Radiolabeled red blood cells: status, problems, and prospects

International Nuclear Information System (INIS)

Srivastava, S.C.

1983-01-01

Radionuclidic labels for red cells can be divided into two main categories - cohort or pulse labels, and random labels. The random labels are incorporated into circulating cells of all ages and the labeling process is usually carried out in vitro. The red cell labels in predominant use involve random labeling and employ technetium-99m, chromium-51, indium-111, and gallium-68, roughly in that order. The extent of usefulness depends on the properties of the label such as the half-life, decay mode, and in-vivo stability, etc. Labeled cells can be used for red cell survival measurements when the half-life of the radionuclide is sufficiently long. The major portion of this article deals with random labels

Clustering Single-Cell Expression Data Using Random Forest Graphs.

Science.gov (United States)

Pouyan, Maziyar Baran; Nourani, Mehrdad

2017-07-01

Complex tissues such as brain and bone marrow are made up of multiple cell types. As the study of biological tissue structure progresses, the role of cell-type-specific research becomes increasingly important. Novel sequencing technology such as single-cell cytometry provides researchers access to valuable biological data. Applying machine-learning techniques to these high-throughput datasets provides deep insights into the cellular landscape of the tissue where those cells are a part of. In this paper, we propose the use of random-forest-based single-cell profiling, a new machine-learning-based technique, to profile different cell types of intricate tissues using single-cell cytometry data. Our technique utilizes random forests to capture cell marker dependences and model the cellular populations using the cell network concept. This cellular network helps us discover what cell types are in the tissue. Our experimental results on public-domain datasets indicate promising performance and accuracy of our technique in extracting cell populations of complex tissues.

DNA synthesis and cell survival after X-irradiation of mammalian cells treated with caffeine or adenine

International Nuclear Information System (INIS)

Griffiths, T.D.; Carpenter, J.G.; Dahle, D.B.

1978-01-01

The expression of the transient depression in the rate of DNA synthesis normally observed after exposure of randomly-dividing Chinese hamster V-79 or Chinese hamster CHO cells to ionizing radiation could be postponed by a post-irradiation treatment with 1.0 to 2.0 mM adenine or 1.5 mM caffeine. Caffeine may exert its effect by creating additional sites for replication in irradiated cells. Cells treated with caffeine or adenine for 2 or 4 hours after exposure to 3000 rad of 300 kVp X-rays exhibited depressed synthesis only after the removal of caffeine or adenine. These alterations in the timing of the X-ray-induced depression of the rate of DNA synthesis had no effect on X-ray-induced cell killing. Although a 4 hour post-irradiation treatment of randomly-dividing Chinese hamster V-79 cells with 1.0 or 2.0 mM caffeine potentiated X-ray-induced cell killing, this reduction in survival was due primarily to effects on cells not in S-phase. (author)

A note on crossing the phantom divide in hybrid dark energy model

International Nuclear Information System (INIS)

Wei Hao; Cai Ronggen

2006-01-01

Recently a lot of attention has been given to building dark energy models in which the equation-of-state parameter w can cross the phantom divide w=-1. However, to our knowledge, these models with crossing the phantom divide only provide the possibility that w can cross -1. They do not answer another question: why crossing phantom divide occurs recently? Since in many existing models whose equation-of-state parameter can cross the phantom divide, w undulates around -1 randomly, why are we living in an epochw<-1? This can be regarded as the second cosmological coincidence problem. In this Letter, we propose a possible approach to alleviate this problem within a hybrid dark energy model

The effect of divided attention on false memory depends on how memory is tested.

OpenAIRE

Dewhurst, Stephen A.; Barry, Christopher; Swannell, Ellen R.; Holmes, Selina J.; Bathurst, Gemma J.

2007-01-01

In three experiments, we investigated the effects of divided attention on false memory, using the Deese/Roediger-McDermott (DRM) paradigm. In Experiments 1 and 2, participants studied six DRM lists with full attention and six in one of two divided-attention conditions (random number generation or digit monitoring). Both divided-attention conditions increased false recall of related words (Experiment 1) but reduced false recognition (Experiment 2). These results were confirmed in Experiment 3,...

Strength-balance supplemented with computerized cognitive training to improve dual task gait and divided attention in older adults: a multicenter randomized-controlled trial.

Science.gov (United States)

van het Reve, Eva; de Bruin, Eling D

2014-12-15

Exercise interventions often do not combine physical and cognitive training. However, this combination is assumed to be more beneficial in improving walking and cognitive functioning compared to isolated cognitive or physical training. A multicenter parallel randomized controlled trial was conducted to compare a motor to a cognitive-motor exercise program. A total of 182 eligible residents of homes-for-the-aged (n = 159) or elderly living in the vicinity of the homes (n = 23) were randomly assigned to either strength-balance (SB) or strength-balance-cognitive (SBC) training. Both groups conducted similar strength-balance training during 12 weeks. SBC additionally absolved computerized cognitive training. Outcomes were dual task costs of walking, physical performance, simple reaction time, executive functions, divided attention, fear of falling and fall rate. Participants were analysed with an intention to treat approach. The 182 participants (mean age ± SD: 81.5 ± 7.3 years) were allocated to either SB (n = 98) or SBC (n = 84). The attrition rate was 14.3%. Interaction effects were observed for dual task costs of step length (preferred walking speed: F(1,174) = 4.94, p = 0.028, η2 = 0.027, fast walking speed: F(1,166) = 6.14, p = 0.009, η2 = 0.040) and dual task costs of the standard deviation of step length (F(1,166) = 6.14, p = 0.014, η2 = 0.036), in favor of SBC. Significant interactions in favor of SBC revealed for in gait initiation (F(1,166) = 9.16, p = 0.003, η2 = 0.052), 'reaction time' (F(1,180) = 5.243, p = 0.023, η² = 0.028) & 'missed answers' (F(1,180) = 11.839, p = 0.001, η² = 0.062) as part of the test for divided attention. Within-group comparison revealed significant improvements in dual task costs of walking (preferred speed; velocity (p = 0.002), step time (p = 0.018), step length (p = 0.028), fast speed; velocity (p divided

TRAPping telomerase within the intestinal stem cell niche

OpenAIRE

Pech, Matthew F; Artandi, Steven E

2011-01-01

Recent work from Hans Clevers' lab reveals high telomerase activity and telomere length in dividing LGR5-positive intestinal stem cells. They further report random chromosome segregation and thus challenge the ‘immortal strand' hypothesis at least for this stem cell population.

Migratory divides and their consequences for dispersal, population size and parasite-host interactions.

Science.gov (United States)

Møller, A P; Garamszegi, L Z; Peralta-Sánchez, J M; Soler, J J

2011-08-01

Populations of migratory birds differ in their direction of migration with neighbouring populations often migrating in divergent directions separated by migratory divides. A total of 26% of 103 passerine bird species in Europe had migratory divides that were located disproportionately often along a longitudinal gradient in Central Europe, consistent with the assumption of a Quaternary glacial origin of such divides in the Iberian and Balkan peninsulas followed by recolonization. Given that studies have shown significant genetic differentiation and reduced gene flow across migratory divides, we hypothesized that an absence of migratory divides would result in elevated rates of gene flow and hence a reduced level of local adaptation. In a comparative study, species with migratory divides had larger population sizes and population densities and longer dispersal distances than species without migratory divides. Species with migratory divides tended to be habitat generalists. Bird species with migratory divides had higher richness of blood parasites and higher growth rates of Staphylococcus on their eggs during the incubation period. There was weaker cell-mediated immunity in adults and stronger cell lysis in species with migratory divides. These findings may suggest that migratory divides constitute barriers to dispersal with consequences for ecology and evolution of distributions, population sizes, habitats and parasite-host interactions. They also suggest that migratory divides may play a role in local adaptation in host-parasite interactions. © 2011 The Authors. Journal of Evolutionary Biology © 2011 European Society For Evolutionary Biology.

An autoradiographic study of the synthesis of nucleic acids and protein during the cell cycle of synchronously dividing antheridial filaments in Chara vulgaris L

Energy Technology Data Exchange (ETDEWEB)

Olszewska, M J; Godlewski, M [Lodz Univ. (Poland)

1972-01-01

The synthesis of DNA, RNA, and protein in successive mitotic cycles of the synchronously dividing antheridial filaments of Chara vulgaris was studied autoradiographically. In all the generations examined, which enter the next mitosis, i.e., in the 4-, 8-, 16-, and 32-cell generations, the synthesis of DNA begins as early as telephase and continues into the early stages of interphase. The telephase cells of the 32-cell filaments do not incorporate //sup 3/H/thymidine, because the cells which arise from them do not divide but are transformed into spermatozoa. The DNA synthesis is accompanied by intense synthesis of RNA. The intensity of radioactivity calculated for 100 ..mu../sup 2/ of the area of the nucleus and cytoplasm is similar in all the generations, whereas the radioactivity induced by the incorporation of /8-/sup 14/C/adenine and//sup 3/H/phenylalanine calculated for one cell decreases proportionally to the reduction of the volume of the cytoplasm and nucleus in successive generations. (auth)

High incidence of non-random template strand segregation and asymmetric fate determination in dividing stem cells and their progeny.

Science.gov (United States)

Conboy, Michael J; Karasov, Ariela O; Rando, Thomas A

2007-05-01

Decades ago, the "immortal strand hypothesis" was proposed as a means by which stem cells might limit acquiring mutations that could give rise to cancer, while continuing to proliferate for the life of an organism. Originally based on observations in embryonic cells, and later studied in terms of stem cell self-renewal, this hypothesis has remained largely unaccepted because of few additional reports, the rarity of the cells displaying template strand segregation, and alternative interpretations of experiments involving single labels or different types of labels to follow template strands. Using sequential pulses of halogenated thymidine analogs (bromodeoxyuridine [BrdU], chlorodeoxyuridine [CldU], and iododeoxyuridine [IdU]), and analyzing stem cell progeny during induced regeneration in vivo, we observed extraordinarily high frequencies of segregation of older and younger template strands during a period of proliferative expansion of muscle stem cells. Furthermore, template strand co-segregation was strongly associated with asymmetric cell divisions yielding daughters with divergent fates. Daughter cells inheriting the older templates retained the more immature phenotype, whereas daughters inheriting the newer templates acquired a more differentiated phenotype. These data provide compelling evidence of template strand co-segregation based on template age and associated with cell fate determination, suggest that template strand age is monitored during stem cell lineage progression, and raise important caveats for the interpretation of label-retaining cells.

High incidence of non-random template strand segregation and asymmetric fate determination in dividing stem cells and their progeny.

