered animals, including the Japanese crested ibis, and there is a question of whether neonicotinoids affect the reproduction of this bird, since they are used in its habitat. Hence, we investigated whether the daily oral administration of the neonicotinoid clothianidin (CTD) has any deleterious effects on the reproductive function of mature male only or both young male and female quails as experimental animals. Vacuolization and the number of germ cells having fragmented DNA in seminiferous tubules, as well as the number and size of vacuoles in hepatocytes, increased dose-dependently. The ovaries showed abnormal histology in the granulosa cells, which produce progesterone. There were significant differences in egg-laying rates and embryo weights between the groups. Glutathione Peroxidase 4 (GPx4) and Manganese Superoxide Dismutase (Mn-SOD), which protect the organism from oxidative damage, showed a dose-dependent decrease. Thus, it is possible neonicotinoids affect the bird's reproductive system through oxidative stress, reflecting an imbalance between the production of reactive oxygen species (ROS) and a biological system's ability to readily detoxify the reactive intermediates or easily repair the resulting damage. Responding to our study, Sado Island has since succeeded in breeding Japanese crested ibis in the wild without the use of neonicotinoids.

  15. DMPP causes relaxation of rat distal colon by a purinergic and a nitrergic mechanism.

    Science.gov (United States)

    Börjesson, L; Nordgren, S; Delbro, D S

    1997-09-10

    The non-adrenergic relaxation of carbachol precontracted longitudinal muscle of the rat distal colon was investigated. Intrinsic nerves were activated by the nicotinic, ganglionic receptor agonist, 1,1-dimethyl-4-phenylpiperazinium iodide (DMPP). DMPP at 1 and 4 microM caused a relaxation that was markedly antagonized by the nerve blocker tetrodotoxin (1 microM) or the nicotinic receptor antagonist, hexamethonium (1 mM). The response to DMPP was significantly antagonized by apamin (an inhibitor of ATP-sensitive K+-channels), by reactive blue 2 (a blocker of P2y purinoceptors) and by an inhibitor of nitric oxide (NO)-synthase (N(G)-nitro-L-arginine, L-NNA). The combined treatment with reactive blue 2 and L-NNA reduced the relaxatory response to 1 microM DMPP by 77 +/- 8% and to 4 microM DMPP by 58 +/- 4% of control, but left a residual component. Our results indicate that ATP and NO, together with at least one additional (hitherto unidentified) substance may be inhibitory neurotransmitters in rat distal colon.

  16. Mechanism underlying the inner membrane retention of Escherichia coli lipoproteins caused by Lol avoidance signals.

    Science.gov (United States)

    Hara, Takashi; Matsuyama, Shin-ichi; Tokuda, Hajime

    2003-10-10

    Escherichia coli lipoproteins are localized to either the inner or outer membrane depending on the residue at position 2. The inner membrane retention signal, Asp at position 2 in combination with certain residues at position 3, functions as a Lol avoidance signal, i.e. the signal inhibits the recognition of lipoproteins by LolCDE that releases lipoproteins from the inner membrane. To understand the role of the residue at position 2, outer membrane-specific lipoproteins with Cys at position 2 were subjected to chemical modification followed by the release reaction in reconstituted proteoliposomes. Sulfhydryl-specific introduction of nonprotein molecules or a negative charge to Cys did not inhibit the LolCDE-dependent release. In contrast, oxidation of Cys to cysteic acid resulted in generation of the Lol avoidance signal, indicating that the Lol avoidance signal requires a critical length of negative charge at the second residue. Furthermore, not only modification of the carboxylic acid of Asp at position 2 but also that of the amine of phosphatidylethanolamine abolished the Lol avoidance function. Based on these results, the Lol avoidance mechanism is discussed.

  17. Interference and Polarized Light.

    Science.gov (United States)

    Charas, Seymour

    1988-01-01

    Discusses a demonstration of interference phenomena using three sheets of polaroid material, a light source, and a light meter. Describes instructional procedures with mathematical expressions and a diagram. (YP)

  18. Desiccation resistance in tropical insects: causes and mechanisms underlying variability in a Panama ant community.

    Science.gov (United States)

    Bujan, Jelena; Yanoviak, Stephen P; Kaspari, Michael

    2016-09-01

    Desiccation resistance, the ability of an organism to reduce water loss, is an essential trait in arid habitats. Drought frequency in tropical regions is predicted to increase with climate change, and small ectotherms are often under a strong desiccation risk. We tested hypotheses regarding the underexplored desiccation potential of tropical insects. We measured desiccation resistance in 82 ant species from a Panama rainforest by recording the time ants can survive desiccation stress. Species' desiccation resistance ranged from 0.7 h to 97.9 h. We tested the desiccation adaptation hypothesis, which predicts higher desiccation resistance in habitats with higher vapor pressure deficit (VPD) - the drying power of the air. In a Panama rainforest, canopy microclimates averaged a VPD of 0.43 kPa, compared to a VPD of 0.05 kPa in the understory. Canopy ants averaged desiccation resistances 2.8 times higher than the understory ants. We tested a number of mechanisms to account for desiccation resistance. Smaller insects should desiccate faster given their higher surface area to volume ratio. Desiccation resistance increased with ant mass, and canopy ants averaged 16% heavier than the understory ants. A second way to increase desiccation resistance is to carry more water. Water content was on average 2.5% higher in canopy ants, but total water content was not a good predictor of ant desiccation resistance or critical thermal maximum (CT max), a measure of an ant's thermal tolerance. In canopy ants, desiccation resistance and CT max were inversely related, suggesting a tradeoff, while the two were positively correlated in understory ants. This is the first community level test of desiccation adaptation hypothesis in tropical insects. Tropical forests do contain desiccation-resistant species, and while we cannot predict those simply based on their body size, high levels of desiccation resistance are always associated with the tropical canopy.

  19. Study on sand particles creep model and open pit mine landslide mechanism caused by sand fatigue liquefaction

    Science.gov (United States)

    Du, Dong-Ning; Wang, Lai-Gui; Zhang, Xiang-Dong; Zhang, Shu-Kun

    2017-06-01

    The sand particles in the sand - rock composite slope of the open pit mine occurs creep deformation and fatigue liquefaction under the action of vehicle load vibration and hydraulic gradient, which causes landslide geological disasters and it destroys the surface environment. To reveal the mechanism, a mechanics model based on the model considering the soil structural change with a new “plastic hinge” element is developed, to improve its constitutive and creep curve equations. Data from sand creep experiments are used to identify the parameters in the model and to validate the model. The results show that the mechanical model can describe the rotation progress between the sand particles, disclose the negative acceleration creep deformation stage during the third phase, and require fewer parameters while maintaining accuracy. It provides a new creep model considering rotation to analyze sand creep mechanism, which provides a theoretical basis for revealing the open pit mine landslide mechanism induced by creep deformation and fatigue liquefaction of sandy soil.

  20. Adhesions due to peritoneal carcinomatosis caused by a renal carcinoma leading to mechanical gastric outlet obstruction: a case report

    Directory of Open Access Journals (Sweden)

    Gruttadauria Salvatore

    2011-07-01

    Full Text Available Abstract Introduction Gastric outlet obstruction is a clinical syndrome caused by a variety of mechanical obstructions. Peptic ulcer disease used to be responsible for most gastric outlet obstruction, but in the last 40 years the prevalence of malignant tumors has risen significantly. Adhesive disease is an infrequent and insidious cause of mechanical gastric outlet obstruction. Case presentation We report the case of a 78-year-old Caucasian man who had a clinical history of a right nephrectomy for malignancy three years earlier and who was admitted for a severe gastric outlet obstruction (score of 1 confirmed both by an upper endoscopy and by a fluoroscopic view after contrast injection. A computed tomography scan and a laparotomy, with omental biopsies, showed a peritoneal carcinomatosis with the development of abdominal adhesions that prompted an abnormal gastric rotation around the perpendicular axis of his antrum with a dislocation in the empty space of his right kidney. Symptoms disappeared after surgical bypass through a gastrojejunostomy. Conclusions Our patient experienced a very rare complication characterized by the development of adhesions due to peritoneal carcinomatosis caused by a renal carcinoma treated with nephrectomy. These adhesions prompted an abnormal dislocation of his antrum, as an internal hernia, in the empty space of his right kidney.

  1. Differential ammonia decay kinetics indicates more than one concurrent etiological mechanism for symptomatic hyperammonemia caused by valproate overdose

    Directory of Open Access Journals (Sweden)

    Deb Kumar Mojumder

    2014-01-01

    Full Text Available Valproic acid (VPA has successfully been used in the therapy of a number of conditions including absence seizures, partial seizures, tonic-clonic seizures, bipolar disorder, schizoaffective disorder, social phobias, neuropathic pain and migraine headaches. There is a high rise in number of cases of toxicity due to overdose of VPA. Hyperammonemia, a common side-effect of VPA, is caused by several proposed etiologies, reported as having uncertain correlation with VPA dose or concentration. We present here a case of a 25-year-old female patient with a past history of psychiatric complaints, presented with elevated serum VPA levels associated with elevated venous ammonia levels subsequent to VPA overdose. Later in the presence of sub-therapeutic serum VPA levels her venous ammonia levels remained raised and slowly down-trending. VPA levels and ammonia levels were found to be normal after 14 days. Patient was treated with levocarnitine. Her liver enzymes were never elevated. Different decay kinetics of venous ammonia in presence of high and low concentrations of VPA indicates that VPA can cause symptomatic hyperammonemia via more than one concurrent etiological mechanism. In this patient, the mechanisms causing hyperammonia secondary to VPA use were not related to hepatic damage or carnitine deficiency.

  2. Embracing interference in wireless systems

    CERN Document Server

    Gollakota, Shyamnath

    2014-01-01

    The wireless medium is a shared resource. If nearby devices transmit at thesame time, their signals interfere, resulting in a collision. In traditionalnetworks, collisions cause the loss of the transmitted information. For thisreason, wireless networks have been designed with the assumption thatinterference is intrinsically harmful and must be avoided.This book, a revised version of the author's award-winning Ph.D.dissertation, takes an alternate approach: Instead of viewing interferenceas an inherently counterproductive phenomenon that should to be avoided, wedesign practical systems that tra

  3. Therapeutic mechanism investigation of RNA interference in Alzheimer's disease%RNA干扰对老年性痴呆症的治疗机制研究

    Institute of Scientific and Technical Information of China (English)

    罗焕敏; 邓惠; 黄丰

    2005-01-01

    Alzheimer's disease is a neurodengenerative disorder disease with the progressive cognition malfunction and memory impairment. This article analyze the biochemical cause of Alzheimer's disease and evaluate the eurrent status of drug therapy for the disease, and prediet the possibility of RNA intefferenee in the therapy of Alzheimer's disease.

  4. CRISPR interference: a structural perspective

    Science.gov (United States)

    Reeks, Judith; Naismith, James H.; White, Malcolm F.

    2013-01-01

    CRISPR (cluster of regularly interspaced palindromic repeats) is a prokaryotic adaptive defence system, providing immunity against mobile genetic elements such as viruses. Genomically encoded crRNA (CRISPR RNA) is used by Cas (CRISPR-associated) proteins to target and subsequently degrade nucleic acids of invading entities in a sequence-dependent manner. The process is known as ‘interference’. In the present review we cover recent progress on the structural biology of the CRISPR/Cas system, focusing on the Cas proteins and complexes that catalyse crRNA biogenesis and interference. Structural studies have helped in the elucidation of key mechanisms, including the recognition and cleavage of crRNA by the Cas6 and Cas5 proteins, where remarkable diversity at the level of both substrate recognition and catalysis has become apparent. The RNA-binding RAMP (repeat-associated mysterious protein) domain is present in the Cas5, Cas6, Cas7 and Cmr3 protein families and RAMP-like domains are found in Cas2 and Cas10. Structural analysis has also revealed an evolutionary link between the small subunits of the type I and type III-B interference complexes. Future studies of the interference complexes and their constituent components will transform our understanding of the system. PMID:23805973

  5. UHV交流输电线路有源干扰下无方向信标台功率限值的分析%Analysis of Non-directional Radio Beacon Power Limit Under the Condition of Active Interference Caused by UHV AC Transmission Line

    Institute of Scientific and Technical Information of China (English)

    周铖路; 翁木云; 陈凤

    2015-01-01

    有关UHV交流输电线路与无方向信标台电磁兼容方面的研究主要集中在防护距离的分析,对间距无法满足要求时的兼容问题研究较少。为此,从台站频谱参数入手,分析特高压交流输电线路有源干扰下无方向信标台的发射功率限值。首先介绍无方向信标台的工作原理及配置区域,然后分析UHV交流输电线路对台站的干扰机理,最后根据飞行航迹,以防护率为干扰判别依据,结合防护距离的研究,分别针对航路无方向信标台、近距无方向信标台和远距无方向信标台进行有效辐射功率的分析。结果表明,在给定条件下,对于航路和远距无方向信标台,有效辐射功率分别大于5.298 W、5.273 W时,机载无线电罗盘不受干扰;对于近距无方向信标台,与输电线路始终满足兼容的要求,无需分析限值。%The EMC research between UHV AC transmission line and non-directional radio beacon mainly focused on the protection distance while the study of EMC is little when the protection distance cannot meet the requirements. Therefore, the non-directional radio beacon power limit under the condition of active interference caused by UHV AC transmission line is analyzed from the aspect of spectrum parameters. Firstly, the working principle and configuration area of non-directional radio beacon are introduced. Then the interference mechanism of non-directional radio beacon from UHV AC transmission line is analyzed. Finally, the effective radiated power (ERP) of route non-directional radio beacon, close non-directional radio beacon and distance non-directional radio beacon are analyzed according to the flight path and protection ratio in combination with protection distance research. The results show that under the given conditions, route non-directional radio beacon and distance non-directional radio beacon’s ERP should be greater than 5.298 W and 5.273 W respectively to keep

  6. Interference susceptibility measurements for an MSK satellite communication link

    Science.gov (United States)

    Kerczewski, Robert J.; Fujikawa, Gene

    1992-01-01

    The results are presented of measurements of the degradation of an MSK satellite link due to modulated and CW (unmodulated) interference. These measurements were made using a hardware based satellite communication link simulator at NASA-Lewis. The results indicate the amount of bit error rate degradation caused by CW interference as a function of frequency and power level, and the degradation caused by adjacent channel and cochannel modulated interference as a function of interference power level. Results were obtained for both the uplink case (including satellite nonlinearity) and the downlink case (linear channel).

  7. Pathogenic Cx31 is un/misfolded to cause skin abnormality via a Fos/JunB-mediated mechanism.

    Science.gov (United States)

    Tang, Chengyuan; Chen, Xiang; Chi, Jingwei; Yang, Dawei; Liu, Shu; Liu, Mujun; Pan, Qian; Fan, Jianbing; Wang, Danling; Zhang, Zhuohua

    2015-11-01

    Mutations in connexin-31 (Cx31) are associated with multiple human diseases, including familial erythrokeratodermia variabilis (EKV). The pathogenic mechanism of EKV-associated Cx31 mutants remains largely elusive. Here, we show that EKV-pathogenic Cx31 mutants are un/misfolded and temperature sensitive. In Drosophila, expression of pathogenic Cx31, but not wild-type Cx31, causes depigmentation and degeneration of ommatidia that are rescued by expression of either dBip or dHsp70. Ectopic expression of Cx31 in mouse skin results in skin abnormalities resembling human EKV. The affected tissues show remarkable disrupted gap junction formation and significant upregulation of chaperones Bip and Hsp70 as well as AP-1 proteins c-Fos and JunB, in addition to molecular signatures of skin diseases. Consistently, c-Fos, JunB, Bip and Hsp70 are strikingly higher in keratinocytes of EKV patients than their matched control individuals. Furthermore, a druggable AP-1 inhibitory small molecule suppresses skin phenotype and pathological abnormalities of transgenic Cx31 mice. The study suggests that Cx31 mutant proteins are un/misfolded to cause EKV likely via an AP-1-mediated mechanism and identifies a small molecule with therapeutic potential of the disease.

  8. Italian, French, Polish: in the Bermuda Triangle of linguistic interference

    Directory of Open Access Journals (Sweden)

    Małgorzata Balicka

    2009-01-01

    Full Text Available Increasing contacts between nations make people learn foreign languages. Unfortunately, the use of more than one language system may cause errors due to linguistic interference. In the present paper we consider different definitions of this phenomenon and describe the conditions reąuired for its presence, along with proposals on how to eliminate interference mistakes. A specific case is false friends, words similar in form but different in meaning, which can lead to misunderstandings or even disgrace. As interference implies the knowledge of at least two languages, bilingualism is another problem discussed in the paper. We present different approaches to interference and study the relation between bilingualism and interference. Finally, we discuss loanwords as one of the results of interference. With all these considerations in mind we can make a specific study of interference mistakes made by Polish students of Italian philology.

  9. Characteristics and mechanisms of cardiopulmonary injury caused by mine blasts in shoals: a randomized controlled study in a rabbit model.

    Directory of Open Access Journals (Sweden)

    Gengfen Han

    Full Text Available BACKGROUND: Because the characteristics of blast waves in water are different from those in air and because kinetic energy is liberated by a pressure wave at the water-air interface, thoracic injuries from mine blasts in shoals may be serious. The aim of the present study was to investigate the characteristics and mechanisms of cardiopulmonary injury caused by mine blasts in shoals. METHODS: To study the characteristics of cardiopulmonary injury, 56 animals were divided randomly into three experimental groups (12 animals in the sham group, 22 animals in the land group and 22 animals in the shoal group. To examine the biomechanics of injury, 20 animals were divided randomly into the land group and the shoal group. In the experimental model, the water surface was at the level of the rabbit's xiphoid process, and paper electric detonators (600 mg RDX were used to simulate mines. Electrocardiography and echocardiography were conducted, and arterial blood gases, serum levels of cardiac troponin I and creatine kinase-MB and other physiologic parameters were measured over a 12-hour period after detonation. Pressures in the thorax and abdomen and the acceleration of the thorax were measured. CONCLUSION: The results indicate that severe cardiopulmonary injury and dysfunction occur following exposure to mine blasts in shoals. Therefore, the mechanisms of cardiopulmonary injury may result from shear waves that produce strain at the water-air interface. Another mechanism of injury includes the propagation of the shock wave from the planta to the thorax, which causes a much higher peak overpressure in the abdomen than in the thorax; as a result, the abdominal organs and diaphragm are thrust into the thorax, damaging the lungs and heart.

  10. Understanding ghost interference

    Science.gov (United States)

    Qureshi, Tabish; Chingangbam, Pravabati; Shafaq, Sheeba

    2016-08-01

    The ghost interference observed for entangled photons is theoretically analyzed using wave-packet dynamics. It is shown that ghost interference is a combined effect of virtual double-slit creation due to entanglement, and quantum erasure of which-path information for the interfering photon. For the case where the two photons are of different color, it is shown that fringe width of the interfering photon depends not only on its own wavelength, but also on the wavelength of the other photon which it is entangled with.

  11. Retroactive Interference and Forgetting

    Directory of Open Access Journals (Sweden)

    Vinishaa Ankala

    2011-01-01

    Full Text Available Retroactive interference is the amount of information that can be forgotten by a person over time due to newly learned material. In this paper we establish a relationship between the amount of information forgotten by college students while they read and watch television and the time taken to forget it. We equate these numerical equations to solve for the unknown constants. By doing so, we can find the exact equation and also the amount of forgetting information due to retroactive interference.

  12. Telomerase inhibition by siRNA causes senescence and apoptosis in Barrett's adenocarcinoma cells: mechanism and therapeutic potential

    Directory of Open Access Journals (Sweden)

    Batchu Ramesh B

    2005-07-01

    Full Text Available Abstract Background In cancer cells, telomerase induction helps maintain telomere length and thereby bypasses senescence and provides enhanced replicative potential. Chemical inhibitors of telomerase have been shown to reactivate telomere shortening and cause replicative senescence and apoptotic cell death of tumor cells while having little or no effect on normal diploid cells. Results We designed siRNAs against two different regions of telomerase gene and evaluated their effect on telomere length, proliferative potential, and gene expression in Barrett's adenocarcinoma SEG-1 cells. The mixture of siRNAs in nanomolar concentrations caused a loss of telomerase activity that appeared as early as day 1 and was essentially complete at day 3. Inhibition of telomerase activity was associated with marked reduction in median telomere length and complete loss of detectable telomeres in more than 50% of the treated cells. Telomere loss caused senescence in 40% and apoptosis in 86% of the treated cells. These responses appeared to be associated with activation of DNA sensor HR23B and subsequent activation of p53 homolog p73 and p63 and E2F1. Changes in these gene regulators were probably the source of observed up-regulation of cell cycle inhibitors, p16 and GADD45. Elevated transcript levels of FasL, Fas and caspase 8 that activate death receptors and CARD 9 that interacts with Bcl10 and NFKB to enhance mitochondrial translocation and activation of caspase 9 were also observed. Conclusion These studies show that telomerase siRNAs can cause effective suppression of telomerase and telomere shortening leading to both cell cycle arrest and apoptosis via mechanisms that include up-regulation of several genes involved in cell cycle arrest and apoptosis. Telomerase siRNAs may therefore be strong candidates for highly selective therapy for chemoprevention and treatment of Barrett's adenocarcinoma.

  13. Cognitive Aware Interference Mitigation Scheme for LTE Femtocells

    KAUST Repository

    Alqerm, Ismail

    2015-04-21

    Femto-cells deployment in today’s cellular networks came into practice to fulfill the increasing demand for data services. However, interference to other femto and macro-cells users remains an unresolved challenge. In this paper, we propose an interference mitigation scheme to control the cross-tier interference caused by femto-cells to the macro users and the co-tier interference among femtocells. Cognitive radio spectrum sensing capability is utilized to determine the non-occupied channels or the ones that cause minimal interference to the macro users. An awareness based channel allocation scheme is developed with the assistance of the graph-coloring algorithm to assign channels to the femto-cells base stations with power optimization, minimal interference, maximum throughput, and maximum spectrum efficiency. In addition, the scheme exploits negotiation capability to match traffic load and QoS with the channel capacity, and to maintain efficient utilization of the available channels.

  14. Numerical correction of coherence gate in full-field swept-source interference microscopy.

    Science.gov (United States)

    Grebenyuk, Anton A; Ryabukho, Vladimir P

    2012-07-01

    A big problem in low-coherence interference microscopy is the degradation of the coherence signal caused by shift of the angular and temporal spectrum gates. It limits the depth of field in confocal optical coherence microscopy and degrades images of sample inner structure in most interference microscopy techniques. To overcome this problem we propose numerical correction of the coherence gate in application to full-field swept-source interference microscopy. The proposed technique allows three-dimensional sample imaging without mechanical movement of the microscope components and is also capable of determining separately the geometrical thickness and the refractive index of the sample layers, when the sample contains a transversal pattern. The applicability of the proposed technique is verified with numerical simulation.

  15. Direct observation of large quantum interference effect in anthraquinone solid-state junctions.

    Science.gov (United States)

    Rabache, Vincent; Chaste, Julien; Petit, Philippe; Della Rocca, Maria Luisa; Martin, Pascal; Lacroix, Jean-Christophe; McCreery, Richard L; Lafarge, Philippe

    2013-07-17

    Quantum interference in cross-conjugated molecules embedded in solid-state devices was investigated by direct current-voltage and differential conductance transport measurements of anthraquinone (AQ)-based large area planar junctions. A thin film of AQ was grafted covalently on the junction base electrode by diazonium electroreduction, while the counter electrode was directly evaporated on top of the molecular layer. Our technique provides direct evidence of a large quantum interference effect in multiple CMOS compatible planar junctions. The quantum interference is manifested by a pronounced dip in the differential conductance close to zero voltage bias. The experimental signature is well developed at low temperature (4 K), showing a large amplitude dip with a minimum >2 orders of magnitude lower than the conductance at higher bias and is still clearly evident at room temperature. A temperature analysis of the conductance curves revealed that electron-phonon coupling is the principal decoherence mechanism causing large conductance oscillations at low temperature.

  16. DANOS MECÂNICOS OCASIONADOS POR SISTEMAS DOSADORES DE SEMENTES MECHANICAL DAMAGE CAUSED BY SEED METERING SYSTEMS

    Directory of Open Access Journals (Sweden)

    Paulo Alcanfor Ximenes

    2007-09-01

    Full Text Available

    Avaliaram-se os efeitos de danos mecânicos ocasionados por cinco sistemas dosadores de sementes, em quatro culturas. Amostras das sementes foram coletadas antes e após passarem pelos sistemas dosadores e foram submetidas a testes de pureza, germinação e vigor. Não houve diferença entre os efeitos de danos mecânicos ocasionados pelos sistemas dosadores empregados nas sementes de milho. Para as sementes de feijão, menores efeitos foram verificados quando da utilização dos dosadores pneumático a vácuo e copo dosador. O sistema rotor acanalado causou menores danos às sementes de arroz e os sistemas disco  horizontal perfurado e copo dosador foram os que menos danificaram as sementes de soja. O sistema dosador pneumático a vácuo ocasionou o maior índice de dano mecânico nas sementes de soja.

    PALAVRAS-CHAVE: Semeadoras; distribuidores de sementes; rotor acanalado.

    Effects of mechanical damage caused by five seed metering systems were evaluated in four crops. Seed samples were collected before and after passing through the measuring systems and submitted to tests of purity, germination and vigor. There was no difference in the level of mechanical damage caused by the metering systems used for maize seeds. For common bean seeds, minor effects were verified when using the vacuum metering disk and the feed cup. The fluted feed system showed the best performance for rice seeds, and the horizontal perforated disk and feed cup systems exhibited the best results for soybean seeds. The vacuum metering disk system caused the highest level of mechanical damage to soybean seeds.

    KEY-WORDS: Planter machine; seed distributor; fluted feed.

  17. Dynamic spectrum management as an anti-interference method

    Science.gov (United States)

    Suchanski, M.; Matyszkiel, R.; Kaniewski, P.; Kustra, M.; Gajewski, P.; Łopatka, J.

    2017-04-01

    The rapid development of systems which use wireless technologies causes the escalation of the spectrum shortage problem. That is why the concept of coordinated dynamic spectrum management has appeared. It improves efficiency of the spectrum use and makes radio communication systems more resistant to interferences. The main element of the proposed solution is a frequency broker which provides frequency assignment plans for radio networks. Direct communication between the frequency broker and radio networks enables fast change of radio data. This paper presents an anti-interference method based on dynamic spectrum management, which is an implementation and extension of IST- 104/RTG-050 research task group "Cognitive Radio in NATO II" recommendations. The solution presented by the authors was tested in emulated and real environment. The designed algorithm of frequency assignment can effectively prevent interferences (including jamming) thanks to the implementation of monitoring mechanisms capable of obtaining information about the current state of radio channels from radio networks. Directions for further development of frequency planning algorithm based on belief distorted Nash equilibria for deterministic or stochastic beliefs were proposed.

  18. Interference cancellation technique under imperfect synchronization in cellular systems

    Institute of Scientific and Technical Information of China (English)

    WANG; Xin; WU; Zhuo

    2009-01-01

    In this paper, an asynchronous cooperative cellular system applied with space-time block coding(STBC)is investigated. A signal detector is proposed based on parallel interference cancellation(PIC), to cancel the inter-symbol interference(ISI)caused by the imperfect synchronization. Simulation results show that the proposed PIC detector can effectively suppress the ISI, but there is still a comparatively high error floor, due to the co-channel interference(CCI)of the cellular system.

  19. Destructive Interference of Dualities

    CERN Document Server

    Wotzasek, C

    1998-01-01

    We show that the fusion of two (diffeomorphism) invariant self-dual scalars described by right and left chiral-WZW actions, produces a Hull non-mover field. After fusion, right and left moving modes disappear from the spectrum, displaying in this way the phenomenon of (destructive) quantum interference of dualities.

  20. Interference Alignment for Secrecy

    CERN Document Server

    Koyluoglu, Onur Ozan; Lai, Lifeng; Poor, H Vincent

    2008-01-01

    This paper studies the frequency/time selective $K$-user Gaussian interference channel with secrecy constraints. Two distinct models, namely the interference channel with confidential messages and the one with an external eavesdropper, are analyzed. The key difference between the two models is the lack of channel state information (CSI) about the external eavesdropper. Using interference alignment along with secrecy pre-coding, it is shown that each user can achieve non-zero secure Degrees of Freedom (DoF) for both cases. More precisely, the proposed coding scheme achieves $\\frac{K-2}{2K-2}$ secure DoF {\\em with probability one} per user in the confidential messages model. For the external eavesdropper scenario, on the other hand, it is shown that each user can achieve $\\frac{K-2}{2K}$ secure DoF {\\em in the ergodic setting}. Remarkably, these results establish the {\\em positive impact} of interference on the secrecy capacity region of wireless networks.

  1. Quantum interference in polyenes

    Science.gov (United States)

    Tsuji, Yuta; Hoffmann, Roald; Movassagh, Ramis; Datta, Supriyo

    2014-12-01

    The explicit form of the zeroth Green's function in the Hückel model, approximated by the negative of the inverse of the Hückel matrix, has direct quantum interference consequences for molecular conductance. We derive a set of rules for transmission between two electrodes attached to a polyene, when the molecule is extended by an even number of carbons at either end (transmission unchanged) or by an odd number of carbons at both ends (transmission turned on or annihilated). These prescriptions for the occurrence of quantum interference lead to an unexpected consequence for switches which realize such extension through electrocyclic reactions: for some specific attachment modes the chemically closed ring will be the ON position of the switch. Normally the signs of the entries of the Green's function matrix are assumed to have no physical significance; however, we show that the signs may have observable consequences. In particular, in the case of multiple probe attachments - if coherence in probe connections can be arranged - in some cases new destructive interference results, while in others one may have constructive interference. One such case may already exist in the literature.

  2. Quantum interference in polyenes

    Energy Technology Data Exchange (ETDEWEB)

    Tsuji, Yuta; Hoffmann, Roald, E-mail: rh34@cornell.edu [Department of Chemistry and Chemical Biology, Cornell University, Baker Laboratory, Ithaca, New York 14853 (United States); Movassagh, Ramis [Department of Mathematics, Northeastern University, Boston, Massachusetts 02115, USA and Department of Mathematics, Massachusetts Institute of Technology, Building E18, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139-4307 (United States); Datta, Supriyo [School of Electrical and Computer Engineering, Purdue University, Electrical Engineering Building, 465 Northwestern Ave., West Lafayette, Indiana 47907-2035 (United States)

    2014-12-14

    The explicit form of the zeroth Green's function in the Hückel model, approximated by the negative of the inverse of the Hückel matrix, has direct quantum interference consequences for molecular conductance. We derive a set of rules for transmission between two electrodes attached to a polyene, when the molecule is extended by an even number of carbons at either end (transmission unchanged) or by an odd number of carbons at both ends (transmission turned on or annihilated). These prescriptions for the occurrence of quantum interference lead to an unexpected consequence for switches which realize such extension through electrocyclic reactions: for some specific attachment modes the chemically closed ring will be the ON position of the switch. Normally the signs of the entries of the Green's function matrix are assumed to have no physical significance; however, we show that the signs may have observable consequences. In particular, in the case of multiple probe attachments – if coherence in probe connections can be arranged – in some cases new destructive interference results, while in others one may have constructive interference. One such case may already exist in the literature.

  3. Laser Interference Lithography

    NARCIS (Netherlands)

    van Wolferen, Hendricus A.G.M.; Abelmann, Leon; Hennessy, Theodore C.

    In this chapter we explain how submicron gratings can be prepared by Laser Interference Lithography (LIL). In this maskless lithography technique, the standing wave pattern that exists at the intersection of two coherent laser beams is used to expose a photosensitive layer. We show how to build the

  4. Interference and radioastronomy

    Science.gov (United States)

    Thompson, A. R.; Vanden Bout, Paul A.; Gergely, Tomas E.

    1991-11-01

    The vulnerabilty of radio astronomy to the growing flood of interfering sources ranging from garage door openers to digital audio broadcast satellites is reviewed. Technical solutions to these problems are briefly examined, and work that needs to be done in the international regulatory system to ameliorate the interference is addressed. An overview is given of existing regulations.

  5. Mechanism study on mitochondrial fragmentation under oxidative stress caused by high-fluence low-power laser irradiation

    Science.gov (United States)

    Wu, Shengnan; Zhou, Feifan; Xing, Da

    2012-03-01

    Mitochondria are dynamic organelles that undergo continual fusion and fission to maintain their morphology and functions, but the mechanism involved is still not clear. Here, we investigated the effect of mitochondrial oxidative stress triggered by high-fluence low-power laser irradiation (HF-LPLI) on mitochondrial dynamics in human lung adenocarcinoma cells (ASTC-a-1). Upon HF-LPLI-triggered oxidative stress, mitochondria displayed a fragmented structure, which was abolished by exposure to dehydroascorbic acid (DHA), a reactive oxygen species scavenger, indicating that oxidative stress can induce mitochondrial fragmentation. Mitochondrial translocation of the profission protein dynamin-related protein 1 (Drp1) was observed following HF-LPLI, demonstrating apoptosis-related activation of Drp1. Notably, DHA pre-treatment prevented HF-LPLI-induced Drp1 activation. We conclude that mitochondrial oxidative stress through activation of Drp1 causes mitochondrial fragmentation.

  6. The effect of interference of endurance and concurrent (endurance-resistance training programs on femoral bone mineral density and mechanical strength of osteoporotic male rats

    Directory of Open Access Journals (Sweden)

    F nazem

    2016-01-01

    Full Text Available Background: There is no information available regarding the effect of an incremental Concurrent aerobic and resistance training protocol on osteogenic response of bone tissue for osteoporosis prevention and treatment. This study evaluate the efficacy of Concurrent training compared to endurance training for enhancing femoral bone mineral density and mechanical strength of osteoporotic male Wistar Rats. Methodology: In this experimental design, firstly among forty male Wistar rats, 8 rats were separated as healthy group. Then Osteoporosis induced in other rats by intraperitoneal injection of 20% alcohol/saline solution (3 g per kg of body weight. Injection were carried out in the first 4 days of the week, once a day for three consecutive weeks. Osteoporotic rats divided into 4 groups (n=8 per group: baseline, resistance training, concurrent training and control. The endurance training protocol included running on a treadmill with a 0% grade and at a constant speed 12 m/min to a maximum of 60 minutes per day. Concurrent group carried out a combination of both endurance and resistance trainings (4 series of climbs on the 110-cm vertical ladder angled at 80º with weights tied to animal tail and Observance the principle of overload at 50% of the total body mass of the animal in the first series to 100% in the fourth series. After completing 12 weeks of exercise trainings (5 days a week, the animals were euthanized, and excised left femurs were scanned for BMD measurement and examined by three point bending test to obtain the Maximum breaking-force and stiffness. Data analysis performed by Independent t-test for comparing among healthy and baseline groups, as well, one way- ANOVA was applied for assessment of inter groups viabilities. A p- value (0.05 was set for data statistical analysis. Result: The Concurrent group showed a significantly increased on BMD (p=0.000, maximum force (p=0.000 and stiffness (p=0.000 versus to control group. Endurance

  7. RNA interference and antiviral therapy

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    RNA interference (RNAi) is an evolutionally conserved gene silencing mechanism present in a variety of eukaryotic species. RNAi uses short double-stranded RNA (dsRNA) to trigger degradation or translation repression of homologous RNA targets in a sequence-specific manner. This system can be induced effectively in vitro and in vivo by direct application of small interfering RNAs (siRNAs), or by expression of short hairpin RNA (shRNA) with non-viral and viral vectors. To date, RNAi has been extensively used as a novel and effective tool for functional genomic studies, and has displayed great potential in treating human diseases, including human genetic and acquired disorders such as cancer and viral infections. In the present review, we focus on the recent development in the use of RNAi in the prevention and treatment of viral infections. The mechanisms,strategies, hurdles and prospects of employing RNAi in the pharmaceutical industry are also discussed.