Directory of Open Access Journals (Sweden)

Michael J Conboy

2007-05-01

Full Text Available Decades ago, the "immortal strand hypothesis" was proposed as a means by which stem cells might limit acquiring mutations that could give rise to cancer, while continuing to proliferate for the life of an organism. Originally based on observations in embryonic cells, and later studied in terms of stem cell self-renewal, this hypothesis has remained largely unaccepted because of few additional reports, the rarity of the cells displaying template strand segregation, and alternative interpretations of experiments involving single labels or different types of labels to follow template strands. Using sequential pulses of halogenated thymidine analogs (bromodeoxyuridine [BrdU], chlorodeoxyuridine [CldU], and iododeoxyuridine [IdU], and analyzing stem cell progeny during induced regeneration in vivo, we observed extraordinarily high frequencies of segregation of older and younger template strands during a period of proliferative expansion of muscle stem cells. Furthermore, template strand co-segregation was strongly associated with asymmetric cell divisions yielding daughters with divergent fates. Daughter cells inheriting the older templates retained the more immature phenotype, whereas daughters inheriting the newer templates acquired a more differentiated phenotype. These data provide compelling evidence of template strand co-segregation based on template age and associated with cell fate determination, suggest that template strand age is monitored during stem cell lineage progression, and raise important caveats for the interpretation of label-retaining cells.

The Zebrafish Anillin-eGFP Reporter Marks Late Dividing Retinal Precursors and Stem Cells Entering Neuronal Lineages.

Directory of Open Access Journals (Sweden)

Meret Cepero Malo

Full Text Available Monitoring cycling behaviours of stem and somatic cells in the living animal is a powerful tool to better understand tissue development and homeostasis. The tg(anillin:anillin-eGFP transgenic line carries the full-length zebrafish F-actin binding protein Anillin fused to eGFP from a bacterial artificial chromosome (BAC containing Anillin cis-regulatory sequences. Here we report the suitability of the Anillin-eGFP reporter as a direct indicator of cycling cells in the late embryonic and post-embryonic retina. We show that combining the anillin:anillin-eGFP with other transgenes such as ptf1a:dsRed and atoh7:gap-RFP allows obtaining spatial and temporal resolution of the mitotic potentials of specific retinal cell populations. This is exemplified by the analysis of the origin of the previously reported apically and non-apically dividing late committed precursors of the photoreceptor and horizontal cell layers.

Expanding the potential of NAI-107 for treating serious ESKAPE pathogens: synergistic combinations against Gram-negatives and bactericidal activity against non-dividing cells.

Science.gov (United States)

Brunati, Cristina; Thomsen, Thomas T; Gaspari, Eleonora; Maffioli, Sonia; Sosio, Margherita; Jabes, Daniela; Løbner-Olesen, Anders; Donadio, Stefano

2018-02-01

To characterize NAI-107 and related lantibiotics for their in vitro activity against Gram-negative pathogens, alone or in combination with polymyxin, and against non-dividing cells or biofilms of Staphylococcus aureus. NAI-107 was also evaluated for its propensity to select or induce self-resistance in Gram-positive bacteria. We used MIC determinations and chequerboard experiments to establish the antibacterial activity of the examined compounds against target microorganisms. Time-kill assays were used to evaluate killing of exponential and stationary-phase cells. The effects on biofilms (growth inhibition and biofilm eradication) were evaluated using biofilm-coated pegs. The frequency of spontaneous resistant mutants was evaluated by either direct plating or by continuous sub-culturing at 0.5 × MIC levels, followed by population analysis profiles. The results showed that NAI-107 and its brominated variant are highly active against Neisseria gonorrhoeae and some other fastidious Gram-negative pathogens. Furthermore, all compounds strongly synergized with polymyxin against Acinetobacter baumannii, Escherichia coli, Klebsiella pneumoniae and Pseudomonas aeruginosa, and showed bactericidal activity. Surprisingly, NAI-107 alone was bactericidal against non-dividing A. baumannii cells. Against S. aureus, NAI-107 and related lantibiotics showed strong bactericidal activity against dividing and non-dividing cells. Activity was also observed against S. aureus biofilms. As expected for a lipid II binder, no significant resistance to NAI-107 was observed by direct plating or serial passages. Overall, the results of the current work, along with previously published results on the efficacy of NAI-107 in experimental models of infection, indicate that this lantibiotic represents a promising option in addressing the serious threat of antibiotic resistance. © The Author 2017. Published by Oxford University Press on behalf of the British Society for Antimicrobial

First unitary, then divided: the temporal dynamics of dividing attention.

Science.gov (United States)

Jefferies, Lisa N; Witt, Joseph B

2018-04-24

Whether focused visual attention can be divided has been the topic of much investigation, and there is a compelling body of evidence showing that, at least under certain conditions, attention can be divided and deployed as two independent foci. Three experiments were conducted to examine whether attention can be deployed in divided form from the outset, or whether it is first deployed as a unitary focus before being divided. To test this, we adapted the methodology of Jefferies, Enns, and Di Lollo (Journal of Experimental Psychology: Human Perception and Performance 40: 465, 2014), who used a dual-stream Attentional Blink paradigm and two letter-pair targets. One aspect of the AB, Lag-1 sparing, has been shown to occur only if the second target pair appears within the focus of attention. By presenting the second target pair at various spatial locations and assessing the magnitude of Lag-1 sparing, we probed the spatial distribution of attention. By systematically manipulating the stimulus-onset-asynchrony between the targets, we also tracked changes to the spatial distribution of attention over time. The results showed that even under conditions which encourage the division of attention, the attentional focus is first deployed in unitary form before being divided. It is then maintained in divided form only briefly before settling on a single location.

Why do bacteria divide?

Science.gov (United States)

Norris, Vic

2015-01-01

The problem of not only how but also why cells divide can be tackled using recent ideas. One idea from the origins of life – Life as independent of its constituents – is that a living entity like a cell is a particular pattern of connectivity between its constituents. This means that if the growing cell were just to get bigger the average connectivity between its constituents per unit mass – its cellular connectivity – would decrease and the cell would lose its identity. The solution is division which restores connectivity. The corollary is that the cell senses decreasing cellular connectivity and uses this information to trigger division. A second idea from phenotypic diversity – Life on the Scales of Equilibria – is that a bacterium must find strategies that allow it to both survive and grow. This means that it has learnt to reconcile the opposing constraints that these strategies impose. The solution is that the cell cycle generates daughter cells with different phenotypes based on sufficiently complex equilibrium (E) and non-equilibrium (NE) cellular compounds and structures appropriate for survival and growth, respectively, alias ‘hyperstructures.’ The corollary is that the cell senses both the quantity of E material and the intensity of use of NE material and then uses this information to trigger the cell cycle. A third idea from artificial intelligence – Competitive Coherence – is that a cell selects the active subset of elements that actively determine its phenotype from a much larger set of available elements. This means that the selection of an active subset of a specific size and composition must be done so as to generate both a coherent cell state, in which the cell’s contents work together harmoniously, and a coherent sequence of cell states, each coherent with respect to itself and to an unpredictable environment. The solution is the use of a range of mechanisms ranging from hyperstructure dynamics to the cell cycle itself. PMID

Conquering the digital divide: Botswana and South Korea digital divide status and interventions

Directory of Open Access Journals (Sweden)

Nonofo C. Sedimo

2011-11-01

Objectives: Bridging the digital divide and narrowing the intra-national divide brings about global information and communication technology (ICT usage that translates into changing work patterns and eventually transformed economies. This article outlines the different interventions implemented in Botswana to bridge the divide. The South Korean experience in bridging the divide is discussed so as to serve as lessons on how to effectively bridge the divide to Botswana’s initiatives. Method: Using a mix of exploratory and empirical study, this article presents the findings on the status of ICT uptake in Botswana and investigates the level of the digital divide in the country. Results: The results of the study show that the digital divide is much more evident in Botswana than in South Korea. South Korea has put in place robust strategic initiatives towards reducing the digital divide and this has largely transcended into its transformation into a full-fledged knowledge society. Conclusion: This article is timely as it unearths the different pointers that may be utilised in policy formation and what interventions need to be taken at both the individual and national level to bridge the digital divide.

Human mammary epithelial cells exhibit a bimodal correlated random walk pattern.

Science.gov (United States)

Potdar, Alka A; Jeon, Junhwan; Weaver, Alissa M; Quaranta, Vito; Cummings, Peter T

2010-03-10

Organisms, at scales ranging from unicellular to mammals, have been known to exhibit foraging behavior described by random walks whose segments confirm to Lévy or exponential distributions. For the first time, we present evidence that single cells (mammary epithelial cells) that exist in multi-cellular organisms (humans) follow a bimodal correlated random walk (BCRW). Cellular tracks of MCF-10A pBabe, neuN and neuT random migration on 2-D plastic substrates, analyzed using bimodal analysis, were found to reveal the BCRW pattern. We find two types of exponentially distributed correlated flights (corresponding to what we refer to as the directional and re-orientation phases) each having its own correlation between move step-lengths within flights. The exponential distribution of flight lengths was confirmed using different analysis methods (logarithmic binning with normalization, survival frequency plots and maximum likelihood estimation). Because of the presence of non-uniform turn angle distribution of move step-lengths within a flight and two different types of flights, we propose that the epithelial random walk is a BCRW comprising of two alternating modes with varying degree of correlations, rather than a simple persistent random walk. A BCRW model rather than a simple persistent random walk correctly matches the super-diffusivity in the cell migration paths as indicated by simulations based on the BCRW model.

Human mammary epithelial cells exhibit a bimodal correlated random walk pattern.

Directory of Open Access Journals (Sweden)

Alka A Potdar

2010-03-01

Full Text Available Organisms, at scales ranging from unicellular to mammals, have been known to exhibit foraging behavior described by random walks whose segments confirm to Lévy or exponential distributions. For the first time, we present evidence that single cells (mammary epithelial cells that exist in multi-cellular organisms (humans follow a bimodal correlated random walk (BCRW.Cellular tracks of MCF-10A pBabe, neuN and neuT random migration on 2-D plastic substrates, analyzed using bimodal analysis, were found to reveal the BCRW pattern. We find two types of exponentially distributed correlated flights (corresponding to what we refer to as the directional and re-orientation phases each having its own correlation between move step-lengths within flights. The exponential distribution of flight lengths was confirmed using different analysis methods (logarithmic binning with normalization, survival frequency plots and maximum likelihood estimation.Because of the presence of non-uniform turn angle distribution of move step-lengths within a flight and two different types of flights, we propose that the epithelial random walk is a BCRW comprising of two alternating modes with varying degree of correlations, rather than a simple persistent random walk. A BCRW model rather than a simple persistent random walk correctly matches the super-diffusivity in the cell migration paths as indicated by simulations based on the BCRW model.

Autocatalytic polymerization generates persistent random walk of crawling cells.

Science.gov (United States)

Sambeth, R; Baumgaertner, A

2001-05-28

The autocatalytic polymerization kinetics of the cytoskeletal actin network provides the basic mechanism for a persistent random walk of a crawling cell. It is shown that network remodeling by branching processes near the cell membrane is essential for the bimodal spatial stability of the network which induces a spontaneous breaking of isotropic cell motion. Details of the phenomena are analyzed using a simple polymerization model studied by analytical and simulation methods.

Continental Divide Trail

Data.gov (United States)

Earth Data Analysis Center, University of New Mexico — This shapefile was created to show the proximity of the Continental Divide to the Continental Divide National Scenic Trail in New Mexico. This work was done as part...

Effect of disorder on condensation in the lattice gas model on a random graph.

Science.gov (United States)

Handford, Thomas P; Dear, Alexander; Pérez-Reche, Francisco J; Taraskin, Sergei N

2014-07-01

The lattice gas model of condensation in a heterogeneous pore system, represented by a random graph of cells, is studied using an exact analytical solution. A binary mixture of pore cells with different coordination numbers is shown to exhibit two phase transitions as a function of chemical potential in a certain temperature range. Heterogeneity in interaction strengths is demonstrated to reduce the critical temperature and, for large-enough degreeS of disorder, divides the cells into ones which are either on average occupied or unoccupied. Despite treating the pore space loops in a simplified manner, the random-graph model provides a good description of condensation in porous structures containing loops. This is illustrated by considering capillary condensation in a structural model of mesoporous silica SBA-15.

International Divider Walls

NARCIS (Netherlands)

Kruis, A.; Sneller, Lineke

2013-01-01

The subject of this teaching case is the Enterprise Resource Planning (ERP) system implementation at International Divider Walls, the world market leader in design, production, and sales of divider walls. The implementation in one of the divisions of this multinational company had been successful,

Reimplantation of cultivated human bone cells from the posterior maxilla for sinus floor augmentation. Histological results from a randomized controlled clinical trial

DEFF Research Database (Denmark)

Hermund, N.U.; Stavropoulos, Andreas; Donatsky, O

2012-01-01

OBJECTIVES: The aim of the present randomized clinical study was to evaluate histologically whether the addition of cultivated, autogenous bone cells to a composite graft of deproteinized bovine bone mineral (DBBM) and autogenous bone (AB) for sinus floor augmentation (SFA) enhance bone formation...... bone cells, which were cultivated from a bone biopsy harvested earlier from the tuberosity area. Four months after SFA, two cylindrical biopsies were taken from the augmented sinuses concomitantly with the implant site preparation by means of a trephine bur. An additional biopsy was taken from...... the tuberosity area. Bone density at the augmented sinus and the tuberosity area and the height of augmentation were estimated on non-decalcified histological sections prepared from the biopsies. A relative bone density index (RBD) was also calculated by dividing bone density at the augmented sinus with bone...

Cell Division and Evolution of Biological Tissues

Science.gov (United States)

Rivier, Nicolas; Arcenegui-Siemens, Xavier; Schliecker, Gudrun

A tissue is a geometrical, space-filling, random cellular network; it remains in this steady state while individual cells divide. Cell division (fragmentation) is a local, elementary topological transformation which establishes statistical equilibrium of the structure. Statistical equilibrium is characterized by observable relations (Lewis, Aboav) between cell shapes, sizes and those of their neighbours, obtained through maximum entropy and topological correlation extending to nearest neighbours only, i.e. maximal randomness. For a two-dimensional tissue (epithelium), the distribution of cell shapes and that of mother and daughter cells can be obtained from elementary geometrical and physical arguments, except for an exponential factor favouring division of larger cells, and exponential and combinatorial factors encouraging a most symmetric division. The resulting distributions are very narrow, and stationarity severely restricts the range of an adjustable structural parameter

Newly divided eosinophils limit ozone-induced airway hyperreactivity in nonsensitized guinea pigs.

Science.gov (United States)

Wicher, Sarah A; Jacoby, David B; Fryer, Allison D

2017-06-01

Ozone causes vagally mediated airway hyperreactivity and recruits inflammatory cells, including eosinophils, to lungs, where they mediate ozone-induced hyperreactivity 1 day after exposure but are paradoxically protective 3 days later. We aimed to test the role of newly divided eosinophils in ozone-induced airway hyperreactivity in sensitized and nonsensitized guinea pigs. Nonsensitized and sensitized guinea pigs were treated with 5-bromo-2-deoxyuridine (BrdU) to label newly divided cells and were exposed to air or ozone for 4 h. Later (1 or 3 days later), vagally induced bronchoconstriction was measured, and inflammatory cells were harvested from bone marrow, blood, and bronchoalveolar lavage. Ozone induced eosinophil hematopoiesis. One day after ozone, mature eosinophils dominate the inflammatory response and potentiate vagally induced bronchoconstriction. However, by 3 days, newly divided eosinophils have reached the lungs, where they inhibit ozone-induced airway hyperreactivity because depleting them with antibody to IL-5 or a TNF-α antagonist worsened vagally induced bronchoconstriction. In sensitized guinea pigs, both ozone-induced eosinophil hematopoiesis and subsequent recruitment of newly divided eosinophils to lungs 3 days later failed to occur. Thus mature eosinophils dominated the ozone-induced inflammatory response in sensitized guinea pigs. Depleting these mature eosinophils prevented ozone-induced airway hyperreactivity in sensitized animals. Ozone induces eosinophil hematopoiesis and recruitment to lungs, where 3 days later, newly divided eosinophils attenuate vagally mediated hyperreactivity. Ozone-induced hematopoiesis of beneficial eosinophils is blocked by a TNF-α antagonist or by prior sensitization. In these animals, mature eosinophils are associated with hyperreactivity. Thus interventions targeting eosinophils, although beneficial in atopic individuals, may delay resolution of airway hyperreactivity in nonatopic individuals. Copyright �

Gentilly 2 divider plate replacement

International Nuclear Information System (INIS)

Forest, J.; Klisel, E.; McClellan, G.; Schnelder, W.

1995-01-01

The steam generators at the Gentilly 2 Nuclear Plant in operation since 1983 were built with primary divider plates of a bolted panel configuration. During a routine outage inspection, it was noted that two bolts had dislodged from the divider and were located lying in the primary head. Subsequent inspections revealed erosion damage to a substantial number of divider plate bolts and to a lesser extent, to the divider plate itself. After further inspection and repair the units were returned to operation, however, it was determined that a permanent replacement of the primary divider plates was going to be necessary. After evaluation of various options, it was decided that the panel type dividers would be replaced with a single piece floating design. The divider itself was to be of a one piece all-welded arrangement to be constructed from individual panels to be brought in through the manways. In view of the strength limitations of the bolted attachment of the upper seat bar to the tubesheet, a new welded seat bar was provided. To counteract erosion concerns, the new divider is fitted with erosion resistant inserts or weld buildup and with improved sealing features in order to minimize leakage and erosion. At an advanced stage in the design and manufacture of the components, the issue of divider strength during LOCA conditions came into focus. Analysis was performed to determine the strength and/or failure characteristics of the divider to a variety of small and large LOCA conditions. The paper describes the diagnosis of the original divider plates and the design, manufacture, field mobilization, installation and subsequent operation of the replacement divider plates. (author)

Evolutionary dynamics of adult stem cells: Comparison of random and immortal strand segregation mechanisms

OpenAIRE

Tannenbaum, Emmanuel; Sherley, James L.; Shakhnovich, Eugene I.

2004-01-01

This paper develops a point-mutation model describing the evolutionary dynamics of a population of adult stem cells. Such a model may prove useful for quantitative studies of tissue aging and the emergence of cancer. We consider two modes of chromosome segregation: (1) Random segregation, where the daughter chromosomes of a given parent chromosome segregate randomly into the stem cell and its differentiating sister cell. (2) ``Immortal DNA strand'' co-segregation, for which the stem cell reta...

The effect of sleep deprivation on BOLD activity elicited by a divided attention task.

Science.gov (United States)

Jackson, Melinda L; Hughes, Matthew E; Croft, Rodney J; Howard, Mark E; Crewther, David; Kennedy, Gerard A; Owens, Katherine; Pierce, Rob J; O'Donoghue, Fergal J; Johnston, Patrick

2011-06-01

Sleep loss, widespread in today's society and associated with a number of clinical conditions, has a detrimental effect on a variety of cognitive domains including attention. This study examined the sequelae of sleep deprivation upon BOLD fMRI activation during divided attention. Twelve healthy males completed two randomized sessions; one after 27 h of sleep deprivation and one after a normal night of sleep. During each session, BOLD fMRI was measured while subjects completed a cross-modal divided attention task (visual and auditory). After normal sleep, increased BOLD activation was observed bilaterally in the superior frontal gyrus and the inferior parietal lobe during divided attention performance. Subjects reported feeling significantly more sleepy in the sleep deprivation session, and there was a trend towards poorer divided attention task performance. Sleep deprivation led to a down regulation of activation in the left superior frontal gyrus, possibly reflecting an attenuation of top-down control mechanisms on the attentional system. These findings have implications for understanding the neural correlates of divided attention and the neurofunctional changes that occur in individuals who are sleep deprived.

Relay-aided multi-cell broadcasting with random network coding

DEFF Research Database (Denmark)

Lu, Lu; Sun, Fan; Xiao, Ming

2010-01-01

We investigate a relay-aided multi-cell broadcasting system using random network codes, where the focus is on devising efficient scheduling algorithms between relay and base stations. Two scheduling algorithms are proposed based on different feedback strategies; namely, a one-step scheduling...

Contact-free Stress Monitoring for User's Divided Attention

OpenAIRE

Shastri, Dvijesh; Wesley, Avinash; Pavlidis, Ioannis

2008-01-01

This research work demonstrates the feasibility of stress quantification in situations where the attention of the user is divided. Psychologically kosher (i.e., unobtrusive) quantification of stress and its correlation to user performance and emotion are of singular importance in man-machine interaction. We have also proved that talking on a cell phone during simulated driving increases the supraorbital skin temperature significantly. This finding clearly demonstrates that concurrent performa...

Evolutionary dynamics of adult stem cells: comparison of random and immortal-strand segregation mechanisms.

Science.gov (United States)

Tannenbaum, Emmanuel; Sherley, James L; Shakhnovich, Eugene I

2005-04-01

This paper develops a point-mutation model describing the evolutionary dynamics of a population of adult stem cells. Such a model may prove useful for quantitative studies of tissue aging and the emergence of cancer. We consider two modes of chromosome segregation: (1) random segregation, where the daughter chromosomes of a given parent chromosome segregate randomly into the stem cell and its differentiating sister cell and (2) "immortal DNA strand" co-segregation, for which the stem cell retains the daughter chromosomes with the oldest parent strands. Immortal strand co-segregation is a mechanism, originally proposed by [Cairns Nature (London) 255, 197 (1975)], by which stem cells preserve the integrity of their genomes. For random segregation, we develop an ordered strand pair formulation of the dynamics, analogous to the ordered strand pair formalism developed for quasispecies dynamics involving semiconservative replication with imperfect lesion repair (in this context, lesion repair is taken to mean repair of postreplication base-pair mismatches). Interestingly, a similar formulation is possible with immortal strand co-segregation, despite the fact that this segregation mechanism is age dependent. From our model we are able to mathematically show that, when lesion repair is imperfect, then immortal strand co-segregation leads to better preservation of the stem cell lineage than random chromosome segregation. Furthermore, our model allows us to estimate the optimal lesion repair efficiency for preserving an adult stem cell population for a given period of time. For human stem cells, we obtain that mispaired bases still present after replication and cell division should be left untouched, to avoid potentially fixing a mutation in both DNA strands.