  8. Influences of soil hydraulic and mechanical parameters on land subsidence and ground fissures caused by groundwater exploitation

    Institute of Scientific and Technical Information of China (English)

    陈兴贤; 骆祖江; 周世玲

    2014-01-01

    In order to study the influences of hydraulic and mechanical parameters on land subsidence and ground fissure caused by groundwater exploitation, based on the Biot’s consolidation theory and combined with the nonlinear rheological theory of soil, the constitutive relation in Biot’s consolidation theory is extended to include the viscoelastic plasticity, and the dynamic relationship among the porosity, the hydraulic conductivity, the parameters of soil deformation and effective stress is also considered, a three-dimensional full coupling mathematical model is established and applied to the study of land subsidence and ground fissures of Cangzhou in Hebei Province, through the analysis of parameter sensitivity, the influences of soil hydraulic and mechanical parame-ters on land subsidence and ground fissure are revealed. It is shown that the elastic modulus E , the Poisson ratio, the specific yield m and the soil cohesion c have a great influence on the land subsidence and the ground fissures. In addition, the vertical hydraulic conductivity zk and the horizontal hydraulic conductivity ks also have a great influence on the land subsidence and the ground fissures.

  9. Rice-Infecting Pseudomonas Genomes Are Highly Accessorized and Harbor Multiple Putative Virulence Mechanisms to Cause Sheath Brown Rot.

    Science.gov (United States)

    Quibod, Ian Lorenzo; Grande, Genelou; Oreiro, Eula Gems; Borja, Frances Nikki; Dossa, Gerbert Sylvestre; Mauleon, Ramil; Cruz, Casiana Vera; Oliva, Ricardo

    2015-01-01

    Sheath rot complex and seed discoloration in rice involve a number of pathogenic bacteria that cannot be associated with distinctive symptoms. These pathogens can easily travel on asymptomatic seeds and therefore represent a threat to rice cropping systems. Among the rice-infecting Pseudomonas, P. fuscovaginae has been associated with sheath brown rot disease in several rice growing areas around the world. The appearance of a similar Pseudomonas population, which here we named P. fuscovaginae-like, represents a perfect opportunity to understand common genomic features that can explain the infection mechanism in rice. We showed that the novel population is indeed closely related to P. fuscovaginae. A comparative genomics approach on eight rice-infecting Pseudomonas revealed heterogeneous genomes and a high number of strain-specific genes. The genomes of P. fuscovaginae-like harbor four secretion systems (Type I, II, III, and VI) and other important pathogenicity machinery that could probably facilitate rice colonization. We identified 123 core secreted proteins, most of which have strong signatures of positive selection suggesting functional adaptation. Transcript accumulation of putative pathogenicity-related genes during rice colonization revealed a concerted virulence mechanism. The study suggests that rice-infecting Pseudomonas causing sheath brown rot are intrinsically diverse and maintain a variable set of metabolic capabilities as a potential strategy to occupy a range of environments.

  10. [Induction mechanism of shock: applying the etiology in judgment of the cause of death in forensic practice].

    Science.gov (United States)

    Tanaka, Noriyuki

    2004-09-01

    In the field of forensic medicine, shock has been identified as a cause of death owing to various kinds of exogenous insults. The etiology and pathogenesis of shock cannot be explained well by the usual gross appearance in medicolegal autopsies, because it is now generally established that the shock is a functional reaction of the vascular system to bodily injury, and that several organs are secondarily impaired during shock. Thus it seemed to forensic pathologists that these morphological changes in several organs after shock did not reveal any significant differences among the causes of death. We approached to the induction mechanism of shock, and we investigated what etiology induced these morphological changes after shock in order to identify shock as the cause of death. It is now generally accepted that the kidney is a target organ of shock, so we mainly investigated the cause of kidney disorder in a case of burn shock and hemorrhagic shock. 1. Consequences of bacterial translocation (BT) in the shock. The concept of BT indicates that the beginning of shock is induced by the loss of gut barrier function and consequent translocation of bacteria. In general, impaired gut barrier function can be caused either during the shock period by decreased intestinal blood flow and reduced oxygen delivery, resulting during reperfusion in a stage of increased intestinal blood flow, or at a later stage again by reduced flow. A variety of physiological stresses, such as trauma, hemorrhage, thermal injury, surgical operation, various kinds of drags and mental stress, have been shown to cause failure of the gut mucosal barrier, with translocation of bacteria/endotoxin from the gastrointestinal into the mesenteric lymph nodes, and translocation into remote organs and systemic circulation. 2. Burn shock. We designed to evaluate the BT in a burn shock rat model (following 20% full-thickness scald injury). The p38 MAPK pathway is an important stress-responsive signal molecule

  11. Cyclic mechanical load causes global translational arrest in articular chondrocytes: a process which is partially dependent upon PKR phosphorylation

    Directory of Open Access Journals (Sweden)

    C Lomas

    2011-09-01

    Full Text Available he cellular mechanisms by which articular cartilage responds to load are poorly understood, but such responses may involve regulation at the level of protein translation rather than synthesis of mRNA. We investigated the role of translational control in cyclically (0.5 Hz, 0.1 Hz and 0.05 Hz and statically loaded porcine articular cartilage explants. Messenger RNA was extracted for real time polymerase chain reaction (RT-PCR and newly synthesised proteins were measured by their incorporation of radiolabelled 35S[methionine/cysteine] or 35SO4. Some medium from loaded and unloaded explants was immunoblotted for type II collagen, CTGF and TIMP3. The pathways that control protein translation were investigated by immunoblotting explant lysates for PKR, PERK (PKR like endoplasmic reticulum kinase, eIF2a (eukaryotic initiation factor 2a, eEFs (eukaryotic elongation factors, and AMP-dependent kinase. Explants were also loaded in the presence of inhibitors of PKR, the fibroblast growth factor (FGF receptor and PI3 kinase. Cyclic loading caused complete global translational arrest as evidenced by a total suppression of new protein synthesis whilst maintaining mRNA levels. Translational arrest did not occur following static loading and was partly dependent upon the load frequency. There was a rebound increase in protein synthesis when labelling was performed after load had been withdrawn. Phosphorylation of PKR occurred in explants following cyclic load and inhibition of PKR modestly reversed suppression of newly synthesised proteins suggesting that PKR, at least in part, was responsible for loading induced translational arrest. These results show that translational control provides a rapid and potentially important mechanism for controlling the synthetic responses of articular chondrocytes in response to different types of mechanical load.

  12. Interference Decoding for Deterministic Channels

    CERN Document Server

    Bandemer, Bernd

    2010-01-01

    An inner bound to the capacity region of a class of three user pair deterministic interference channels is presented. The key idea is to simultaneously decode the combined interference signal and the intended message at each receiver. It is shown that this interference decoding inner bound is strictly larger than the inner bound obtained by treating interference as noise, which includes interference alignment for deterministic channels. The gain comes from judicious analysis of the number of combined interference sequences in different regimes of input distributions and message rates.

  13. Transparency induced by two photon interference in a beam splitter

    Institute of Scientific and Technical Information of China (English)

    Wang Kai-Ge; Yang Guo-Jian

    2004-01-01

    We propose a special two-photon state which is completely transparent in a 50/50 beam splitter. This effect is caused by the destructive two-photon interference and shows the signature of photon entanglement. We find that the symmetry of the two-photon spectrum plays the key role for the properties of two-photon interference.

  14. 47 CFR 80.92 - Prevention of interference.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false Prevention of interference. 80.92 Section 80.92... MARITIME SERVICES Operating Requirements and Procedures Operating Procedures-General § 80.92 Prevention of...-communication causes interference to a communication which is already in progress, the interfering station...

  15. Transmission of Correlated Messages over Interference Channels with Strong Interference

    Science.gov (United States)

    Choi, Suhan; Yoon, Eunchul; Moon, Hichan

    Transmission of correlated messages over interference channels with strong interference is considered. As a result, an achievable rate region is presented. It is shown that if the messages are correlated, the achievable rate region can be larger than the capacity region given by Costa and El Gamal. As an example, the Gaussian interference channel is considered.

  16. Electromagnetic interference: a radiant future!

    NARCIS (Netherlands)

    Leferink, Frank Bernardus Johannes

    2015-01-01

    Although Electromagnetic Interference and Electromagnetic Compatibility are well established domains, the introduction of new technologies results in new challenges. Changes in both measurement techniques, and technological trends resulting in new types of interference are described. These are the S

  17. Electromagnetic interference: a radiant future!

    NARCIS (Netherlands)

    Leferink, Frank Bernardus Johannes

    2015-01-01

    Although Electromagnetic Interference and Electromagnetic Compatibility are well established domains, the introduction of new technologies results in new challenges. Changes in both measurement techniques, and technological trends resulting in new types of interference are described. These are the

  18. Heuristic explanation of quantum interference experiments

    CERN Document Server

    Guowen, W

    2005-01-01

    A particle is described as a non-spreading wave packet satisfying a linear equation within the framework of special relativity. Young's and other interference experiments are explained with a hypothesis that there is a coupling interaction between the peaked and non-peaked pieces of the wave packet. This explanation of the interference experiments provides a realistic interpretation of quantum mechanics. The interpretation implies that there is physical reality of particles and no wave function collapse. It also implies that neither classical mechanics nor current quantum mechanics is a complete theory for describing physical reality and the Bell inequalities are not the proper touchstones for reality and locality. The problems of the boundary between the macro-world and micro-world and the de-coherence in the transition region (meso-world) between the two are discussed. The present interpretation of quantum mechanics is consistent with the physical aspects of the Copenhagen interpretation, such as, the super...

  19. Transverse relativistic effects in paraxial wave interference

    CERN Document Server

    Bliokh, Konstantin Y; Nori, Franco

    2013-01-01

    We consider relativistic deformations of interfering paraxial waves moving in the transverse direction. Owing to superluminal transverse phase velocities, noticeable deformations of the interference patterns arise when the waves move with respect to each other with non-relativistic velocities. Similar distortions also appear on a mutual tilt of the interfering waves, which causes a phase delay analogous to the relativistic time delay. We illustrate these observations by the interference between a vortex wave beam and a plane wave, which exhibits a pronounced deformation of the radial fringes into a fork-like pattern (relativistic Hall effect). Furthermore, we describe an additional relativistic motion of the interference fringes (a counter-rotation in the vortex case), which become noticeable at the same non-relativistic velocities.

  20. Proactive interference effects on sentence production

    Science.gov (United States)

    FERREIRA, VICTOR S.; FIRATO, CARLA E.

    2007-01-01

    Proactive interference refers to recall difficulties caused by prior similar memory-related processing. Information-processing approaches to sentence production predict that retrievability affects sentence form: Speakers may word sentences so that material that is difficult to retrieve is spoken later. In this experiment, speakers produced sentence structures that could include an optional that, thereby delaying the mention of a subsequent noun phrase. This subsequent noun phrase was either (1) conceptually similar to three previous noun phrases in the same sentence, leading to greater proactive interference, or (2) conceptually dissimilar, leading to less proactive interference. Speakers produced more thats (and were more disfluencies) before conceptually similar noun phrases, suggesting that retrieval difficulties during sentence production affect the syntactic structures of sentences that speakers produce. PMID:12613685

  1. The Cause of the Cauca, Colombia, Cluster of Intermediate-Depth Earthquakes From Earthquake Relocation and Focal Mechanisms

    Science.gov (United States)

    Warren, L. M.; Chang, Y.; Prieto, G. A.

    2016-12-01

    In subducting slabs, a high seismicity rate in a concentrated volume (an earthquake cluster) is often associated with geometric complexities such as slab detachment, tearing, or contortions. The intermediate-depth Cauca, Colombia, cluster (3.5°N-5.5°N), in contrast, appears to be located in a slab without such complexities. However, previous constraints on the slab geometry are based on global data. We use regional data to investigate the cause of the Cauca cluster by estimating its geometry from earthquake relocations and stress regime from focal mechanism calculations and stress inversions. The Cauca segment of the Nazca Plate is characterized by relatively sparse seismicity away from the cluster and a narrow volcanic arc. To the northeast of the Cauca cluster, six active volcanoes are concentrated within an 80-km along-trench distance and are isolated 180 km from the rest of the northern Andes volcanic arc. The Colombian National Seismic Network, from Jan 2010 to Mar 2014, reports 433 earthquakes in the cluster at depths of 50-200 km with local magnitudes ranging from 2.0-4.7. Earthquake relocations show a continuous 20-km-thick seismic zone dipping at 33°-43°, with the angle increasing to the south. In addition, earthquakes locate in two columns that extend normal to the slab and into the mantle wedge. The focal mechanisms show various types, including down-dip extension, strike slip, and trench-parallel compression, but are consistent with a predominantly down-dip extensional stress field. The maximum and intermediate stress axes are interchangeable because of their similar magnitudes. The down-dip extensional stress regime may expel dehydrated fluid from the slab into the mantle wedge. As the fluid moves through the mantle wedge, it may generate hydrofractures and the observed mantle-wedge earthquakes. The fluid in the mantle wedge may be transported along the trench, from the steeper southern section to the more shallowly-dipping northern section, and

  2. Diet-Induced Nutritional Stress and Pathogen Interference in Wolbachia-Infected Aedes aegypti

    Science.gov (United States)

    Caragata, Eric Pearce; Rezende, Fernanda Oliveira; Simões, Taynãna César; Moreira, Luciano Andrade

    2016-01-01

    The pathogen interference phenotype greatly restricts infection with dengue virus (DENV) and other pathogens in Wolbachia-infected Aedes aegypti, and is a vital component of Wolbachia-based mosquito control. Critically, the phenotype’s causal mechanism is complex and poorly understood, with recent evidence suggesting that the cause may be species specific. To better understand this important phenotype, we investigated the role of diet-induced nutritional stress on interference against DENV and the avian malarial parasite Plasmodium gallinaceum in Wolbachia-infected Ae. aegypti, and on physiological processes linked to the phenotype. Wolbachia-infected mosquitoes were fed one of four different concentrations of sucrose, and then challenged with either P. gallinaceum or DENV. Interference against P. gallinaceum was significantly weakened by the change in diet however there was no effect on DENV interference. Immune gene expression and H2O2 levels have previously been linked to pathogen interference. These traits were assayed for mosquitoes on each diet using RT-qPCR and the Amplex Red Hydrogen Peroxide/Peroxidase Assay Kit, and it was observed that the change in diet did not significantly affect immune expression, but low carbohydrate levels led to a loss of ROS induction in Wolbachia-infected mosquitoes. Our data suggest that host nutrition may not influence DENV interference for Wolbachia-infected mosquitoes, but Plasmodium interference may be linked to both nutrition and oxidative stress. This pathogen-specific response to nutritional change highlights the complex nature of interactions between Wolbachia and pathogens in mosquitoes. PMID:27893736

  3. Epulis and pyogenic granuloma with occlusal interference

    Directory of Open Access Journals (Sweden)

    Widowati Witjaksono

    2005-06-01

    Full Text Available In dental clinic of Hospital University Science Malaysia (HUSM, there were cases with Localized Gingival Enlargement (LGE in the oral cavity with occlusal interference. In this study, three cases were observed. They were a 13 - year- old female with fibrous lge around 31 and 32 with occlusal interference in protrusive movement due to X bite, a 15 - year – old female with pyogenic granuloma near 11 & 21 with occlusal interference due to deep bite; and a 24 – year – old female who was eight months in pregnancy with pyogenic granuloma on the 34-35 and severe generalized pregnancy gingivitis with occlusal interference in centric occlusion and lateral movement. Clinical and histopathological diagnosis of the first case showed fibrous epulis, whereas the second and third cases disclosed pyogenic granuloma. Chronic trauma of the gingiva due to occlusal interference was assumed to be the cause of those LGE in case 1 and 2, while in case 3 poor oral hygiene and chronic trauma were assumed to be the etiologic factors.

  4. Sequence-dependent upstream DNA-RNA polymerase interactions in the open complex with λPR λPRM promoters and implications for the mechanism of promoter interference

    Science.gov (United States)

    Mangiarotti, Laura; Cellai, Sara; Ross, Wilma; Bustamante, Carlos; Rivetti, Claudio

    2015-01-01

    The upstream interactions of Escherichia coli RNA polymerase in open complex (RPo) formed at the PR and PRM promoters of bacteriophage lambda, have been studied by atomic force microscopy (AFM). We demonstrate that the previously described 30 nm DNA compaction observed upon RPo formation at PR1 is a consequence of the specific interaction of the RNAP with two AT-rich sequence determinants positioned from −36 to −59 and from −80 to −100. Likewise, RPos formed at PRM showed a specific contact between the RNAP and the DNA sequence from −36 to −60. We further demonstrate that this interaction, which results in DNA wrapping against the polymerase surface, is mediated by the C-terminal domains of the alpha subunits (αCTD). Substitution of these AT-rich sequences with heterologous DNA reduces DNA wrapping but has little effect on the activity of the PR promoter. We find, however, that the frequency of DNA templates with both PR and PRM occupied by an RNAP significantly increases upon loss of DNA wrapping. These results suggest that αCTD interactions with upstream DNA can also play a role in regulating the expression of closely spaced promoters. Finally, a model for a possible mechanism of promoter interference between PR and PRM is proposed. PMID:19061900

  5. [Advances in molecular mechanisms of bacterial resistance caused by stress-induced transfer of resistance genes--a review].

    Science.gov (United States)

    Sun, Dongchang; Wang, Bing; Zhu, Lihong

    2013-07-04

    The transfer of resistance gene is one of the most important causes of bacterial resistance. Recent studies reveal that stresses induce the transfer of antibiotic resistance gene through multiple mechanisms. DNA damage stresses trigger bacterial SOS response and induce the transfer of resistance gene mediated by conjugative DNA. Antibiotic stresses induce natural bacterial competence for transformation in some bacteria which lack the SOS system. In addition, our latest studies show that the general stress response regulator RpoS regulates a novel type of resistance gene transfer which is mediated by double-stranded plasmid DNA and occurs exclusively on the solid surface. In this review, we summarized recent advances in SOS dependent and independent stress-induced DNA transfer which is mediated by conjugation and transformation respectively, and the transfer of double-stranded plasmid DNA on the solid surface which is regulated by RpoS. We propose that future work should address how stresses activate the key regulators and how these regulators control the expression of gene transfer related genes. Answers to the above questions would pave the way for searching for candidate targets for controlling bacterial resistance resulted from the transfer of antibiotic genes.

  6. Mechanism of the effect caused by highway construction on plant biomass in Longitudinal Range-Gorge Region

    Institute of Scientific and Technical Information of China (English)

    Jie LIU; Honglei XU; Chunping CHANG

    2013-01-01

    Taking Dabao (from Dali City to Baoshan City,Yunnan Province,China) and Sixiao (from Simao City to Xiaomengyang Town,Yurnan Province,China) highways in Longitudinal Range-Gorge Region as examples.Biomass,coverage and photosynthesis rate of different plant types on sampling points (at the distances from road of 5,20,40,80,120 and 200 m) and their control points were estimated on ground.The relations among biomass,coverage,photosynthesis rate were analyzed with an aim to explore the mechanism of the effect caused by highway construction on plant biomass.The results show,i) the impacts of highway construction on plant biomass are both positive and negative.Arbor is mainly negatively impacted,while shrub and herbage are mainly positively impacted.The effect of highway construction decrease with the increase of distance from the road; ii) highway construction exert obvious influence on plant biomass through altering the physiologic processes (reflected by the plant number) and photosynthesis,iii) highway construction will result in the decrease of arbor number,photosynthesis rate and biomass,and increase of plant number,photosynthesis rate and biomass of shrub and herbage.

  7. EXPERIMENTAL MODELLING OF MECHANISMS CAUSING OCCURRENCE OF SEISMIC OSCILLATION SOURCES IN CASE OF INTERACTIONS OF UNEVEN SURFACES IN FAULTS

    Directory of Open Access Journals (Sweden)

    V. V. Ruzhich

    2015-09-01

    Full Text Available Field experiments were carried out using TRIBO, a specially designed testing stand including a concrete plate that can be moved at different rates. In our experiment, the plate served as an artificial allochtonous wing placed at the uneven surface of the segment of the Angarsky fault in Pribaikalie. Tribological effects of contact interaction of the uneven surfaces in the zone of sliding movements of the plate were recorded by strain gauges, linear displacement gauges and four Baikal-7HR seismic stations; such stations are commonly used for earthquake recording. The effect of shocks in initiation of seismic oscillation sources was studied with changes of the regimes of destruction of the uneven surfaces (underneath the base of the plate which differ in size and strength. The study was focused on stages in the process of friction at preparation to transition from quasi-regular decelerated sliding movement of the plate to its breakaway and occurrence of a high-energy seismic impulse.The applied method of large-scale modelling at natural objects in field provides new data that may prove useful for stu­dies of mechanisms causing seismicity, identification of stages in occurrence of earthquakes in fault zones and interpretation of seismic monitoring data. Results of such physical tests can contribute to the development of methods aimed at forecasting of rock shocks and earthquakes and also for the development of new physical models showing formation of earthquake foci of various scales in tectonic faults.

  8. Non-classical paths in interference experiments

    CERN Document Server

    Sawant, Rahul; Sinha, Aninda; Sinha, Supurna; Sinha, Urbasi

    2014-01-01

    In a double slit interference experiment, the wave function at the screen with both slits open is not exactly equal to the sum of the wave functions with the slits individually open one at a time. The three scenarios represent three different boundary conditions and as such, the superposition principle should not be applicable. However, most well known text books in quantum mechanics implicitly and/or explicitly use this assumption which is only approximately true. In our present study, we have used the Feynman path integral formalism to quantify contributions from non-classical paths in quantum interference experiments which provide a measurable deviation from a naive application of the superposition principle. A direct experimental demonstration for the existence of these non-classical paths is hard. We find that contributions from such paths can be significant and we propose simple three-slit interference experiments to directly confirm their existence.

  9. Nonclassical Paths in Quantum Interference Experiments

    Science.gov (United States)

    Sawant, Rahul; Samuel, Joseph; Sinha, Aninda; Sinha, Supurna; Sinha, Urbasi

    2014-09-01

    In a double slit interference experiment, the wave function at the screen with both slits open is not exactly equal to the sum of the wave functions with the slits individually open one at a time. The three scenarios represent three different boundary conditions and as such, the superposition principle should not be applicable. However, most well-known text books in quantum mechanics implicitly and/or explicitly use this assumption that is only approximately true. In our present study, we have used the Feynman path integral formalism to quantify contributions from nonclassical paths in quantum interference experiments that provide a measurable deviation from a naive application of the superposition principle. A direct experimental demonstration for the existence of these nonclassical paths is difficult to present. We find that contributions from such paths can be significant and we propose simple three-slit interference experiments to directly confirm their existence.

  10. Electromagnetic Interference on Large Wind Turbines

    Directory of Open Access Journals (Sweden)

    Florian Krug

    2009-11-01

    Full Text Available Electromagnetic interference (EMI can both affect and be transmitted by mega-watt wind turbines. This paper provides a general overview on EMI with respect to mega-watt wind turbines. Possibilities of measuring all types of electromagnetic interference are shown. Electromagnetic fields resulting from a GSM transmitter mounted on a mega-watt wind turbine will be analyzed in detail. This cellular system operates as a real-time communication link. The method-of-moments is used to analytically describe the electro-magnetic fields. The electromagnetic interference will be analyzed under the given boundary condition with a commercial simulation tool. Different transmitter positions are judged on the basis of their radiation patterns. The principal EMI mechanisms are described and taken into consideration.

  11. Gravitational and rotational effects in quantum interference

    Energy Technology Data Exchange (ETDEWEB)

    Anandan, J.

    1977-03-15

    The phase shift due to gravitation and rotation in the quantum interference of two coherent beams is obtained relativistically and compared with the recent experiment of Colella, Overhauser, and Werner. A general expression relating the quantum phase shift to the transverse acceleration of a classical particle in the plane of interference for an arbitrary interaction with any external field is given. This can serve as a correspondence principle between quantum physics and classical physics. The phase shift due to the coupling of spin to curvature of space-time is deduced and written explicitly for the special case of a Schwarzschild field. The last result implies that a massless spinning particle can have at most two helicity states and its world line in a gravitational field is a null geodesic. Finally, new experiments are proposed to test the effect of rotation on quantum interference and to obtain direct evidence of the equivalence principle in quantum mechanics.

  12. Endothelial neuropilin disruption in mice causes DiGeorge syndrome-like malformations via mechanisms distinct to those caused by loss of Tbx1.

    Directory of Open Access Journals (Sweden)

    Jingjing Zhou

    Full Text Available The spectrum of human congenital malformations known as DiGeorge syndrome (DGS is replicated in mice by mutation of Tbx1. Vegfa has been proposed as a modifier of DGS, based in part on the occurrence of comparable phenotypes in Tbx1 and Vegfa mutant mice. Many additional genes have been shown to cause DGS-like phenotypes in mice when mutated; these generally intersect in some manner with Tbx1, and therefore impact the same developmental processes in which Tbx1 itself is involved. In this study, using Tie2Cre, we show that endothelial-specific mutation of the gene encoding the VEGFA coreceptor neuropilin-1 (Nrp1 also replicates the most prominent terminal phenotypes that typify DGS. However, the developmental etiologies of these defects are fundamentally different from those caused by absence of TBX1. In Tie2Cre/Nrp1 mutants, initial pharyngeal organization is normal but subsequent pharyngeal organ growth is impaired, second heart field differentiation is normal but cardiac outflow tract cushion organization is distorted, neural crest cell migration is normal, and palatal mesenchyme proliferation is impaired with no change in apoptosis. Our results demonstrate that impairment of VEGF-dependent endothelial pathways leads to a spectrum of DiGeorge syndrome-type malformations, through processes that are distinguishable from those controlled by Tbx1.

  13. Interference effects and phase sensitivity in hearing.

    Science.gov (United States)

    Moore, Brian C J

    2002-05-15

    This paper reviews interference effects in the auditory system, particularly effects occurring in the outer ear and the inner ear (cochlea). Sounds enter the ear canal both directly and after reflections from the pinna. This results in complex spectral patterns, which vary systematically with the direction of incidence of the sound source relative to the head. Evidence is described indicating that these spectral patterns are used in the localization of sounds in space. The cochlea behaves like a limited-resolution frequency analyser. When the components of a complex sound are closely spaced in frequency, they can interfere on the basilar membrane (BM) within the cochlea. Interference effects on the BM are complex, as they are influenced by a physiologically active mechanism which introduces strong nonlinearities, including level-dependent amplification. Interference effects on the BM play a role in many aspects of auditory perception, including the perception of consonance and dissonance, the perception of pitch, the perception of changes in phase, and the perception of timbre. Interference effects in the cochlea may also play a role in producing the spectral regularity observed in sounds reflected from the ear (otoacoustic emissions).

  14. Holographic interference filters

    Science.gov (United States)

    Diehl, Damon W.

    Holographic mirrors have wavelength-selection properties and thus qualify as a class of interference filters. Two theoretical methods for analyzing such structures are developed. The first method uses Hill's matrix method to yield closed-forms solutions in terms of the Floquet-Bloch waves within a periodic structure. A process is developed for implementing this solution method on a computer, using sparse-matrix memory allocation, numerical root-finding algorithms, and inverse-iteration techniques. It is demonstrated that Hill's matrix method is valid for the analysis of finite and multi-periodic problems. The second method of theoretical analysis is a transfer-matrix technique, which is herein termed thin-film decomposition. It is shown that the two methods of solution yield results that differ by, at worst, a fraction of a percent. Using both calculation techniques, a number of example problems are explored. Of key importance is the construction of a set of curves that are useful for the design and characterization of holographic interference filters. In addition to the theoretical development, methods are presented for the fabrication of holographic interference filters using DuPont HRF-800X001 photopolymer. Central to the exposure system is a frequency-stabilized, tunable dye laser. The types of filters fabricated include single-tone reflection filters, two types of multitone reflection filters, and reflection filters for infrared wavelengths. These filters feature index profiles that are not easily attainable through other fabrication methods. As a supplement to the body of the dissertation, the computer algorithms developed to implement Hill's matrix method and thin-film decomposition are also included as an appendix. Further appendices provide more information on Floquet's theorem and Hill's matrix method. A final appendix presents a design for an infrared laser spectrophotometer.

  15. Domain motions of Argonaute, the catalytic engine of RNA interference

    Directory of Open Access Journals (Sweden)

    Wall Michael E

    2007-11-01

    Full Text Available Abstract Background The Argonaute protein is the core component of the RNA-induced silencing complex, playing the central role of cleaving the mRNA target. Visual inspection of static crystal structures already has enabled researchers to suggest conformational changes of Argonaute that might occur during RNA interference. We have taken the next step by performing an all-atom normal mode analysis of the Pyrococcus furiosus and Aquifex aeolicus Argonaute crystal structures, allowing us to quantitatively assess the feasibility of these conformational changes. To perform the analysis, we begin with the energy-minimized X-ray structures. Normal modes are then calculated using an all-atom molecular mechanics force field. Results The analysis reveals low-frequency vibrations that facilitate the accommodation of RNA duplexes – an essential step in target recognition. The Pyrococcus furiosus and Aquifex aeolicus Argonaute proteins both exhibit low-frequency torsion and hinge motions; however, differences in the overall architecture of the proteins cause the detailed dynamics to be significantly different. Conclusion Overall, low-frequency vibrations of Argonaute are consistent with mechanisms within the current reaction cycle model for RNA interference.

  16. Partial Interference Alignment for K-user MIMO Interference Channels

    CERN Document Server

    Huang, Huang

    2011-01-01

    In this paper, we consider a Partial Interference Alignment and Interference Detection (PIAID) design for $K$-user quasi-static MIMO interference channels with discrete constellation inputs. Each transmitter has M antennas and transmits L independent data streams to the desired receiver with N receive antennas. We focus on the case where not all K-1 interfering transmitters can be aligned at every receiver. As a result, there will be residual interference at each receiver that cannot be aligned. Each receiver detects and cancels the residual interference based on the constellation map. However, there is a window of unfavorable interference profile at the receiver for Interference Detection (ID). In this paper, we propose a low complexity Partial Interference Alignment scheme in which we dynamically select the user set for IA so as to create a favorable interference profile for ID at each receiver. We first derive the average symbol error rate (SER) by taking into account of the non-Guassian residual interfere...

  17. Interference tables: a useful model for interference analysis in asynchronous multicarrier transmission

    Science.gov (United States)

    Medjahdi, Yahia; Terré, Michel; Ruyet, Didier Le; Roviras, Daniel

    2014-12-01

    In this paper, we investigate the impact of timing asynchronism on the performance of multicarrier techniques in a spectrum coexistence context. Two multicarrier schemes are considered: cyclic prefix-based orthogonal frequency division multiplexing (CP-OFDM) with a rectangular pulse shape and filter bank-based multicarrier (FBMC) with physical layer for dynamic spectrum access and cognitive radio (PHYDYAS) and isotropic orthogonal transform algorithm (IOTA) waveforms. First, we present the general concept of the so-called power spectral density (PSD)-based interference tables which are commonly used for multicarrier interference characterization in spectrum sharing context. After highlighting the limits of this approach, we propose a new family of interference tables called `instantaneous interference tables'. The proposed tables give the interference power caused by a given interfering subcarrier on a victim one, not only as a function of the spectral distance separating both subcarriers but also with respect to the timing misalignment between the subcarrier holders. In contrast to the PSD-based interference tables, the accuracy of the proposed tables has been validated through different simulation results. Furthermore, due to the better frequency localization of both PHYDYAS and IOTA waveforms, FBMC technique is demonstrated to be more robust to timing asynchronism compared to OFDM one. Such a result makes FBMC a potential candidate for the physical layer of future cognitive radio systems.

  18. Quantum Interference and Selectivity through Biological Ion Channels

    Science.gov (United States)

    Salari, Vahid; Naeij, Hamidreza; Shafiee, Afshin

    2017-01-01

    The mechanism of selectivity in ion channels is still an open question in biology for more than half a century. Here, we suggest that quantum interference can be a solution to explain the selectivity mechanism in ion channels since interference happens between similar ions through the same size of ion channels. In this paper, we simulate two neighboring ion channels on a cell membrane with the famous double-slit experiment in physics to investigate whether there is any possibility of matter-wave interference of ions via movement through ion channels. Our obtained decoherence timescales indicate that the quantum states of ions can only survive for short times, i.e. ≈100 picoseconds in each channel and ≈17–53 picoseconds outside the channels, giving the result that the quantum interference of ions seems unlikely due to environmental decoherence. However, we discuss our results and raise few points, which increase the possibility of interference. PMID:28134331

  19. Iron metabolism in obesity: how interaction between homoeostatic mechanisms can interfere with their original purpose. Part I: underlying homoeostatic mechanisms of energy storage and iron metabolisms and their interaction.

    Science.gov (United States)

    Becker, Christiane; Orozco, Mónica; Solomons, Noel W; Schümann, Klaus

    2015-04-01

    Adipose tissue plasticity mediated by inflammation is an important evolutionary achievement to survive seasonal climate changes. It permits to store excessive calories and to release them if required, using inflammatory cells to remove the debris. This process is regulated by a complex interaction of cytokines (TNF-α, IL-6), adipokines (adiponectin, apelin, liptin), adhesion molecules (ICAM-1, VCAM-1, E-selectin) and transcription factors (NF-κB, HIF-1α). Iron mediates electron transfer as an essential component of e.g. myeloperoxidase, hemoglobin, cytochrome C and ribonucleotide reductase. Conversely, unbound iron can catalyze oxidation of lipids, proteins, and DNA. To balance the essential with the potentially toxic function requires an efficient iron homoeostasis. This is mediated by hepcidin's interaction with the iron-exporter ferroportin, to adapt intestinal iron absorption and body iron-sequestration to changes in demand. In addition, the interaction of iron-responsive elements (IRE) and iron-responsive proteins (IRP), the IRE/IRP-mechanism, regulates cellular iron homoeostasis. Obesity-induced inflammation interacts with both these mechanisms and disturbs iron availability by impairing its absorption, and by sequestering it in the reticuloendothelial system. Both mechanisms lead to anemia and reduce physical fitness which, in a vicious cycle, can support the development of pathological obesity. Thus, interaction between these two sets of beneficial regulatory mechanisms can become detrimental in situations of ample calorie supply.