Random small interfering RNA library screen identifies siRNAs that induce human erythroleukemia cell differentiation.

Science.gov (United States)

Fan, Cuiqing; Xiong, Yuan; Zhu, Ning; Lu, Yabin; Zhang, Jiewen; Wang, Song; Liang, Zicai; Shen, Yan; Chen, Meihong

2011-03-01

Cancers are characterized by poor differentiation. Differentiation therapy is a strategy to alleviate malignant phenotypes by inducing cancer cell differentiation. Here we carried out a combinatorial high-throughput screen with a random siRNA library on human erythroleukemia K-562 cell differentiation. Two siRNAs screened from the library were validated to be able to induce erythroid differentiation to varying degrees, determined by CD235 and globin up-regulation, GATA-2 down-regulation, and cell growth inhibition. The screen we performed here is the first trial of screening cancer differentiation-inducing agents from a random siRNA library, demonstrating that a random siRNA library can be considered as a new resource in efforts to seek new therapeutic agents for cancers. As a random siRNA library has a broad coverage for the entire genome, including known/unknown genes and protein coding/non-coding sequences, screening using a random siRNA library can be expected to greatly augment the repertoire of therapeutic siRNAs for cancers.

The effect of divided attention on novices and experts in laparoscopic task performance.

Science.gov (United States)

Ghazanfar, Mudassar Ali; Cook, Malcolm; Tang, Benjie; Tait, Iain; Alijani, Afshin

2015-03-01

Attention is important for the skilful execution of surgery. The surgeon's attention during surgery is divided between surgery and outside distractions. The effect of this divided attention has not been well studied previously. We aimed to compare the effect of dividing attention of novices and experts on a laparoscopic task performance. Following ethical approval, 25 novices and 9 expert surgeons performed a standardised peg transfer task in a laboratory setup under three randomly assigned conditions: silent as control condition and two standardised auditory distracting tasks requiring response (easy and difficult) as study conditions. Human reliability assessment was used for surgical task analysis. Primary outcome measures were correct auditory responses, task time, number of surgical errors and instrument movements. Secondary outcome measures included error rate, error probability and hand specific differences. Non-parametric statistics were used for data analysis. 21109 movements and 9036 total errors were analysed. Novices had increased mean task completion time (seconds) (171 ± 44SD vs. 149 ± 34, p 0.05). Divided attention conditions in theatre environment require careful consideration during surgical training as the junior surgeons are less able to focus their attention during these conditions.

Guiding the orientation of smooth muscle cells on random and aligned polyurethane/collagen nanofibers.

Science.gov (United States)

Jia, Lin; Prabhakaran, Molamma P; Qin, Xiaohong; Ramakrishna, Seeram

2014-09-01

Fabricating scaffolds that can simulate the architecture and functionality of native extracellular matrix is a huge challenge in vascular tissue engineering. Various kinds of materials are engineered via nano-technological approaches to meet the current challenges in vascular tissue regeneration. During this study, nanofibers from pure polyurethane and hybrid polyurethane/collagen in two different morphologies (random and aligned) and in three different ratios of polyurethane:collagen (75:25; 50:50; 25:75) are fabricated by electrospinning. The fiber diameters of the nanofibrous scaffolds are in the range of 174-453 nm and 145-419 for random and aligned fibers, respectively, where they closely mimic the nanoscale dimensions of native extracellular matrix. The aligned polyurethane/collagen nanofibers expressed anisotropic wettability with mechanical properties which is suitable for regeneration of the artery. After 12 days of human aortic smooth muscle cells culture on different scaffolds, the proliferation of smooth muscle cells on hybrid polyurethane/collagen (3:1) nanofibers was 173% and 212% higher than on pure polyurethane scaffolds for random and aligned scaffolds, respectively. The results of cell morphology and protein staining showed that the aligned polyurethane/collagen (3:1) scaffold promote smooth muscle cells alignment through contact guidance, while the random polyurethane/collagen (3:1) also guided cell orientation most probably due to the inherent biochemical composition. Our studies demonstrate the potential of aligned and random polyurethane/collagen (3:1) as promising substrates for vascular tissue regeneration. © The Author(s) 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

Regulatory mechanisms of apoptosis in regularly dividing cells

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Ribal S Darwish

2010-08-01

Full Text Available Ribal S DarwishDepartment of Anesthesiology, Division of Critical Care Medicine, University of Maryland Medical Center, Baltimore, Maryland, USAAbstract: The balance between cell survival and death is essential for normal development and homeostasis of organisms. Apoptosis is a distinct type of cell death with ultrastructural features that are consistent with an active, inherently controlled process. Abnormalities and ­dysregulation of apoptosis contribute to the pathophysiology of multiple disease processes. Apoptosis is strictly regulated by several positive and negative feedback mechanisms that regulate cell death and determine the final outcome after cell exposure to apoptotic stimuli. Mitochondria and caspases are central components of the regulatory mechanisms of ­apoptosis. Recently, noncaspase pathways of apoptosis have been explored through the studies of ­apoptosis-inducing factor and endonuclease G. Multiple difficulties in the apoptosis research relate to apoptosis detection and imaging. This article reviews current understanding of the regulatory mechanisms of apoptosis.Keywords: caspases, apoptosis-inducing factor, apoptosis inhibitory proteins, cytochrome c, mitochondria 

Autoradoigraphic study of 3H colchicine binding in synchronously dividing cells of antheridial filaments of Chara vulgaris L. during successive stages of development

International Nuclear Information System (INIS)

Olszewska, M.J.

1975-01-01

The intensity of 3 H colchicine binding was investigated autoradiographically as a marker of an amount of the microtubule subunits during interphase and mitosis in synchronously dividing 4-, 8-, 16- and 32-celled antheridial filaments of Chara vulgaris. These cells were incubated with 3 H colchicine in vivo or after fixation. The radioactivity of cells in the successive generations of antheridial filaments diminishes, similarly as the surface of cytoplasm and intensity of protein synthesis. During interphase the intensity of 3 H colchicine binding is proportional to the increase of cytoplasmic surface. During mitosis the increase of radioactivity continues in prophase; the highest radioactivity was found in prophase and telophase cells, the lowest in anaphase cells; a comparatively pronounced radioactivity is visible in metaphase. Radioactivity in posttelophase, as estimated per one daughter cell, is approximately one half of that of the mother cells in telophase of the previous generation suggesting the reutilization of microtubule proteins in the next mitotic cycle. (author)

The digital divide: philosophical reflection

Directory of Open Access Journals (Sweden)

Dedyulina Marina Anatolevna

2017-07-01

Full Text Available The problem of digital divide itself is interesting for philosophical reflection as it lies at the crossroads of interests of social and political philosophy, philosophy of technology and epistemology, and these are just some of them. Due to the constant development of information technologies and the introduction of new technologies the digital divide is a dynamic problem. The main aim of this work is to analyse the conceptual and descriptive aspects of the problem of the digital divide, to get a more complete picture of the phenomenon. The digital divide is a complex problem that has social, political, cultural and ethical aspects.

Bone marrow stromal cell therapy for ischemic stroke: A meta-analysis of randomized control animal trials.

Science.gov (United States)

Wu, Qing; Wang, Yuexiang; Demaerschalk, Bart M; Ghimire, Saruna; Wellik, Kay E; Qu, Wenchun

2017-04-01

Background Results of animal studies assessing efficacy of bone marrow stromal cell therapy for ischemic stroke remain inconsistent. Aims The aims are to assess efficacy of bone marrow stromal cell therapy for ischemic stroke in animal studies. Methods Randomized controlled animal trials assessing efficacy of bone marrow stromal cell therapy were eligible. Stroke therapy academic industry round table was used to assess methodologic quality of included studies. Primary outcomes were total infarction volume and modified Neurological Severity Score. Multiple prespecified sensitivity analyses and subgroup analyses were conducted. Random effects models were used for meta-analysis. Results Thirty-three randomized animal trials were included with a total of 796 animals. The median quality score was 6 (interquartile range, 5-7). Bone marrow stromal cell therapy decreased total infarction volume (standardized mean difference, 0.897; 95% confidence interval, 0.553-1.241; P animals treated with bone marrow stromal cell and controls was 2.47 (95% confidence interval, 1.84-3.11; P animal studies. Conclusions Bone marrow stromal cell therapy significantly decreased total infarction volume and increased neural functional recovery in randomized controlled animal models of ischemic stroke.

Stem cells propagate their DNA by random segregation in the flatworm Macrostomum lignano.

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Freija Verdoodt

Full Text Available Adult stem cells are proposed to have acquired special features to prevent an accumulation of DNA-replication errors. Two such mechanisms, frequently suggested to serve this goal are cellular quiescence, and non-random segregation of DNA strands during stem cell division, a theory designated as the immortal strand hypothesis. To date, it has been difficult to test the in vivo relevance of both mechanisms in stem cell systems. It has been shown that in the flatworm Macrostomum lignano pluripotent stem cells (neoblasts are present in adult animals. We sought to address by which means M. lignano neoblasts protect themselves against the accumulation of genomic errors, by studying the exact mode of DNA-segregation during their division. In this study, we demonstrated four lines of in vivo evidence in favor of cellular quiescence. Firstly, performing BrdU pulse-chase experiments, we localized 'Label-Retaining Cells' (LRCs. Secondly, EDU pulse-chase combined with Vasa labeling demonstrated the presence of neoblasts among the LRCs, while the majority of LRCs were differentiated cells. We showed that stem cells lose their label at a slow rate, indicating cellular quiescence. Thirdly, CldU/IdU- double labeling studies confirmed that label-retaining stem cells showed low proliferative activity. Finally, the use of the actin inhibitor, cytochalasin D, unequivocally demonstrated random segregation of DNA-strands in LRCs. Altogether, our data unambiguously demonstrated that the majority of neoblasts in M. lignano distribute their DNA randomly during cell division, and that label-retention is a direct result of cellular quiescence, rather than a sign of co-segregation of labeled strands.

Dividing Discipline

DEFF Research Database (Denmark)

Kristensen, Peter Marcus

2012-01-01

the periphery of the network—security studies and international political economy in particular—but communication is also divided along the lines of geography and policy/theory. The article concludes that divisions notwithstanding, IR communication remains centered around American, general, and theoretical IR...