  20. Filtering algorithm for dotted interferences

    Energy Technology Data Exchange (ETDEWEB)

    Osterloh, K., E-mail: kurt.osterloh@bam.de [Federal Institute for Materials Research and Testing (BAM), Division VIII.3, Radiological Methods, Unter den Eichen 87, 12205 Berlin (Germany); Buecherl, T.; Lierse von Gostomski, Ch. [Technische Universitaet Muenchen, Lehrstuhl fuer Radiochemie, Walther-Meissner-Str. 3, 85748 Garching (Germany); Zscherpel, U.; Ewert, U. [Federal Institute for Materials Research and Testing (BAM), Division VIII.3, Radiological Methods, Unter den Eichen 87, 12205 Berlin (Germany); Bock, S. [Technische Universitaet Muenchen, Lehrstuhl fuer Radiochemie, Walther-Meissner-Str. 3, 85748 Garching (Germany)

    2011-09-21

    An algorithm has been developed to remove reliably dotted interferences impairing the perceptibility of objects within a radiographic image. This particularly is a major challenge encountered with neutron radiographs collected at the NECTAR facility, Forschungs-Neutronenquelle Heinz Maier-Leibnitz (FRM II): the resulting images are dominated by features resembling a snow flurry. These artefacts are caused by scattered neutrons, gamma radiation, cosmic radiation, etc. all hitting the detector CCD directly in spite of a sophisticated shielding. This makes such images rather useless for further direct evaluations. One approach to resolve this problem of these random effects would be to collect a vast number of single images, to combine them appropriately and to process them with common image filtering procedures. However, it has been shown that, e.g. median filtering, depending on the kernel size in the plane and/or the number of single shots to be combined, is either insufficient or tends to blur sharp lined structures. This inevitably makes a visually controlled processing image by image unavoidable. Particularly in tomographic studies, it would be by far too tedious to treat each single projection by this way. Alternatively, it would be not only more comfortable but also in many cases the only reasonable approach to filter a stack of images in a batch procedure to get rid of the disturbing interferences. The algorithm presented here meets all these requirements. It reliably frees the images from the snowy pattern described above without the loss of fine structures and without a general blurring of the image. It consists of an iterative, within a batch procedure parameter free filtering algorithm aiming to eliminate the often complex interfering artefacts while leaving the original information untouched as far as possible.

  1. Interference-Cancellation Scheme for Multilayer Cellular Systems

    Institute of Scientific and Technical Information of China (English)

    Wei Li; Yue Zhang; LiKe Huang

    2015-01-01

    A 5G network must be heterogeneous and support the co⁃existence of multilayer cells, multiple standards, and multiple applica⁃tion systems. This greatly improves link performance and increases link capacity. A network with co⁃existing macro and pico cells can alleviate traffic congestion caused by multicast or unicast subscribers, help satisfy huge traffic demands, and further extend converge. In order to practically implement advanced 5G technology, a number of technical problems have to be solved, one of which is inter⁃cell interference. A method called Almost Blank Subframe (ABS) has been proposed to mitigate interference;howev⁃er, the reference signal in ABS still causes interference. This paper describes how interference can be cancelled by using the in⁃formation in the ABS. First, the interference⁃signal model, which takes into account channel effect, time and frequency error, is presented. Then, an interference⁃cancellation scheme based on this model is studied. The timing and carrier frequency offset of the interference signal is compensated. Afterwards, the reference signal of the interfering cell is generated locally and the channel response is estimated using channel statistics. Then, the interference signal is reconstructed according to previous estimation of channel, timing, and carrier frequency offset. The interference is mitigated by subtracting the estimated interference signal. Com⁃puter simulation shows that this interference⁃cancellation algorithm significantly improves performance under different channel conditions.

  2. Dependency-dependent interference: NPI interference, agreement attraction, and global pragmatic inferences.

    Science.gov (United States)

    Xiang, Ming; Grove, Julian; Giannakidou, Anastasia

    2013-01-01

    Previous psycholinguistics studies have shown that when forming a long distance dependency in online processing, the parser sometimes accepts a sentence even though the required grammatical constraints are only partially met. A mechanistic account of how such errors arise sheds light on both the underlying linguistic representations involved and the processing mechanisms that put such representations together. In the current study, we contrast the negative polarity items (NPI) interference effect, as shown by the acceptance of an ungrammatical sentence like "The bills that democratic senators have voted for will ever become law," with the well-known phenomenon of agreement attraction ("The key to the cabinets are … "). On the surface, these two types of errors look alike and thereby can be explained as being driven by the same source: similarity based memory interference. However, we argue that the linguistic representations involved in NPI licensing are substantially different from those of subject-verb agreement, and therefore the interference effects in each domain potentially arise from distinct sources. In particular, we show that NPI interference at least partially arises from pragmatic inferences. In a self-paced reading study with an acceptability judgment task, we showed NPI interference was modulated by participants' general pragmatic communicative skills, as quantified by the Autism-Spectrum Quotient (AQ, Baron-Cohen et al., 2001), especially in offline tasks. Participants with more autistic traits were actually less prone to the NPI interference effect than those with fewer autistic traits. This result contrasted with agreement attraction conditions, which were not influenced by individual pragmatic skill differences. We also show that different NPI licensors seem to have distinct interference profiles. We discuss two kinds of interference effects for NPI licensing: memory-retrieval based and pragmatically triggered.

  3. Dependency-dependent interference: NPI interference, agreement attraction, and global pragmatic inferences

    Directory of Open Access Journals (Sweden)

    Ming eXiang

    2013-10-01

    Full Text Available Previous psycholinguistics studies have shown that when forming a long distance dependency in online processing, the parser sometimes accepts a sentence even though the required grammatical constraints are only partially met. A mechanistic account of how such errors arise sheds light on both the underlying linguistic representations involved and the processing mechanisms that put such representations together. In the current study, we contrast the NPI (negative polarity items interference effect, as shown by the acceptance of an ungrammatical sentence like The bills that democratic senators have voted for will ever become law, with the well-known phenomenon of agreement attraction (The key to the cabinets are…. On the surface, these two types of errors look alike and thereby can be explained as being driven by the same source: similarity based memory interference. However, we argue that the linguistic representations involved in NPI licensing are substantially different from those of subject-verb agreement, and therefore the interference effects in each domain potentially arise from distinct sources. In particular, we show that NPI interference at least partially arises from pragmatic inferences. In a self-paced reading study with an acceptability judgment task, we showed NPI interference was modulated by participants’ general pragmatic communicative skills, as quantified by the Autism-Spectrum Quotient (Baron-Cohen 2001, especially in offline tasks. Participants with more autistic traits were actually less prone to the NPI interference effect than those with fewer autistic traits. This result contrasted with agreement attraction conditions, which were not influenced by individual pragmatic skill differences. We also show that different NPI licensors have distinct interference profiles. We discuss two kinds of interference effects for NPI licensing: memory-retrieval based and pragmatically triggered.

  4. Sequence-dependent upstream DNA-RNA polymerase interactions in the open complex with lambdaPR and lambdaPRM promoters and implications for the mechanism of promoter interference.

    Science.gov (United States)

    Mangiarotti, Laura; Cellai, Sara; Ross, Wilma; Bustamante, Carlos; Rivetti, Claudio

    2009-01-23

    Upstream interactions of Escherichia coli RNA polymerase (RNAP) in an open promoter complex (RPo) formed at the P(R) and P(RM) promoters of bacteriophage lambda have been studied by atomic force microscopy. We demonstrate that the previously described 30-nm DNA compaction observed upon RPo formation at P(R) [Rivetti, C., Guthold, M. & Bustamante, C. (1999). Wrapping of DNA around the E. coli RNA polymerase open promoter complex. EMBO J., 18, 4464-4475.] is a consequence of the specific interaction of the RNAP with two AT-rich sequence determinants positioned from -36 to -59 and from -80 to -100. Likewise, RPos formed at P(RM) showed a specific contact between RNAP and the upstream DNA sequence. We further demonstrate that this interaction, which results in DNA wrapping against the polymerase surface, is mediated by the C-terminal domains of alpha-subunits (carboxy-terminal domain). Substitution of these AT-rich sequences with heterologous DNA reduces DNA wrapping but has only a small effect on the activity of the P(R) promoter. We find, however, that the frequency of DNA templates with both P(R) and P(RM) occupied by an RNAP significantly increases upon loss of DNA wrapping. These results suggest that alpha carboxy-terminal domain interactions with upstream DNA can also play a role in regulating the expression of closely spaced promoters. Finally, a model for a possible mechanism of promoter interference between P(R) and P(RM) is proposed.

  5. The right posterior paravermis and the control of language interference.

    Science.gov (United States)

    Filippi, Roberto; Richardson, Fiona M; Dick, Frederic; Leech, Robert; Green, David W; Thomas, Michael S C; Price, Cathy J

    2011-07-20

    Auditory and written language in humans' comprehension necessitates attention to the message of interest and suppression of interference from distracting sources. Investigating the brain areas associated with the control of interference is challenging because it is inevitable that activation of the brain regions that control interference co-occurs with activation related to interference per se. To isolate the mechanisms that control verbal interference, we used a combination of structural and functional imaging techniques in Italian and German participants who spoke English as a second language. First, we searched structural MRI images of Italian participants for brain regions in which brain structure correlated with the ability to suppress interference from the unattended dominant language (Italian) while processing heard sentences in their weaker language (English). This revealed an area in the posterior paravermis of the right cerebellum in which gray matter density was higher in individuals who were better at controlling verbal interference. Second, we found functional activation in the same region when our German participants made semantic decisions on written English words in the presence of interference from unrelated words in their dominant language (German). This combination of structural and functional imaging therefore highlights the contribution of the right posterior paravermis to the control of verbal interference. We suggest that the importance of this region for language processing has previously been missed because most fMRI studies limit the field of view to increase sensitivity, with the lower part of the cerebellum being the region most likely to be excluded.

  6. Development of Studies on RNA Interference

    Institute of Scientific and Technical Information of China (English)

    Li ZHANG; Yaqiong ZHANG; Lina SHE; Wenting XU; Yangying JIA; Shiqing XIE; WenliSUN; Quan LIANG

    2012-01-01

    RNA interference (RNAi), caused by endogenous or exogenous double- stranded RNA (dsRNA) homologous with target genes, refers to gene silencing widely existing in animals and plants. It was first found in plants, and now it has developed into a kind of biotechnology as well as an important approach in post- genome era. This paper is to summarize the achievements of studies on RNAi tech- nology in basic biology, medicine, pharmacy, botany and other fields.

  7. Causes, Effects of Stress and the Coping Mechanism of the Bachelor of Science in Information Technology Students in a Philippine University

    Directory of Open Access Journals (Sweden)

    Generoso N. Mazo

    2015-02-01

    Full Text Available The causes and levels of stress vary. The study of Information Technology is basically a rigorous one as it is designed to prepare students for the actual demands in the world of work. This study sought to determine the causes of stress, the effects of stress, and the stress coping mechanisms of Bachelor of Science in Information Technology students in the Leyte Normal University, Tacloban City. It tested some assumptions using the descriptive survey method with 51 respondents. Thesis writing/research and school requirements/projects were the most common causes of stress. Sleepless nights and irritable/moody feeling were the common effects of stress. There was disparity on the causes and effects of stress between the male and female respondents. The use of computer and praying to God were the common stress coping mechanisms. There was an observed disparity between the male and female responses.

  8. Perspectives of antiviral RNA interference (RNAi pathway of insects with special reference to mosquito in the context of dengue infection: a review

    Directory of Open Access Journals (Sweden)

    Probal Basu

    2014-09-01

    Full Text Available RNA interference is a post-transcriptional sequence selective gene control mechanism. Antiviral RNA interference (RNAi pathway is one of the most momentous constituents of the insect innate immune system that can stymie versatile range of RNA virus like flavivirus. It has been demonstrated that RNA production by alphavirus replication is higher in proportion compared to flavivirus replication in mosquito cells. Studies demonstrated that infection by virus from Togaviridae and Bunyaviridae family of arbovirus to mosquito cells causes defect in RNAi response in-vitro but interestingly, it has also been stated that Dengue virus (DENV could be actively inhibited by RNA interference (RNAi. This article is an endeavor to review the perspectives of the functional significance of antiviral RNA interference as a potent agent of controlling dengue infection in the vector.

  9. Sensing via optical interference

    Directory of Open Access Journals (Sweden)

    Ryan C. Bailey

    2005-04-01

    Full Text Available Chemical and biological sensing are problems of tremendous contemporary technological importance in multiple regulatory and human health contexts, including environmental monitoring, water quality assurance, workplace air quality assessment, food quality control, many aspects of biodiagnostics, and, of course, homeland security. Frequently, what is needed, or at least wanted, are sensors that are simultaneously cheap, fast, reliable, selective, sensitive, robust, and easy to use. Unfortunately, these are often conflicting requirements. Over the past few years, however, a number of promising ideas based on optical interference effects have emerged. Each is based to some extent on advances in the design and fabrication of functional materials. Generally, the advances are of two kinds: chemo- and bio-selective recognition and binding, and efficient methods for micropatterning or microstructuring.

  10. Stroop interference in adults with dyslexia.

    Science.gov (United States)

    Proulx, Michael J; Elmasry, Hannah-May

    2015-01-01

    Prior research on developmental dyslexia using Stroop tasks with young participants has found increased interference in participants with dyslexia relative to controls. Here we extend these findings to adult participants, and introduce a novel test of Stroop incongruity, whereby the color names appeared on an object colored in the incongruent color. The results imply that impaired inhibitory and executive attentional mechanisms are still deficient in adults with dyslexia and that other forms of attentional mechanisms, such as object-based attention, might also be impaired in dyslexia. Dyslexia arises not only from deficits in phonological processing, but from attentional mechanisms as well.

  11. Does a sixth mechanism exist to explain lightning injuries?: investigating a possible new injury mechanism to determine the cause of injuries related to close lightning flashes.

    Science.gov (United States)

    Blumenthal, Ryan; Jandrell, Ian R; West, Nicholas J

    2012-09-01

    Five mechanisms have been described in the literature regarding lightning injury mechanisms. A sixth mechanism is proposed in this article, namely, lightning barotrauma. A simple laboratory experiment was conducted using ordnance gelatin for ballistic studies. Lightning was simulated in a high-voltage laboratory using an 8/20-microsecond current impulse generator and discharged through ballistic gel. Temporary and permanent cavity formations were confirmed. The cavities formed were directly proportional to the currents used. Findings suggest that a sixth mechanism of lightning injury, namely, barotrauma, should be considered.

  12. Characteristics and formation mechanism of a heavy air pollution episode caused by biomass burning in Chengdu, Southwest China.

    Science.gov (United States)

    Chen, Yuan; Xie, Shao-Dong

    2014-03-01

    To track the chemical characteristics and formation mechanism of biomass burning pollution, the hourly variations of meteorological factors and pollutant concentrations during a heavy pollution on 18-21 May, 2012 in Chengdu are presented in this study. The episode was the heaviest and most long-lasting pollution event in the historical record of Chengdu caused by a combination of stagnant dispersion conditions and enhanced PM2.5 emission from intensive biomass burning, with peak values surpassing 500 μg m(-3). The event was characterized by three nighttime peaks, relating to the burning practice and decreased boundary layer height at night. The prevailing northeasterly wind during nighttime preferentially brought more pollutants to the urban regions from northern suburbs of Chengdu, where dense fire spots were observed. Due to the obstruction of hilly topography and weak wind speed, minor regional features were reflected from the PM10 variations in nearby cities, whereas the long-distance transport of the plume impacted extensive regions in northern and eastern China. Carbon monoxide (CO) concentrations increased by more than 200%, while exceptionally high PM2.5 levels of 190.1 and 268.4 μg m(-3) on 17 May and 18 May, were observed and showed high correlation with CO (r=0.75). The relative contribution of biomass burning smoke to organic carbon was estimated from OC/EC ratios (organic carbon/elemental carbon) and elevated to 81.3% during the episode, indicating a significant impact on urban aerosol levels. The occurrence of high PM2.5/PM10 ratios (>0.80) and K(+)/EC ratios (>1.0), along with the increased carbonaceous concentrations and their fraction in PM2.5 (>40%) and high OC/EC ratios (about 8), could be used as immediate indicators for biomass burning pollution in cities. In addition, the heavy pollution involved a mixture of anthropogenic sources, reflected from the high SOR and NOR values and increases in the EFs (enrichment factors) of Mo, Zn, Cd, and Pb.

  13. ``Quantum'' interference with bouncing drops

    Science.gov (United States)

    Bohr, Tomas; Andersen, Anders; Madsen, Jacob; Reichelt, Christian; Lautrup, Benny; Ellegaard, Clive; Levinsen, Mogens

    2013-11-01

    In a series of recent papers (most recently) Yves Couder and collaborators have explored the dynamics of walking drops on the surface of a vibrated bath of silicon oil and have demonstrated a close analogy to quantum phenomena. The bouncing drop together with the surface wave that it excites seems to be very similar to the pilot wave envisaged by de Broglie for quantum particles. In particular, have studied a double slit experiment with walking drops, where an interference pattern identical to the quantum version is found even though it is possible to follow the orbits of the drops and unambigously determine which slit it goes through, something which in quantum mechanics would be ruled out by the Heisenberg uncertainly relations. We have repeated the experiment and present a somewhat more complicated picture. Theoretically, we study a Schrödinger equation with a source term originating from a localised ``particle'' being simultaneously guided by the wave. We present simple solutions to such a field theory and discuss the fundamental difficulties met by such a theory in order to comply with quantum mechanics.

  14. Quantum Interference in Graphene Nanoconstrictions.

    Science.gov (United States)

    Gehring, Pascal; Sadeghi, Hatef; Sangtarash, Sara; Lau, Chit Siong; Liu, Junjie; Ardavan, Arzhang; Warner, Jamie H; Lambert, Colin J; Briggs, G Andrew D; Mol, Jan A

    2016-07-13

    We report quantum interference effects in the electrical conductance of chemical vapor deposited graphene nanoconstrictions fabricated using feedback controlled electroburning. The observed multimode Fabry-Pérot interferences can be attributed to reflections at potential steps inside the channel. Sharp antiresonance features with a Fano line shape are observed. Theoretical modeling reveals that these Fano resonances are due to localized states inside the constriction, which couple to the delocalized states that also give rise to the Fabry-Pérot interference patterns. This study provides new insight into the interplay between two fundamental forms of quantum interference in graphene nanoconstrictions.

  15. Topological Mass Generation as an Interference Phenomenon

    CERN Document Server

    Ilha, A; Ilha, Anderson; Wotzasek, Clovis

    2000-01-01

    It is proposed a new mechanism for the phenomenon of topological mass generation in three spacetime dimensions as the result of the interference of two opposite massless chiral modes. This mechanism, already used to produce the massive vectorial mode of the 2D Schwinger model, is here exploited to produce the gauge invariant massive mode of the Maxwell-Chern-Simons theory. Moreover the procedure is clearly dimensionally independent: a new chiral boson action is proposed for odd and even dimensional space-times to be used as the basic building blocks of the interference schemes. This is a new result that extends the two-dimensional Floreanini-Jackiw action to higher dimensional spaces and is in clear contrast with the twice odd dimensional chiral form extensions.

  16. Wakeful rest alleviates interference-based forgetting.

    Science.gov (United States)

    Mercer, Tom

    2015-01-01

    Retroactive interference (RI)--the disruptive influence of events occurring after the formation of a new memory--is one of the primary causes of forgetting. Placing individuals within an environment that postpones interference should, therefore, greatly reduce the likelihood of information being lost from memory. For example, a short period of wakeful rest should diminish interference-based forgetting. To test this hypothesis, participants took part in a foreign language learning activity and were shown English translations of 20 Icelandic words for immediate recall. Half of the participants were then given an 8-min rest before completing a similar or dissimilar interfering distractor task. The other half did not receive a rest until after the distractor task, at which point interference had already taken place. All participants were then asked to translate the Icelandic words for a second time. Results revealed that retention was significantly worse at the second recall test, but being allowed a brief rest before completing the distractor task helped reduce the amount of forgetting. Taking a short, passive break can shield new memories from RI and alleviate forgetting.

  17. Jam-X: Wireless Agreement under Interference

    CERN Document Server

    Boano, Carlo Alberto; Zúñiga, Marco Antonio; Voigt, Thiemo

    2012-01-01

    Wireless low-power transceivers used in sensor networks such as IEEE 802.15.4 typically operate in unlicensed frequency bands that are subject to external interference from devices transmitting at much higher power. Communication protocols should therefore be designed to be robust against such interference. A critical building block of many protocols at all layers is agreement on a piece of information among a set of nodes. At the MAC layer, nodes may need to agree on a new time slot or frequency channel; at the application layer nodes may need to agree on handing over a leader role from one node to another. Message loss caused by interference may break agreement in two different ways: none of the nodes use the new information (time slot, channel, leader) and stick with the previous assignment, or - even worse - some nodes use the new information and some do not. This may lead to reduced performance or failures. In this paper we investigate the problem of agreement under interference and point out the limitat...

  18. Enhancement and suppression in a lexical interference fMRI-paradigm.

    Science.gov (United States)

    Abel, Stefanie; Dressel, Katharina; Weiller, Cornelius; Huber, Walter

    2012-03-01

    Previous picture-word interference (PWI) fMRI-paradigms revealed ambiguous mechanisms underlying facilitation and inhibition in healthy subjects. Lexical distractors revealed increased (enhancement) or decreased (suppression) activation in language and monitoring/control areas. Performing a secondary examination and data analysis, we aimed to illuminate the relation between behavioral and neural interference effects comparing target-related distractors (REL) with unrelated distractors (UNREL). We hypothesized that interference involves both (A) suppression due to priming and (B) enhancement due to simultaneous distractor and target processing. Comparisons to UNREL should remain distractor unspecific even at a low threshold. (C) Distractor types with common characteristics should reveal overlapping brain areas. In a 3T MRI scanner, participants were asked to name pictures while auditory words were presented (stimulus onset asynchrony [SOA] = -200 msec). Associatively and phonologically related distractors speeded responses (facilitation), while categorically related distractors slowed them down (inhibition) compared to UNREL. As a result, (A) reduced brain activations indeed resembled previously reported patterns of neural priming. Each target-related distractor yielded suppressions at least in areas associated with vision and conflict/competition monitoring (anterior cingulate cortex [ACC]), revealing least priming for inhibitors. (B) Enhancements concerned language-related but distractor-unspecific regions. (C) Some wider brain regions were commonly suppressed for combinations of distractor types. Overlapping areas associated with conceptual priming were found for facilitatory distractors (inferior frontal gyri), and areas related to phonetic/articulatory processing (precentral gyri and left parietal operculum/insula) for distractors sharing feature overlap. Each distractor with semantic relatedness revealed nonoverlapping suppressions in lexical

  19. Proposal of interference reduction routing for ad-hoc networks

    Directory of Open Access Journals (Sweden)

    Katsuhiro Naito

    2010-10-01

    Full Text Available In this paper, we propose an interference reduction routing protocol for ad-hoc networks. The interference is one of the degradation factors in wireless communications. In the ad-hoc network, some nodes communicate simultaneously. Therefore, these communications cause interference each other, and some packets are corrupted due to interference from another node. In the proposed protocol, each node estimates required transmission power according to hello messages. Therefore, the node can transmit a data packet with minimum required transmission power. Consequently, the interference against neighbor nodes can be reduced. From simulation results, we can find that the proposed protocol can reduce the number of control messages and can improve the throughput performance.

  20. Proposal of interference reduction routing for ad-hoc networks

    Directory of Open Access Journals (Sweden)

    Katsuhiro Naito

    2010-10-01

    Full Text Available In this paper, we propose an interference reduction routing protocol for ad-hoc networks. The interference is one of the degradation factors in wireless communications. In the ad-hoc network, some nodes communicate simultaneously. Therefore, these communications cause interference each other, and some packets are corrupted due to interference from another node. In the proposed protocol, each node estimates required transmission power according to hello messages. Therefore, the node can transmit a data packet with minimum required transmission power. Consequently, the interference against neighbor nodes can be reduced. From simulation results, we can find that the proposed protocol can reduce the number of control messages and can improve the throughput performance.

  1. Control and signal processing by transcriptional interference

    OpenAIRE

    2009-01-01

    A transcriptional activator can suppress gene expression by interfering with transcription initiated by another activator. Transcriptional interference has been increasingly recognized as a regulatory mechanism of gene expression. The signals received by the two antagonistically acting activators are combined by the polymerase trafficking along the DNA. We have designed a dual-control genetic system in yeast to explore this antagonism systematically. Antagonism by an upstream activator bears ...

  2. Effective Carrier Sensing in CSMA Networks under Cumulative Interference

    CERN Document Server

    Fu, Liqun; Huang, Jianwei

    2009-01-01

    This paper proposes and investigates the concept of a safe carrier-sensing range that can guarantee interference safe (also termed hidden-node-free) transmissions in CSMA networks under the cumulative interference model. Compared with the safe carrier-sensing range under the commonly assumed but less realistic pairwise interference model, we show that the safe carrier-sensing range required under the cumulative interference model is larger by a constant multiplicative factor. The concept of a safe carrier-sensing range, although amenable to elegant analytical results, is inherently not compatible with the conventional power threshold carrier-sensing mechanism (e.g., that used in IEEE 802.11). Specifically, the absolute power sensed by a node in the conventional mechanism does not contain enough information for it to derive its distances from other concurrent transmitter nodes. We show that, fortunately, a carrier-sensing mechanism called Incremental-Power Carrier-Sensing (IPCS) can realize the carrier-sensing...

  3. Nonmonotonic quantum-to-classical transition in multiparticle interference

    DEFF Research Database (Denmark)

    Ra, Young-Sik; Tichy, Malte; Lim, Hyang-Tag

    2013-01-01

    Quantum-mechanical wave–particle duality implies that probability distributions for granular detection events exhibit wave-like interference. On the single-particle level, this leads to self-interference—e.g., on transit across a double slit—for photons as well as for large, massive particles...... that interference fades away monotonically with increasing distinguishability—in accord with available experimental evidence on the single- and on the many-particle level. Here, we demonstrate experimentally and theoretically that such monotonicity of the quantum-to-classical transition is the exception rather than...... the rule whenever more than two particles interfere. As the distinguishability of the particles is continuously increased, different numbers of particles effectively interfere, which leads to interference signals that are, in general, nonmonotonic functions of the distinguishability of the particles...

  4. Mechanism of interaction between electromagnetic fields and living organisms

    Institute of Scientific and Technical Information of China (English)

    Fritz-Albert; Popp; 张锦珠

    2000-01-01

    Based on nonlinear phenomena of biophoton emission observed in the past, an interference model concerning with the mechanism of interaction between living organisms and electromagnetic fields was raised. Caused by biological nonlinearly polarizable double layer, destructive interference of incoming and reflected waves establishes in the outside. As a consequence, in the inside constructive interference takes place at the same time. The interference patterns may play an important role in biological self organization and in biological functions. We investigate the boundary conditions necessary for explaining these non-linear optical effects in terms of the phase conjugation. It turns out that there are solutions of the Maxwell equations which satisfy destructive interference of biophotons in agreement with the experimental results. Necessary provisions are nonlinearly polarizable optically active double layers of distances which are small compared to the wavelength of light. In addition, they have to be a

  5. Transient transmembrane secretion of H2O2: a mechanism for the citral-caused inhibition of aflatoxin production from Aspergillus flavus.

    Science.gov (United States)

    Li, Jinhan; Li, Jialin; Lu, Zhisong; Liu, Yang; Li, Chang Ming

    2015-12-21

    A polydopamine-Fe3O4 nanocomposite-based H2O2 electrochemical sensor is fabricated to real-time monitor the transmembrane release of reactive oxygen species from citral-treated Aspergillus flavus, revealing a mechanism involving transient transmembrane secretion of H2O2 for the citral-caused inhibition of aflatoxin production from a fungus for the first time.

  6. Intragenic deletions and a deep intronic mutation affecting pre-mRNA splicing in the dihydropyrimidine dehydrogenase gene as novel mechanisms causing 5-fluorouracil toxicity

    NARCIS (Netherlands)

    van Kuilenburg, A.B.P.; Meijer, J.; Mul, A.N.P.M.; Meinsma, R.; Schmid, V.; Dobritzsch, D.; Hennekam, R.C.M.; Mannens, M.M.A.M.; Kiechle, M.; Etienne-Grimaldi, M.C.; Klümpen, H.J.; Maring, J.G.; Derleyn, V.A.; Maartense, E.; Milano, G.; Vijzelaar, R.; Gross, E.

    2010-01-01

    Dihydropyrimidine dehydrogenase (DPD) is the initial enzyme acting in the catabolism of the widely used antineoplastic agent 5-fluorouracil (5FU). DPD deficiency is known to cause a potentially lethal toxicity following administration of 5FU. Here, we report novel genetic mechanisms underlying DPD d

  7. Output Interference in Recognition Memory

    Science.gov (United States)

    Criss, Amy H.; Malmberg, Kenneth J.; Shiffrin, Richard M.

    2011-01-01

    Dennis and Humphreys (2001) proposed that interference in recognition memory arises solely from the prior contexts of the test word: Interference does not arise from memory traces of other words (from events prior to the study list or on the study list, and regardless of similarity to the test item). We evaluate this model using output…

  8. Insecticidal Bacillus thuringiensis silences Erwinia carotovora virulence by a new form of microbial antagonism, signal interference.

    Science.gov (United States)

    Dong, Yi-Hu; Zhang, Xi-Fen; Xu, Jin-Ling; Zhang, Lian-Hui

    2004-02-01

    It is commonly known that bacteria may produce antibiotics to interfere with the normal biological functions of their competitors in order to gain competitive advantages. Here we report that Bacillus thuringiensis suppressed the quorum-sensing-dependent virulence of plant pathogen Erwinia carotovora through a new form of microbial antagonism, signal interference. E. carotovora produces and responds to acyl-homoserine lactone (AHL) quorum-sensing signals to regulate antibiotic production and expression of virulence genes, whereas B. thuringiensis strains possess AHL-lactonase, which is a potent AHL-degrading enzyme. B. thuringiensis did not seem to interfere with the normal growth of E. carotovora; rather, it abolished the accumulation of AHL signal when they were cocultured. In planta, B. thuringiensis significantly decreased the incidence of E. carotovora infection and symptom development of potato soft rot caused by the pathogen. The biocontrol efficiency is correlated with the ability of bacterial strains to produce AHL-lactonase. While all the seven AHL-lactonase-producing B. thuringiensis strains provided significant protection against E. carotovora infection, Bacillus fusiformis and Escherichia coli strains that do not process AHL-degradation enzyme showed little effect in biocontrol. Mutation of aiiA, the gene encoding AHL-lactonase in B. thuringiensis, resulted in a substantial decrease in biocontrol efficacy. These results suggest that signal interference mechanisms existing in natural ecosystems could be explored as a new version of antagonism for prevention of bacterial infections.

  9. Transgenic Sugarcane Resistant to Sorghum mosaic virus Based on Coat Protein Gene Silencing by RNA Interference

    Directory of Open Access Journals (Sweden)

    Jinlong Guo

    2015-01-01

    Full Text Available As one of the critical diseases of sugarcane, sugarcane mosaic disease can lead to serious decline in stalk yield and sucrose content. It is mainly caused by Potyvirus sugarcane mosaic virus (SCMV and/or Sorghum mosaic virus (SrMV, with additional differences in viral strains. RNA interference (RNAi is a novel strategy for producing viral resistant plants. In this study, based on multiple sequence alignment conducted on genomic sequences of different strains and isolates of SrMV, the conserved region of coat protein (CP genes was selected as the target gene and the interference sequence with size of 423 bp in length was obtained through PCR amplification. The RNAi vector pGII00-HACP with an expression cassette containing both hairpin interference sequence and cp4-epsps herbicide-tolerant gene was transferred to sugarcane cultivar ROC22 via Agrobacterium-mediated transformation. After herbicide screening, PCR molecular identification, and artificial inoculation challenge, anti-SrMV positive transgenic lines were successfully obtained. SrMV resistance rate of the transgenic lines with the interference sequence was 87.5% based on SrMV challenge by artificial inoculation. The genetically modified SrMV-resistant lines of cultivar ROC22 provide resistant germplasm for breeding lines and can also serve as resistant lines having the same genetic background for study of resistance mechanisms.

  10. The development of stimulus and response interference control in mid-childhood

    OpenAIRE

    Cragg, Lucy

    2015-01-01

    Interference control, the ability to overcome distraction from irrelevant information, undergoes considerable improvement during childhood yet the mechanisms driving these changes remain unclear. The present study investigated the relative influence of interference at the level of the stimulus or the response. 7-, 10- and 20-year-olds completed a flanker paradigm in which stimulus and response interference were experimentally manipulated. The influence of stimulus interference decreased from ...

  11. Extreme ultraviolet Talbot interference lithography.

    Science.gov (United States)

    Li, Wei; Marconi, Mario C

    2015-10-05

    Periodic nanopatterns can be generated using lithography based on the Talbot effect or optical interference. However, these techniques have restrictions that limit their performance. High resolution Talbot lithography is limited by the very small depth of focus and the demanding requirements in the fabrication of the master mask. Interference lithography, with large DOF and high resolution, is limited to simple periodic patterns. This paper describes a hybrid extreme ultraviolet lithography approach that combines Talbot lithography and interference lithography to render an interference pattern with a lattice determined by a Talbot image. As a result, the method enables filling the arbitrary shaped cells produced by the Talbot image with interference patterns. Detailed modeling, system design and experimental results using a tabletop EUV laser are presented.

  12. Communications in interference limited networks

    CERN Document Server

    2016-01-01

    This book offers means to handle interference as a central problem of operating wireless networks. It investigates centralized and decentralized methods to avoid and handle interference as well as approaches that resolve interference constructively. The latter type of approach tries to solve the joint detection and estimation problem of several data streams that share a common medium. In fact, an exciting insight into the operation of networks is that it may be beneficial, in terms of an overall throughput, to actively create and manage interference. Thus, when handled properly, "mixing" of data in networks becomes a useful tool of operation rather than the nuisance as which it has been treated traditionally. With the development of mobile, robust, ubiquitous, reliable and instantaneous communication being a driving and enabling factor of an information centric economy, the understanding, mitigation and exploitation of interference in networks must be seen as a centrally important task.

  13. Alternative splicing interference by xenobiotics.

    Science.gov (United States)

    Zaharieva, Emanuela; Chipman, J Kevin; Soller, Matthias

    2012-06-14

    The protein coding sequence of most eukaryotic genes (exons) is interrupted by non-coding parts (introns), which are excised in a process termed splicing. To generate a mature messenger RNA (mRNA) hundreds of combinatorial protein-protein and RNA-protein interactions are required to splice out often very large introns with high fidelity and accuracy. Inherent to splicing is the use of alternative splice sites generating immense proteomic diversity from a limited number of genes. In humans, alternative splicing is a major mode of regulating gene expression, occurs in over 90% of genes and is particularly abundant in the brain. Only recently, it has been recognized that the complexity of the splicing process makes it susceptible to interference by various xenobiotics. These compounds include antineoplastic substances, commonly used drugs and food supplements and cause a spectrum of effects ranging from deleterious inhibition of general splicing to highly specific modifications of alternative splicing affecting only certain genes. Alterations in splicing have been implicated in numerous diseases such as cancer and neurodegeneration. Splicing regulation plays an important role in the execution of programmed cell death. The switch between anti- and pro-apoptotic isoforms by alternative splice site selection and misregulation of a number of splicing factors impacts on cell survival and disease. Here, our current knowledge is summarized on compounds interfering with general and alternative splicing and of the current methodology to study changes in these processes relevant to the field of toxicology and future risk assessments.

  14. Attentional switches and dual-task interference.

    Directory of Open Access Journals (Sweden)

    Janne F Ettwig

    Full Text Available In four experiments, we studied the time course of interference between detection of an oddball orientation target (OT in an 8-item circular search display, and identification of a letter target (LT in a central stream of distractor letters. Dual-task performance for different temporal lags between targets was compared to single-task performance. When the LT preceded the OT, dual-task performance levels were reduced at short inter-target intervals of 0 and 166 ms; when the OT preceded the LT, the dual-task interference was unexpectedly stronger and lasted for up to 500 ms. Resource competition due to temporally overlapping target processing cannot account for this result, because the feature search task is easier than the letter identification task, and therefore would have generated less interference when presented first. Two alternative explanations were explored. First, by manipulating the spatial inter-target distance, we investigated to what degree there is a penalty associated with directing the attentional window from a large object (the search display to a smaller object (the central letter stream. Second, by varying the duration of the OT and subsequent mask, we studied whether the interference was caused by the difficulty of disengaging attention from the search display. Results support this second explanation and thus indicate that switching attention to the letter stream is hampered by the continuing presence of (masked search display items. This result shows that attentional effects may play a major role in dual-task execution and can easily obscure interference due to other factors such as resource competition.

  15. PROBABILISTIC-STATISTICAL MODELING THE INTERFERENCES FROM ELECTRIC LOCOMOTIVES

    Directory of Open Access Journals (Sweden)

    Orlov A. I.

    2015-02-01

    Full Text Available The movements of electric locomotives create the interferences affecting the wired link. The creation of sufficiently technical effective and at the same time cost-effective means of protection from wireline interferences generated traction networks assumes as a preparatory phase to develop mathematical models of interference caused by electric locomotives. We have developed a probabilistic-statistical model of interferences caused by electric locomotives. The asymptotic distribution of the total interference is the distribution of the length of the two-dimensional random vector whose coordinates - independent normally distributed random variables with mean 0 and variance 1. Limit theorem is proved for the expectation of the total amplitude of the interferences. Monte-Carlo method is used to study the rate of convergence of the expectation of the total amplitude of the interferences to the limiting value. We used an algorithm of mixing developed by MacLaren-Marsaglia (M-algorithm. Five sets of amplitudes are analyzed, selected in accordance with the recommendations of experts in the field of traction AC networks. The most rapid convergence to the limit takes place in the case of equal amplitudes. It was found that the maximum possible average value of the amplitude of the random noise by 7.4% less than the previously used value, which promises a significant economic impact

  16. Reaction mechanism of the acidic hydrolysis of highly twisted amides: Rate acceleration caused by the twist of the amide bond.

    Science.gov (United States)

    Mujika, Jon I; Formoso, Elena; Mercero, Jose M; Lopez, Xabier

    2006-08-03

    We present an ab initio study of the acid hydrolysis of a highly twisted amide and a planar amide analogue. The aim of these studies is to investigate the effect that the twist of the amide bond has on the reaction barriers and mechanism of acid hydrolysis. Concerted and stepwise mechanisms were investigated using density functional theory and polarizable continuum model calculations. Remarkable differences were observed between the mechanism of twisted and planar amide, due mainly to the preference for N-protonation of the former and O-protonation of the latter. In addition, we were also able to determine that the hydrolytic mechanism of the twisted amide will be pH dependent. Thus, there is a preference for a stepwise mechanism with formation of an intermediate in the acid hydrolysis, whereas the neutral hydrolysis undergoes a concerted-type mechanism. There is a nice agreement between the characterized intermediate and available X-ray data and a good agreement with the kinetically estimated rate acceleration of hydrolysis with respect to analogous undistorted amide compounds. This work, along with previous ab initio calculations, describes a complex and rich chemistry for the hydrolysis of highly twisted amides as a function of pH. The theoretical data provided will allow for a better understanding of the available kinetic data of the rate acceleration of amides upon twisting and the relation of the observed rate acceleration with intrinsic differential reactivity upon loss of amide bond resonance.

  17. Interference Cancelation Schemes for Uplink Transmission in Femtocells

    DEFF Research Database (Denmark)

    Thai, Chan; Popovski, Petar

    2010-01-01

    We present techniques that solve the near-far problems in femtocell networks. When a co-channel configuration is used, a transmission in the macrocell may cause interference to a femtocell. We introduce methods to cancel the interference caused by the macrocell to a femtocell by using the high-rate...... link between the macrocell base station (BS) and the femtocell BS. In such a way, the interference from macrocell transmitters is completely cancelled when uplink transmission is used in the femtocell. Therefore, the allocation of time slots for uplink/downlink in a femtocell can be done by trying only...... to minimize the interference that a femtocell terminal experiences during a downlink transmission....

  18. Interference effects of categorization on decision making.

    Science.gov (United States)

    Wang, Zheng; Busemeyer, Jerome R

    2016-05-01

    Many decision making tasks in life involve a categorization process, but the effects of categorization on subsequent decision making has rarely been studied. This issue was explored in three experiments (N=721), in which participants were shown a face stimulus on each trial and performed variations of categorization-decision tasks. On C-D trials, they categorized the stimulus and then made an action decision; on X-D trials, they were told the category and then made an action decision; on D-alone trials, they only made an action decision. An interference effect emerged in some of the conditions, such that the probability of an action on the D-alone trials (i.e., when there was no explicit categorization before the decision) differed from the total probability of the same action on the C-D or X-D trials (i.e., when there was explicit categorization before the decision). Interference effects are important because they indicate a violation of the classical law of total probability, which is assumed by many cognitive models. Across all three experiments, a complex pattern of interference effects systematically occurred for different types of stimuli and for different types of categorization-decision tasks. These interference effects present a challenge for traditional cognitive models, such as Markov and signal detection models, but a quantum cognition model, called the belief-action entanglement (BAE) model, predicted that these results could occur. The BAE model employs the quantum principles of superposition and entanglement to explain the psychological mechanisms underlying the puzzling interference effects. The model can be applied to many important and practical categorization-decision situations in life.

  19. Italian, French, Polish: in the Bermuda Triangle of linguistic interference

    OpenAIRE

    Małgorzata Balicka

    2009-01-01

    Increasing contacts between nations make people learn foreign languages. Unfortunately, the use of more than one language system may cause errors due to linguistic interference. In the present paper we consider different definitions of this phenomenon and describe the conditions reąuired for its presence, along with proposals on how to eliminate interference mistakes. A specific case is false friends, words similar in form but different in meaning, which can lead to misunderstandings or even ...

  20. Radio Interference Modeling and Prediction for Satellite Operation Applications

    Science.gov (United States)

    2015-08-25

    RFI sources can cause co- channel interference (CCI) or adjacent channel interference (ACI), depending on the transmitting carrier frequencies. Potential...friendly RFI sources that are common for civil and commercial personal communication systems include 3G wireless, 4G wireless, WiFi and WIMAX...o Smart jammer: Purposed to monitor the USB SATOPS data links and inject weak jamming signals in the channel with the intention to degrade the USB

  1. Mechanisms for Nonrecurrent Genomic Rearrangements Associated with CMT1A or HNPP: Rare CNVs as a Cause for Missing Heritability

    NARCIS (Netherlands)

    F. Zhang; P. Seeman; P. Liu; M.A.J. Weterman; C. Gonzaga-Jauregui; C.F. Towne; S.D. Batish; E. de Vriendt; P. de Jonghe; B. Rautenstrauss; K.H. Krause; M. Khajavi; J. Posadka; A. Vandenberghe; F. Palau; L. van Maldergem; F. Baas; V. Timmerman; J.R. Lupski

    2010-01-01

    Genomic rearrangements involving the peripheral myelin protein gene (PMP22) in human chromosome 17p12 are associated with neuropathy: duplications cause Charcot-Marie-Tooth disease type IA (CMT1A), whereas deletions lead to hereditary neuropathy with liability to pressure palsies (HNPP). Our previou

  2. Control and signal processing by transcriptional interference

    Science.gov (United States)

    Buetti-Dinh, Antoine; Ungricht, Rosemarie; Kelemen, János Z; Shetty, Chetak; Ratna, Prasuna; Becskei, Attila

    2009-01-01

    A transcriptional activator can suppress gene expression by interfering with transcription initiated by another activator. Transcriptional interference has been increasingly recognized as a regulatory mechanism of gene expression. The signals received by the two antagonistically acting activators are combined by the polymerase trafficking along the DNA. We have designed a dual-control genetic system in yeast to explore this antagonism systematically. Antagonism by an upstream activator bears the hallmarks of competitive inhibition, whereas a downstream activator inhibits gene expression non-competitively. When gene expression is induced weakly, the antagonistic activator can have a positive effect and can even trigger paradoxical activation. Equilibrium and non-equilibrium models of transcription shed light on the mechanism by which interference converts signals, and reveals that self-antagonism of activators imitates the behavior of feed-forward loops. Indeed, a synthetic circuit generates a bell-shaped response, so that the induction of expression is limited to a narrow range of the input signal. The identification of conserved regulatory principles of interference will help to predict the transcriptional response of genes in their genomic context. PMID:19690569

  3. Quantum interference of molecules -- probing the wave nature of matter

    CERN Document Server

    Venugopalan, Anu

    2012-01-01

    The double slit interference experiment has been famously described by Richard Feynman as containing the "only mystery of quantum mechanics". The history of quantum mechanics is intimately linked with the discovery of the dual nature of matter and radiation. While the double slit experiment for light is easily undertsood in terms of its wave nature, the very same experiment for particles like the electron is somewhat more difficult to comprehend. By the 1920s it was firmly established that electrons have a wave nature. However, for a very long time, most discussions pertaining to interference experiments for particles were merely gedanken experiments. It took almost six decades after the establishment of its wave nature to carry out a 'double slit interference' experiment for electrons. This set the stage for interference experiments with larger particles. In the last decade there has been spectacular progress in matter-wave interefernce experiments. Today, molecules with over a hundred atoms can be made to i...

  4. [Turning the head, an unusual mechanism to compensate for diplopia caused by abduction restriction of one eye

    NARCIS (Netherlands)

    Kappelle, A.C.; Schelhaas, H.J.; Pasman, J.W.; Bloem, B.R.

    2004-01-01

    A 59-year-old-man visited the neurological outpatient clinic because of a leftward rotation of his head for the last 8 months. This head deviation turned out to represent a compensatory mechanism to alleviate diplopia that resulted from an abduction restriction of his left eye. By turning his head i

  5. What can long-lived mutants tell us about mechanisms causing aging and lifespan variation in natural environments?

    NARCIS (Netherlands)

    Briga, Michael; Verhulst, Simon

    2015-01-01

    Long-lived mutants of model organisms have brought remarkable progress in our understanding of aging mechanisms. However, long-lived mutants are usually maintained in optimal standardized laboratory environments (SLEs), and it is not obvious to what extent insights from long-lived mutants in SLEs ca

  6. What can long-lived mutants tell us about mechanisms causing aging and lifespan variation in natural environments?

    NARCIS (Netherlands)

    Briga, Michael; Verhulst, Simon

    2015-01-01

    Long-lived mutants of model organisms have brought remarkable progress in our understanding of aging mechanisms. However, long-lived mutants are usually maintained in optimal standardized laboratory environments (SLEs), and it is not obvious to what extent insights from long-lived mutants in SLEs

  7. Mechanical vibrations in the transport of hatching eggs and the losses caused in the hatch and quality of broiler chicks

    Directory of Open Access Journals (Sweden)

    Ana Carolina Donofre

    2017-02-01

    Full Text Available Many factors present in eggs’ transportation from incubator to growing confinements can damage their integrity and, consequently, the results of the incubation. This study aimed to evaluate whether the intensity and duration of exposures of hatching eggs to mechanical vibrations were capable of affecting the hatch and the quality of broiler chicks. Four treatments, determined by two intensities of vibrations and two durations of exposures were evaluated and compared with a control group in a randomised design in blocks with four repetitions. The vibrations were applied by a mechanical shaker before incubation. Then the eggs were incubated and as the following responses were evaluated: hatchability, the type of embryonic mortality, the quality of the birds and the total of losses. The analyses were carried out by a binomial regression model, with application of the Wald test at 5% significance level. The results showed that the exposure of eggs to mechanical vibrations harmfully affects the hatchability and reduces the ratio (percentage of high quality chicks. Highest vibration level together with longer duration of exposure resulted in worst hatchability and losses. It is argued that the mechanical vibrations are potentially damaging and should be regarded as an important factor in the management of hatching eggs.

  8. ECONOMIC AND SOCIAL CHALLENGES IN A GLOBAL ENVIRONMENT. LABOUR MARKET CHANGES IN ROMANIA. FACTORS, CAUSES, ADJUSTMENT MECHANISMS

    Directory of Open Access Journals (Sweden)

    Valentina VASILE

    2008-06-01

    Full Text Available The reform of labour market and the modification of the human capital management model evolved unsteadily, much behind the demand from the economic and social environment. Labour market was pushed to a secondary plane, considering that the adjustment of the other markets would cause necessary changes for ensuring the functioning of the labour market. Now, Romania is involved in consolidating the market economy, which requires integrated procedures of dealing with the policies able to respond efficiently to challenges. Similarly to the economic reform, the chances in the labour market were gradual but there were no coherence and no correlation of the measures taken, which caused non-typical behaviours, often contrary to reforms.

  9. Optical interference with digital holograms

    Science.gov (United States)

    Gossman, David; Perez-Garcia, Benjamin; Hernandez-Aranda, Raul I.; Forbes, Andrew

    2016-07-01

    In 1804, Thomas Young reported the observation of fringes in the intensity of light, and attributed it to the concept of interference between coherent sources. In this paper, we revisit this famous experiment and show how it can easily be demonstrated with digital holography. We look closely at the concept of interference with light and ask, "fringes in what?" We then show that depending on how light interferes, fringe patterns in observables other than intensity can be seen. We explain this conceptually and demonstrate it experimentally. We provide a holistic approach to the topic, aided by modern laboratory practices for a straightforward demonstration of the underlying physics.

  10. General relativistic effects in quantum interference of "clocks"

    CERN Document Server

    Zych, Magdalena; Costa, Fabio; Brukner, Časlav

    2016-01-01

    Quantum mechanics and general relativity have been each successfully tested in numerous experiments. However, the regime where both theories are jointly required to explain physical phenomena remains untested by laboratory experiments, and is also not fully understood by theory. This contribution reviews recent ideas for a new type of experiments: quantum interference of "clocks", which aim to test novel quantum effects that arise from time dilation. "Clock" interference experiments could be realised with atoms or photons in near future laboratory experiments.

  11. Interference in ballistic motor learning: specificity and role of sensory error signals

    DEFF Research Database (Denmark)

    Lundbye-Jensen, Jesper; Petersen, Tue Hvass; Rothwell, John C;

    2011-01-01

    not antagonist) peripheral nerve caused interference. The present study is, to our knowledge, the first to demonstrate that peripheral nerve stimulation may cause interference. The finding underscores the importance of sensory feedback as error signals in motor learning. We conclude that interference requires......Humans are capable of learning numerous motor skills, but newly acquired skills may be abolished by subsequent learning. Here we ask what factors determine whether interference occurs in motor learning. We speculated that interference requires competing processes of synaptic plasticity...... in overlapping circuits and predicted specificity. To test this, subjects learned a ballistic motor task. Interference was observed following subsequent learning of an accuracy-tracking task, but only if the competing task involved the same muscles and movement direction. Interference was not observed from a non-learning...

  12. Iatrogenic causes of salivary gland dysfunction

    Energy Technology Data Exchange (ETDEWEB)

    Schubert, M.M.; Izutsu, K.T.

    1987-02-01

    Saliva is important for maintaining oral health and function. There are instances when medical therapy is intended to decrease salivary flow, such as during general anesthesia, but most instances of iatrogenic salivary gland dysfunction represent untoward or unavoidable side-effects. The clinical expression of the salivary dysfunction can range from very minor transient alteration in saliva flow to a total loss of salivary function. The most common forms of therapy that interfere with salivation are drug therapies, cancer therapies (radiation or chemotherapy), and surgical therapy. These therapies can affect salivation by a number of different mechanisms that include: disruption of autonomic nerve function related to salivation, interference with acinar or ductal cell functions related to salivation, cytotoxicity, indirect effects (vasoconstriction/dilation, fluid and electrolyte balance, etc.), and physical trauma to salivary glands and nerves. A wide variety of drugs is capable of increasing or decreasing salivary flow by mimicking autonomic nervous system actions or by directly acting on cellular processes necessary for salivation: drugs can also indirectly affect salivation by altering fluid and electrolyte balance or by affecting blood flow to the glands. Ionizing radiation can cause permanent damage to salivary glands, damage that is manifest as acinar cell destruction with subsequent atrophy and fibrosis of the glands. Cancer chemotherapy can cause changes in salivation, but the changes are usually much less severe and only transient. Finally, surgical and traumatic injuries interfere with salivation because of either disruption of gland innervation or gross physical damage (or removal) of glandular tissue (including ducts).

  13. Thrombus or vegetation: A mystery causing ST elevation myocardial infarction with infective endocarditis of mechanical aortic valve.

    Science.gov (United States)

    Khan, Safi U; Lone, Ahmad N; Subramanian, Charumathi Raghu; DePersis, Michael; Sporn, Daniel

    2017-03-07

    Acute myocardial infarction (MI) in the setting of infective endocarditis (IE) of mechanical cardiac valve is a rare phenomenon. The most challenging aspect is the recognition between septic embolus versus thromboembolism from prosthesis in the setting of sub-therapeutic INR especially when the coronary vasculature is normal and etiology is not clear. We are presenting a case of 56-year-old patient who developed ST elevation MI during treatment of IE of mechanical aortic valve. Cardiac catheterization showed a very subtle blockade at most distal end of LAD therefore percutaneous coronary intervention (PCI) could not be carried out. Given the lack of clear etiology between septic embolus versus prosthesis associated thromboembolism, we opted for a successful conservative approach.

  14. Development of a direct exposure system for studying the mechanisms of central neurotoxicity caused by volatile organic compounds

    OpenAIRE

    2015-01-01

    Many volatile organic compounds (VOCs) used in work places are neurotoxic. However, it has been difficult to study the cellular mechanisms induced by a direct exposure to neurons because of their high volatility. The objective of this study was to establish a stable system for exposing brain slices to VOCs. With a conventional recording system for brain slices, it is not possible to keep a constant bath concentration of relatively highly volatile solvents, e.g. 1-bromopropane (1-BP). Here we ...

  15. Picropodophyllin causes mitotic arrest and catastrophe by depolymerizing microtubules via insulin-like growth factor-1 receptor-independent mechanism.

    Science.gov (United States)

    Waraky, Ahmed; Akopyan, Karen; Parrow, Vendela; Strömberg, Thomas; Axelson, Magnus; Abrahmsén, Lars; Lindqvist, Arne; Larsson, Olle; Aleem, Eiman

    2014-09-30

    Picropodophyllin (PPP) is an anticancer drug undergoing clinical development in NSCLC. PPP has been shown to suppress IGF-1R signaling and to induce a G2/M cell cycle phase arrest but the exact mechanisms remain to be elucidated. The present study identified an IGF-1-independent mechanism of PPP leading to pro-metaphase arrest. The mitotic block was induced in human cancer cell lines and in an A549 xenograft mouse but did not occur in normal hepatocytes/mouse tissues. Cell cycle arrest by PPP occurred in vitro and in vivo accompanied by prominent CDK1 activation, and was IGF-1R-independent since it occurred also in IGF-1R-depleted and null cells. The tumor cells were not arrested in G2/M but in mitosis. Centrosome separation was prevented during mitotic entry, resulting in a monopolar mitotic spindle with subsequent prometaphase-arrest, independent of Plk1/Aurora A or Eg5, and leading to cell features of mitotic catastrophe. PPP also increased soluble tubulin and decreased spindle-associated tubulin within minutes, indicating that it interfered with microtubule dynamics. These results provide a novel IGF-1R-independent mechanism of antitumor effects of PPP.

  16. Pathophysiological mechanisms of diarrhea caused by the Vibrio cholerae O1 El Tor variant: an in vivo study in mice.

    Science.gov (United States)

    Satitsri, Saravut; Pongkorpsakol, Pawin; Srimanote, Potjanee; Chatsudthipong, Varanuj; Muanprasat, Chatchai

    2016-10-02

    Cholera is caused by infection with Vibrio cholerae. This study aimed to investigate the pathophysiology of diarrhea caused by the V. cholerae O1 El Tor variant (EL), a major epidemic strain causing severe diarrhea in several regions. In the ligated ileal loop model of EL-induced diarrhea in the ICR mice, a cystic fibrosis transmembrane conductance regulator (CFTR) inhibitor and a calcium-activated chloride channel (CaCC) inhibitor similarly inhibited intestinal fluid secretion. In addition, barrier disruption and NF-κB-mediated inflammatory responses, e.g., iNOS and COX-2 expression, were observed in the infected ileal loops. Interestingly, intestinal fluid secretion and barrier disruption were suppressed by NF-κB and COX-2 inhibitors, whereas an iNOS inhibitor suppressed barrier disruption without affecting fluid secretion. Furthermore, EP2 and EP4 PGE2 receptor antagonists ameliorated the fluid secretion in the infected ileal loops. The amount of cholera toxin (CT) produced in the ileal loops by the EL was ∼2.4-fold of the classical biotype. The CT transcription inhibitor virstatin, a toll-like receptor-4 (TLR-4) antibody and a CT antibody suppressed the EL-induced intestinal fluid secretion, barrier disruption and COX-2 expression. The CT at levels detected during EL infection induced mild intestinal barrier disruption without inducing inflammatory responses in mouse intestine. Collectively, this study indicates that CT-induced intestinal barrier disruption and subsequent TLR-4-NF-κB-mediated COX-2 expression are involved in the pathogenesis of EL-induced diarrhea and represent promising novel therapeutic targets of cholera.

  17. Propagation mechanisms of incident tsunami wave in Jiangsu coastal area, caused by eastern Japan earthquake on March 11, 2011

    Science.gov (United States)

    Yuan, Chun-guang; Wang, Yi-gang; Huang, Hui-ming; Chen, Cheng; Chen, Da-ke

    2016-03-01

    At 13:46 on March 11, 2011 (Beijing time), an earthquake of Mw=9.0 occurred in Japan. By comparing the tsunami data from Guanhekou marine station with other tsunami wave observation gathered from southeast coastal area of China, it was evident that, only in Guanhekou, the position of the maximum wave height appeared in the middle part rather than in the front of the tsunami wave train. A numerical model of tsunami propagation based on 2-D nonlinear shallow water equations was built to study the impact range and main causes of the special tsunami waveform discovered in Jiangsu coastal area. The results showed that nearly three-quarters of the Jiangsu coastal area, mainly comprised the part north of the radial sand ridges, reached its maximum tsunami wave height in the middle part of the wave train. The main cause of the special waveform was the special underwater topography condition of the Yellow Sea and the East China Sea area, which influenced the tsunami propagation and waveform significantly. Although land boundary reflection brought an effect on the position of the maximum wave height to a certain extent, as the limits of the incident waveform and distances between the observation points and shore, it was not the dominant influence factor of the special waveform. Coriolis force's impact on the tsunami waves was so weak that it was not the main cause for the special phenomenon in Jiangsu coastal area. The study reminds us that the most destructive wave might not appear in the first one in tsunami wave train.

  18. Propagation Mechanisms of Incident Tsunami Wave in Jiangsu Coastal Area, Caused by Eastern Japan Earthquake on March 11, 2011

    Institute of Scientific and Technical Information of China (English)

    袁春光; 王义刚; 黄惠明; 陈橙; 陈大可

    2016-01-01

    At 13:46 on March 11, 2011 (Beijing time), an earthquake of Mw=9.0 occurred in Japan. By comparing the tsunami data from Guanhekou marine station with other tsunami wave observation gathered from southeast coastal area of China, it was evident that, only in Guanhekou, the position of the maximum wave height appeared in the middle part rather than in the front of the tsunami wave train. A numerical model of tsunami propagation based on 2-D nonlinear shallow water equations was built to study the impact range and main causes of the special tsunami waveform discovered in Jiangsu coastal area. The results showed that nearly three-quarters of the Jiangsu coastal area, mainly comprised the part north of the radial sand ridges, reached its maximum tsunami wave height in the middle part of the wave train. The main cause of the special waveform was the special underwater topography condition of the Yellow Sea and the East China Sea area, which influenced the tsunami propagation and waveform significantly. Although land boundary reflection brought an effect on the position of the maximum wave height to a certain extent, as the limits of the incident waveform and distances between the observation points and shore, it was not the dominant influence factor of the special waveform. Coriolis force’s impact on the tsunami waves was so weak that it was not the main cause for the special phenomenon in Jiangsu coastal area. The study reminds us that the most destructive wave might not appear in the first one in tsunami wave train.

  19. Interference of Quantum Market Strategies

    CERN Document Server

    Piotrowski, E W; Syska, J

    2003-01-01

    Recent development in quantum computation and quantum information theory allows to extend the scope of game theory for the quantum world. The paper is devoted to the analysis of interference of quantum strategies in quantum market games.

  20. Multipolar interference effects in nanophotonics

    CERN Document Server

    Liu, Wei

    2016-01-01

    Scattering of electromagnetic waves by an arbitrary nanoscale object can be characterized by a multipole decomposition of the electromagnetic field that allows to describe the scattering intensity and radiation pattern through interferences of dominating excited multipole modes. In modern nanophotonics, both generation and interference of multipole modes start to play an indispensable role, and they enable nanoscale manipulation of light with many related applications. Here we review the multipolar interference effects in metallic, metal-dielectric, and dielectric nanostructures, and suggest a comprehensive view on many phenomena involving the interferences of electric, magnetic and toroidal multipoles, which drive a number of recently discussed effects in nanophotonics such as unidirectional scattering, effective optical antiferromagnetism, generalized Kerker scattering with controlled angular patterns, generalized Brewster angle, and nonradiating optical anapoles. We further discuss other types of possible ...

  1. Evaluate interference in digital channels

    Science.gov (United States)

    Davarian, F.; Sumida, J.

    1985-01-01

    Any future mobile satellite service (MSS) which is to provide simultaneous mobile communications for a large number of users will have to make very efficient use of the spectrum. As the spectrum available for an MSS is limited, the system's channels should be packed as closely together as possible, with minimum-width guard bands. In addition the employment of frequency reuse schemes is an important factor. Difficulties regarding these solutions are related to the introduction of interference in the link. A balance must be achieved between the competing aims of spectrum conservation and low interference. While the interference phenomenon in narrowband FM voice channels is reasonably well understood, very little effort, however, has been devoted to the problem in digital radios. Attention is given to work, which illuminates the effects of cochannel and adjacent channel interference on digital FM (FSK) radios.

  2. Interference, reduced action, and trajectories

    OpenAIRE

    2006-01-01

    Instead of investigating the interference between two stationary, rectilinear wave functions in a trajectory representation by examining the two rectilinear wave functions individually, we examine a dichromatic wave function that is synthesized from the two interfering wave functions. The physics of interference is contained in the reduced action for the dichromatic wave function. As this reduced action is a generator of the motion for the dichromatic wave function, it determines the dichroma...

  3. 氟中毒致机体损伤及其机制%Injuries caused by fluorosis and its mechanisms

    Institute of Scientific and Technical Information of China (English)

    李薛燕; 黄文丽

    2015-01-01

    地方性氟中毒简称地氟病,是由氟导致的全身慢性蓄积性中毒。地氟病不仅给患者带来精神和肉体上的痛苦,而且加重家庭经济负担,同时严重影响病区的经济发展。本文将主要从氟对机体各器官系统的损伤作用及其发病机制加以阐述,以期为氟中毒相关研究提供参考。%Endemic fluorosis is a systemic chronic chemical poisoning caused by fluorine . Fluorosis not only imposes mental and physical harm to patients ,but also increases their financial burdens while adversely affecting the economical developments in the area .This article summarizes the injuries on various body organs caused by fluorosis and its pathogenesis ,in hopes of providing references for future fluorosis‐related studies .

  4. How Cannabis Causes Paranoia: Using the Intravenous Administration of ∆9-Tetrahydrocannabinol (THC) to Identify Key Cognitive Mechanisms Leading to Paranoia

    OpenAIRE

    Freeman, Daniel; Dunn, Graham; Murray, Robin M.; Evans, Nicole; Lister, Rachel; Antley, Angus; Slater, Mel; Godlewska, Beata; Cornish, Robert; Williams, Jonathan; Di Simplicio, Martina; Igoumenou, Artemis; Brenneisen, Rudolf; Tunbridge, Elizabeth M.; Harrison, Paul J

    2014-01-01

    Paranoia is receiving increasing attention in its own right, since it is a central experience of psychotic disorders and a marker of the health of a society. Paranoia is associated with use of the most commonly taken illicit drug, cannabis. The objective was to determine whether the principal psychoactive ingredient of cannabis—∆9-tetrahydrocannabinol (THC)—causes paranoia and to use the drug as a probe to identify key cognitive mechanisms underlying paranoia. A randomized, placebo-controlled...

  5. Brd2 gene disruption causes ‘metabolically healthy’ obesity: Epigenetic and chromatin-based mechanisms that uncouple obesity from Type 2 diabetes

    OpenAIRE

    WANG, Fangnian; Deeney, Jude T.; Denis, Gerald V.

    2013-01-01

    Disturbed body energy balance can lead to obesity and obesity-driven diseases such as Type 2 diabetes, which have reached an epidemic level. Evidence indicates that obesity induced inflammation is a major cause of insulin resistance and Type 2 diabetes. Environmental factors, such as nutrients, affect body energy balance through epigenetic or chromatin-based mechanisms. As a bromodomain and external domain family transcription regulator, Brd2 regulates expression of many genes through interpr...

  6. Multipolar interference effects in nanophotonics.

    Science.gov (United States)

    Liu, Wei; Kivshar, Yuri S

    2017-03-28

    Scattering of electromagnetic waves by an arbitrary nanoscale object can be characterized by a multipole decomposition of the electromagnetic field that allows one to describe the scattering intensity and radiation pattern through interferences of dominating multipole modes excited. In modern nanophotonics, both generation and interference of multipole modes start to play an indispensable role, and they enable nanoscale manipulation of light with many related applications. Here, we review the multipolar interference effects in metallic, metal-dielectric and dielectric nanostructures, and suggest a comprehensive view on many phenomena involving the interferences of electric, magnetic and toroidal multipoles, which drive a number of recently discussed effects in nanophotonics such as unidirectional scattering, effective optical antiferromagnetism, generalized Kerker scattering with controlled angular patterns, generalized Brewster angle, and non-radiating optical anapoles. We further discuss other types of possible multipolar interference effects not yet exploited in the literature and envisage the prospect of achieving more flexible and advanced nanoscale control of light relying on the concepts of multipolar interference through full phase and amplitude engineering.This article is part of the themed issue 'New horizons for nanophotonics'.

  7. Interference Cancellation in Cooperative CDMA Networks

    Directory of Open Access Journals (Sweden)

    A. Rajeswari

    2011-01-01

    Full Text Available The wireless communication networks are subjected to multi access interference and multipath fading. To minimize the interference cancellation in CDMA networks, multiple user detection schemes and cooperative communication networks are used. consider the uplink of a cooperative CDMA network, where users cooperate by relaying each other’s messages to the base station. When spreading waveforms are not orthogonal, multiple access interference (MAI exists at the relays and the destination, causing cooperative diversity gains to diminish. To overcome this problem, we integrate various multiuser detection (MUD schemes to mitigate MAI in achieving the full advantages of cooperation. Specifically, the relay-assisted decorrelating multiuser detector (RADMUD is proposed to separate interfering signals at the destination with the help of precoding at the relays along with pre-whitening at the destination. In this paper we examined the BER performance of various MUD schemes are analyzed and compared with cooperative system. The advantages of RAD-MUD with co-operative communication shows better BER performance compared with non co-operative wireless communication system and other existing cooperative MUD schemes are also shown through MATLAB Simulations.

  8. Physical mechanism causing rapid changes in ultrarelativistic electron pitch angle distributions right after a shock arrival: Evaluation of an electron dropout event

    Science.gov (United States)

    Zhang, X.-J.; Li, W.; Thorne, R. M.; Angelopoulos, V.; Ma, Q.; Li, J.; Bortnik, J.; Nishimura, Y.; Chen, L.; Baker, D. N.; Reeves, G. D.; Spence, H. E.; Kletzing, C. A.; Kurth, W. S.; Hospodarsky, G. B.; Blake, J. B.; Fennell, J. F.

    2016-09-01

    Three mechanisms have been proposed to explain relativistic electron flux depletions (dropouts) in the Earth's outer radiation belt during storm times: adiabatic expansion of electron drift shells due to a decrease in magnetic field strength, magnetopause shadowing and subsequent outward radial diffusion, and precipitation into the atmosphere (driven by EMIC wave scattering). Which mechanism predominates in causing electron dropouts commonly observed in the outer radiation belt is still debatable. In the present study, we evaluate the physical mechanism that may be primarily responsible for causing the sudden change in relativistic electron pitch angle distributions during a dropout event observed by Van Allen Probes during the main phase of the 27 February 2014 storm. During this event, the phase space density of ultrarelativistic (>1 MeV) electrons was depleted by more than 1 order of magnitude over the entire radial extent of the outer radiation belt (3 highly anisotropic (peaked in 90°), energy-dependent pitch angle distributions, which appear to be associated with the typical EMIC wave scattering, comparison of the modeled electron distribution to electron measurements indicates that drift shell splitting is responsible for this rapid change in electron pitch angle distributions. This further indicates that magnetopause loss is the predominant cause of the electron dropout right after the shock arrival.

  9. A witnessed case of a classic metaphyseal fracture caused during IV line placement in a child: Insight into mechanism of injury.

    Science.gov (United States)

    Burrell, Tanya; Opfer, Erin; Berglund, Lisa; Lowe, Lisa H; Anderst, James

    2015-10-01

    Recent publications argue that classic metaphyseal fractures are caused by rickets as opposed to trauma. Previous case reports of accidental traumatic classic metaphyseal fractures have been discounted due to lack of identification of the fracture at the time of the traumatic event, and lack of an evaluation for boney metabolic disorders. We report a case of a 20 day old male with a diagnosis of congenital vertical talus who sustained a classic metaphyseal fracture of the distal tibia during manipulation in preparation for intravenous line placement. The mechanics of the event causing the classic metaphyseal fracture were witnessed and accompanied by an audible "pop". Prior x-rays of the tibia demonstrate normal osseous morphology, and an evaluation for boney metabolic disorders was normal. This case identifies a traumatic classic metaphyseal fracture and provides insight into the types of forces necessary to cause such a fracture.