Electrochemical reduction and oxidation pathways for Reactive Black 5 dye using nickel electrodes in divided and undivided cells

International Nuclear Information System (INIS)

Méndez-Martínez, Ana J.; Dávila-Jiménez, Martin M.; Ornelas-Dávila, Omar; Elizalde-González, María P.; Arroyo-Abad, Uriel; Sirés, Ignasi; Brillas, Enric

2012-01-01

Highlights: ► Ni electrodes were used for the mild degradation of the azo dye Reactive Black 5. ► Potentiostatic degradation was performed in undivided and divided cells. ► Degradation by-products were detected and monitored by RP-HPLC and LC–MS/MS. ► Small alkylsulfonyl phenol and isoxazole derivatives were identified. ► The cathodic and anodic degradation pathways for Reactive Black 5 were elucidated. - Abstract: The cathodic reduction and anodic ·OH-mediated oxidation of the azo dye Reactive Black 5 (RB5) have been studied potentiostatically by using undivided and divided cells with a Ni-polyvinylchloride (Ni-PVC) composite cathode and a Ni wire mesh anode. Solutions of 50–100 cm 3 of 20–80 mg dm −3 RB5 in 0.1 mol dm −3 KOH were degraded to assess the effect of electrolysis time and electrode potentials on the infrared and absorbance spectra, as well as on the decay of the total organic carbon and chemical oxygen demand. Reversed-phase high performance liquid chromatography (RP-HPLC) with ion-pairing and diode array detection (ion pair chromatography), along with coupling to tandem mass spectrometry (LC–MS/MS), were used for the identification of the aromatic degradation by-products and monitoring their time course. These analyses revealed the progressive conversion of the RB5 dye to simpler molecules with m/z 200, 369.5 and 547 under the direct action of the electron at the cathode and the formation of polar compounds such as alkylsulfonyl phenol derivatives with m/z 201, 185 and 171 by the ·OH mediation at the anode. From these results, the electrochemical reduction and oxidation pathways for the RB5 dye were elucidated.

[Randomized clinical trial of IEP and EP regimens in the treatment of patients with small cell lung cancer].

Science.gov (United States)

Zhou, Hui; Wang, Anlan; Huang, Zhihua; Zhou, Wenwei

2004-06-20

To observe and compare the efficacy and safety of IEP and EP regimens for small cell lung cancer (SCLC). Sixty-four patients with SCLC pathologically proved were randomly divided into IEP group ( n =32) and EP group ( n =32). All the 64 patients were evaluable for response and toxicity. In IEP group, the total responsive rate, responsive rates of limited-stage patients and extensive-stage patients were 84.4%(27/32), 100.0%(15/15) and 70.6%(12/17) respectively; while in EP group, those were 75.0%(24/32), 85.7%(12/14) and 66.7% (12/18) respectively. The median duration of remission was 6 months and 1-year survival rate was 62.5% in IEP group, and 5 months and 56.2% in EP group. There was no significant difference in response rate, median duration of remission and 1-year survival between the two groups ( P > 0.05). The main toxicity was myelosuppression. Incidences of leukopenia at grade III-IV, nausea, vomiting and alopecia were significantly higher in the IEP arm than those in the EP arm ( P IEP and EP. IEP regimen shows a similar response rate compared with EP regimen. They might be considered as relevant regimens in initial patients with small cell lung cancer.

Autoradoigraphic study of /sup 3/H colchicine binding in synchronously dividing cells of antheridial filaments of Chara vulgaris L. during successive stages of development

Energy Technology Data Exchange (ETDEWEB)

Olszewska, M J [Lodz Univ. (Poland)

1975-01-01

The intensity of /sup 3/H colchicine binding was investigated autoradiographically as a marker of an amount of the microtubule subunits during interphase and mitosis in synchronously dividing 4-, 8-, 16- and 32-celled antheridial filaments of Chara vulgaris. These cells were incubated with /sup 3/H colchicine in vivo or after fixation. The radioactivity of cells in the successive generations of antheridial filaments diminishes, similarly as the surface of cytoplasm and intensity of protein synthesis. During interphase the intensity of /sup 3/H colchicine binding is proportional to the increase of cytoplasmic surface. During mitosis the increase of radioactivity continues in prophase; the highest radioactivity was found in prophase and telophase cells, the lowest in anaphase cells; a comparatively pronounced radioactivity is visible in metaphase. Radioactivity in posttelophase, as estimated per one daughter cell, is approximately one half of that of the mother cells in telophase of the previous generation suggesting the reutilization of microtubule proteins in the next mitotic cycle.

Digital Divide in India: Measurement, Determinants and Policy for Addressing the Challenges in Bridging the Digital Divide

OpenAIRE

Sumanjeet Singh

2010-01-01

Existing studies of the digital divide reveals the gap that exists between those who have access to ICTs and those who do not create exclusion, endanger social integration and hamper economic growth. The digital divide has many dimensions and can be categorized as global, regional and national. At national level, there is no single divide, but multiple divides: for instance, within countries, between men and women, young and elderly, rich and poor and most importantly rural and urban. The pre...

Tech, Teachers & Teens: Bridging the Divide

Science.gov (United States)

Stuht, Amy Colcord; Colcord, Cean

2011-01-01

In past decades, the "digital divide" referred to the gap between those who could afford access to technology and those who could not. The divide has shifted in recent years to reflect the growing technological chasm between teachers and their students: today's schools and teenagers' worlds. The digital divide is widening and deepening…

Analog and digital dividers for mass spectrometers

International Nuclear Information System (INIS)

Osipov, A.K.

1980-01-01

Errors of four different types of stress dividers used in statical mass-spectrometers for determination of mass number by accelerating stress are analyzed. The simplest flowsheet of the analog divider comprises operation amplifier, in the chain of the negative feedback of which a multiplication device on differential cascade is switched- in. This analog divider has high sensitivity to temperature and high error approximately 5%. Application of the multiplier on differential cascade with normalization permits to increase temperature stability and decrease the error up to 1%. Another type of the analog divider is a logarithmic divider the error of which is constant within the whole operation range and it constitutes 1-5%. The digital divider with a digital-analog transformer (DAT) has the error of +-0.015% which is determined by the error of detectors and resistance of keys in the locked state. Considered is the design of a divider based on transformation of the inlet stress into the time period. The error of the divider is determined in this case mainly by stress of the zero shift of the operation amplifier (it should be compensated) and relative threshold stability of the comparator triggering which equals (2-3)x10 -4 . It is noted that the divider with DAT application and the divider with the use of stress transformation within the time period are most perspective ones for statical mass-spectrometers [ru

The effects of divided attention at study and test on false recognition: a comparison of DRM and categorized lists.

Science.gov (United States)

Knott, Lauren M; Dewhurst, Stephen A

2007-12-01

Three experiments investigated the effects of divided attention at encoding and retrieval on false recognition. In Experiment 1, participants studied word lists in either full or divided attention (random number generation) conditions and then took part in a recognition test with full attention. In Experiment 2, after studying word lists with full attention, participants carried out a recognition test with either full or divided attention. Experiment 3 manipulated attention at both study and test. We also compared Deese/Roediger-McDermott (DRM) and categorized lists, due to recent claims regarding the locus of false memories produced by such lists (Smith, Gerkens, Pierce, & Choi, 2002). With both list types, false "remember" responses were reduced by divided attention at encoding and increased by divided attention at retrieval. The findings suggest that the production of false memories occurs as a result of the generation of associates at encoding and failures of source monitoring retrieval. Crucially, this is true for both DRM and categorized lists.

A randomized controlled trial of cell salvage in routine cardiac surgery.

Science.gov (United States)

Klein, Andrew A; Nashef, Samer A M; Sharples, Linda; Bottrill, Fiona; Dyer, Matthew; Armstrong, Johanna; Vuylsteke, Alain

2008-11-01

Previous trials have indicated that cell salvage may reduce allogeneic blood transfusion during cardiac surgery, but these studies have limitations, including inconsistent use of other blood transfusion-sparing strategies. We designed a randomized controlled trial to determine whether routine cell salvage for elective uncomplicated cardiac surgery reduces blood transfusion and is cost effective in the setting of a rigorous transfusion protocol and routine administration of antifibrinolytics. Two-hundred-thirteen patients presenting for first-time coronary artery bypass grafting and/or cardiac valve surgery were prospectively randomized to control or cell salvage groups. The latter group had blood aspirate during surgery and mediastinal drainage the first 6 h after surgery processed in a cell saver device and autotransfused. All patients received tranexamic acid and were subjected to an algorithm for red blood cell and hemostatic blood factor transfusion. There was no difference between the two groups in the proportion of patients exposed to allogeneic blood (32% in both groups, relative risk 1.0 P = 0.89). At current blood products and cell saver prices, the use of cell salvage increased the costs per patient by a minimum of $103. When patients who had mediastinal re-exploration for bleeding were excluded (as planned in the protocol), significantly fewer units of allogeneic red blood cells were transfused in the cell salvage compared with the control group (65 vs 100 U, relative risk 0.71 P = 0.04). In patients undergoing routine first-time cardiac surgery in an institution with a rigorous blood conservation program, the routine use of cell salvage does not further reduce the proportion of patients exposed to allogeneic blood transfusion. However, patients who do not have excessive bleeding after surgery receive significantly fewer units of blood with cell salvage. Although the use of cell savage may reduce the demand for blood products during cardiac surgery, this

Replacement divider plate performance under LOCA loading

International Nuclear Information System (INIS)

Huynk, H.M.; MClellan, G.H.; Schneider, W.G.

1997-01-01

A primary divider plate in a nuclear steam generator is required to perform its partitioning function with a minimum of cross leakage, without degradation in operating performance and without loss of structural integrity resulting from normal and accident loading. The design of the replacement divider plate for normal operating conditions is discussed in some detail in reference 1 and 2. This paper describes the structural response of the replacement divider plate to the severe loading resulting from a burst primary pipe. The loads for which the divider plate structural performance must be evaluated are mild to severe differential pressure transients resulting from several postulated sizes and types of pipe break scenarios. In the unlikely event of a severe Loss of Coolant Accident (LOCA) the divider plate or parts thereof must not exit the steam generator nor completely block the outlet nozzle. For the milder LOCA loads, the integrity of the divider plate and seat bars must be maintained. Analysis for the milder LOCA loads was carried out employing a conservative approach which ignores the actual interaction between the structure and the primary fluid. For these load cases it was shown that the divider plate does not become disengaged from the seat bars. For the more severe pipe breaks, the thermal-hydraulic analysis was coupled iteratively with the structural analysis, thereby taking into account divider plate deformation, in order to obtain a better prediction of the behaviour of the divider plate. In this manner substantial reduction in divider plate response to the more severe LOCA loading was achieved. It has been shown that, for the case of a postulated large LOCA (100% reactor inlet header), the disengagement of the divider plate from the seat bars resulted in an opening smaller than 1% of the divider plate area. (author)

Washed cell salvage in surgical patients: A review and meta-analysis of prospective randomized trials under PRISMA.