  10. RNA Interference and its Role in Cancer Therapy

    Directory of Open Access Journals (Sweden)

    Behzad Mansoori

    2014-12-01

    Full Text Available In todays’ environment, it is becoming increasingly difficult to ignore the role of cancer in social health. Although a huge budget is allocated on cancer research every year, cancer remains the second global cause of death. And, exclusively, less than 50% of patients afflicted with advanced cancer live one year subsequent to standard cancer treatments. RNA interference (RNAi is a mechanism for gene silencing. Such mechanism possesses uncanny ability in targeting cancer-related genes. A majority of gene products involved in tumorigenesis have recently been utilized as targets in RNAi based therapy. The evidence from these studies indicates that RNAi application for targeting functional carcinogenic molecules, tumor resistance to chemotherapy and radiotherapy is required in today’s cancer treatment. Knock downing of gene products by RNAi technology exerts antiproliferative and proapoptotic effects upon cell culture systems, animal models and in clinical trials in the most studies. The recognition of RNAi mechanism and the progress in this field leaded several new RNAi-based drugs to Clinical Trial phases. This has also developed genome based personalized cancer therapeutics. Hopefully, this type of treatment will work as one of the efficient one for cancer patients.

  11. Development of a direct exposure system for studying the mechanisms of central neurotoxicity caused by volatile organic compounds.

    Science.gov (United States)

    Kanemitsu, Masanari; Fueta, Yukiko; Ishidao, Toru; Aou, Shuji; Hori, Hajime

    2016-01-01

    Many volatile organic compounds (VOCs) used in work places are neurotoxic. However, it has been difficult to study the cellular mechanisms induced by a direct exposure to neurons because of their high volatility. The objective of this study was to establish a stable system for exposing brain slices to VOCs. With a conventional recording system for brain slices, it is not possible to keep a constant bath concentration of relatively highly volatile solvents, e.g. 1-bromopropane (1-BP). Here we report a new exposure system for VOCs that we developed in which a high concentration of oxygen is dissolved to a perfused medium applying a gas-liquid equilibrium, and in which the tubing is made of Teflon, non adsorptive material. Using our system, the bath concentration of the perfused 1-BP remained stable for at least 2 h in the slice chamber. Both 6.4 and 2.2 mM of 1-BP did not change the paired-pulse response, but fully suppressed long-term potentiation in the dentate gyrus (DG) of hippocampal slices obtained from rats, suggesting that 1-BP decreases synaptic plasticity in the DG at the concentrations tested. Our new system can be applicable for investigating the underlying mechanisms of the neurotoxicity of VOCs at the cellular level.

  12. Development of a direct exposure system for studying the mechanisms of central neurotoxicity caused by volatile organic compounds

    Science.gov (United States)

    KANEMITSU, Masanari; FUETA, Yukiko; ISHIDAO, Toru; AOU, Shuji; HORI, Hajime

    2015-01-01

    Many volatile organic compounds (VOCs) used in work places are neurotoxic. However, it has been difficult to study the cellular mechanisms induced by a direct exposure to neurons because of their high volatility. The objective of this study was to establish a stable system for exposing brain slices to VOCs. With a conventional recording system for brain slices, it is not possible to keep a constant bath concentration of relatively highly volatile solvents, e.g. 1-bromopropane (1-BP). Here we report a new exposure system for VOCs that we developed in which a high concentration of oxygen is dissolved to a perfused medium applying a gas-liquid equilibrium, and in which the tubing is made of Teflon, non adsorptive material. Using our system, the bath concentration of the perfused 1-BP remained stable for at least 2 h in the slice chamber. Both 6.4 and 2.2 mM of 1-BP did not change the paired-pulse response, but fully suppressed long-term potentiation in the dentate gyrus (DG) of hippocampal slices obtained from rats, suggesting that 1-BP decreases synaptic plasticity in the DG at the concentrations tested. Our new system can be applicable for investigating the underlying mechanisms of the neurotoxicity of VOCs at the cellular level. PMID:26320726

  13. Acute mechanical overstimulation of isolated outer hair cells causes changes in intracellular calcium levels without shape changes.

    Science.gov (United States)

    Fridberger, A; Ulfendahl, M

    1996-01-01

    Impaired auditory function following acoustic overstimulation, or noise, is mainly reported to be accompanied by cellular changes such as damage to the sensory hair bundles, but changes in the cell bodies of the outer hair cells have also been described. To investigate more closely the immediate cellular responses to overstimulation, isolated guinea pig outer hair cells were subjected to a 200 Hz oscillating water jet producing intense mechanical stimulation. The water jet was aimed at the cell body of the isolated outer hair cell. Cell shape changes were studied using video microscopy, and intracellular calcium concentration changes were monitored by means of the fluorescent calcium indicator Fluo-3. Cells exposed to a high-intensity stimulus showed surprisingly small light-microscopical alterations. The cytoplasmic calcium concentration increased in most cells, although some cells appeared very resistant to the mechanical stress. No correlation could be found be tween the calcium concentration changes and the cell length. The changes in calcium concentration reported here are suggested to be involved in the long-term pathogenesis of noise-induced hair cell damage.

  14. Stimulation causing the double effect as in dyspraxia, a universal mechanism of disease, and auto-electrocution, the fatal factor.

    Science.gov (United States)

    Baggot, M G

    1993-05-01

    Almost every action in the body involves the nervous system which uses electricity for its speed and versatility. Operating and controlling muscular activity is a major function of the nervous system. Muscles are paired so every normal contraction requires a reciprocal relaxation of its doppelganger (Newton said 'Equal and opposite'). Minor failures of co-operation, i.e. neuromuscular dysfunction make common survivable diseases. Multiple and major stimuli can create chaotic conflicts within these couplings and lead to fatalities. Excessive, abnormal, even ordinary stimulation will cause the (irritable?) partner(s) which should relax also to contract. Thus function is impaired or impossible. In the limbs faulty neuromuscular co-ordination is obvious as stiffness, Parkinson's Disease, Erb's Palsy etc. Less evident, it is even more important in the cardiovascular, gastrointestinal, genitourinary and respiratory systems.

  15. Cognitive Aware Interference Mitigation Scheme for OFDMA Femtocells

    KAUST Repository

    Alqerm, Ismail

    2015-04-09

    Femto-cells deployment in today’s cellular networks came into practice to fulfill the increasing demand for data services. It also extends the coverage in the indoor areas. However, interference to other femto and macro-cells users remains an unresolved challenge. In this paper, we propose an interference mitigation scheme to control the cross-tier interference caused by femto-cells to the macro users and the co-tier interference among femtocells. Cognitive radio spectrum sensing capability is utilized to determine the non-occupied channels or the ones that cause minimal interference to the macro users. An awareness based channel allocation scheme is developed with the assistance of the graph-coloring algorithm to assign channels to the femto-cells base stations with power optimization, minimal interference, maximum throughput, and maximum spectrum efficiency. In addition, the scheme exploits negotiation capability to match traffic load and QoS with the channel, and to maintain efficient utilization of the available channels.

  16. Ammonia-induced energy disorders interfere with bilirubin metabolism in hepatocytes.

    Science.gov (United States)

    Wang, Qiongye; Wang, Yanfang; Yu, Zujiang; Li, Duolu; Jia, Bin; Li, Jingjing; Guan, Kelei; Zhou, Yubing; Chen, Yanling; Kan, Quancheng

    2014-08-01

    Hyperammonemia and jaundice are the most common clinical symptoms of hepatic failure. Decreasing the level of ammonia in the blood is often accompanied by a reduction in bilirubin in patients with hepatic failure. Previous studies have shown that hyperammonemia can cause bilirubin metabolism disorders, however it is unclear exactly how hyperammonemia interferes with bilirubin metabolism in hepatocytes. The purpose of the current study was to determine the mechanism or mechanisms by which hyperammonemia interferes with bilirubin metabolism in hepatocytes. Cell viability and apoptosis were analyzed in primary hepatocytes that had been exposed to ammonium chloride. Mitochondrial morphology and permeability were observed and analyzed, intermediates of the tricarboxylic acid (TCA) cycle were determined and changes in the expression of enzymes related to bilirubin metabolism were analyzed after ammonia exposure. Hyperammonemia inhibited cell growth, induced apoptosis, damaged the mitochondria and hindered the TCA cycle in hepatocytes. This led to a reduction in energy synthesis, eventually affecting the expression of enzymes related to bilirubin metabolism, which then caused further problems with bilirubin metabolism. These effects were significant, but could be reversed with the addition of adenosine triphosphate (ATP). This study demonstrates that ammonia can cause problems with bilirubin metabolism by interfering with energy synthesis.

  17. CRISPR interference directs strand specific spacer acquisition.

    Directory of Open Access Journals (Sweden)

    Daan C Swarts

    Full Text Available BACKGROUND: CRISPR/Cas is a widespread adaptive immune system in prokaryotes. This system integrates short stretches of DNA derived from invading nucleic acids into genomic CRISPR loci, which function as memory of previously encountered invaders. In Escherichia coli, transcripts of these loci are cleaved into small RNAs and utilized by the Cascade complex to bind invader DNA, which is then likely degraded by Cas3 during CRISPR interference. RESULTS: We describe how a CRISPR-activated E. coli K12 is cured from a high copy number plasmid under non-selective conditions in a CRISPR-mediated way. Cured clones integrated at least one up to five anti-plasmid spacers in genomic CRISPR loci. New spacers are integrated directly downstream of the leader sequence. The spacers are non-randomly selected to target protospacers with an AAG protospacer adjacent motif, which is located directly upstream of the protospacer. A co-occurrence of PAM deviations and CRISPR repeat mutations was observed, indicating that one nucleotide from the PAM is incorporated as the last nucleotide of the repeat during integration of a new spacer. When multiple spacers were integrated in a single clone, all spacer targeted the same strand of the plasmid, implying that CRISPR interference caused by the first integrated spacer directs subsequent spacer acquisition events in a strand specific manner. CONCLUSIONS: The E. coli Type I-E CRISPR/Cas system provides resistance against bacteriophage infection, but also enables removal of residing plasmids. We established that there is a positive feedback loop between active spacers in a cluster--in our case the first acquired spacer--and spacers acquired thereafter, possibly through the use of specific DNA degradation products of the CRISPR interference machinery by the CRISPR adaptation machinery. This loop enables a rapid expansion of the spacer repertoire against an actively present DNA element that is already targeted, amplifying the

  18. Verification of the Mechanism of the Head-Positioning Error Caused by Disk Flutter and Slider Supporting Structure for Reducing Head-Positioning Error

    Science.gov (United States)

    Imai, Satomitsu

    In magnetic disk drives, the disk flutter due to high-rotational speed causes the increase of the head-positioning error. It is important to clear the mechanism of the head-positioning error caused by the disk flutter. This paper conducts the experiments to verify the mechanism proposed in the former report. The experiment was conducted by comparing the head-positioning error predicted by the proposed mechanism with the measured head-positioning error signal. It is confirmed that the proposed mechanism can predict the head-positioning error within the 10% error. The former reports also said that the flutter transfer ratio defined in the report could decrease the head-positioning error without reducing the amplitude of the disk flutter. This paper also verifies it experimentally. In the experiment, the thickness of the slider was changed to make the flutter transfer ratio small. This paper also proposes the method of making the beam angle of the gimbal slant to make the flutter transfer ratio small. The effectiveness was confirmed by the simulation.

  19. An Interference-Aware Traffic-Priority-Based Link Scheduling Algorithm for Interference Mitigation in Multiple Wireless Body Area Networks

    Directory of Open Access Journals (Sweden)

    Thien T. T. Le

    2016-12-01

    Full Text Available Currently, wireless body area networks (WBANs are effectively used for health monitoring services. However, in cases where WBANs are densely deployed, interference among WBANs can cause serious degradation of network performance and reliability. Inter-WBAN interference can be reduced by scheduling the communication links of interfering WBANs. In this paper, we propose an interference-aware traffic-priority-based link scheduling (ITLS algorithm to overcome inter-WBAN interference in densely deployed WBANs. First, we model a network with multiple WBANs as an interference graph where node-level interference and traffic priority are taken into account. Second, we formulate link scheduling for multiple WBANs as an optimization model where the objective is to maximize the throughput of the entire network while ensuring the traffic priority of sensor nodes. Finally, we propose the ITLS algorithm for multiple WBANs on the basis of the optimization model. High spatial reuse is also achieved in the proposed ITLS algorithm. The proposed ITLS achieves high spatial reuse while considering traffic priority, packet length, and the number of interfered sensor nodes. Our simulation results show that the proposed ITLS significantly increases spatial reuse and network throughput with lower delay by mitigating inter-WBAN interference.

  20. Assay of methylglyoxal and glyoxal and control of peroxidase interference.

    Science.gov (United States)

    Thornalley, Paul J; Rabbani, Naila

    2014-04-01

    Methylglyoxal and glyoxal are endogenous α-oxoaldehyde metabolites and substrates of the glyoxalase system. These and related α-oxoaldehydes are often determined in cell, tissue and body fluid samples by derivatization with 1,2-diaminobenzene and similar compounds. Peroxidase activity in physiological tissues is a potential interference in estimation of methylglyoxal and glyoxal as it catalyses the conversion of 1,2-diaminobenzene into trace amounts of these dicarbonyl metabolites. Residual peroxidase activity in deproteinized extracts is found to cause significant interference in methylglyoxal and glyoxal estimations. This interference is blocked by the addition of sodium azide in the derivatizing buffer. Estimates of methylglyoxal concentration thereby obtained are in keeping with those predicted by systems modelling of methylglyoxal glycation kinetics in situ. Blocking sample peroxidase activity is important to avoid overestimation in the measurement of glyoxal and methylglyoxal. A dicarbonyl assay protocol resistant to interferences is described in the present article.

  1. [Relationship between PMI and fourier transform infrared spectral changes in muscle of rats after death caused by mechanical asphyxial].

    Science.gov (United States)

    Li, Shi-ying; Shao, Yu; Li, Zheng-dong; Liu, Ning-guo; Zou, Dong-hua; Qin, Zhi-qiang; Chen, Yi-jiu; Huang, Ping

    2012-06-01

    To observe the postmortem degradation process in rat myocardium and skeletal muscle using Fourier transform infrared (FTIR) spectroscopy and to provide a new method for estimating postmortem interval (PMI). Left ventricle and skeletal muscles of rats dying of mechanical asphyxiated were sampled at different PMIs. The changes of different chemical functional group in the myocardium and skeletal muscle samples were measured by FTIR spectroscopy. The different absorbance (A) ratios of peaks were calculated and the curve estimation analysis between absorbance ratios (x) and PMI (y) were performed to establish six mathematical models. FTIR spectral absorption peak of rat myocardium and skeletal muscle showed three changes: increase, decrease and stable. The cubic model function showed the strongest correlation coefficient. The A1080/A1396 ratio of skeletal muscle showed the strongest correlation coefficient (r = 0.832) with more accurate determination of PMI. FYIR spectroscopy can be potentially used as an effective method for estimating PMI in forensic practice using myocardium and skeletal muscle.

  2. A plasma source driven predator-prey like mechanism as a potential cause of spiraling intermittencies in linear plasma devices

    Energy Technology Data Exchange (ETDEWEB)

    Reiser, D. [Research Center Jülich GmbH, Institute for Energy and Climate Research—Plasma Physics, D-52425 Jülich (Germany); Ohno, N. [Department of Energy Engineering and Science, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603 (Japan); Tanaka, H. [National Institute for Fusion Science, Toki 509-5292 (Japan); Vela, L. [Physics Department, Universidad Carlos III de Madrid, Avda de la Universidad 30, 28911-Leganés, Madrid (Spain)

    2014-03-15

    Three-dimensional global drift fluid simulations are carried out to analyze coherent plasma structures appearing in the NAGDIS-II linear device (nagoya divertor plasma Simulator-II). The numerical simulations reproduce several features of the intermittent spiraling structures observed, for instance, statistical properties, rotation frequency, and the frequency of plasma expulsion. The detailed inspection of the three-dimensional plasma dynamics allows to identify the key mechanism behind the formation of these intermittent events. The resistive coupling between electron pressure and parallel electric field in the plasma source region gives rise to a quasilinear predator-prey like dynamics where the axisymmetric mode represents the prey and the spiraling structure with low azimuthal mode number represents the predator. This interpretation is confirmed by a reduced one-dimensional quasilinear model derived on the basis of the findings in the full three-dimensional simulations. The dominant dynamics reveals certain similarities to the classical Lotka-Volterra cycle.

  3. A plasma source driven predator-prey like mechanism as a potential cause of spiraling intermittencies in linear plasma devices

    Science.gov (United States)

    Reiser, D.; Ohno, N.; Tanaka, H.; Vela, L.

    2014-03-01

    Three-dimensional global drift fluid simulations are carried out to analyze coherent plasma structures appearing in the NAGDIS-II linear device (nagoya divertor plasma Simulator-II). The numerical simulations reproduce several features of the intermittent spiraling structures observed, for instance, statistical properties, rotation frequency, and the frequency of plasma expulsion. The detailed inspection of the three-dimensional plasma dynamics allows to identify the key mechanism behind the formation of these intermittent events. The resistive coupling between electron pressure and parallel electric field in the plasma source region gives rise to a quasilinear predator-prey like dynamics where the axisymmetric mode represents the prey and the spiraling structure with low azimuthal mode number represents the predator. This interpretation is confirmed by a reduced one-dimensional quasilinear model derived on the basis of the findings in the full three-dimensional simulations. The dominant dynamics reveals certain similarities to the classical Lotka-Volterra cycle.

  4. Muscle lengthening surgery causes differential acute mechanical effects in both targeted and non-targeted synergistic muscles.

    Science.gov (United States)

    Ateş, Filiz; Özdeşlik, Rana N; Huijing, Peter A; Yucesoy, Can A

    2013-10-01

    Epimuscular myofascial force transmission (EMFT) is a major determinant of muscle force exerted, as well as length range of force exertion. Therefore, EMFT is of importance in remedial surgery performed, e.g., in spastic paresis. We aimed to test the following hypotheses: (1) muscle lengthening surgery (involving preparatory dissection (PD) and subsequent proximal aponeurotomy (AT)) affects the target muscle force exerted at its distal and proximal tendons differentially, (2) forces of non-operated synergistic muscles are affected as well, (3) PD causes some of these effects. In three conditions (control, post-PD, and post-AT exclusively on m. extensor digitorum longus (EDL)), forces exerted by rat anterior crural muscles were measured simultaneously. Our results confirm hypotheses (1-2), and hypothesis (3) in part: Reduction of EDL maximal force differed by location (i.e. 26.3% when tested distally and 44.5% when tested proximally). EDL length range of active force exertion increased only distally. Force reductions were shown also for non-operated tibialis anterior (by 11.9%), as well as for extensor hallucis longus (by 8.4%) muscles. In tibialis anterior only, part of the force reduction (4.9%) is attributable to PD. Due to EMFT, remedial surgery should be considered to have differential effects for targeted and non-targeted synergistic muscles. Copyright © 2013 Elsevier Ltd. All rights reserved.

  5. Baldness may be caused by the weight of the scalp: gravity as a proposed mechanism for hair loss.

    Science.gov (United States)

    Ustuner, E Tuncay

    2008-10-01

    Available theories on the etiology and pathogenesis of male pattern baldness have not been satisfactory. Nonetheless, the most widely adopted theory today is the androgenetic theory. The current article introduces a new theory. According to the new theory the pressure created by the weight of the scalp is the cause of the baldness. The weight of the whole scalp over the loose areolar tissue is the operative weight. Hair follicles are pressed between the scalp skin and the cranial bones. The soft tissues around the hair follicles work as a buffer against the pressure. When the buffer decreases and becomes inadequate with age the effective pressure on the hair follicles increases. Unlike the existing theories, the new theory is able to explain every feature of male and female pattern baldness and agrees completely with all scientifically established facts and produced data. The new theory promises a radical change in how baldness is conceived and treated. Notice by the author: The materials and methods that utilize the new theory described in this article for prevention and treatment of hair loss are in patent pending status.

  6. Mechanism of accelerated current decay caused by an episodic ataxia type-1-associated mutant in a potassium channel pore.

    Science.gov (United States)

    Peters, Christian J; Werry, Daniel; Gill, Hira S; Accili, Eric A; Fedida, David

    2011-11-30

    In Kv1.1, single point mutants found below the channel activation gate at residue V408 are associated with human episodic ataxia type-1, and impair channel function by accelerating decay of outward current during periods of membrane depolarization and channel opening. This decay is usually attributed to C-type inactivation, but here we provide evidence that this is not the case. Using voltage-clamp fluorimetry in Xenopus oocytes, and single-channel patch clamp in mouse ltk- cells, of the homologous Shaker channel (with the equivalent mutation V478A), we have determined that the mutation may cause current decay through a local effect at the activation gate, by destabilizing channel opening. We demonstrate that the effect of the mutant is similar to that of trapped 4-aminopyridine in antagonizing channel opening, as the mutation and 10 mm 4-AP had similar, nonadditive effects on fluorescence recorded from the voltage-sensitive S4 helix. We propose a model where the Kv1.1 activation gate fails to enter a stabilized open conformation, from which the channel would normally C-type inactivate. Instead, the lower pore lining helix is able to enter an activated-not-open conformation during depolarization. These results provide an understanding of the molecular etiology underlying episodic ataxia type-1 due to V408A, as well as biophysical insights into the links between the potassium channel activation gate, the voltage sensor and the selectivity filter.

  7. Occurrence and characteristics of mutual interference between LIDAR scanners

    Science.gov (United States)

    Kim, Gunzung; Eom, Jeongsook; Park, Seonghyeon; Park, Yongwan

    2015-05-01

    The LIDAR scanner is at the heart of object detection of the self-driving car. Mutual interference between LIDAR scanners has not been regarded as a problem because the percentage of vehicles equipped with LIDAR scanners was very rare. With the growing number of autonomous vehicle equipped with LIDAR scanner operated close to each other at the same time, the LIDAR scanner may receive laser pulses from other LIDAR scanners. In this paper, three types of experiments and their results are shown, according to the arrangement of two LIDAR scanners. We will show the probability that any LIDAR scanner will interfere mutually by considering spatial and temporal overlaps. It will present some typical mutual interference scenario and report an analysis of the interference mechanism.

  8. Improving Dense Network Performance through Centralized Scheduling and Interference Coordination

    DEFF Research Database (Denmark)

    Lopez, Victor Fernandez; Pedersen, Klaus I.; Alvarez, Beatriz Soret

    2017-01-01

    . Interference management at the receiver is achieved through the use of a Network-Assisted Interference Cancellation and Suppression (NAICS) receiver. In order to further boost the 5th percentile user data rates, the transmission rank at the interferers is selectively reduced by a centralized rank coordination......Dense network deployments comprising small cells pose a series of important challenges when it comes to achieving an efficient resource use and curbing inter-cell interference in the downlink. This article examines different techniques to treat these problems in a dynamic way, from the network...... and the receiver sides. As a network coordination scheme, we apply a centralized joint cell association and scheduling mechanism based on dynamic cell switching, by which users are not always served by the strongest perceived cell. The method simultaneously resultsin more balanced loads and increased performance...

  9. Angular momentum sensitive two-center interference.

    Science.gov (United States)

    Ilchen, M; Glaser, L; Scholz, F; Walter, P; Deinert, S; Rothkirch, A; Seltmann, J; Viefhaus, J; Decleva, P; Langer, B; Knie, A; Ehresmann, A; Al-Dossary, O M; Braune, M; Hartmann, G; Meissner, A; Tribedi, L C; AlKhaldi, M; Becker, U

    2014-01-17

    In quantum mechanics the Young-type double-slit experiment can be performed with electrons either traveling through a double slit or being coherently emitted from two inversion symmetric molecular sites. In the latter one the valence photoionization cross sections of homonuclear diatomic molecules were predicted to oscillate over kinetic energy almost 50 years ago. Beyond the direct proof of the oscillatory behavior of these photoionization cross sections σ, we show that the angular distribution of the emitted electrons reveals hitherto unexplored information on the relative phase shift between the corresponding partial waves through two-center interference patterns.

  10. Angular Momentum Sensitive Two-Center Interference

    Science.gov (United States)

    Ilchen, M.; Glaser, L.; Scholz, F.; Walter, P.; Deinert, S.; Rothkirch, A.; Seltmann, J.; Viefhaus, J.; Decleva, P.; Langer, B.; Knie, A.; Ehresmann, A.; Al-Dossary, O. M.; Braune, M.; Hartmann, G.; Meissner, A.; Tribedi, L. C.; AlKhaldi, M.; Becker, U.

    2014-01-01

    In quantum mechanics the Young-type double-slit experiment can be performed with electrons either traveling through a double slit or being coherently emitted from two inversion symmetric molecular sites. In the latter one the valence photoionization cross sections of homonuclear diatomic molecules were predicted to oscillate over kinetic energy almost 50 years ago. Beyond the direct proof of the oscillatory behavior of these photoionization cross sections σ, we show that the angular distribution of the emitted electrons reveals hitherto unexplored information on the relative phase shift between the corresponding partial waves through two-center interference patterns.

  11. Preserved cumulative semantic interference despite amnesia

    Directory of Open Access Journals (Sweden)

    Gary Michael Oppenheim

    2015-05-01

    As predicted by Oppenheim et al’s (2010 implicit incremental learning account, WRP’s BCN RTs demonstrated strong (and significant repetition priming and semantic blocking effects (Figure 1. Similar to typical results from neurally intact undergraduates, WRP took longer to name pictures presented in semantically homogeneous blocks than in heterogeneous blocks, an effect that increased with each cycle. This result challenges accounts that ascribe cumulative semantic interference in this task to explicit memory mechanisms, instead suggesting that the effect has the sort of implicit learning bases that are typically spared in hippocampal amnesia.

  12. Stochastic slowly adapting ionic currents may provide a decorrelation mechanism for neural oscillators by causing wander in the intrinsic period.

    Science.gov (United States)

    Norman, Sharon E; Butera, Robert J; Canavier, Carmen C

    2016-09-01

    Oscillatory neurons integrate their synaptic inputs in fundamentally different ways than normally quiescent neurons. We show that the oscillation period of invertebrate endogenous pacemaker neurons wanders, producing random fluctuations in the interspike intervals (ISI) on a time scale of seconds to minutes, which decorrelates pairs of neurons in hybrid circuits constructed using the dynamic clamp. The autocorrelation of the ISI sequence remained high for many ISIs, but the autocorrelation of the ΔISI series had on average a single nonzero value, which was negative at a lag of one interval. We reproduced these results using a simple integrate and fire (IF) model with a stochastic population of channels carrying an adaptation current with a stochastic component that was integrated with a slow time scale, suggesting that a similar population of channels underlies the observed wander in the period. Using autoregressive integrated moving average (ARIMA) models, we found that a single integrator and a single moving average with a negative coefficient could simulate both the experimental data and the IF model. Feeding white noise into an integrator with a slow time constant is sufficient to produce the autocorrelation structure of the ISI series. Moreover, the moving average clearly accounted for the autocorrelation structure of the ΔISI series and is biophysically implemented in the IF model using slow stochastic adaptation. The observed autocorrelation structure may be a neural signature of slow stochastic adaptation, and wander generated in this manner may be a general mechanism for limiting episodes of synchronized activity in the nervous system.

  13. [Using atomic force microscopy to analyze morphological changes and mechanical properties caused by cellular exposure to low doses of pesticides].

    Science.gov (United States)

    L'Abbate, N; Lasalvia, M; Perna, G; D'Antonio, P; Quartucci, G; Gallo, C; Capozzi, V

    2012-01-01

    A commercial pesticide is usually composed of active ingredients and formulants. Among the active ingredients, Deltamethrin is a pyrethroid chemical widely used for synthesizing pesticides products which are very effective in damaging the central nervous system of pests. In this work, we analyze, by means of atomic force microscopy (AFM), cellular morphological changes induced by exposure to a Deltamethrin-based commercial pesticide (Decaflow). AFM microscopy, in addition to the well-known characterization of the cellular topography, has the ability to monitor interesting biomechanical parameters of the surface as roughness and elastic modulus. In particular, we exposed normal human keratinocytes for 24 hours at different solutions of Decaflow, well below the threshold of cytotoxicity. The AFM images of exposed cells show alterations of surface cell shape. Moreover exposed cells are characterized by an increase of the value of membrane roughness. The mechanical properties of cells are also modified after Decaflow exposure, as confirmed by a decrease of the elasticity modulus with increasing the concentration of pesticide.

  14. Down-regulation of glycosyltransferase 8D genes in Populus trichocarpa caused reduced mechanical strength and xylan content in wood.

    Science.gov (United States)

    Li, Quanzi; Min, Douyong; Wang, Jack Peng-Yu; Peszlen, Ilona; Horvath, Laszlo; Horvath, Balazs; Nishimura, Yufuko; Jameel, Hasan; Chang, Hou-Min; Chiang, Vincent L

    2011-02-01

    Members of glycosyltransferase protein families GT8, GT43 and GT47 are implicated in the biosynthesis of xylan in the secondary cell walls of Arabidopsis. The Arabidopsis mutant irx8 has a 60% reduction in xylan. However, over-expression of an ortholog of Arabidopsis IRX8, poplar PoGT8D, in Arabidopsis irx8 mutant could not restore xylan synthesis. The functions of tree GT8D genes remain unclear. We identified two GT8 gene homologs, PtrGT8D1 and PtrGT8D2, in Populus trichocarpa. They are the only two GT8D members and are abundantly and specifically expressed in the differentiating xylem of P. trichocarpa. PtrGT8D1 transcript abundance was >7 times that of PtrGT8D2. To elucidate the genetic function of GT8D in P. trichocarpa, the expression of PtrGT8D1 and PtrGT8D2 was simultaneously knocked down through RNAi. Four transgenic lines had 85-94% reduction in transcripts of PtrGT8D1 and PtrGT8D2, resulting in 29-36% reduction in stem wood xylan content. Xylan reduction had essentially no effect on cellulose quantity but caused an 11-25% increase in lignin. These transgenics exhibit a brittle wood phenotype, accompanied by increased vessel diameter and thinner fiber cell walls in stem xylem. Stem modulus of elasticity and modulus of rupture were reduced by 17-29% and 16-23%, respectively, and were positively correlated with xylan content but negatively correlated with lignin quantity. These results suggest that PtrGT8Ds play key roles in xylan biosynthesis in wood. Xylan may be a more important factor than lignin affecting the stiffness and fracture strength of wood.

  15. MECANISMOS MOLECULARES POR LOS CUALES LOS ÁCIDOS GRASOS PODRÍAN INFLUIR EN LA CAPTACIÓN DE GLUCOSA Molecular mechanisms by which free fatty acids might interfere with periferic insuline action

    Directory of Open Access Journals (Sweden)

    Clara Eugenia Pérez

    2005-04-01

    Full Text Available Esta revisión tiene el propósito de actualizar el probable mecanismo molecular que ejercen los ácidos grasos en las células que captan glucosa, bajo el estimulo de la insulina y su posible implicación en la diabetes mellitus tipo 2 en la que suelen asociarse resistencia a la insulina, obesidad y síndrome metabólico. Entre los mecanismos moleculares por los cuales un aumento de los ácidos grasos libres podría producir resistencia a la insulina, se encuentra la disminución de los niveles de xilulosa 5-fosfato que bloquea la glucólisis por inhibición de la fosfofructocinasa, ello conduce a un aumento de los productos finales en la vía de las hexosaminas y a la activación de la proteincinasa C, un conocido activador de inhibidor de la cinasa Kappa Beta que inhibe la fosforilación del receptor del sustrato de insulina en tirosina, bloqueando los transportadores de glucosa. Existen investigaciones que sugieren que los ácidos grasos libres están implicados en la insulino-resistencia pero el mecanismo bioquímico no esta dilucidado del todo, pues no hay un mecanismo integral que los relacione o interconecte para concluir determinantemente cómo los altos niveles de ácidos grasos libres inducen la resistencia a la insulina.Previous research suggests that free fatty acids are implicated in insulin resistance, but the molecular mechanism for it isn't completely elucidated, given the lack of an integrated hypothesis relating all of the proposed mechanisms. At the present time, the causes of insulin resistance, obesity and metabolic syndrome, a common feature in patients with diabetes mellitus are matter of intense study. Among several molecular mechanisms by which the increase in free fatty acids could raise insulin resistance is decrease in xylulose-5-phosphate that leads to an inhibition of phosphofructokinase-2, and consequently to a blockade in glycol sis with a subsequent increase in the final products of the hexosamine pathway and

  16. Molecular mechanism and structural basis of gain-of-function of STAT1 caused by pathogenic R274Q mutation.

    Science.gov (United States)

    Fujiki, Ryoji; Hijikata, Atsushi; Shirai, Tsuyoshi; Okada, Satoshi; Kobayashi, Masao; Ohara, Osamu

    2017-04-14

    Gain-of-function (GOF) mutations in the STAT1 gene are critical for the onset of chronic mucocutaneous candidiasis (CMC) disease. However, the molecular basis for the gain of STAT1 function remains largely unclear. Here, we investigated the structural features of STAT1 GOF residues to better understand the impact of these pathogenic mutations. We constructed STAT1 alanine mutants of the α3 helix residues of the coiled-coil domain, which are frequently found in CMC pathogenic mutations, and measured their transcriptional activities. Most of the identified GOF residues were located inside the coiled-coil domain stem structure or at the protein surface of the anti-parallel dimer interface. Unlike those, Arg-274 was adjacent to the DNA-binding domain. In addition, Arg-274 was found to functionally interact with Gln-441 in the DNA-binding domain. Because Gln-441 is located at the anti-parallel dimer contact site, Gln-441 reorientation by Arg-274 mutation probably impedes formation of the dimer. Further, the statistical analysis of RNA-seq data with STAT1-deficient epithelial cells and primary T cells from a CMC patient revealed that the R274Q mutation affected gene expression levels of 66 and 76 non-overlapping RefSeq genes, respectively. Because their transcription levels were only slightly modulated by wild-type STAT1, we concluded that the R274Q mutation increased transcriptional activity but did not change dramatically the repertoire of STAT1 targets. Hence, we provide a novel mechanism of STAT1 GOF triggered by a CMC pathogenic mutation. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

  17. Research progression on the molecular mechanism of RNA interference and the application of this technique%RNAi的分子机制及其应用的研究进展

    Institute of Scientific and Technical Information of China (English)

    邵世滨

    2005-01-01

    RNA干扰(RNA interference,RNAi)是最近几年发现和发展起来的一门新兴的在转录水平上的基因阻断技术。它与反义RNA技术有很大不同,是一种双链RNA(Doublestranded RNA,dsRNA)分子在mRNA水平上关闭相应序列基因的表达或使其沉默的过程,也就是序列特异性的转录后基因沉默。

  18. Effects of L-Carnitine Theraphy On Methabolic and Biochemical Changes Caused By Propofol Infusion in Rabbits Undergoing Mechanical Ventilation

    Directory of Open Access Journals (Sweden)

    Savaş Yılbaş

    2011-08-01

    Full Text Available Objective: Increased lipid mass in the body secondary to long term and high doses of propofol infusion may cause carnitine deficiency. In this study; we aimed to investigate the effects of carnitine, given for treatment purposes and have not been analyzed before, during high doses of propofol infusion in rabbits. Materials and Methods: Following ethical committee approval; 2500-3500 grams weight, 3-4 months-old, healthy, male, white 20 New Zealand rabbits were included in the study. The rabbits were premedicated with xsilazine and atropine. After the preparation period including tracheostomy, monitorization, catheterization of the ear arteries and veins and urinary vesical; basal blood samples for biochemical and metabolic parameters included in the study were taken and rabbits were divided into 4 groups, 5 rabbits in each,randomly (Group P, Group PC, Group S, Group SC. For sedation 20 mg/kg/h propofol infusion was given to Group P, 20 mg/kg/h propofol and 100 mg/kg L-carnitine infusions were given simultaneously to Group PC, sevoflurane for sedation was given to Group S, sevoflurane and L-carnitine infusion were given simultaneously to Group SC. Their sedation levels were evaluated every 30 minutes and their vital signs were reported every 15 minutes. Every 2 hours arterial blood gases analysis and every 12 hours electrolytes and metabolic parameters were repeated. Euthanasia with high doses (60 mg/kg of ketamin is performed for rabbits that were alive at the end of 24 hours. Results: All groups were similar in weight, vital parameters, all parameters searched in arterial blood gases, life time, liver enzymes, lactate dehydrogenase, serum electrolytes, creatine kinase and renal function tests (p>0.05. However; amylase levels before death or euthanasia were lower in Group PC compared to other groups;myoglobin and CK-MB levels in Group P were higher compared to other groups; cholesterol levels at 12th hour, before death or euthanasia were higher

  19. Demonstrations of Beats as Moving Interference Patterns.

    Science.gov (United States)

    Stein, T. S.; Dishman, L. G.