Science.gov (United States)

Meybohm, Patrick; Choorapoikayil, Suma; Wessels, Anke; Herrmann, Eva; Zacharowski, Kai; Spahn, Donat R

2016-08-01

Cell salvage is commonly used as part of a blood conservation strategy. However concerns among clinicians exist about the efficacy of transfusion of washed cell salvage. We performed a meta-analysis of randomized controlled trials in which patients, scheduled for all types of surgery, were randomized to washed cell salvage or to a control group with no cell salvage. Data were independently extracted, risk ratio (RR), and weighted mean differences (WMD) with 95% confidence intervals (CIs) were calculated. Data were pooled using a random effects model. The primary endpoint was the number of patients exposed to allogeneic red blood cell (RBC) transfusion. Out of 1140 search results, a total of 47 trials were included. Overall, the use of washed cell salvage reduced the rate of exposure to allogeneic RBC transfusion by a relative 39% (RR = 0.61; 95% CI 0.57 to 0.65; P platelets, or rate of myocardial infarction and stroke. Washed cell salvage is efficacious in reducing the need for allogeneic RBC transfusion and risk of infection in surgery.

Perception of young adults with sickle cell disease or sickle cell trait about participation in the CHOICES randomized controlled trial.

Science.gov (United States)

Hershberger, Patricia E; Gallo, Agatha M; Molokie, Robert; Thompson, Alexis A; Suarez, Marie L; Yao, Yingwei; Wilkie, Diana J

2016-06-01

To gain an in-depth understanding of the perceptions of young adults with sickle cell disease and sickle cell trait about parenthood and participating in the CHOICES randomized controlled trial that used computer-based, educational programmes. In the USA, there is insufficient education to assure that all young adults with sickle cell disease or sickle cell trait understand genetic inheritance risks and reproductive options to make informed reproductive decisions. To address this educational need, we developed a computer-based, multimedia program (CHOICES) and reformatted usual care into a computer-based (e-Book) program. We then conducted a two-year randomized controlled trial that included a qualitative component that would deepen understanding of young adults' perceptions of parenthood and use of computer-based, educational programmes. A qualitative descriptive approach completed after a randomized controlled trial. Sixty-eight men and women of childbearing age participated in semi-structured interviews at the completion of the randomized controlled trial from 2012-2013. Thematic content analysis guided the qualitative description. Three main themes were identified: (1) increasing knowledge and new ways of thinking and behaving; (2) rethinking parenting plans; and (3) appraising the program design and delivery. Most participants reported increased knowledge and rethinking of their parenting plans and were supportive of computer-based learning. Some participants expressed difficulty in determining individual transmission risks. Participants perceived the computer programs as beneficial to their learning. Future development of an Internet-based educational programme is warranted, with emphasis on providing tailored education or memory boosters about individual transmission risks. © 2015 John Wiley & Sons Ltd.

Essays on the Digital Divide

Science.gov (United States)

Abdelfattah, Belal M. T.

2013-01-01

The digital divide is a phenomenon that is globally persistent, despite rapidly decreasing costs in technology. While much of the variance in the adoption and use of information communication technology (ICT) that defines the digital divide can be explained by socioeconomic and demographic variables, there is still significant unaccounted variance…

When the genome plays dice: circumvention of the spindle assembly checkpoint and near-random chromosome segregation in multipolar cancer cell mitoses.

Science.gov (United States)

Gisselsson, David; Håkanson, Ulf; Stoller, Patrick; Marti, Dominik; Jin, Yuesheng; Rosengren, Anders H; Stewénius, Ylva; Kahl, Fredrik; Panagopoulos, Ioannis

2008-04-02

Normal cell division is coordinated by a bipolar mitotic spindle, ensuring symmetrical segregation of chromosomes. Cancer cells, however, occasionally divide into three or more directions. Such multipolar mitoses have been proposed to generate genetic diversity and thereby contribute to clonal evolution. However, this notion has been little validated experimentally. Chromosome segregation and DNA content in daughter cells from multipolar mitoses were assessed by multiphoton cross sectioning and fluorescence in situ hybridization in cancer cells and non-neoplastic transformed cells. The DNA distribution resulting from multipolar cell division was found to be highly variable, with frequent nullisomies in the daughter cells. Time-lapse imaging of H2B/GFP-labelled multipolar mitoses revealed that the time from the initiation of metaphase to the beginning of anaphase was prolonged and that the metaphase plates often switched polarity several times before metaphase-anaphase transition. The multipolar metaphase-anaphase transition was accompanied by a normal reduction of cellular cyclin B levels, but typically occurred before completion of the normal separase activity cycle. Centromeric AURKB and MAD2 foci were observed frequently to remain on the centromeres of multipolar ana-telophase chromosomes, indicating that multipolar mitoses were able to circumvent the spindle assembly checkpoint with some sister chromatids remaining unseparated after anaphase. Accordingly, scoring the distribution of individual chromosomes in multipolar daughter nuclei revealed a high frequency of nondisjunction events, resulting in a near-binomial allotment of sister chromatids to the daughter cells. The capability of multipolar mitoses to circumvent the spindle assembly checkpoint system typically results in a near-random distribution of chromosomes to daughter cells. Spindle multipolarity could thus be a highly efficient generator of genetically diverse minority clones in transformed cell

When the genome plays dice: circumvention of the spindle assembly checkpoint and near-random chromosome segregation in multipolar cancer cell mitoses.

Directory of Open Access Journals (Sweden)

David Gisselsson

Full Text Available BACKGROUND: Normal cell division is coordinated by a bipolar mitotic spindle, ensuring symmetrical segregation of chromosomes. Cancer cells, however, occasionally divide into three or more directions. Such multipolar mitoses have been proposed to generate genetic diversity and thereby contribute to clonal evolution. However, this notion has been little validated experimentally. PRINCIPAL FINDINGS: Chromosome segregation and DNA content in daughter cells from multipolar mitoses were assessed by multiphoton cross sectioning and fluorescence in situ hybridization in cancer cells and non-neoplastic transformed cells. The DNA distribution resulting from multipolar cell division was found to be highly variable, with frequent nullisomies in the daughter cells. Time-lapse imaging of H2B/GFP-labelled multipolar mitoses revealed that the time from the initiation of metaphase to the beginning of anaphase was prolonged and that the metaphase plates often switched polarity several times before metaphase-anaphase transition. The multipolar metaphase-anaphase transition was accompanied by a normal reduction of cellular cyclin B levels, but typically occurred before completion of the normal separase activity cycle. Centromeric AURKB and MAD2 foci were observed frequently to remain on the centromeres of multipolar ana-telophase chromosomes, indicating that multipolar mitoses were able to circumvent the spindle assembly checkpoint with some sister chromatids remaining unseparated after anaphase. Accordingly, scoring the distribution of individual chromosomes in multipolar daughter nuclei revealed a high frequency of nondisjunction events, resulting in a near-binomial allotment of sister chromatids to the daughter cells. CONCLUSION: The capability of multipolar mitoses to circumvent the spindle assembly checkpoint system typically results in a near-random distribution of chromosomes to daughter cells. Spindle multipolarity could thus be a highly efficient

Compact Unequal Power Divider with Filtering Response

Directory of Open Access Journals (Sweden)

Wei-Qiang Pan

2015-01-01

Full Text Available We present a novel unequal power divider with bandpass responses. The proposed power divider consists of five resonators and a resistor. The power division ratio is controlled by altering the coupling strength among the resonators. The output ports have the characteristic impedance of 50 Ω and impedance transformers in classical Wilkinson power dividers are not required in this design. Use of resonators enables the filtering function of the power divider. Two transmission zeros are generated near the passband edges, resulting in quasielliptic bandpass responses. For validation, a 2 : 1 filtering power divider is implemented. The fabricated circuit size is 0.22 λg × 0.08 λg, featuring compact size for unequal filtering power dividers, which is suitable for the feeding networks of antenna arrays.

Dividing Attention Increases Operational Momentum

Directory of Open Access Journals (Sweden)

Koleen McCrink

2017-12-01

Full Text Available When adding or subtracting two quantities, adults often compute an estimated outcome that is larger or smaller, respectively, than the actual outcome, a bias referred to as “operational momentum”. The effects of attention on operational momentum were investigated. Participants viewed a display in which two arrays of objects were added, or one array was subtracted from another array, and judged whether a subsequent outcome (probe array contained the correct or incorrect number of objects. In a baseline condition, only the arrays to be added or subtracted were viewed. In divided attention conditions, participants simultaneously viewed a sequence of colors or shapes, and judged which color (a non-spatial judgment or shape (a spatial judgment was repeated. Operational momentum occurred in all conditions, but was higher in divided attention conditions than in the baseline condition, primarily for addition problems. This pattern suggests that dividing attention, rather than decreasing operational momentum by decreasing attentional shifts, actually increased operational momentum. These results are consistent with a heightened use of arithmetic heuristics under conditions of divided attention.

A contribution of glutathione to interphase death of dividing cells

International Nuclear Information System (INIS)

Rybina, V.V.; Korystov, Yu.N.; Degtyareva, O.V.; Dobrovinskaya, O.R.; Ehjdus, L.Kh.

1988-01-01

A study was made of a change in the content of reduced glutathionine (GSH) in Ehrlich ascites tumor (EAT) cells after irradiation with doses evoking their interphase death (ID). GSH content was determined in a suspension of EAT cells fixed by hot ethanol. The postirradiation decrease in the GSH content of the suspension was due to its oxidation by hydrogen peroxide resulting from radiochemical reactions after releasing thereof from cells upon fixation. In the absence of an irradiated medium no changes occurred in the GSH content of EAT cells. It is concluded that ID of EAT cells is not associated with the radiation-induced decrease in the content of GSH, an endogenous antioxidant

Development of a randomized 3D cell model for Monte Carlo microdosimetry simulations

Energy Technology Data Exchange (ETDEWEB)

Douglass, Michael; Bezak, Eva; Penfold, Scott [School of Chemistry and Physics, University of Adelaide, North Terrace, Adelaide 5005, South Australia (Australia) and Department of Medical Physics, Royal Adelaide Hospital, North Terrace, Adelaide 5000, South Australia (Australia)

2012-06-15

Purpose: The objective of the current work was to develop an algorithm for growing a macroscopic tumor volume from individual randomized quasi-realistic cells. The major physical and chemical components of the cell need to be modeled. It is intended to import the tumor volume into GEANT4 (and potentially other Monte Carlo packages) to simulate ionization events within the cell regions. Methods: A MATLAB Copyright-Sign code was developed to produce a tumor coordinate system consisting of individual ellipsoidal cells randomized in their spatial coordinates, sizes, and rotations. An eigenvalue method using a mathematical equation to represent individual cells was used to detect overlapping cells. GEANT4 code was then developed to import the coordinate system into GEANT4 and populate it with individual cells of varying sizes and composed of the membrane, cytoplasm, reticulum, nucleus, and nucleolus. Each region is composed of chemically realistic materials. Results: The in-house developed MATLAB Copyright-Sign code was able to grow semi-realistic cell distributions ({approx}2 Multiplication-Sign 10{sup 8} cells in 1 cm{sup 3}) in under 36 h. The cell distribution can be used in any number of Monte Carlo particle tracking toolkits including GEANT4, which has been demonstrated in this work. Conclusions: Using the cell distribution and GEANT4, the authors were able to simulate ionization events in the individual cell components resulting from 80 keV gamma radiation (the code is applicable to other particles and a wide range of energies). This virtual microdosimetry tool will allow for a more complete picture of cell damage to be developed.