    1982-01-01

    Describes a ripple tank demonstration that displays interference patterns responsible for producing beats and provides photographs of computer simulations of various beat interference patterns. Includes programs for the computer simulation and equations of constructive interference paths in beat interference patterns. (Author/SK)

  20. Robust Lattice Alignment for K-user MIMO Interference Channels with Imperfect Channel Knowledge

    CERN Document Server

    Huang, Huang; Du, Yinggang; Liu, Sheng

    2011-01-01

    In this paper, we consider a robust lattice alignment design for K-user quasi-static MIMO interference channels with imperfect channel knowledge. With random Gaussian inputs, the conventional interference alignment (IA) method has the feasibility problem when the channel is quasi-static. On the other hand, structured lattices can create structured interference as opposed to the random interference caused by random Gaussian symbols. The structured interference space can be exploited to transmit the desired signals over the gaps. However, the existing alignment methods on the lattice codes for quasi-static channels either require infinite SNR or symmetric interference channel coefficients. Furthermore, perfect channel state information (CSI) is required for these alignment methods, which is difficult to achieve in practice. In this paper, we propose a robust lattice alignment method for quasi-static MIMO interference channels with imperfect CSI at all SNR regimes, and a two-stage decoding algorithm to decode th...

  1. Alternate transmission with half-duplex relaying in MIMO interference relay networks

    KAUST Repository

    Park, Seongho

    2013-12-01

    In this paper, we consider an alternate transmission scheme for a multiple-input multiple-output interference relay channel where multiple sources transmit their own signals to their corresponding destinations via one of two relaying groups alternately every time phase. Each of the relaying groups has arbitrary number of relays, and each relay operates in half-duplex amplify-and-forward mode. In our scheme, the received signals at the relay nodes consist of desired signals and two different interference signals such as the inter-source interferences and the inter-group interferences which are caused by the phase incoherence of relaying. As such, we propose an iterative interference alignment algorithm to mitigate the interferences. We show that our proposed scheme achieves additional degrees of freedom compared to the conventional half-duplex relaying system in the interference relay channels. © 2013 IEEE.

  2. Transmission Techniques for Relay-Interference Networks

    CERN Document Server

    Mohajer, Soheil; Fragouli, Christina; Tse, David N C

    2008-01-01

    In this paper we study the relay-interference wireless network, in which relay (helper) nodes are to facilitate competing information flows over a wireless network. We examine this in the context of a deterministic wireless interaction model, which eliminates the channel noise and focuses on the signal interactions. Using this model, we show that almost all the known schemes such as interference suppression, interference alignment and interference separation are necessary for relay-interference networks. In addition, we discover a new interference management technique, which we call interference neutralization, which allows for over-the-air interference removal, without the transmitters having complete access the interfering signals. We show that interference separation, suppression, and neutralization arise in a fundamental manner, since we show complete characterizations for special configurations of the relay-interference network.

  3. Interference in ballistic motor learning - is motor interference really sensory?

    DEFF Research Database (Denmark)

    Lundbye-Jensen, Jesper; Petersen, Tue Hvass; Rothwell, John C

    learned a ballistic ankle plantarflexion task. Interference was observed following subsequent learning of a precision tracking task with the same movement direction and agonist muscles, but not by learning involving the opposite movement and antagonist muscles or by voluntary agonist contractions that did...

  4. Interference, Reduced Action, and Trajectories

    Science.gov (United States)

    Floyd, Edward R.

    2007-09-01

    Instead of investigating the interference between two stationary, rectilinear wave functions in a trajectory representation by examining the trajectories of the two rectilinear wave functions individually, we examine a dichromatic wave function that is synthesized from the two interfering wave functions. The physics of interference is contained in the reduced action for the dichromatic wave function. As this reduced action is a generator of the motion for the dichromatic wave function, it determines the dichromatic wave function’s trajectory. The quantum effective mass renders insight into the behavior of the trajectory. The trajectory in turn renders insight into quantum nonlocality.

  5. Interference, reduced action, and trajectories

    CERN Document Server

    Floyd, E R

    2006-01-01

    Instead of investigating the interference between two stationary, rectilinear wave functions in a trajectory representation by examining the two rectilinear wave functions individually, we examine a dichromatic wave function that is synthesized from the two interfering wave functions. The physics of interference is contained in the reduced action for the dichromatic wave function. As this reduced action is a generator of the motion for the dichromatic wave function, it determines the dichromatic wave function's trajectory. The quantum effective mass renders insight into the behavior of the trajectory. The trajectory in turn renders insight into quantum nonlocality.

  6. Interference of diffusive light waves.

    Science.gov (United States)

    Schmitt, J M; Knüttel, A; Knutson, J R

    1992-10-01

    We examine interference effects resulting from the superposition of photon-density waves produced by coherently modulated light incident upon a turbid medium. Photon-diffusion theory is used to derive expressions for the ac magnitude and phase of the aggregate diffusive wave produced in full- and half-space volumes by two sources. Using a frequency-domain spectrometer operating at 410 MHz, we verify interference patterns predicted by the model in scattering samples having optical properties similar to those of skin tissue. Potential imaging applications of interfering diffusive waves are discussed in the context of the theoretical and experimental results.

  7. Histopathological changes in lungs of the mountain snow avalanche victims and its potential usefulness in determination of cause and mechanism of death

    Directory of Open Access Journals (Sweden)

    Mariusz Kobek

    2016-09-01

    Full Text Available On 28 January 2003 snow avalanche in the Polish Tatras happened, in which 8 people died and 5 were injured. We tried to determine cause and manner of death in 6 fatal victims instead of advanced late post mortem changes in internal organs. Taking into consideration the circumstances of death, we paid special attention to histopathological examination of lungs, extended by Gomori’s and AZAN staining. Pattern of the changes was similar to those observed in forensic medicine in cases of asphyxia due to airway obstruction and/or immobilization of chest and abdomen (Perthes’ syndrome. Histopathological study with the use of more specific staining methods has a significant diagnostic value during establishing the cause and mechanism of death of the deceased snow avalanche victims with advanced post mortem changes.

  8. Histopathological changes in lungs of the mountain snow avalanche victims and its potential usefulness in determination of cause and mechanism of death

    Directory of Open Access Journals (Sweden)

    Mariusz Kobek

    2016-09-01

    Full Text Available On 28 January 2003 snow avalanche in the Polish Tatras happened, in which 8 people died and 5 were injured. We tried to determine cause and manner of death in 6 fatal victims instead of advanced late post mortem changes in internal organs. Taking into consideration the circumstances of death, we paid special attention to histopathological examination of lungs, extended by Gomori’s and AZAN staining. Pattern of the changes was similar to those observed in forensic medicine in cases of asphyxia due to airway obstruction and/or immobilization of chest and abdomen (Perthes’ syndrome. Histopathological study with the use of more specific staining methods has a significant diagnostic value during establishing the cause and mechanism of death of the deceased snow avalanche victims with advanced post mortem changes.

  9. [Histopathological changes in lungs of the mountain snow avalanche victims and its potential usefulness in determination of cause and mechanism of death].

    Science.gov (United States)

    Kobek, Mariusz; Skowronek, Rafał; Jabłoński, Christian; Jankowski, Zbigniew; Pałasz, Artur

    On 28 January 2003 snow avalanche in the Polish Tatras happened, in which 8 people died and 5 were injured. We tried to determine cause and manner of death in 6 fatal victims instead of advanced late post mortem changes in internal organs. Taking into consideration the circumstances of death, we paid special attention to histopathological examination of lungs, extended by Gomori's and AZAN staining. Pattern of the changes was similar to those observed in forensic medicine in cases of asphyxia due to airway obstruction and/or immobilization of chest and abdomen (Perthes' syndrome). Histopathological study with the use of more specific staining methods has a significant diagnostic value during establishing the cause and mechanism of death of the deceased snow avalanche victims with advanced post mortem changes.

  10. Role of dressed-state interference in electromagnetically induced transparency

    Science.gov (United States)

    Khan, Sumanta; Bharti, Vineet; Natarajan, Vasant

    2016-12-01

    Electromagnetically induced transparency (EIT) in three-level systems uses a strong control laser on one transition to modify the absorption of a weak probe laser on a second transition. The control laser creates dressed states whose decay pathways show interference. We study the role of dressed-state interference in causing EIT in the three types of three-level systems-lambda (Λ), ladder (Ξ), and vee (V). In order to get realistic values for the linewidths of the energy levels involved, we consider appropriate hyperfine levels of 87Rb. For such realistic systems, we find that dressed-state interference causes probe absorption-given by the imaginary part of the susceptibility-to go to zero in a Λ system, but plays a negligible role in Ξ and V systems.

  11. Role of dressed-state interference in electromagnetically induced transparency

    CERN Document Server

    Khan, Sumanta; Natarajan, Vasant

    2016-01-01

    Electromagnetically induced transparency (EIT) in three-level systems uses a strong control laser on one transition to modify the absorption of a weak probe laser on a second transition. The control laser creates dressed states whose decay pathways show interference. We study the role of dressed-state interference in causing EIT in the three types of three-level systems - lambda ({\\Lambda}), ladder ({\\Xi}), and vee (V). In order to get realistic values for the linewidths of the energy levels involved, we consider appropriate hyperfine levels of 87 Rb. For such realistic systems, we find that dressed-state interference causes probe absorption (and hence EIT) to go to zero in a {\\Lambda} system, but plays a negligible role in {\\Xi} and V systems.

  12. An eye-to-hand magnet effect reveals distinct spatial interference in motor planning and execution.

    Science.gov (United States)

    Richardson, Brian A; Cluff, Tyler; Lyons, James; Balasubramaniam, Ramesh

    2013-03-01

    An important question in oculomanual control is whether motor planning and execution modulate interference between motion of the eyes and hands. Here we investigated oculomanual interference using a novel paradigm that required saccadic eye movements and unimanual finger tapping. We examined finger trajectories for spatial interference caused by concurrent saccades. The first experiment used synchronous cues so that saccades and taps shared a common timekeeping goal. We found that finger trajectories showed bilateral interference where either finger was attracted in the direction of the accompanying saccade. The second experiment avoided interference due to shared planning resources by examining interference caused by reactive saccades. Here, we observed a lesser degree of execution-dependent coupling where the finger trajectory deviated only when reactive saccades were directed toward the hemifield of the responding hand. Our results show that distinct forms of eye-to-hand coupling emerge according to the demands of the task.

  13. Research and development of a stabilizing holographic interference fringe system based on linear CCD

    Science.gov (United States)

    Li, Chaoming; Chen, Xinrong; Wu, Jianhong; Ju, Jianzhi; Zhu, Yayi; Hu, Zuyuan

    2009-07-01

    A method that is to stabilize holographic interference fringe during holographic recording process is put forward in this paper. As the kernel of this method, a negative feedback system based on linear CCD and piezoelectric ceramics (PZT) which is used to compensate the interference fringe random drift caused by various external vibrations in long time recording process was introduced in details. The proportion-integral-derivative method (PID) is adopted to control the moving of PZT which is used to compensate the drift of the interference fringes accurately. Thus the interference fringe can be frozen. Experiment results shows that this negative feedback system by controlling the optical path difference can effectively compensate the interference fringe random drift caused by various external vibrations in long time recording process. After using this system, the mean squared error of the interference fringe drift value can be under λ / 60 and the quality of the holographic grating is improved greatly.

  14. Coloration using higher order optical interference in the wing pattern of the Madagascan sunset moth.

    Science.gov (United States)

    Yoshioka, S; Nakano, T; Nozue, Y; Kinoshita, S

    2008-04-06

    Colour patterns of animals' bodies are usually produced by the spatial distribution of pigments with different colours. However, some animals use the spatial variation of colour-producing microstructures. We have studied one distinctive example of such structurally produced colour patterns, the wing of the Madagascan sunset moth, to clarify the physical rules that underlie the colour variation. It is known that the iridescent wing scale of the sunset moth has the alternate air-cuticle multilayer structure that causes optical interference. The microscopic and optical investigations of various parts of the wing have confirmed that the thickness of the cuticle layers within the scale largely varies to produce the colour pattern. However, it varies in very different ways between the dorsal and ventral sides of the hind wing; the thickness gradually varies on the dorsal side from scale to scale, while the abrupt changes are found on the ventral side to form distinctive borders between differently coloured areas. It is also revealed that an unusual coloration mechanism is involved in the green part of the ventral hind wing: the colour is caused by higher order optical interference of the highly non-ideal multilayer structure. The physical mechanism of the colour pattern formation is briefly discussed with the several mathematical models proposed so far.

  15. Interference in Time: A Comment

    CERN Document Server

    Horwitz, L P

    2005-01-01

    I comment on the interpretation of a recent experiment showing quantum interference in time. It is pointed out that the standard nonrelativistic quantum theory, used by the authors in their analysis, cannot account for the results found, and therefore that this experiment has fundamental importance beyond the technical advances it represents.

  16. Political Interference in Climate Science

    Science.gov (United States)

    Kumar, Mohi

    2007-02-01

    ``All of us have a right to our own views about the seriousness of global warming,'' U.S. Rep. Henry Waxman (D-Calif.), chair of the House Oversight and Government Reform Committee, said at a 30 January committee hearing held to examine political interference in climate science. ``But we don't have a right to our own science.''

  17. Interference and memory capacity limitations.

    Science.gov (United States)

    Endress, Ansgar D; Szabó, Szilárd

    2017-10-01

    Working memory (WM) is thought to have a fixed and limited capacity. However, the origins of these capacity limitations are debated, and generally attributed to active, attentional processes. Here, we show that the existence of interference among items in memory mathematically guarantees fixed and limited capacity limits under very general conditions, irrespective of any processing assumptions. Assuming that interference (a) increases with the number of interfering items and (b) brings memory performance to chance levels for large numbers of interfering items, capacity limits are a simple function of the relative influence of memorization and interference. In contrast, we show that time-based memory limitations do not lead to fixed memory capacity limitations that are independent of the timing properties of an experiment. We show that interference can mimic both slot-like and continuous resource-like memory limitations, suggesting that these types of memory performance might not be as different as commonly believed. We speculate that slot-like WM limitations might arise from crowding-like phenomena in memory when participants have to retrieve items. Further, based on earlier research on parallel attention and enumeration, we suggest that crowding-like phenomena might be a common reason for the 3 major cognitive capacity limitations. As suggested by Miller (1956) and Cowan (2001), these capacity limitations might arise because of a common reason, even though they likely rely on distinct processes. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  18. Thin Film Interference: An Experiment with Microwaves and Paraffin Oil

    Science.gov (United States)

    D'Anna, Michele; Corridoni, Tommaso

    2015-01-01

    Thin film interference manifests itself in a wide range of visually pleasing situations in everyday life (in the colored effects caused by a drop of oil on water, in soap bubbles, etc.) and is also involved in important technical applications (semi-reflecting mirrors, anti-reflection lenses, etc.). Yet, despite its familiarity, high school…

  19. Thin Film Interference: An Experiment with Microwaves and Paraffin Oil

    Science.gov (United States)

    D'Anna, Michele; Corridoni, Tommaso

    2015-01-01

    Thin film interference manifests itself in a wide range of visually pleasing situations in everyday life (in the colored effects caused by a drop of oil on water, in soap bubbles, etc.) and is also involved in important technical applications (semi-reflecting mirrors, anti-reflection lenses, etc.). Yet, despite its familiarity, high school…

  20. Time-domain quantum interference in graphene

    Science.gov (United States)

    Fillion-Gourdeau, François; Gagnon, Denis; Lefebvre, Catherine; MacLean, Steve

    2016-09-01

    The electron momentum density obtained from the Schwinger-like mechanism is evaluated for a graphene sample immersed in a homogeneous time-dependent electric field. Based on the analogy between graphene low-energy electrons and quantum electrodynamics (QED), numerical techniques borrowed from strong field QED are employed and compared to approximate analytical approaches. It is demonstrated that for some range of experimentally accessible parameters, the pair production proceeds by sequences of adiabatic evolutions followed by nonadiabatic Landau-Zener transitions, reminiscent of the Kibble-Zurek mechanism describing topological defect density in second order phase transitions. For some field configurations, this yields interference patterns in momentum space which are explained in terms of the adiabatic-impulse model and the Landau-Zener-Stückelberg interferometry.

  1. Mechanics

    CERN Document Server

    Hartog, J P Den

    1961-01-01

    First published over 40 years ago, this work has achieved the status of a classic among introductory texts on mechanics. Den Hartog is known for his lively, discursive and often witty presentations of all the fundamental material of both statics and dynamics (and considerable more advanced material) in new, original ways that provide students with insights into mechanical relationships that other books do not always succeed in conveying. On the other hand, the work is so replete with engineering applications and actual design problems that it is as valuable as a reference to the practicing e

  2. Analytical Solution for Interference Fit for Multi-Layer Thick-Walled Cylinders and the Application in Crankshaft Bearing Design

    Directory of Open Access Journals (Sweden)

    Jun Qiu

    2016-06-01

    Full Text Available Interference fit is an important contact mode used for torque transmission existing widely in engineering design. To prevent trackslip, a certain magnitude of interference has to be ensured; meanwhile, the interference needs to be controlled to avoid failure of the mechanical components caused by high assembly stress. The finite element method (FEM can be used to analyze the stress, while the computational cost of FEM involving nonlinear contact algorithm is relatively high, and likely to come across low precision and convergence problems. Therefore, a rapid and accurate analytical method for estimation is of vital need, especially for the initial design stage when the parameters vary in a large range. In this study, an analytical method to calculate the contact pressure and stress between multi-layer thick-walled cylinders (MLTWC with multi-contact pairs and temperature-raising effect is proposed, and evaluated by FEM. The analytical solution of the interference for tri-layer thick-walled cylinders is applied to the design of engine crankshaft bearing. The results indicate that the analytical method presented in this study can reduce complexity of MLTWC problems and improve the computational efficiency. It is well suited to be used for the calculation model of parameter optimization in early design.

  3. Subcellular mechanisms in pulmonary arterial hypertension: combinatorial modalities that inhibit anterograde trafficking and cause bone morphogenetic protein receptor type 2 mislocalization.

    Science.gov (United States)

    Yang, Yang-Ming; Lane, Kirk B; Sehgal, Pravin B

    2013-09-01

    Abstract The natural history of familial pulmonary arterial hypertension (PAH) typically involves mutations in and/or haploinsuffciency of BMPR2 (gene for bone morphogenetic protein receptor type 2) but with low penetrance (10%-15%), delayed onset (in the third or fourth decade), and a gender bias (two- to fourfold more prevalent in postpubertal women). Thus, investigators have sought an understanding of "second-hit" modalities that might affect BMPR2 anterograde trafficking and/or function. Indeed, vascular lung lesions in PAH have been reported to contain enlarged "vacuolated" endothelial and smooth muscle cells with dilated endoplasmic reticulum (ER) cisternae, increased ER structural protein reticulon 4 (also called Nogo-B), and enlarged and fragmented Golgi apparatus. We recently replicated this cellular phenotype in primary human pulmonary arterial endothelial cells and human pulmonary arterial smooth muscle cells in culture by acute knockdown of the estradiol 17β (E2)-responsive proteins signal transducer and activator of transcription 5a (STAT5a) and STAT5b using small interfering RNAs (siRNAs). We have now investigated whether functional haploinsufficiences of these molecules, alone or in combination with other modalities, might interfere with anterograde membrane trafficking using (a) the quantitative tsO45VSV-G-GFP trafficking assay and (b) assays for cell-surface localization of Flag-tagged BMPR2 molecules. The G glycoprotein of the vesicular stomatitis virus (VSV-G) trafficking assay was validated in EA.hy926 endothelial cells by showing that cells exposed to monocrotaline pyrrole displayed reduced anterograde trafficking. Thereafter, the combinatorial knockdowns of STAT5a, STAT5b, BMPR2, and/or endothelial nitric oxide synthase as well as exposure to E2 or 2-methoxyestradiol were observed to significantly inhibit VSV-G trafficking. These combinations also led to intracellular trapping of wild-type Flag-tagged BMPR2. Overexpression of the PAH disease

  4. Mechanism in formation of liver fibrosis caused by schistosomiasis%血吸虫病肝纤维化形成的作用机制

    Institute of Scientific and Technical Information of China (English)

    冯安贵(综述); 肖建华(审校)

    2015-01-01

    schistosomiasis is one of the most harmful parasitic zoonoses in the world.It has a worldwide distribution.The schistosoma japonicum is the major epidemic in China.Its pathogenic mechanism is,due to schistosome eggs depositing within the patient’s liver,and producing egg granuloma,causing liver fibrosis.In the immune responses against liver fibro-sis caused by schistosomiasis,the adjustment from hepatic stellate cells,T-cells,B-cells and various cytokines performs a cruicial function.This paper will present a review on related studies about mechanism in formation of liver fibrosis caused by schistosomiasis.%血吸虫病(schistosomiasis)是世界上严重危害人类健康的人兽共患寄生虫病之一。在中国主要流行的是日本血吸虫病,其致病机制是由于血吸虫卵沉积于宿主肝内,形成虫卵肉芽肿,导致肝纤维化。血吸虫病肝纤维化免疫过程中,肝星状细胞、T 细胞、B 细胞及多种细胞因子的调节起着重要作用。现就血吸虫病肝纤维化形成机制的相关研究进展进行了综述。

  5. Mechanisms by which a lack of germinal vesicle (GV) material causes oocyte meiotic defects: a study using oocytes manipulated to replace GV with primary spermatocyte nuclei.

    Science.gov (United States)

    Zhang, Jie; Cui, Wei; Li, Qing; Wang, Tian-Yang; Sui, Hong-Shu; Wang, Jun-Zuo; Luo, Ming-Jiu; Tan, Jing-He

    2013-10-01

    Oocytes with germinal vesicles (GVs) replaced with somatic nuclei exhibit meiotic abnormalities. Although this suggests an exclusive role for GV material in meiosis, mechanisms by which a lack of GV material causes meiotic defects are unknown. Knowledge of these mechanisms will help us to understand meiotic control, nuclear-cytoplasmic interactions, and cellular reprogramming. This study showed that although oocytes with prometaphase I chromosomes replaced with primary spermatocyte nuclei (PSN) did not, oocytes with GV replaced with PSN (PSG oocytes) did display meiotic defects. Among the defects, insufficient chromosome condensation with chromosome bridges was associated with spindle abnormalities. Abnormal spindle migration, cortical nonpolarization, and the aberrant spindle caused randomly positioning of cleavage furrows, leading to large first polar bodies (PB1) and unequal allocation of chromosomes and mitogen-activated protein kinases (MAPK) between oocyte and PB1. Spindle assembly checkpoint was activated but did not stop the incorrect division. The unequal MAPK allocation resulted in differences in pronuclear formation and PB1 degeneration; oocytes receiving more MAPK were more capable of forming pronuclear rudiments, whereas PB1 receiving more MAPK degenerated sooner than those that received less. Because none of the PSG oocytes or the enucleated GV oocytes injected with sperm heads showed cortical polarization in spite of chromosome localization close to the oolemma and because the PSG oocytes receiving more MAPK could form only pronuclear rudiments and not normal pronuclei, we suggest that the GV material plays essential roles in polarization and pronuclear formation on top of those played by chromosomes or MAPK. In conclusion, using PSG oocytes as models, this study has revealed the primary pathways by which a lack of GV material cause meiotic defects, laying a foundation for future research on the role of GV material in oocyte meiotic control.

  6. Impact Assessment of the Causes and Prevention of Farm Accidents on Mechanized Farms of North Central Zone/States of Nigeria

    Directory of Open Access Journals (Sweden)

    J. K. Yohanna.

    2012-03-01

    Full Text Available Accidents occurring on mechanized farms have been a thing of concern to farmers and researchers both within and outside Nigeria. An investigation into the causes and prevention of farm accidents on mechanized farm was carried out in Benue, Federal Capital Territory, Kwara, Nasarawa, Niger and Plateau states that constitute the north central zone/states of Nigeria. The data collection instrument was a questionnaire designed and distributed to all the states mentioned. The questionnaire addressed demographic variables and issues linked directly with the types, causes and prevention of farm accidents. A total of 2283 tractors were available in the mechanized farms surveyed, while a total of 1014 constituted other farm machinery/equipment. Results show that 81.7% of accidents victims are male. About 45.5% of the accident victims were aged between 40years and above. About 33.96% of the minor accidents resulted in slight damage to equipment and machinery. Similarly 43.4% of accidents resulted in substantial loss in time, while about 22.64% of accidents resulted in medical attention. There was no attempt made to quantify the monetary terms of the cost of each accidents, as there was dearth of information. The results obtained in this work are in agreement with the previous studies both outside and inside Nigeria. Also, from this survey work, there was a problem of good record keeping in most of the establishment surveyed. It is therefore, recommended among other things that adequate training and retraining of tractors/machinery operators should be carried out periodically, to intimate operators on recent use of farm equipment due to environmental and human factors

  7. Mechanical analysis of substrate bending deformation caused by film stress%薄膜应力造成基片弯曲变形的力学分析

    Institute of Scientific and Technical Information of China (English)

    赵明炬

    2014-01-01

    针对平板力学理论结构进行分析,研究薄膜应力造成基片弯曲变形的数学结构与力学行为。推算出两者间精确解与Stoney公式比较,探讨两者推导机制差异,进一步分析Stoney公式误差原因。利用电脑软件ABAQUS建立合理模型来提供数值解,探讨数学模式的正确性。%The mechanical structure of flat-panel was analyzed,and the mathematical model and mechanical behavior of the substrate bending deformation caused by film stress were studied. The numerical solution was calculated and compared with that calculated by Stoney formula,the difference of both derivation mechanisms was discussed,and Stoney formula error was furtherly analyzed. With computer software ABAQUS,the reasonable model was established to provide numerical solution and explore the correctness of mathematical model is correct.

  8. New mechanism of γ-H2AX generation: Surfactant-induced actin disruption causes deoxyribonuclease I translocation to the nucleus and forms DNA double-strand breaks.

    Science.gov (United States)

    Zhao, Xiaoxu; Yang, Gang; Toyooka, Tatsushi; Ibuki, Yuko

    2015-12-01

    We previously showed that nonionic surfactants, nonylphenol polyethoxylates (NPEOs), induced phosphorylation of histone H2AX, forming γ-H2AX. In this study, we analyzed the mechanism of γ-H2AX generation by an NPEO with 15 ethylene oxide units (NPEO(15)). In MCF-7 breast carcinoma cells, NPEO(15) treatment induced γ-H2AX in a dose-dependent manner. EDTA and ZnCl2, two inhibitors of deoxyribonuclease I (DNase I), inhibited both the γ-H2AX and DNA double-strand breaks induced by NPEO(15). NPEO(15) disrupted filamentous actin and released free DNase I as detected by cell fractionation analysis. Based on immunofluorescence staining of DNase I and monitoring DNase I-GFP localization, DNase I was translocated from the cytosol to the nucleus of cells after treatment with NPEO(15). This translocation did not occur with the common DNA damage inducers ultraviolet B irradiation and hydrogen peroxide. Other surfactants, Tween 20, Triton X-100 and Nonidet P-40, also generated γ-H2AX. These results show that γ-H2AX induction by surfactants including NPEOs, occurs via a new mechanism involving release of free DNase I with actin disruption. This mechanism is distinct from the process of γ-H2AX generation caused by direct chemically induced DNA damage.

  9. Where Should We Look for Clues to Resolve the Physical Mechanism Causing Deep Earthquakes? Consider: Deep Moonquakes, and Isolated Deep Earthquakes

    Science.gov (United States)

    Frohlich, C.; Nakamura, Y.

    2014-12-01

    The physical mechanism responsible for deep earthquakes has been a puzzle since their discovery by Wadati 85 years ago. Today the three most widely accepted mechanisms are dehydration embrittlement (for depths above about 300 km), 'anticracks' in metastable olivine (for deeper events), and thermal runaway. Yet, the puzzle remains: no single mechanism seems satisfactory, and having three mechanisms seems contrary to Occams Razor. Where might we look for observations to help resolve this problem? One of the 20thcenturies greatest scientific surprises was when seismic data collected during the Apollo projects proved that the Moon was seismically active at depths of 850-1100 km. These deep moonquakes occurred repeatedly within clusters or "nests", with occurrence times strongly correlated with solid tides. Although they occur under temperature-pressure conditions highly similar to terrestrial earthquakes at depths of ~120 km, it seems unlikely they are caused by dehydration embrittlement, as there is no subduction on the Moon, and possibly little or no water. Must we propose a fourth mechanism for deep quakes? Or are our explanations for terrestrial deep quakes incorrect? The development of plate tectonics was one of the 20thcentury science's great paradigm shifts; one observation it helped explain was why numerous earthquakes with focal depths exceeding 400 km occurred in the mantle in areas like Tonga where very old, fast-moving plates converged. But some "isolated deep earthquakes" are exceptional; these earthquakes occur separated from neighboring events by hundreds of km. Some, like earthquakes in Spain in 1954 and Colombia in 1970, with Mw exceeding 7.5 are among the largest deep-focus earthquakes known, yet occurred singly without any fore- or aftershocks. What physical mechanism allows such large, isolated earthquakes to occur? The tendency is to focus attention on areas like Tonga where the majority of deep events occur. But understanding rare isolated events

  10. Relay self interference minimisation using tapped filter

    KAUST Repository

    Jazzar, Saleh

    2013-05-01

    In this paper we introduce a self interference (SI) estimation and minimisation technique for amplify and forward relays. Relays are used to help forward signals between a transmitter and a receiver. This helps increase the signal coverage and reduce the required transmitted signal power. One problem that faces relays communications is the leaked signal from the relay\\'s output to its input. This will cause an SI problem where the new received signal at the relay\\'s input will be added with the unwanted leaked signal from the relay\\'s output. A Solution is proposed in this paper to estimate and minimise this SI which is based upon using a tapped filter at the destination. To get the optimum weights for this tapped filter, some channel parameters must be estimated first. This is performed blindly at the destination without the need of any training. This channel parameter estimation method is named the blind-self-interference-channel-estimation (BSICE) method. The next step in the proposed solution is to estimate the tapped filter\\'s weights. This is performed by minimising the mean squared error (MSE) at the destination. This proposed method is named the MSE-Optimum Weight (MSE-OW) method. Simulation results are provided in this paper to verify the performance of BSICE and MSE-OW methods. © 2013 IEEE.

  11. Convergent evolution of pathogenicity islands in helper cos phage interference

    Science.gov (United States)

    Manning, Keith A.; Dokland, Terje; Marina, Alberto

    2016-01-01

    Staphylococcus aureus pathogenicity islands (SaPIs) are phage satellites that exploit the life cycle of their helper phages for their own benefit. Most SaPIs are packaged by their helper phages using a headful (pac) packaging mechanism. These SaPIs interfere with pac phage reproduction through a variety of strategies, including the redirection of phage capsid assembly to form small capsids, a process that depends on the expression of the SaPI-encoded cpmA and cpmB genes. Another SaPI subfamily is induced and packaged by cos-type phages, and although these cos SaPIs also block the life cycle of their inducing phages, the basis for this mechanism of interference remains to be deciphered. Here we have identified and characterized one mechanism by which the SaPIs interfere with cos phage reproduction. This mechanism depends on a SaPI-encoded gene, ccm, which encodes a protein involved in the production of small isometric capsids, compared with the prolate helper phage capsids. As the Ccm and CpmAB proteins are completely unrelated in sequence, this strategy represents a fascinating example of convergent evolution. Moreover, this result also indicates that the production of SaPI-sized particles is a widespread strategy of phage interference conserved during SaPI evolution. This article is part of the themed issue ‘The new bacteriology’. PMID:27672154

  12. Convergent evolution of pathogenicity islands in helper cos phage interference.

    Science.gov (United States)

    Carpena, Nuria; Manning, Keith A; Dokland, Terje; Marina, Alberto; Penadés, José R

    2016-11-05

    Staphylococcus aureus pathogenicity islands (SaPIs) are phage satellites that exploit the life cycle of their helper phages for their own benefit. Most SaPIs are packaged by their helper phages using a headful (pac) packaging mechanism. These SaPIs interfere with pac phage reproduction through a variety of strategies, including the redirection of phage capsid assembly to form small capsids, a process that depends on the expression of the SaPI-encoded cpmA and cpmB genes. Another SaPI subfamily is induced and packaged by cos-type phages, and although these cos SaPIs also block the life cycle of their inducing phages, the basis for this mechanism of interference remains to be deciphered. Here we have identified and characterized one mechanism by which the SaPIs interfere with cos phage reproduction. This mechanism depends on a SaPI-encoded gene, ccm, which encodes a protein involved in the production of small isometric capsids, compared with the prolate helper phage capsids. As the Ccm and CpmAB proteins are completely unrelated in sequence, this strategy represents a fascinating example of convergent evolution. Moreover, this result also indicates that the production of SaPI-sized particles is a widespread strategy of phage interference conserved during SaPI evolution.This article is part of the themed issue 'The new bacteriology'.

  13. Coupled interference based rate adaptation in ad hoc networks

    CSIR Research Space (South Africa)

    Awuor, F

    2011-09-01

    Full Text Available on Karush-Kuhn-Tucker (KKT) conditions. The users determine data rates based on their local observations (i.e. coupled interference). Both pricing and limited message passing mechanisms are employed in the NUM wherein pricing restrict users from self...

  14. Bringing RNA Interference (RNAi) into the High School Classroom

    Science.gov (United States)

    Sengupta, Sibani

    2013-01-01

    RNA interference (abbreviated RNAi) is a relatively new discovery in the field of mechanisms that serve to regulate gene expression (a.k.a. protein synthesis). Gene expression can be regulated at the transcriptional level (mRNA production, processing, or stability) and at the translational level (protein synthesis). RNAi acts in a gene-specific…

  15. Rheumatoid factor and its interference with cytokine measurements

    DEFF Research Database (Denmark)

    Bartels, Else Marie; Falbe Wätjen, Inger; Littrup Andersen, Eva;

    2011-01-01

    Use of cytokines as biomarkers for disease is getting more widespread. Cytokines are conveniently determined by immunoassay, but interference from present antibodies is known to cause problems. In rheumatoid arthritis (RA), interference of rheumatoid factor (RF) may be problematic. RF covers...... a group of autoantibodies from immunoglobulin subclasses and is present in 65-80% of RA patients. Partly removal of RF is possible by precipitation. This study aims at determining the effects of presence of RF in blood and synovial fluid on cytokine measurements in samples from RA patients and finding...