Fast frequency divider circuit using combinational logic

Science.gov (United States)

Helinski, Ryan

2017-05-30

The various technologies presented herein relate to performing on-chip frequency division of an operating frequency of a ring oscillator (RO). Per the various embodiments herein, a conflict between RO size versus operational frequency can be addressed by dividing the output frequency of the RO to a frequency that can be measured on-chip. A frequency divider circuit (comprising NOR gates and latches, for example) can be utilized in conjunction with the RO on the chip. In an embodiment, the frequency divider circuit can include a pair of latches coupled to the RO to facilitate dividing the oscillating frequency of the RO by 2. In another embodiment, the frequency divider circuit can include four latches (operating in pairs) coupled to the RO to facilitate dividing the oscillating frequency of the RO by 4. A plurality of ROs can be MUXed to the plurality of ROs by a single oscillation-counting circuit.

Sp1 transcriptional activity is up-regulated by phosphatase 2A in dividing T lymphocytes.

Science.gov (United States)

Lacroix, Isabelle; Lipcey, Carol; Imbert, Jean; Kahn-Perlès, Brigitte

2002-03-15

We have followed Sp1 expression in primary human T lymphocytes induced, via CD2 plus CD28 costimulation, to sustained proliferation and subsequent return to quiescence. Binding of Sp1 to wheat germ agglutinin lectin was not modified following activation, indicating that the overall glycosylation of the protein was unchanged. Sp1 underwent, instead, a major dephosphorylation that correlated with cyclin A expression and, thus, with cell cycle progression. A similar change was observed in T cells that re-entered cell cycle following secondary interleukin-2 stimulation, as well as in serum-induced proliferating NIH/3T3 fibroblasts. Phosphatase 2A (PP2A) appears involved because 1) treatment of dividing cells with okadaic acid or cantharidin inhibited Sp1 dephosphorylation and 2) PP2A dephosphorylated Sp1 in vitro and strongly interacted with Sp1 in vivo. Sp1 dephosphorylation is likely to increase its transcriptional activity because PP2A overexpression potentiated Sp1 site-driven chloramphenicol acetyltransferase expression in dividing Kit225 T cells and okadaic acid reversed this effect. This increase might be mediated by a stronger affinity of dephosphorylated Sp1 for DNA, as illustrated by the reduced DNA occupancy by hyperphosphorylated Sp factors from cantharidin- or nocodazole-treated cells. Finally, Sp1 dephosphorylation appears to occur throughout cell cycle except for mitosis, a likely common feature to all cycling cells.

Random vibrations theory and practice

CERN Document Server

Wirsching, Paul H; Ortiz, Keith

1995-01-01

Random Vibrations: Theory and Practice covers the theory and analysis of mechanical and structural systems undergoing random oscillations due to any number of phenomena— from engine noise, turbulent flow, and acoustic noise to wind, ocean waves, earthquakes, and rough pavement. For systems operating in such environments, a random vibration analysis is essential to the safety and reliability of the system. By far the most comprehensive text available on random vibrations, Random Vibrations: Theory and Practice is designed for readers who are new to the subject as well as those who are familiar with the fundamentals and wish to study a particular topic or use the text as an authoritative reference. It is divided into three major sections: fundamental background, random vibration development and applications to design, and random signal analysis. Introductory chapters cover topics in probability, statistics, and random processes that prepare the reader for the development of the theory of random vibrations a...

The efficacy of an intraoperative cell saver during cardiac surgery: a meta-analysis of randomized trials.

Science.gov (United States)

Wang, Guyan; Bainbridge, Daniel; Martin, Janet; Cheng, Davy

2009-08-01

Cell salvage may be used during cardiac surgery to avoid allogeneic blood transfusion. It has also been claimed to improve patient outcomes by removing debris from shed blood, which may increase the risk of stroke or neurocognitive dysfunction. In this study, we sought to determine the overall safety and efficacy of cell salvage in cardiac surgery by performing a systematic review and meta-analysis of published randomized controlled trials. A comprehensive search was undertaken to identify all randomized trials of cell saver use during cardiac surgery. MEDLINE, Cochrane Library, EMBASE, and abstract databases were searched up to November 2008. All randomized trials comparing cell saver use and no cell saver use in cardiac surgery and reporting at least one predefined clinical outcome were included. The random effects model was used to calculate the odds ratios (OR, 95% confidence intervals [CI]) and the weighted mean differences (WMD, 95% CI) for dichotomous and continuous variables, respectively. Thirty-one randomized trials involving 2282 patients were included in the meta-analysis. During cardiac surgery, the use of an intraoperative cell saver reduced the rate of exposure to any allogeneic blood product (OR 0.63, 95% CI: 0.43-0.94, P = 0.02) and red blood cells (OR 0.60, 95% CI: 0.39-0.92, P = 0.02) and decreased the mean volume of total allogeneic blood products transfused per patient (WMD -256 mL, 95% CI: -416 to -95 mL, P = 0.002). There was no difference in hospital mortality (OR 0.65, 95% CI: 0.25-1.68, P = 0.37), postoperative stroke or transient ischemia attack (OR 0.59, 95% CI: 0.20-1.76, P = 0.34), atrial fibrillation (OR 0.92, 95% CI: 0.69-1.23, P = 0.56), renal dysfunction (OR 0.86, 95% CI: 0.41-1.80, P = 0.70), infection (OR 1.25, 95% CI: 0.75-2.10, P = 0.39), patients requiring fresh frozen plasma (OR 1.16, 95% CI: 0.82-1.66, P = 0.40), and patients requiring platelet transfusions (OR 0.90, 95% CI: 0.63-1.28, P = 0.55) between cell saver and

Nanostructure-property relations for phase-change random access memory (PCRAM) line cells

NARCIS (Netherlands)

Kooi, B. J.; Oosthoek, J. L. M.; Verheijen, M. A.; Kaiser, M.; Jedema, F. J.; Gravesteijn, D. J.

2012-01-01

Phase-change random access memory (PCRAM) cells have been studied extensively using electrical characterization and rather limited by detailed structure characterization. The combination of these two characterization techniques has hardly been exploited and it is the focus of the present work.

Gentilly-2 and Point Lepreau divider plate replacement

International Nuclear Information System (INIS)

Schneider, W.; McClellan, G.; Weston, S.

1996-01-01

The steam generators at Hydro Quebec's Gentilly-2 and New Brunswick Power's Point Lepreau Nuclear Plants have been in operation since 1983, and were built with primary divider plates of a bolted panel configuration. During a routine outage inspection at Gentilly-2, it was noted that two bolts had dislodged from the divider plate and were located lying in the primary head. Subsequent inspections revealed erosion damage to a a substantial number of divider plate bolts and to a lesser extent, to the divider plate itself. After further inspection and repair the units were returned to operation, however, it was determined that a permanent replacement of the primary divider plates was going to be necessary. Upon evaluation of various options, it was decided that the panel type divider plates would be replaced with a single piece floating design. The divider plate itself was to be of one piece all-welded arrangement to be constructed from individual panels to be brought in through the manways. In view of the strength limitations of the bolted attachment of the upper seat bar to the tubesheet, a new welded seat was was provided. To counteract erosion concerns, the new divider plate is fitted with erosion resistant inserts of weld buildup and with improved sealing features in order to minimize leakage and erosion. At an advanced stage in the design and manufacture of the components, the issue of divider plate strength during loss of coolant accident (LOCA) conditions came into focus. Analysis was performed to determine the strength and/or failure characteristics of the divider plate to a variety of small and large LOCA conditions. Subsequently, Point Lepreau decided to replace their divider plates to address LOCA concerns. The paper describes the diagnosis of the original divider plates and the design. manufacture, field mobilization, installation and subsequent operation of the replacement divider plates. (author)

Planar Cell Polarity Breaks the Symmetry of PAR Protein Distribution prior to Mitosis in Drosophila Sensory Organ Precursor Cells.

Science.gov (United States)

Besson, Charlotte; Bernard, Fred; Corson, Francis; Rouault, Hervé; Reynaud, Elodie; Keder, Alyona; Mazouni, Khalil; Schweisguth, François

2015-04-20

During development, cell-fate diversity can result from the unequal segregation of fate determinants at mitosis. Polarization of the mother cell is essential for asymmetric cell division (ACD). It often involves the formation of a cortical domain containing the PAR complex proteins Par3, Par6, and atypical protein kinase C (aPKC). In the fly notum, sensory organ precursor cells (SOPs) divide asymmetrically within the plane of the epithelium and along the body axis to generate two distinct cells. Fate asymmetry depends on the asymmetric localization of the PAR complex. In the absence of planar cell polarity (PCP), SOPs divide with a random planar orientation but still asymmetrically, showing that PCP is dispensable for PAR asymmetry at mitosis. To study when and how the PAR complex localizes asymmetrically, we have used a quantitative imaging approach to measure the planar polarization of the proteins Bazooka (Baz, fly Par3), Par6, and aPKC in living pupae. By using imaging of functional GFP-tagged proteins with image processing and computational modeling, we find that Baz, Par6, and aPKC become planar polarized prior to mitosis in a manner independent of the AuroraA kinase and that PCP is required for the planar polarization of Baz, Par6, and aPKC during interphase. This indicates that a "mitosis rescue" mechanism establishes asymmetry at mitosis in PCP mutants. This study therefore identifies PCP as the initial symmetry-breaking signal for the planar polarization of PAR proteins in asymmetrically dividing SOPs. Copyright © 2015 Elsevier Ltd. All rights reserved.

Divided by the Market, Divided by the State

DEFF Research Database (Denmark)

Wulfgramm, Melike; Starke, Peter

2017-01-01

of the individual differences, the analysis also shows, for the first time, that both high inequality and strongly redistributive policies divide public opinion along the lines of socioeconomic position. Put differently, while market inequality may be associated with less cohesive attitudes, a highly redistributive...... welfare state does not seem to foster agreement among the public, either. These findings have important policy implications for advanced welfare states, including a renewed emphasis on ‘predistribution’ (i.e., policies that influence the primary distribution of income) in order to avoid the scenario...