  16. Recent advances in RNA interference therapeutics for CNS diseases.

    Science.gov (United States)

    Ramachandran, Pavitra S; Keiser, Megan S; Davidson, Beverly L

    2013-07-01

    Over the last decade, RNA interference technology has shown therapeutic promise in rodent models of dominantly inherited brain diseases, including those caused by polyglutamine repeat expansions in the coding region of the affected gene. For some of these diseases, proof-of concept studies in model organisms have transitioned to safety testing in larger animal models, such as the nonhuman primate. Here, we review recent progress on RNA interference-based therapies in various model systems. We also highlight outstanding questions or concerns that have emerged as a result of an improved (and ever advancing) understanding of the technologies employed.

  17. The Price of Fame: The Impact of Stimulus Familiarity on Proactive Interference Resolution

    Science.gov (United States)

    Prabhakaran, Ranjani; Thompson-Schill, Sharon L.

    2011-01-01

    Interference from previously learned information, known as proactive interference (PI), limits our memory retrieval abilities. Previous studies of PI resolution have focused on the role of short-term familiarity, or recency, in causing PI. In the present study, we investigated the impact of long-term stimulus familiarity on PI resolution…

  18. Excitation, two-center interference and the orbital geometry in laser-induced nonsequential double ionization of diatomic molecules

    CERN Document Server

    Shaaran, T; Faria, C Figueira de Morisson

    2011-01-01

    We address the influence of the molecular orbital geometry and of the molecular alignment with respect to the laser-field polarization on laser-induced nonsequential double ionization of diatomic molecules for different molecular species, namely $\\mathrm{N}_2$ and $\\mathrm{Li}_2$. We focus on the recollision excitation with subsequent tunneling ionization (RESI) mechanism, in which the first electron, upon return, promotes the second electron to an excited state, from where it subsequently tunnels. We show that the electron-momentum distributions exhibit interference maxima and minima due to the electron emission at spatially separated centers. We provide generalized analytical expressions for such maxima or minima, which take into account $s$ $p$ mixing and the orbital geometry. The patterns caused by the two-center interference are sharpest for vanishing alignment angle and get washed out as this parameter increases. Apart from that, there exist features due to the geometry of the lowest occupied molecular ...

  19. Parasitic interference in nulling interferometry

    CERN Document Server

    Matter, Alexis; Danchi, William C; Lopez, Bruno; Absil, Olivier

    2013-01-01

    Nulling interferometry aims to detect faint objects close to bright stars. Its principle is to produce a destructive interference along the line-of-sight so that the stellar flux is rejected, while the flux of the off-axis source can be transmitted. In practice, various instrumental perturbations can degrade the nulling performance. Any imperfection in phase, amplitude, or polarization produces a spurious flux that leaks to the interferometer output and corrupts the transmitted off-axis flux. One of these instrumental pertubations is the crosstalk phenomenon, which occurs because of multiple parasitic reflections inside transmitting optics, and/or diffraction effects related to beam propagation along finite size optics. It can include a crosstalk of a beam with itself, and a mutual crosstalk between different beams. This can create a parasitic interference pattern, which degrades the intrinsic transmission map - or intensity response - of the interferometer. In this context, we describe how this instrumental ...

  20. [The mechanism of phenoptosis: I. Age-dependent decrease of the overall rate of protein synthesis is caused by the programmed attenuation of bio-energetics].

    Science.gov (United States)

    Trubitsyn, A G

    2009-01-01

    The age-dependent degradation of all vital processes of an organism can be result of influences of destructive factors (the stochastic mechanism of aging), or effect of realizations of the genetic program (phenoptosis). The stochastic free-radical theory of aging dominating now contradicts the set of empirical data, and the semicentenial attempts to create the means to slow down aging did not give any practical results. It makes obvious that the stochastic mechanism of aging is incorrect. At the same time, the alternative mechanism of the programmed aging is not developed yet but preconditions for it development have already been created. It is shown that the genes controlling process of aging exist (contrary to the customary opinion) and the increase in the level of damaged macromolecules (basic postulate of the free-radical theory) can be explained by programmed attenuation of bio-energetics. As the bio-energetics is a driving force of all vital processes, decrease of its level is capable to cause degradation of all functions of an organism. However to transform this postulate into a basis of the theory of phenoptosis it is necessary to show, that attenuation of bio-energetics predetermines such fundamental processes accompanying aging as decrease of the overall rate of protein biosynthesis, restriction of cellular proliferations (Hayflick limit), loss of telomeres etc. This article is the first step in this direction: the natural mechanism of interaction of overall rate of protein synthesis with a level of cellular bio-energetics is shown. This is built-in into the translation machine and based on dependence of recirculation rate of eukaryotic initiation factor 2 (elF2) from ATP/ADP value that is created by mitochondrial bio-energetic machine.

  1. Effects of electron beam radiation on mechanical properties and on the resistance to punctures caused by Plodia interpunctella in cereal bar packaging

    Energy Technology Data Exchange (ETDEWEB)

    Alves, Juliana N.; Moura, Esperidiana A.B.; Oliveira, Vitor M., E-mail: julianaabc@usp.b, E-mail: eabmoura@ipen.b, E-mail: volmiranda@gmail.co [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Potenza, Marcos R., E-mail: potenza@biologico.sp.gov.b [Instituto Biologico de Sao Paulo/APTA, Sao Paulo, SP (Brazil); Arthur, Valter, E-mail: varthur@cena.usp.b [Centro de Energia Nuclear na Agricultura (CENA/USP), Piracicaba, SP (Brazil)

    2009-07-01

    Plodia interpunctella is an important pest in stored products in the tropical and subtropical regions, infesting grains and flours. The adult of P. interpunctella is a small butterfly with about 15 - 20mm of spread and the female places separately of 100 the 400 eggs in groups on the grains whose hard incubation some days. This insect infesting diverse types of food packaging, depreciating the products and causing economic losses. It is therefore critical for these products a packaging that presents, in addition to good mechanical, barrier and machinability properties, a good resistance to puncture by insects, in order to prevent the contact and spread of pests in the packaged food. This study evaluates the changes on mechanical properties and puncture resistance by P. interpunctella in BOPPmet/BOPP structure, used commercially as cereal bar packaging, after electron beam irradiation. The material samples were irradiated up to 120 kGy using a 1.5 MeV electrostatic accelerator, at room temperature, in air, dose rate 11.22 kGy/s. Irradiation doses were measured using cellulose triacetate film dosimeters 'CTA-FTR-125' from Fuji Photo Film Co. Ltd. After irradiation the BOPPmet/BOPP samples were subjected to tests of puncture resistance by P. interpunctella, tensile tests and penetration resistance. The results showed significant decreases (p<0.05) in the original mechanical properties of the structures according to the radiation doses applied and effective resistance against punctures by P. interpunctella for irradiated and nonirradiated BOPPmet/BOPP samples. These results indicate that non-irradiated and irradiated BOPPmet/BOPP structure presents puncture resistance against P. interpunctella and that electron-beam irradiation, in conditions studied in this work, may turn the structure inappropriate for cereal bar packaging, due to high reduction its mechanical properties after irradiation. (author)

  2. Msh2-Msh3 Interferes with Okazaki Fragment Processing to Promote Trinucleotide Repeat Expansions

    Directory of Open Access Journals (Sweden)

    Athena Kantartzis

    2012-08-01

    Full Text Available Trinucleotide repeat (TNR expansions are the underlying cause of more than 40 neurodegenerative and neuromuscular diseases, including myotonic dystrophy and Huntington’s disease. Although genetic evidence points to errors in DNA replication and/or repair as the cause of these diseases, clear molecular mechanisms have not been described. Here, we focused on the role of the mismatch repair complex Msh2-Msh3 in promoting TNR expansions. We demonstrate that Msh2-Msh3 promotes CTG and CAG repeat expansions in vivo in Saccharomyces cerevisiae. Furthermore, we provide biochemical evidence that Msh2-Msh3 directly interferes with normal Okazaki fragment processing by flap endonuclease1 (Rad27 and DNA ligase I (Cdc9 in the presence of TNR sequences, thereby producing small, incremental expansion events. We believe that this is the first mechanistic evidence showing the interplay of replication and repair proteins in the expansion of sequences during lagging-strand DNA replication.

  3. Study on the Sensitivity of Landmine Electrical Fuse Circuit Under the Interference of Natural Electromagnetic Pulse

    Science.gov (United States)

    Qin, Dechun

    Landmine electrical fuse circuits on the battlefield will be interfered by natural electromagnetic pulse such as electrostatic discharge and lightning, which will undermine the circuit performance and trigger the early burst or mistaken burst of the landmines. In this paper, numerically simulation analysis is conducted on the electrostatic and lightning effects received by the landmine fuse circuit by means of building simulation model of the fuse circuit and analyzing the electric and magnetic field changes of the observation The mechanism of the influence of electrostatic discharge and lightning on the sensitivity of the fuse circuit is explored. The conclusion is that electrostatic effect cause the mistaken burst of the landmines by enabling the interference voltage to reach the components turn-on threshold and cause the circuit malfunction, and lighting effect by long period accumulation of energy.

  4. Silicon superconducting quantum interference device

    Energy Technology Data Exchange (ETDEWEB)

    Duvauchelle, J. E.; Francheteau, A.; Marcenat, C.; Lefloch, F., E-mail: francois.lefloch@cea.fr [Université Grenoble Alpes, CEA - INAC - SPSMS, F-38000 Grenoble (France); Chiodi, F.; Débarre, D. [Université Paris-sud, CNRS - IEF, F-91405 Orsay - France (France); Hasselbach, K. [Université Grenoble Alpes, CNRS - Inst. Néel, F-38000 Grenoble (France); Kirtley, J. R. [Center for probing at nanoscale, Stanford University, Palo Alto, California 94305-4045 (United States)

    2015-08-17

    We have studied a Superconducting Quantum Interference Device (SQUID) made from a single layer thin film of superconducting silicon. The superconducting layer is obtained by heavily doping a silicon wafer with boron atoms using the gas immersion laser doping technique. The SQUID is composed of two nano-bridges (Dayem bridges) in a loop and shows magnetic flux modulation at low temperature and low magnetic field. The overall behavior shows very good agreement with numerical simulations based on the Ginzburg-Landau equations.

  5. Interference Mitigation in Cognitive Femtocells

    DEFF Research Database (Denmark)

    Da Costa, Gustavo Wagner Oliveira; Cattoni, Andrea Fabio; Alvarez Roig, Victor;

    2010-01-01

    in densely deployed femto scenarios. In this paper, two key elements of cognitive femtocells are combined: a power control algorithm and a fully distributed dynamic spectrum allocation method. The resulting solution was evaluated through system-level simulations and compared to the separate algorithms...... and fixed frequency reuses. The outage throughput performance of the combined algorithm exceeds all other options, proving the efficiency of the method in reducing inter-cell interference....

  6. RNA干扰%RNA Interference

    Institute of Scientific and Technical Information of China (English)

    陈颖; 朱明华

    2003-01-01

    RNA干扰(RNA interference,RNAi)是一种古老的生物抗病毒机制,能介导序列特异性的mRNA降解,是基因功能研究和蛋白组学的有效工具,在药物靶基因的筛选、抗病毒、肿瘤基因治疗等领域有很好的发展前景.

  7. Distractor interference during a choice limb reaching task.

    Directory of Open Access Journals (Sweden)

    Matthew Ray

    Full Text Available According to action-centered models of attention, the patterns of distractor interference that emerge in selective reaching tasks are related to the time and effort required to resolve a race for activation between competing target and non-target response producing processes. Previous studies have only used unimanual aiming tasks and, as such, only examined the effects of competition that occurs within a limb. The results of studies using unimanual aiming movements often reveal an "ipsilateral effect"--distractors on the same side of space as the effector cause greater interference than distractors on the opposite side of space. The cost of the competition when response selection is between the limbs has yet to be addressed. Participants in the present study executed reaching movements to 1 of 4 (2 left, 2 right possible target locations with and without a distractor. Participants made ipsilateral reaches (left hand to left targets, right hand to right targets. In contrast to studies using unimanual aiming movements, a "contralateral effect" was observed; distractors affording responses for the other hand (in contralateral space caused more interference than distractors affording responses for the same hand. The findings from the present research demonstrate that when certain portions of response planning must be resolved prior to response initiation, distractors that code for that dimension cause the greatest interference.

  8. RNA interference-based therapeutics: molecular platforms for infectious diseases.

    Science.gov (United States)

    Dyawanapelly, Sathish; Ghodke, Sharwari Bhagwat; Vishwanathan, Ramya; Dandekar, Prajakta; Jain, Ratnesh

    2014-09-01

    The potential uses and therapeutic benefits of RNA interference (RNAi) are enormous. Recent insights into RNAi technologies have highlighted their role in analyzing the functions and regulation of gene expression in eukaryotes and further utilizing this information for identification and amelioration of many diseases. These studies have also established the role of RNAi mediated post-transcriptional gene silencing (PTGS) mechanism in mammals by several endogenous, gene regulation systems including small interfering RNAs (siRNA), micro RNA (miRNA) and small hairpin RNAs (shRNA). Moreover, these RNAi-based therapeutics have demonstrated the capability to silence therapeutically relevant genes in various in vivo models of cancer, infections autoimmune diseases and other genetic disorders. Over the past few decades, infectious diseases have been one of the leading causes of death around the world. Ubiquitously, intracellular obligate or facultative microorganisms cause serious or fatal infections and associated diseases in humans. Currently available literature suggests that infections caused by intracellular pathogens present an intriguing area, wherein RNAi technology may be effectively employed to neutralize the harmful effects of various intracellular pathogens. In this manuscript, we have emphasized on the challenges and opportunities involved in the therapy of such intracellular infections, especially employing RNAi-based interventions. We have focused our discussion on the current state-of-the-art RNAi-based therapies, which have been explored for various intracellular infections mediated by bacteria, fungi, viruses and protozoa. Nanocarrier mediated delivery of siRNA and shRNA molecules have also been found to overcome the various delivery challenges of these biotherapeutics; these have also been briefly summarized here. Furthermore, the outcomes and progresses that have been made in pre-clinical models and clinical trials have also been presented to review the

  9. Improved Linear Parallel Interference Cancellers

    CERN Document Server

    Srikanth, T; Chockalingam, A; Milstein, L B

    2007-01-01

    In this paper, taking the view that a linear parallel interference canceller (LPIC) can be seen as a linear matrix filter, we propose new linear matrix filters that can result in improved bit error performance compared to other LPICs in the literature. The motivation for the proposed filters arises from the possibility of avoiding the generation of certain interference and noise terms in a given stage that would have been present in a conventional LPIC (CLPIC). In the proposed filters, we achieve such avoidance of the generation of interference and noise terms in a given stage by simply making the diagonal elements of a certain matrix in that stage equal to zero. Hence, the proposed filters do not require additional complexity compared to the CLPIC, and they can allow achieving a certain error performance using fewer LPIC stages. We also extend the proposed matrix filter solutions to a multicarrier DS-CDMA system, where we consider two types of receivers. In one receiver (referred to as Type-I receiver), LPIC...

  10. 49 CFR 193.2633 - Interference currents.

    Science.gov (United States)

    2010-10-01

    ...: FEDERAL SAFETY STANDARDS Maintenance § 193.2633 Interference currents. (a) Each component that is subject to electrical current interference must be protected by a continuing program to minimize...

  11. Brd2 gene disruption causes ‘metabolically healthy’ obesity: Epigenetic and chromatin-based mechanisms that uncouple obesity from Type 2 diabetes

    Science.gov (United States)

    Wang, Fangnian; Deeney, Jude T.; Denis, Gerald V.

    2014-01-01

    Disturbed body energy balance can lead to obesity and obesity-driven diseases such as Type 2 diabetes, which have reached an epidemic level. Evidence indicates that obesity induced inflammation is a major cause of insulin resistance and Type 2 diabetes. Environmental factors, such as nutrients, affect body energy balance through epigenetic or chromatin-based mechanisms. As a bromodomain and external domain family transcription regulator, Brd2 regulates expression of many genes through interpretation of chromatin codes, and participates in the regulation of body energy balance and immune function. In the severely obese state, Brd2 knockdown in mice prevented obesity-induced inflammatory responses, protected animals from Type 2 diabetes, and thus uncoupled obesity from diabetes. Brd2 provides an important model for investigation of the function of transcription regulators and the development of obesity and diabetes; it also provides a possible target to treat obesity and diabetes through modulation of the function of a chromatin code reader. PMID:23374712

  12. Potentiation of glutamate release caused by delta—methrin and the possible mechanism associated with carbon monoxide pathway and protein kinase C

    Institute of Scientific and Technical Information of China (English)

    AiBM; LiuYG

    2002-01-01

    The acute neurotoxicity of delta-methrin is thought to be associated with the release of grutamate from synaptosomes in brain.However,the mechanism how delta-methrin enhances the glutamate release has still not been elucidated.Here we report that both carbon monoxide(CO) and the activator of protein kinase C(PKC),similarly to delta-methrin,potentiate the Ca2+-dependent glutamate release from rat cerebral cortical synaptosomes,otherwise,the release of glutamate is inhibited by zinc proporphyrin-9(ZnPP-9) and inhibitors of PKC or of protein kinase G(PKG).In addition,the inhibitors of ZnPP-9 PKC and PKG seem to weaken the enhancement of glutamate releas caused by delta-methrin.So,we conclude that CO signal transduction pathway and PKC mediate the glutamate release from synptosomes by delta-methrin.

  13. Max-Min Fairness in WMNs with Interference Cancelation Using Overheard Transmissions

    Directory of Open Access Journals (Sweden)

    Mateusz Żotkiewicz

    2014-01-01

    Full Text Available We show an impact of using interference cancelation mechanisms for signals that have been overheard in the past on performance of fair wireless mesh networks. In our research we show that even in those very restricted conditions and max-min cost function, the idea of interference cancelation can significantly increase the capacity of such networks. In order to approximate possible advantages of using interference cancelation in the considered conditions, we propose a novel MIP model that allows for calculating perfect scheduling and maximal throughput in a network. We compare the results with cases when the interference cancelation mechanisms are disabled. Our results show that using interference cancelation mechanisms for signals that have been overheard in the past increases a network throughput by 40% on average in approximately 20% of test cases.

  14. Rheumatoid factor and its interference with cytokine measurements

    DEFF Research Database (Denmark)

    Bartels, Else Marie; Falbe Wätjen, Inger; Littrup Andersen, Eva

    2011-01-01

    Use of cytokines as biomarkers for disease is getting more widespread. Cytokines are conveniently determined by immunoassay, but interference from present antibodies is known to cause problems. In rheumatoid arthritis (RA), interference of rheumatoid factor (RF) may be problematic. RF covers...... possible solutions for recognized problems. IL-1β, IL-4, IL-6, and IL-8 were determined with multiplex immunoassays (MIA) in samples from RA patients prior to and after polyethylene glycol (PEG 6000) precipitation. Presence of RF does interfere with MIA. PEG 6000 precipitation abolishes this RF...... a group of autoantibodies from immunoglobulin subclasses and is present in 65-80% of RA patients. Partly removal of RF is possible by precipitation. This study aims at determining the effects of presence of RF in blood and synovial fluid on cytokine measurements in samples from RA patients and finding...

  15. General relativistic effects in quantum interference of “clocks”

    Science.gov (United States)

    Zych, M.; Pikovski, I.; Costa, F.; Brukner, Č.

    2016-06-01

    Quantum mechanics and general relativity have been each successfully tested in numerous experiments. However, the regime where both theories are jointly required to explain physical phenomena remains untested by laboratory experiments, and is also not fully understood by theory. This contribution reviews recent ideas for a new type of experiments: quantum interference of “clocks”, which aim to test novel quantum effects that arise from time dilation. “Clock” interference experiments could be realised with atoms or photons in near future laboratory experiments.

  16. Nonmonotonic quantum-to-classical transition in multiparticle interference

    DEFF Research Database (Denmark)

    Ra, Young-Sik; Tichy, Malte; Lim, Hyang-Tag

    2013-01-01

    Quantum-mechanical wave–particle duality implies that probability distributions for granular detection events exhibit wave-like interference. On the single-particle level, this leads to self-interference—e.g., on transit across a double slit—for photons as well as for large, massive particles...... that interference fades away monotonically with increasing distinguishability—in accord with available experimental evidence on the single- and on the many-particle level. Here, we demonstrate experimentally and theoretically that such monotonicity of the quantum-to-classical transition is the exception rather than...

  17. How Cannabis Causes Paranoia: Using the Intravenous Administration of ∆9-Tetrahydrocannabinol (THC) to Identify Key Cognitive Mechanisms Leading to Paranoia

    Science.gov (United States)

    Freeman, Daniel; Dunn, Graham; Murray, Robin M.; Evans, Nicole; Lister, Rachel; Antley, Angus; Slater, Mel; Godlewska, Beata; Cornish, Robert; Williams, Jonathan; Di Simplicio, Martina; Igoumenou, Artemis; Brenneisen, Rudolf; Tunbridge, Elizabeth M.; Harrison, Paul J.; Harmer, Catherine J.; Cowen, Philip; Morrison, Paul D.

    2015-01-01

    Paranoia is receiving increasing attention in its own right, since it is a central experience of psychotic disorders and a marker of the health of a society. Paranoia is associated with use of the most commonly taken illicit drug, cannabis. The objective was to determine whether the principal psychoactive ingredient of cannabis—∆9-tetrahydrocannabinol (THC)—causes paranoia and to use the drug as a probe to identify key cognitive mechanisms underlying paranoia. A randomized, placebo-controlled, between-groups test of the effects of intravenous THC was conducted. A total of 121 individuals with paranoid ideation were randomized to receive placebo, THC, or THC preceded by a cognitive awareness condition. Paranoia was assessed extensively via a real social situation, an immersive virtual reality experiment, and standard self-report and interviewer measures. Putative causal factors were assessed. Principal components analysis was used to create a composite paranoia score and composite causal variables to be tested in a mediation analysis. THC significantly increased paranoia, negative affect (anxiety, worry, depression, negative thoughts about the self), and a range of anomalous experiences, and reduced working memory capacity. The increase in negative affect and in anomalous experiences fully accounted for the increase in paranoia. Working memory changes did not lead to paranoia. Making participants aware of the effects of THC had little impact. In this largest study of intravenous THC, it was definitively demonstrated that the drug triggers paranoid thoughts in vulnerable individuals. The most likely mechanism of action causing paranoia was the generation of negative affect and anomalous experiences. PMID:25031222

  18. How cannabis causes paranoia: using the intravenous administration of ∆9-tetrahydrocannabinol (THC) to identify key cognitive mechanisms leading to paranoia.

    Science.gov (United States)

    Freeman, Daniel; Dunn, Graham; Murray, Robin M; Evans, Nicole; Lister, Rachel; Antley, Angus; Slater, Mel; Godlewska, Beata; Cornish, Robert; Williams, Jonathan; Di Simplicio, Martina; Igoumenou, Artemis; Brenneisen, Rudolf; Tunbridge, Elizabeth M; Harrison, Paul J; Harmer, Catherine J; Cowen, Philip; Morrison, Paul D

    2015-03-01

    Paranoia is receiving increasing attention in its own right, since it is a central experience of psychotic disorders and a marker of the health of a society. Paranoia is associated with use of the most commonly taken illicit drug, cannabis. The objective was to determine whether the principal psychoactive ingredient of cannabis-∆(9)-tetrahydrocannabinol (THC)-causes paranoia and to use the drug as a probe to identify key cognitive mechanisms underlying paranoia. A randomized, placebo-controlled, between-groups test of the effects of intravenous THC was conducted. A total of 121 individuals with paranoid ideation were randomized to receive placebo, THC, or THC preceded by a cognitive awareness condition. Paranoia was assessed extensively via a real social situation, an immersive virtual reality experiment, and standard self-report and interviewer measures. Putative causal factors were assessed. Principal components analysis was used to create a composite paranoia score and composite causal variables to be tested in a mediation analysis. THC significantly increased paranoia, negative affect (anxiety, worry, depression, negative thoughts about the self), and a range of anomalous experiences, and reduced working memory capacity. The increase in negative affect and in anomalous experiences fully accounted for the increase in paranoia. Working memory changes did not lead to paranoia. Making participants aware of the effects of THC had little impact. In this largest study of intravenous THC, it was definitively demonstrated that the drug triggers paranoid thoughts in vulnerable individuals. The most likely mechanism of action causing paranoia was the generation of negative affect and anomalous experiences.

  19. Canceling Stationary Interference Signals Exploiting Secondary Data

    OpenAIRE

    Swärd, Johan; Jakobsson, Andreas

    2014-01-01

    In this paper, we propose a novel interference cancellation method that exploits secondary data to estimate stationary interference components present in both the primary and the secondary data sets, thereby allowing for the removal of such interference from the data sets, even when these components share frequencies with the signal of interest. The algorithm estimates the present interference components one frequency at a time, thus enabling for a computationally efficient algorithm, that re...

  20. Distributed Interference Alignment with Low Overhead

    CERN Document Server

    Ma, Yanjun; Chen, Rui

    2011-01-01

    Based on closed-form interference alignment (IA) solutions, a low overhead distributed interference alignment (LOIA) scheme is proposed in this paper for the $K$-user SISO interference channel, and extension to multiple antenna scenario is also considered. Compared with the iterative interference alignment (IIA) algorithm proposed by Gomadam et al., the overhead is greatly reduced. Simulation results show that the IIA algorithm is strictly suboptimal compared with our LOIA algorithm in the overhead-limited scenario.

  1. A New Model for Interference Analysis in Asynchronous Multi-Carrier Transmission

    CERN Document Server

    Medjahdi, Yahia; Ruyet, Didier Le; Roviras, Daniel

    2010-01-01

    Interference at the radio receiver is a key source of degradation in quality of service of wireless communication systems. This paper presents a unified framework for OFDM/FBMC interference characterization and analysis in asynchronous environment. Multi-user interference is caused by the timing synchronization errors which lead to the destruction of the orthogonality between subcarriers. In this paper, we develop a theoretical analysis of the asynchronous interference considering the multi-path effects on the interference signal. We further propose an accurate model for interference that provides a useful computational tool in order to evaluate the performance of an OFDM/FBMC system in a frequency selective fading environment. Finally, simulation results confirmed the accuracy of the proposed model.

  2. 47 CFR 22.353 - Blanketing interference.

    Science.gov (United States)

    2010-10-01

    ... are not required to resolve blanketing interference to mobile receivers or non-RF devices or... 47 Telecommunication 2 2010-10-01 2010-10-01 false Blanketing interference. 22.353 Section 22.353... Operational and Technical Requirements Technical Requirements § 22.353 Blanketing interference. Licensees of...

  3. An accumulator model of semantic interference

    NARCIS (Netherlands)

    van Maanen, Leendert; van Rijn, Hedderik

    2007-01-01

    To explain latency effects in picture-word interference tasks, cognitive models need to account for both interference and stimulus onset asynchrony (SOA) effects. As opposed to most models of picture-word interference, which model the time course during the task in a ballistic manner, the RACE model

  4. Central mechanism of the cardiovascular responses caused by L-proline microinjected into the paraventricular nucleus of the hypothalamus in unanesthetized rats.

    Science.gov (United States)

    Lopes-Azevedo, Silvana; Busnardo, Cristiane; Corrêa, Fernando Morgan Aguiar

    2016-12-01

    Previously, we reported that microinjection of L-proline (L-Pro) into the paraventricular nucleus of the hypothalamus (PVN) caused vasopressin-mediated pressor responses in unanesthetized rats. In the present study, we report on the central mechanisms involved in the mediation of the cardiovascular effects caused by the microinjection of L-Pro into the PVN. Microinjection of increasing doses of L-Pro (3-100nmol/100nL) into the PVN caused dose-related pressor and bradycardic responses. No cardiovascular responses were observed after the microinjection of equimolar doses (33nmol/100nL) of its isomer D-Proline (D-Pro) or Mannitol. The PVN pretreatment with either a selective non-NMDA (NBQX) or selective NMDA (LY235959 or DL-AP7) glutamate receptor antagonists blocked the cardiovascular response to L-Pro (33nmol/100nL). The dose-effect curve for the pretreatment with increasing doses of LY235959 was located at the left in relation to the curves for NBQX and DL-AP7, showing that LY235959 is more potent than NBQX, which is more potent than DL-AP7 in inhibiting the cardiovascular response to L-Pro. The cardiovascular response to the microinjection of L-Pro into the PVN was not affected by local pretreatment with N(ω)-Propyl-l-arginine (N-Propyl), a selective inhibitor of the neuronal nitric oxide synthase (nNOS), suggesting that NO does not mediate the responses to L-Pro in the PVN. In conclusion, the results suggest that ionotropic receptors in the PVN, blocked by both NMDA and non-NMDA receptor antagonists, mediate the pressor response to L-Pro that results from activation of PVN vasopressinergic magnocellular neurons and vasopressin release into the systemic circulation.

  5. Corpuscular Model of Two-Beam Interference and Double-Slit Experiments with Single Photons

    NARCIS (Netherlands)

    Jin, Fengping; Yuan, Shengjun; De Raedt, Hans; Michielsen, Kristel; Miyashita, Seiji

    2010-01-01

    We introduce an event-based corpuscular simulation model that reproduces the wave mechanical results of single-photon double-slit and two-beam interference experiments and (of a one-to-one copy of an experimental realization) of a single-photon interference experiment with a Fresnel biprism. The sim

  6. Corpuscular Model of Two-Beam Interference and Double-Slit Experiments with Single Photons

    NARCIS (Netherlands)

    Jin, Fengping; Yuan, Shengjun; De Raedt, Hans; Michielsen, Kristel; Miyashita, Seiji

    We introduce an event-based corpuscular simulation model that reproduces the wave mechanical results of single-photon double-slit and two-beam interference experiments and (of a one-to-one copy of an experimental realization) of a single-photon interference experiment with a Fresnel biprism. The

  7. Long-Term Interference at the Semantic Level: Evidence from Blocked-Cyclic Picture Matching

    Science.gov (United States)

    Wei, Tao; Schnur, Tatiana T.

    2016-01-01

    Processing semantically related stimuli creates interference across various domains of cognition, including language and memory. In this study, we identify the locus and mechanism of interference when retrieving meanings associated with words and pictures. Subjects matched a probe stimulus (e.g., cat) to its associated target picture (e.g., yarn)…

  8. Inducing RNA interference in the arbovirus vector, Culicoides sonorensis.

    Science.gov (United States)

    Mills, M K; Nayduch, D; Michel, K

    2015-02-01

    Biting midges in the genus Culicoides are important vectors of arboviral diseases, including epizootic haemorrhagic disease, bluetongue and most likely Schmallenberg, which cause significant economic burdens worldwide. Research on these vectors has been hindered by the lack of a sequenced genome, the difficulty of consistent culturing of certain species and the absence of molecular techniques such as RNA interference (RNAi). Here, we report the establishment of RNAi as a research tool for the adult midge, Culicoides sonorensis. Based on previous research and transcriptome analysis, which revealed putative small interfering RNA pathway member orthologues, we hypothesized that adult C. sonorensis midges have the molecular machinery needed to perform RNA silencing. Injection of control double-stranded RNA targeting green fluorescent protein (dsGFP), into the haemocoel of 2-3-day-old adult female midges resulted in survival curves that support virus transmission. dsRNA injection targeting the newly identified C. sonorensis inhibitor of apoptosis protein 1 (CsIAP1) orthologue resulted in a 40% decrease of transcript levels and 73% shorter median survivals as compared with dsGFP-injected controls. These results reveal the conserved function of IAP1. Importantly, they also demonstrate the feasibility of RNAi by dsRNA injection in adult midges, which will greatly facilitate studies of the underlying mechanisms of vector competence in C. sonorensis.

  9. Many-particle interference beyond many-boson and many-fermion statistics

    DEFF Research Database (Denmark)

    Tichy, Malte C.; Tiersch, Markus; Mintert, Florian

    2012-01-01

    that the collective interference of three or more particles leads to much more diverse behavior than expected from the boson–fermion dichotomy known from quantum statistical mechanics. The emerging complexity of many-particle interference is tamed by a simple law for the strict suppression of events in the Bell...... multiport beam splitter. The law shows that counting events are governed by widely species-independent interference, such that bosons and fermions can even exhibit identical interference signatures, while their statistical character remains subordinate. Recent progress in the preparation of tailored many...

  10. Microhomology-mediated mechanisms underlie non-recurrent disease-causing microdeletions of the FOXL2 gene or its regulatory domain.

    Directory of Open Access Journals (Sweden)

    Hannah Verdin

    Full Text Available Genomic disorders are often caused by recurrent copy number variations (CNVs, with nonallelic homologous recombination (NAHR as the underlying mechanism. Recently, several microhomology-mediated repair mechanisms--such as microhomology-mediated end-joining (MMEJ, fork stalling and template switching (FoSTeS, microhomology-mediated break-induced replication (MMBIR, serial replication slippage (SRS, and break-induced SRS (BISRS--were described in the etiology of non-recurrent CNVs in human disease. In addition, their formation may be stimulated by genomic architectural features. It is, however, largely unexplored to what extent these mechanisms contribute to rare, locus-specific pathogenic CNVs. Here, fine-mapping of 42 microdeletions of the FOXL2 locus, encompassing FOXL2 (32 or its regulatory domain (10, serves as a model for rare, locus-specific CNVs implicated in genetic disease. These deletions lead to blepharophimosis syndrome (BPES, a developmental condition affecting the eyelids and the ovary. For breakpoint mapping we used targeted array-based comparative genomic hybridization (aCGH, quantitative PCR (qPCR, long-range PCR, and Sanger sequencing of the junction products. Microhomology, ranging from 1 bp to 66 bp, was found in 91.7% of 24 characterized breakpoint junctions, being significantly enriched in comparison with a random control sample. Our results show that microhomology-mediated repair mechanisms underlie at least 50% of these microdeletions. Moreover, genomic architectural features, like sequence motifs, non-B DNA conformations, and repetitive elements, were found in all breakpoint regions. In conclusion, the majority of these microdeletions result from microhomology-mediated mechanisms like MMEJ, FoSTeS, MMBIR, SRS, or BISRS. Moreover, we hypothesize that the genomic architecture might drive their formation by increasing the susceptibility for DNA breakage or promote replication fork stalling. Finally, our locus-centered study

  11. Stroop interference and negative priming (NP) suppression in normal aging.

    Science.gov (United States)

    Mayas, J; Fuentes, L J; Ballesteros, S

    2012-01-01

    Age-related differences in the reduction of Stroop interference were explored by comparing the performance of 18 younger (of mean age: 30.0±3.9 years) and 18 older healthy adults (of mean age: 75±7.2 years) in a color-word Stroop task. The aim of this study was to determine whether a decrease in the efficiency of inhibitory mechanisms associated with aging could account for age-related differences in the ability to suppress a pre-potent response. Participants performed a Stroop task to assess Stroop interference and NP suppression concurrently. Results showed a greater Stroop interference in older than in young adults. On the other hand, the NP effect was only reliable in the younger group, the older group not showing NP suppression. These findings suggest that the slowing hypothesis alone cannot explain this pattern of results and that the age-related differences must also involve an inhibitory breakdown during aging.

  12. Spying on photons with photons: quantum interference and information

    Science.gov (United States)

    Ataman, Stefan

    2016-07-01

    The quest to have both which-path knowledge and interference fringes in a double-slit experiment dates back to the inception of quantum mechanics (QM) and to the famous Einstein-Bohr debates. In this paper we propose and discuss an experiment able to spy on one photon's path with another photon. We modify the quantum state inside the interferometer as opposed to the traditional physical modification of the "wave-like" or "particle-like" experimental setup. We are able to show that it is the ability to harvest or not which-path information that finally limits the visibility of the interference pattern and not the "wave-like" or "particle-like" experimental setups. Remarkably, a full "particle-like" experimental setup is able to show interference fringes with 100% visibility if the quantum state is carefully engineered.

  13. Spying on photons with photons: quantum interference and information

    CERN Document Server

    Ataman, Stefan

    2016-01-01

    The quest to have both which-path knowledge and interference fringes in a double-slit experiment dates back to the inception of quantum mechanics (QM) and to the famous Einstein-Bohr debates. In this paper we propose and discuss an experiment able to spy on one photon's path with another photon. We modify the quantum state inside the interferometer as opposed to the traditional physical modification of the "wave-like" or "particle-like" experimental setup. We are able to show that it is the ability to harvest or not which-path information that finally limits the visibility of the interference pattern and not the "wave-like" or "particle-like" experimental setups. Remarkably, a full "particle-like" experimental setup is able to show interference fringes with 100 % visibility if the quantum state is carefully engineered.

  14. Temperature Dependence of Characteristics for Multimode Interference Based 3-dB Coupler in SOI

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The temperature dependence of characteristics for multimode interference(MMI) based 3-dB coupler in silicon-on-insulator is analyzed, which originates from the relatively high thermo-optic coefficient of silicon. For restricted interference 3-dB MMI coupler, the output power uniformity is ideally 0 at room temperature and becomes 0.32dB when temperature rises up to 550K.For symmetric interference 3-dB MMI coupler, the power uniformity keeps ideally 0 due to its intrinsic symmetric interference mechanism. With the temperature rising, the excess loss of the both devices increases. The performance deterioration due to temperature variety is more obvious to restricted interference MMI 3-dB coupler, comparing with that of symmetric interference MMI 3-dB coupler.

  15. Codebook-based interference alignment for uplink MIMO interference channels

    KAUST Repository

    Lee, Hyun Ho

    2014-02-01

    In this paper, we propose a codebook-based interference alignment (IA) scheme in the constant multiple-input multipleoutput (MIMO) interference channel especially for the uplink scenario. In our proposed scheme, we assume cooperation among base stations (BSs) through reliable backhaul links so that global channel knowledge is available for all BSs, which enables BS to compute the transmit precoder and inform its quantized index to the associated user via limited rate feedback link.We present an upper bound on the rate loss of the proposed scheme and derive the scaling law of the feedback load tomaintain a constant rate loss relative to IA with perfect channel knowledge. Considering the impact of overhead due to training, cooperation, and feedback, we address the effective degrees of freedom (DOF) of the proposed scheme and derive the maximization of the effective DOF. From simulation results, we verify our analysis on the scaling law to preserve the multiplexing gain and confirm that the proposed scheme is more effective than the conventional IA scheme in terms of the effective DOF. © 2014 KICS.

  16. INTERFERENCE CANCELLATION FOR MOBILE DISPERSIVE CHANNELS

    Institute of Scientific and Technical Information of China (English)

    Kazi Takpaya

    2003-01-01

    A robust interference canceller for Multi-Carrier Code Division Multiple Access(MC-CDMA) using Orthogonal Frequency Division Multiplexing (OFDM) in Rayleigh fading isproposed. This interference canceller is robust in the sense that it cancels Inter-Carriers Inter-ference (ICI) and is suitable for use in dispersive channels. To come up the effects of the signaldispersion, Doppler shifts and delay spreads on the performance of MC-CDMA systems over mo-bile fading channels, this interference canceller exploits the merit of the orthogonal signaling andpilot signals to evaluate the channel parameters. This interface canceller is well suited to work initerative turbo interference cancellation.

  17. 40 CFR 1065.375 - Interference verification for N2O analyzers.

    Science.gov (United States)

    2010-07-01

    ... certain analyzers by causing a response similar to N2O. If the analyzer uses compensation algorithms that... other measurements to test the compensation algorithms during the analyzer interference verification....

  18. Circuits protection against interferences in high voltage substations; Protecao de circuitos contra interferencias em subestacoes

    Energy Technology Data Exchange (ETDEWEB)

    Hamada, Massayuki [Consultas e Aplicacoes de Engenharia Eletrica Ltda. (CAEEL) (Brazil)

    1989-12-01

    This paper makes a brief analysis of the different phenomena which may cause electromagnetic interference in high voltage substations and suggests adequate solutions to the problem according to the different events that may occur. 5 refs., 1 fig.

  19. Mechanics

    CERN Document Server

    Chester, W

    1979-01-01

    When I began to write this book, I originally had in mind the needs of university students in their first year. May aim was to keep the mathematics simple. No advanced techniques are used and there are no complicated applications. The emphasis is on an understanding of the basic ideas and problems which require expertise but do not contribute to this understanding are not discussed. How­ ever, the presentation is more sophisticated than might be considered appropri­ ate for someone with no previous knowledge of the subject so that, although it is developed from the beginning, some previous acquaintance with the elements of the subject would be an advantage. In addition, some familiarity with element­ ary calculus is assumed but not with the elementary theory of differential equations, although knowledge of the latter would again be an advantage. It is my opinion that mechanics is best introduced through the motion of a particle, with rigid body problems left until the subject is more fully developed. Howev...

  20. Lesions to lateral prefrontal cortex impair interference control in word production

    Directory of Open Access Journals (Sweden)

    Vitória ePiai

    2016-01-01

    Full Text Available Speaking is an action that requires control, for example, to prevent interference from distracting or competing information present in the speaker’s environment. Control over task performance is thought to depend on the lateral prefrontal cortex (PFC. However, the neuroimaging literature does not show a consistent relation between left PFC and interference control in word production. Here, we examined the role of left PFC in interference control in word production by testing six patients with lesions to left PFC (centred around the ventrolateral PFC on a control-demanding task. Patients and age-matched controls named pictures presented along with distractor words, inducing within-trial interference effects. We varied the degree of competing information from distractors to increase the need for interference control. Distractors were semantically related, phonologically related, unrelated to the picture name, or neutral (XXX. Both groups showed lexical interference (slower responses with unrelated than neutral distractors, reflecting naming difficulty in the presence of competing linguistic information. Relative to controls, all six left PFC patients had larger lexical interference effects. By contrast, patients did not show a consistent semantic interference effect (reflecting difficulty in selecting amongst semantic competitors whereas the controls did. This suggests different control mechanisms may be engaged in semantic compared to lexical interference resolution in this paradigm. Finally, phonological facilitation (faster responses with phonological than unrelated distractors was larger in patients than in controls. These findings suggest that the lateral PFC is a necessary structure in providing control over lexical interference in word production, possibly through an early attentional blocking mechanism. By contrast, the left PFC does not seem critical in semantic interference resolution in the picture-word interference paradigm.

  1. Cooperative Feedback for MIMO Interference Channels

    CERN Document Server

    Huang, Kaibin

    2010-01-01

    Multi-antenna precoding effectively mitigates the interference in wireless networks. However, the precoding efficiency can be significantly degraded by the overhead due to the required feedback of channel state information (CSI). This paper addresses such an issue by proposing a systematic method of designing precoders for the two-user multiple-input-multiple-output (MIMO) interference channels based on finite-rate CSI feedback from receivers to their interferers, called cooperative feedback. Specifically, each precoder is decomposed into inner and outer precoders for nulling interference and improving the data link array gain, respectively. The inner precoders are further designed to suppress residual interference resulting from finite-rate cooperative feedback. To regulate residual interference due to precoder quantization, additional scalar cooperative feedback signals are designed to control transmitters' power using different criteria including applying interference margins, maximizing sum throughput, an...

  2. Assessment of life interference in anxious children

    DEFF Research Database (Denmark)

    Rapee, Ronald; Thastum, Mikael; Chavira, Denise

    life interference derived from symptoms of anxiety. Broader and more general life interference measures tend to have minimal relevance for children with anxiety disorders. The current paper will describe two measures of life interference that have been developed at the Centre for Emotional Health...... directed at children and adolescents. One measure, the Children's Anxiety Life Interference Scale (CALIS) was developed to assess interference directly associated with symptoms of anxiety in children and adolescents, while the other, the Adolescent Life Interference Scale (ALIS) is a broader measure....... This imbalance has particularly characterised research on child anxiety where few studies have examined either the impact of anxiety disorders on children's lives or the effects of treatments on life interference. To some extent this lack of attention has come from a lack of well developed measures to assess...

  3. Interference Mitigation in Large Random Wireless Networks

    CERN Document Server

    Aldridge, Matthew

    2011-01-01

    A central problem in the operation of large wireless networks is how to deal with interference -- the unwanted signals being sent by transmitters that a receiver is not interested in. This thesis looks at ways of combating such interference. In Chapters 1 and 2, we outline the necessary information and communication theory background, including the concept of capacity. We also include an overview of a new set of schemes for dealing with interference known as interference alignment, paying special attention to a channel-state-based strategy called ergodic interference alignment. In Chapter 3, we consider the operation of large regular and random networks by treating interference as background noise. We consider the local performance of a single node, and the global performance of a very large network. In Chapter 4, we use ergodic interference alignment to derive the asymptotic sum-capacity of large random dense networks. These networks are derived from a physical model of node placement where signal strength d...

  4. An Efficient Inter Carrier Interference Cancellation Schemes for OFDM Systems

    Directory of Open Access Journals (Sweden)

    B. Sathish Kumar

    2009-12-01

    Full Text Available Orthogonal Frequency Division Multiplexing (OFDM has recently been used widely in wireless communication systems. OFDM is very effective in combating inter-symbol interference and can achieve high data rate in frequency selective channel. For OFDM communication systems, the frequency offsets in mobile radio channels distort the orthogonality between subcarriers resulting in Inter Carrier Interference (ICI. ICI causes power leakage among subcarriers thus degrading the system performance. A well-known problem of OFDM is its sensitivity to frequency offset between the transmitted and received carrier frequencies. There are two deleterious effects caused by frequency offset one is the reduction of signal amplitude in the output of the filters matched to each of the carriers and the second is introduction of ICI from the other carriers. This research work investigates three effective methods for combating the effects of ICI: ICI Self Cancellation (SC, Maximum Likelihood (ML estimation, and Extended Kalman Filter (EKF method. These three methods are compared in terms of bit error rate performance and bandwidth efficiency. Through simulations, it is shown that the three techniques are effective in mitigating the modulation schemes, the ML and EKF methods perform better than the SC method.Keywords- Orthogonal frequency Division Multiplexing (OFDM; Inter Carrier Interference(ICI; Carrier to Interference Power Ratio (CIR;Self Cancellation(SC;Carrier Frequency Offset (CFO; Maximum Likelihood(ML; Extended Kalman Filtering(EKF.

  5. Structure-activity relationships for perfluoroalkane-induced in vitro interference with rat liver mitochondrial respiration.

    Science.gov (United States)

    Wallace, K B; Kissling, G E; Melnick, R L; Blystone, C R

    2013-10-01

    Perfluorinated alkyl acids (PFAAs) represent a broad class of commercial products designed primarily for the coatings industry. However, detection of residues globally in a variety of species led to the discontinuation of production in the U.S. Although PFAAs cause activation of the PPARα and CAR nuclear receptors, interference with mitochondrial bioenergetics has been implicated as an alternative mechanism of cytotoxicity. Although the mechanisms by which the eight carbon chain PFAAs interfere with mitochondrial bioenergetics are fairly well described, the activities of the more highly substituted or shorter chain PFAAs are far less well characterized. The current investigation was designed to explore structure-activity relationships by which PFAAs interfere with mitochondrial respiration in vitro. Freshly isolated rat liver mitochondria were incubated with one of 16 different PFAAs, including perfluorinated carboxylic, acetic, and sulfonic acids, sulfonamides and sulfamido acetates, and alcohols. The effect on mitochondrial respiration was measured at five concentrations and dose-response curves were generated to describe the effects on state 3 and 4 respiration and respiratory control. With the exception of PFOS, all PFAAs at sufficiently high concentrations (>20μM) stimulated state 4 and inhibited state 3 respiration. Stimulation of state 4 respiration was most pronounced for the carboxylic acids and the sulfonamides, which supports prior evidence that the perfluorinated carboxylic and acetic acids induce the mitochondrial permeability transition, whereas the sulfonamides are protonophoric uncouplers of oxidative phosphorylation. In both cases, potency increased with increasing carbon number, with a prominent inflection point between the six and eight carbon congeners. The results provide a foundation for classifying PFAAs according to specific modes of mitochondrial activity and, in combination with toxicokinetic considerations, establishing structure

  6. Structure–activity relationships for perfluoroalkane-induced in vitro interference with rat liver mitochondrial respiration✩

    Science.gov (United States)

    Wallace, K.B.; Kissling, G.E.; Melnick, R.L.; Blystone, C.R.

    2014-01-01

    Perfluorinated alkyl acids (PFAAs) represent a broad class of commercial products designed primarily for the coatings industry. However, detection of residues globally in a variety of species led to the discontinuation of production in the U.S. Although PFAAs cause activation of the PPARα and CAR nuclear receptors, interference with mitochondrial bioenergetics has been implicated as an alternative mechanism of cytotoxicity. Although the mechanisms by which the eight carbon chain PFAAs interfere with mitochondrial bioenergetics are fairly well described, the activities of the more highly substituted or shorter chain PFAAs are far less well characterized. The current investigation was designed to explore structure–activity relationships by which PFAAs interfere with mitochondrial respiration in vitro. Freshly isolated rat liver mitochondria were incubated with one of 16 different PFAAs, including perfluorinated carboxylic, acetic, and sulfonic acids, sulfonamides and sulfamido acetates, and alcohols. The effect on mitochondrial respiration was measured at five concentrations and dose–response curves were generated to describe the effects on state 3 and 4 respiration and respiratory control. With the exception of PFOS, all PFAAs at sufficiently high concentrations (>20 μM) stimulated state 4 and inhibited state 3 respiration. Stimulation of state 4 respiration was most pronounced for the carboxylic acids and the sulfonamides, which supports prior evidence that the perfluorinated carboxylic and acetic acids induce the mitochondrial permeability transition, whereas the sulfonamides are protonophoric uncouplers of oxidative phosphorylation. In both cases, potency increased with increasing carbon number, with a prominent inflection point between the six and eight carbon congeners. The results provide a foundation for classifying PFAAs according to specific modes of mitochondrial activity and, in combination with toxicokinetic considerations, establishing structure

  7. RNA interference and Register Machines (extended abstract

    Directory of Open Access Journals (Sweden)

    Masahiro Hamano

    2012-11-01

    Full Text Available RNA interference (RNAi is a mechanism whereby small RNAs (siRNAs directly control gene expression without assistance from proteins. This mechanism consists of interactions between RNAs and small RNAs both of which may be single or double stranded. The target of the mechanism is mRNA to be degraded or aberrated, while the initiator is double stranded RNA (dsRNA to be cleaved into siRNAs. Observing the digital nature of RNAi, we represent RNAi as a Minsky register machine such that (i The two registers hold single and double stranded RNAs respectively, and (ii Machine's instructions are interpreted by interactions of enzyme (Dicer, siRNA (with RISC com- plex and polymerization (RdRp to the appropriate registers. Interpreting RNAi as a computational structure, we can investigate the computational meaning of RNAi, especially its complexity. Initially, the machine is configured as a Chemical Ground Form (CGF, which generates incorrect jumps. To remedy this problem, the system is remodeled as recursive RNAi, in which siRNA targets not only mRNA but also the machine instructional analogues of Dicer and RISC. Finally, probabilistic termination is investigated in the recursive RNAi system.

  8. Hereditary 1,25-dihydroxyvitamin D-resistant rickets (HVDRR caused by a VDR mutation: A novel mechanism of dominant inheritance

    Directory of Open Access Journals (Sweden)

    Tsuyoshi Isojima

    2015-06-01

    Full Text Available Hereditary 1,25-dihydroxyvitamin D-resistant rickets (HVDRR is caused by mutations in the VDR gene, and its inheritance is autosomal recessive. In this report, we aimed to confirm whether HVDRR is occasionally inherited as a dominant trait. An 18-month-old Japanese boy was evaluated for short stature and bowlegs. His father had been treated for rickets during childhood, and his paternal grandfather had bowlegs. We diagnosed him with HVDRR based on laboratory data and radiographic evidence of rickets. Sequence analyses of VDR were performed, and the functional consequences of the detected mutations were analyzed for transcriptional activity, ligand binding, and interaction with the retinoid X receptor, cofactors, and the vitamin D response element (VDRE. A novel mutation (Q400LfsX7 and a reported variant (R370H were identified in the patient. Heterozygous Q400LfsX7 was detected in his father, and heterozygous R370H was detected in his healthy mother. Functional studies revealed that the transcriptional activity of Q400LfsX7-VDR was markedly disturbed. The mutant had a dominant-negative effect on wild-type-VDR, and the ligand binding affinity of Q400LfsX7-VDR was completely impaired. Interestingly, Q400LfsX7-VDR had a strong interaction with corepressor NCoR and could interact with VDRE without the ligand. R370H-VDR was functionally similar to wild-type-VDR. In conclusion, we found a dominant-negative mutant of VDR causing dominantly inherited HVDRR through a constitutive corepressor interaction, a mechanism similar to that in dominantly inherited thyroid hormone receptor mutations. Our report together with a reported pedigree suggested a distinct inheritance of HVDRR and enriched our understanding of VDR abnormalities.

  9. Oxidative stress causes renal dopamine D1 receptor dysfunction and hypertension via mechanisms that involve nuclear factor-kappaB and protein kinase C.

    Science.gov (United States)

    Banday, Anees Ahmad; Fazili, Fatima Rizwan; Lokhandwala, Mustafa F

    2007-05-01

    Renal dopamine, via activation of D1 receptors, plays a role in maintaining sodium homeostasis and BP. There exists a defect in renal D1 receptor function in hypertension, diabetes, and aging, conditions that are associated with oxidative stress. However, the exact underlying mechanism of the oxidative stress-mediated impaired D1 receptor signaling and hypertension is not known. The effect of oxidative stress on renal D1 receptor function was investigated in healthy animals. Male Sprague-Dawley rats received tap water (vehicle) and 30 mM L-buthionine sulfoximine (BSO), an oxidant, with and without 1 mM tempol for 2 wk. Compared with vehicle, BSO treatment caused oxidative stress and increase in BP, which was accompanied by defective D1 receptor G-protein coupling and loss of natriuretic response to SKF38393. BSO treatment also increased NF-kappaB nuclear translocation, protein kinase C (PKC) activity and expression, G-protein-coupled receptor kinase-2 (GRK-2) membranous translocation, and D1 receptor serine phosphorylation. In BSO-treated rats' supplementation of tempol decreased oxidative stress, normalized BP, and restored D1 receptor G-protein coupling and natriuretic response to SKF38393. Tempol also normalized NF-kappaB translocation, PKC activity and expression, GRK-2 sequestration, and D1 receptor serine phosphorylation. In conclusion, these results show that oxidative stress activates NF-kappaB, causing an increase in PKC activity, which leads to GRK-2 translocation and subsequent D1 receptor hyper-serine phosphorylation and uncoupling. The functional consequence of this phenomenon was the inability of SKF38393 to inhibit Na/K-ATPase activity and promote sodium excretion, which may have contributed to increase in BP. Tempol reduced oxidative stress and thereby restored D1 receptor function and normalized BP.

  10. Malfunctioning of the Iron–Sulfur Cluster Assembly Machinery in Saccharomyces cerevisiae Produces Oxidative Stress via an Iron-Dependent Mechanism, Causing Dysfunction in Respiratory Complexes

    Science.gov (United States)

    Gomez, Mauricio; Pérez-Gallardo, Rocío V.; Sánchez, Luis A.; Díaz-Pérez, Alma L.; Cortés-Rojo, Christian; Meza Carmen, Victor; Saavedra-Molina, Alfredo; Lara-Romero, Javier; Jiménez-Sandoval, Sergio; Rodríguez, Francisco; Rodríguez-Zavala, José S.; Campos-García, Jesús

    2014-01-01

    Biogenesis and recycling of iron–sulfur (Fe–S) clusters play important roles in the iron homeostasis mechanisms involved in mitochondrial function. In Saccharomyces cerevisiae, the Fe–S clusters are assembled into apoproteins by the iron–sulfur cluster machinery (ISC). The aim of the present study was to determine the effects of ISC gene deletion and consequent iron release under oxidative stress conditions on mitochondrial functionality in S. cerevisiae. Reactive oxygen species (ROS) generation, caused by H2O2, menadione, or ethanol, was associated with a loss of iron homeostasis and exacerbated by ISC system dysfunction. ISC mutants showed increased free Fe2+ content, exacerbated by ROS-inducers, causing an increase in ROS, which was decreased by the addition of an iron chelator. Our study suggests that the increment in free Fe2+ associated with ROS generation may have originated from mitochondria, probably Fe–S cluster proteins, under both normal and oxidative stress conditions, suggesting that Fe–S cluster anabolism is affected. Raman spectroscopy analysis and immunoblotting indicated that in mitochondria from SSQ1 and ISA1 mutants, the content of [Fe–S] centers was decreased, as was formation of Rieske protein-dependent supercomplex III2IV2, but this was not observed in the iron-deficient ATX1 and MRS4 mutants. In addition, the activity of complexes II and IV from the electron transport chain (ETC) was impaired or totally abolished in SSQ1 and ISA1 mutants. These results confirm that the ISC system plays important roles in iron homeostasis, ROS stress, and in assembly of supercomplexes III2IV2 and III2IV1, thus affecting the functionality of the respiratory chain. PMID:25356756

  11. Modal interference in spiky nanoshells.

    Science.gov (United States)

    Hastings, Simon P; Qian, Zhaoxia; Swanglap, Pattanawit; Fang, Ying; Engheta, Nader; Park, So-Jung; Link, Stephan; Fakhraai, Zahra

    2015-05-04

    Near-field enhancement of the electric field by metallic nanostructures is important in non-linear optical applications such as surface enhanced Raman scattering. One approach to producing strong localization of the electric field is to couple a dark, non-radiating plasmonic mode with a broad dipolar resonator that is detectable in the far-field. However, characterizing or predicting the degree of the coupling between these modes for a complicated nanostructure can be quite challenging. Here we develop a robust method to solve the T-matrix, the matrix that predicts the scattered electric fields of the incident light, based on finite-difference time-domain (FDTD) simulations and least square fitting algorithms. This method allows us to simultaneously calculate the T-matrix for a broad spectral range. Using this method, the coupling between the electric dipole and quadrupole modes of spiky nanoshells is evaluated. It is shown that the built-in disorder in the structure of these nanoshells allows for coupling between the dipole modes of various orientations as well as coupling between the dipole and the quadrupole modes. A coupling strength of about 5% between these modes can explain the apparent interference features observed in the single particle scattering spectrum. This effect is experimentally verified by single particle backscattering measurements of spiky nanoshells. The modal interference in disordered spiky nanoshells can explain the origin of the spectrally broad quadrupole resonances that result in strong Quadrupole Enhanced Raman Scattering (QERS) in these nanoparticles.

  12. Motor interference in interactive contexts

    Directory of Open Access Journals (Sweden)

    Eris eChinellato

    2015-06-01

    Full Text Available Action observation and execution share overlapping neural substrates, so that simultaneous activation by observation and execution modulates motor performance. Previous literature on simple prehension tasks has revealed that motor influence can be two-sided: facilitation for observed and performed congruent actions and interference for incongruent actions. But little is known of the specific modulations of motor performance in complex forms of interaction. Is it possible that the very same observed movement can lead either to interference or facilitation effects on a temporally overlapping congruent executed action, depending on the context? To answer this question participants were asked to perform a reach-to-grasp movement adopting a precision grip (PG while: (i observing a fixation cross, (ii observing an actor performing a PG with interactive purposes, (iii observing an actor performing a PG without interactive purposes. In particular, in the interactive condition the actor was shown trying to pour some sugar on a large cup located out of her reach but close to the participant watching the video, thus eliciting in reaction a complementary whole-hand grasp. Notably, fine-grained kinematic analysis for this condition revealed a specific delay in the grasping and reaching components and an increased trajectory deviation despite the observed and executed movement’s congruency. Moreover, early peaks of trajectory deviation seem to indicate that socially relevant stimuli are acknowledged by the motor system very early. These data suggest that interactive contexts can determine a prompt modulation of stimulus–response compatibility effects.

  13. Adaptive divergence despite strong genetic drift: genomic analysis of the evolutionary mechanisms causing genetic differentiation in the island fox (Urocyon littoralis).

    Science.gov (United States)

    Funk, W Chris; Lovich, Robert E; Hohenlohe, Paul A; Hofman, Courtney A; Morrison, Scott A; Sillett, T Scott; Ghalambor, Cameron K; Maldonado, Jesus E; Rick, Torben C; Day, Mitch D; Polato, Nicholas R; Fitzpatrick, Sarah W; Coonan, Timothy J; Crooks, Kevin R; Dillon, Adam; Garcelon, David K; King, Julie L; Boser, Christina L; Gould, Nicholas; Andelt, William F

    2016-05-01

    The evolutionary mechanisms generating the tremendous biodiversity of islands have long fascinated evolutionary biologists. Genetic drift and divergent selection are predicted to be strong on islands and both could drive population divergence and speciation. Alternatively, strong genetic drift may preclude adaptation. We conducted a genomic analysis to test the roles of genetic drift and divergent selection in causing genetic differentiation among populations of the island fox (Urocyon littoralis). This species consists of six subspecies, each of which occupies a different California Channel Island. Analysis of 5293 SNP loci generated using Restriction-site Associated DNA (RAD) sequencing found support for genetic drift as the dominant evolutionary mechanism driving population divergence among island fox populations. In particular, populations had exceptionally low genetic variation, small Ne (range = 2.1-89.7; median = 19.4), and significant genetic signatures of bottlenecks. Moreover, islands with the lowest genetic variation (and, by inference, the strongest historical genetic drift) were most genetically differentiated from mainland grey foxes, and vice versa, indicating genetic drift drives genome-wide divergence. Nonetheless, outlier tests identified 3.6-6.6% of loci as high FST outliers, suggesting that despite strong genetic drift, divergent selection contributes to population divergence. Patterns of similarity among populations based on high FST outliers mirrored patterns based on morphology, providing additional evidence that outliers reflect adaptive divergence. Extremely low genetic variation and small Ne in some island fox populations, particularly on San Nicolas Island, suggest that they may be vulnerable to fixation of deleterious alleles, decreased fitness and reduced adaptive potential.

  14. RNA interference as a gene knockdown technique.

    Science.gov (United States)

    Shan, Ge

    2010-08-01

    Not many scientific breakthroughs bring significant advances simultaneously in both basic research and translational applications like the discovery of RNA interference. Along with the elucidation of the RNA interference pathway and the discovery of its participation in crucial biological events, a branch of science has grown to utilize the RNA interference pathway as a biotechnology for both basic and applied research. Small interference RNA, plasmid-, and virus-encoded short-hairpin RNA are now regular reagents in the tool box of biologists to knockdown the expression of specific genes posttranscriptionally. Efforts have also been made to develop RNA interference based therapeutics into reality. Many concerns about the RNA interference technique have now been answered through research and development, although hurdles are still present. In this review, the RNA interference/microRNA pathway is briefly introduced followed with a detailed summary about the design and application of the RNA interference experiments, along with examples of the utilization of the RNA interference technology in animal cells and model organisms. Recent progresses and current concerns are also highlighted. Two techniques, namely morpholino and external guide sequence, are discussed as complementary gene knockdown technology. RNA interference technology, along with several other alternative gene knockdown techniques, is now indispensable to modern biological and medical research.

  15. Cognitive declines in healthy aging: evidence from multiple aspects of interference resolution.

    Science.gov (United States)

    Pettigrew, Corinne; Martin, Randi C

    2014-06-01

    The present study tested the hypothesis that older adults show age-related deficits in interference resolution, also referred to as inhibitory control. Although oftentimes considered as a unitary aspect of executive function, various lines of work support the notion that interference resolution may be better understood as multiple constructs, including resistance to proactive interference (PI) and response-distractor inhibition (e.g., Friedman & Miyake, 2004). Using this dichotomy, the present study assessed whether older adults (relative to younger adults) show impaired performance across both, 1, or neither of these interference resolution constructs. To do so, we used multiple tasks to tap each construct and examined age effects at both the single task and latent variable levels. Older adults consistently demonstrated exaggerated interference effects across resistance to PI tasks. Although the results for the response-distractor inhibition tasks were less consistent at the individual task level analyses, age effects were evident on multiple tasks, as well as at the latent variable level. However, results of the latent variable modeling suggested declines in interference resolution are best explained by variance that is common to the 2 interference resolution constructs measured herein. Furthermore, the effect of age on interference resolution was found to be both distinct from declines in working memory, and independent of processing speed. These findings suggest multiple cognitive domains are independently sensitive to age, but that declines in the interference resolution constructs measured herein may originate from a common cause.

  16. On the Symmetric Feedback Capacity of the K-user Cyclic Z-Interference Channel

    CERN Document Server

    Tandon, Ravi; Poor, H Vincent

    2011-01-01

    The K-user cyclic Z-interference channel models a situation in which the kth transmitter causes interference only to the (k-1)th receiver in a cyclic manner, i.e., the first transmitter causes interference only to the Kth receiver. The impact of noiseless feedback on the capacity of this channel is studied by focusing on the Gaussian cyclic Z-interference channel. To this end, the symmetric feedback capacity of the linear shift deterministic cyclic Z-interference channel (LD-CZIC) is completely characterized for all interference regimes. Using insights from the linear deterministic channel model, the symmetric feedback capacity of the Gaussian cyclic Z-interference channel is characterized up to within a constant number of bits. As a byproduct of the constant gap result, the symmetric degrees of freedom with feedback for the Gaussian cyclic Z-interference channel are also characterized. These results highlight that the symmetric feedback capacities for both linear and Gaussian channel models are in general fu...

  17. Neurotoxic mechanisms caused by the Alzheimer's disease-linked Swedish amyloid precursor protein mutation: oxidative stress, caspases, and the JNK pathway.

    Science.gov (United States)

    Marques, Celio A; Keil, Uta; Bonert, Astrid; Steiner, Barbara; Haass, Christian; Muller, Walter E; Eckert, Anne

    2003-07-25

    Autosomal dominant forms of familial Alzheimer's disease (FAD) are caused by mutations of the amyloid precursor protein (APP) gene and by mutations of the genes encoding for presenilin 1 or presenilin 2. Simultaneously, evidence is provided that increased oxidative stress might play a crucial role in the rapid progression of the Swedish FAD. Here we investigated the effect of the Swedish double mutation (K670M/N671L) in the beta-amyloid precursor protein on oxidative stress-induced cell death mechanisms in PC12 cells. Western blot analysis and cleavage studies of caspase substrates revealed an elevated activity of the executor caspase 3 after treatment with hydrogen peroxide in cells containing the Swedish APP mutation. This elevated activity is the result of the enhanced activation of both intrinsic and extrinsic apoptosis pathways, including activation of caspase 2 and caspase 8. Furthermore, we observed an enhanced activation of JNK pathway and an attenuation of apoptosis by SP600125, a JNK inhibitor, through protection of mitochondrial dysfunction and reduction of caspase 9 activity. Our findings provide evidence that the massive neurodegeneration in early age of FAD patients could be a result of an increased vulnerability of neurons through activation of different apoptotic pathways as a consequence of elevated levels of oxidative stress.

  18. Fusion of nearby inverted repeats by a replication-based mechanism leads to formation of dicentric and acentric chromosomes that cause genome instability in budding yeast.

    Science.gov (United States)

    Paek, Andrew L; Kaochar, Salma; Jones, Hope; Elezaby, Aly; Shanks, Lisa; Weinert, Ted

    2009-12-15

    Large-scale changes (gross chromosomal rearrangements [GCRs]) are common in genomes, and are often associated with pathological disorders. We report here that a specific pair of nearby inverted repeats in budding yeast fuse to form a dicentric chromosome intermediate, which then rearranges to form a translocation and other GCRs. We next show that fusion of nearby inverted repeats is general; we found that many nearby inverted repeats that are present in the yeast genome also fuse, as does a pair of synthetically constructed inverted repeats. Fusion occurs between inverted repeats that are separated by several kilobases of DNA and share >20 base pairs of homology. Finally, we show that fusion of inverted repeats, surprisingly, does not require genes involved in double-strand break (DSB) repair or genes involved in other repeat recombination events. We therefore propose that fusion may occur by a DSB-independent, DNA replication-based mechanism (which we term "faulty template switching"). Fusion of nearby inverted repeats to form dicentrics may be a major cause of instability in yeast and in other organisms.

  19. Brd2 gene disruption causes "metabolically healthy" obesity: epigenetic and chromatin-based mechanisms that uncouple obesity from type 2 diabetes.

    Science.gov (United States)

    Wang, Fangnian; Deeney, Jude T; Denis, Gerald V

    2013-01-01

    Disturbed body energy balance can lead to obesity and obesity-driven diseases such as Type 2 diabetes, which have reached an epidemic level. Evidence indicates that obesity-induced inflammation is a major cause of insulin resistance and Type 2 diabetes. Environmental factors, such as nutrients, affect body energy balance through epigenetic or chromatin-based mechanisms. As a bromodomain and external domain family transcription regulator, Brd2 regulates expression of many genes through interpretation of chromatin codes and participates in the regulation of body energy balance and immune function. In the severely obese state, Brd2 knockdown in mice prevented obesity-induced inflammatory responses, protected animals from insulin resistance, glucose intolerance and pancreatic beta cell dysfunction, and thus uncoupled obesity from diabetes. Brd2 provides an important model for investigation of the function of transcription regulators and the development of obesity and diabetes; it also provides a possible, innovative target to treat obesity and diabetes through modulation of the function of a chromatin code reader. Copyright © 2013 Elsevier Inc. All rights reserved.

  20. Pulse Tube Interference in Cryogenic Sensor Resonant Circuits - Final Paper

    Energy Technology Data Exchange (ETDEWEB)

    Lam, Tyler [SLAC National Accelerator Lab., Menlo Park, CA (United States)

    2015-08-27

    Transition edge sensors (TES) are extremely sensitive superconducting sensors, operating at 100 mK, which can be used to detect X-rays and Cosmic Microwave Background. The goal of our project is to design the electronics to read out an array of 10000 of these sensors by using microwave signals. However, we noticed the pulse tube used to maintain cryogenic temperatures caused interference in our readout. To determine the cause of the signal distortions, we used a detector with a 370 MHz sampling rate to collect and analyze sensor data. Although this data provided little information towards the nature of the noise, it was determined through a maintenance procedure than the 0.3 mm stainless steel wires were being vibrated due to acoustic waves, which distorted the signal. Replacing this wire appeared to cease the interference from the sensor data.