Skin Mast Cell Promotion in Random Skin Flaps in Rats using Bone Marrow Mesenchymal Stem Cells and Amniotic Membrane

Science.gov (United States)

Chehelcheraghi, Farzaneh; Abbaszadeh, Abolfazl; Tavafi, Magid

2018-03-06

Skin flap procedures are employed in plastic surgery, but failure can lead to necrosis of the flap. Studies have used bone marrow mesenchymal stem cells (BM-MSCs) to improve flap viability. BM-MSCs and acellular amniotic membrane (AAM) have been introduced as alternatives. The objective of this study was to evaluate the effect of BM-MSCs and AAM on mast cells of random skin flaps (RSF) in rats. RSFs (80 × 30 mm) were created on 40 rats that were randomly assigned to one of four groups, including (I) AAM, (II) BM-MSCs, (III) BM-MSCs/AAM, and (IV) saline (control). Transplantation was carried out during the procedure (zero day). Flap necrosis was observed on day 7, and skin samples were collected from the transition line of the flap to evaluate the total number and types of mast cells. The development and the total number of mast cells were related to the development of capillaries. The results of one-way ANOVA indicated that there was no statistically significant difference between the mean numbers of mast cell types for different study groups. However, the difference between the total number of mast cells in the study groups was statistically significant (p = 0.001). The present study suggests that the use of AAM/BM-MSCs can improve the total number of mast cells and accelerate the growth of capillaries at the transient site in RSFs in rats.

Splicing the Divide: A Review of Research on the Evolving Digital Divide among K-12 Students

Science.gov (United States)

Dolan, Jennifer E.

2016-01-01

The digital divide has narrowed with regard to one definition of access to technology--the binary view of the "haves" and "have-nots." However, use of technology at home and in school is not equitable for all students. According to recent literature, a broader and more nuanced definition of the technological divide is necessary…

Power Divider for Waveforms Rich in Harmonics

Science.gov (United States)

Sims, William Herbert, III

2005-01-01

A method for dividing the power of an electronic signal rich in harmonics involves the use of an improved divider topology. A divider designed with this topology could be used, for example, to propagate a square-wave signal in an amplifier designed with a push-pull configuration to enable the generation of more power than could be generated in another configuration.

New Media and the Digital Divide

NARCIS (Netherlands)

van Deursen, Alexander Johannes Aloysius Maria; van Dijk, Johannes A.G.M.; Wright, James D.

2015-01-01

During the 1990s, researchers and policy makers began discussing the presence of a so-called ‘digital divide,’ a distinction of people who do and do not have access to information and communication technologies. The concept of the digital divide stems from a comparative perspective of social and

Design of shielded voltage divider for impulse voltage measurement

International Nuclear Information System (INIS)

Kato, Shohei; Kouno, Teruya; Maruyama, Yoshio; Kikuchi, Koji.

1976-01-01

The dividers used for the study of the insulation and electric discharge phenomena in high voltage equipments have the problems of the change of response characteristics owing to adjacent bodies and of induced noise. To improve the characteristics, the enclosed type divider shielded with metal has been investigated, and the divider of excellent response has been obtained by adopting the frequency-separating divider system, which is divided into two parts, resistance divider (lower frequency region) and capacitance divider (higher frequency region), for avoiding to degrade the response. Theoretical analysis was carried out in the cases that residual inductance can be neglected or can not be neglected in the small capacitance divider, and that the connecting wires are added. Next, the structure of the divider and the design of the electric field for the divider manufactured on the basis of the theory are described. The response characteristics were measured. The results show that 1 MV impulse voltage can be measured within the response time of 10 ns. Though this divider aims at the impulse voltage, the duration time of which is about that of standard lightning impulse, in view of the heat capacity because of the input resistance of 10.5 kΩ, it is expected that the divider can be applied to the voltage of longer duration time by increasing the input resistance in future. (Wakatsuki, Y.)

Generation of five phase-locked harmonics by implementing a divide-by-three optical frequency divider.

Science.gov (United States)

Suhaimi, Nurul Sheeda; Ohae, Chiaki; Gavara, Trivikramarao; Nakagawa, Ken'ichi; Hong, Feng-Lei; Katsuragawa, Masayuki

2015-12-15

We report the generation of five phase-locked harmonics, f₁:2403  nm, f₂:1201  nm, f₃:801  nm, f₄:600  nm, and f₅:480  nm with an exact frequency ratio of 1:2:3:4:5 by implementing a divide-by-three optical frequency divider in the high harmonic generation process. All five harmonics are generated coaxially with high phase coherence in time and space, which are applicable for various practical uses.

Abnormal number cell division of human thyroid anaplastic carcinoma cell line, SW 1736

Directory of Open Access Journals (Sweden)

Keiichi Ikeda

2015-12-01

Full Text Available Cell division, during which a mother cell usually divides into two daughter cells during one cell cycle, is the most important physiological event of cell biology. We observed one-to-four cell division during imaging of live SW1736 human thyroid anaplastic carcinoma cells transfected with a plasmid expressing the hybrid protein of green fluorescent protein and histone 2B (plasmid eGFP-H2B. Analysis of the images revealed a mother cell divided into four daughter cells. And one of the abnormally divided daughter cells subsequently formed a dinucleate cell.

Smoking improves divided attention in schizophrenia.

Science.gov (United States)

Ahlers, Eike; Hahn, Eric; Ta, Thi Minh Tam; Goudarzi, Elnaz; Dettling, Michael; Neuhaus, Andres H

2014-10-01

Smoking is highly prevalent in schizophrenia, and there is evidence for beneficial effects on neurocognition. Smoking is therefore hypothesized a self-medication in schizophrenia. Although much effort is devoted to characterize those cognitive domains that potentially benefit from smoking, divided attention has not yet been investigated. The aim of this study was to analyze the interactional effects of diagnosis of schizophrenia and smoking history on divided attention. We investigated behavioral measures of divided attention in a sample of 48 schizophrenic patients and 48 controls (24 current smokers and non-smokers each) carefully matched for age, sex, education, verbal IQ, and smoking status with general linear models. Most important within the scope of this study, significant interactions were found for valid reactions and errors of omission: Performance substantially increased in smoking schizophrenic patients, but not in controls. Further, these interactions were modified by sex, driven by female schizophrenic patients who showed a significant behavioral advantage of smokers over non-smokers, other than male schizophrenic patients or healthy controls who did not express this sex-specific pattern. Results suggest a positive effect of smoking history on divided attention in schizophrenic patients. This study provides first evidence that the complex attention domain of divided attention is improved by smoking, which further substantiates the self-medication hypothesis of smoking in schizophrenia, although this has been shown mainly for sustained and selective attention. Gender-specific effects on cognition need to be further investigated.

Temporal dynamics of divided spatial attention.

Science.gov (United States)

Itthipuripat, Sirawaj; Garcia, Javier O; Serences, John T

2013-05-01

In naturalistic settings, observers often have to monitor multiple objects dispersed throughout the visual scene. However, the degree to which spatial attention can be divided across spatially noncontiguous objects has long been debated, particularly when those objects are in close proximity. Moreover, the temporal dynamics of divided attention are unclear: is the process of dividing spatial attention gradual and continuous, or does it onset in a discrete manner? To address these issues, we recorded steady-state visual evoked potentials (SSVEPs) as subjects covertly monitored two flickering targets while ignoring an intervening distractor that flickered at a different frequency. All three stimuli were clustered within either the lower left or the lower right quadrant, and our dependent measure was SSVEP power at the target and distractor frequencies measured over time. In two experiments, we observed a temporally discrete increase in power for target- vs. distractor-evoked SSVEPs extending from ∼350 to 150 ms prior to correct (but not incorrect) responses. The divergence in SSVEP power immediately prior to a correct response suggests that spatial attention can be divided across noncontiguous locations, even when the targets are closely spaced within a single quadrant. In addition, the division of spatial attention appears to be relatively discrete, as opposed to slow and continuous. Finally, the predictive relationship between SSVEP power and behavior demonstrates that these neurophysiological measures of divided attention are meaningfully related to cognitive function.

The Great Divide

Science.gov (United States)

Robelen, Erik W.

2005-01-01

Steps away from where a concrete wall once divided this city east from west, a group of Muslim 1st graders at E.O. Plauen Elementary School sing a phrase that is unfamiliar to most German ears. Though the Roman Catholic and Protestant churches have long provided voluntary religion classes in Berlin schools, only recently have the courts allowed an…

A Town Divided

OpenAIRE

Waldron, Lucas H

2018-01-01

Residents of rural Patagonia, AZ are bitterly divided over mining. Half of the town supports Arizona Mining Inc., a Canadian mining company that bought up land near town for vast exploratory drilling. The other half of the town is fighting the mining company at every turn, seeking to preserve the region's unique wildlife and steer the economy toward environmental restoration.

Lateral mobility of plasma membrane proteins in dividing eggs of the loach (Misgurnus fossilis): Regional differences and changes during the cell cycle.

Science.gov (United States)

Bozhkova, V P; Budayova, M; Kvasnicka, P; Cigankova, N; Chorvat, D

1994-12-01

Regional differences in lateral diffusion rates of fluorescence-labeled proteins have been studied in the plasma membrane of dividing eggs of the loach (Misgurnus fossilis) by fluorescence recovery after photobleaching (FRAP). Apparent animal-vegetal differences in fluorescence intensity, lateral diffusion coefficients, and fractions of mobile proteins have been found, with all these quantities being higher in the animal pole region than in the yolk region. Cyclic changes in protein diffusion coefficients and mobile fractions during the first few cell cycles have also been recorded. Soon after the end of a cleavage, the diffusion coefficient reaches its minimal value and increases rapidly before the next cleavage.

Cluster randomization and political philosophy.

Science.gov (United States)

Chwang, Eric

2012-11-01

In this paper, I will argue that, while the ethical issues raised by cluster randomization can be challenging, they are not new. My thesis divides neatly into two parts. In the first, easier part I argue that many of the ethical challenges posed by cluster randomized human subjects research are clearly present in other types of human subjects research, and so are not novel. In the second, more difficult part I discuss the thorniest ethical challenge for cluster randomized research--cases where consent is genuinely impractical to obtain. I argue that once again these cases require no new analytic insight; instead, we should look to political philosophy for guidance. In other words, the most serious ethical problem that arises in cluster randomized research also arises in political philosophy. © 2011 Blackwell Publishing Ltd.

Divided Attention Abilities in Young and Old Adults.

Science.gov (United States)

Somberg, Benjamin L.; Salthouse, Timothy A.

1982-01-01

Two experiments on divided attention and adult aging are reported that take into account age differences in single-task performance and that measure divided attention independently of resource allocation strategies. No significant age difference in divided attention ability independent of single-task performance level was found in either…

5 CFR 838.303 - Expressly dividing employee annuity.

Science.gov (United States)

2010-01-01

... 5 Administrative Personnel 2 2010-01-01 2010-01-01 false Expressly dividing employee annuity. 838... Employee Annuities § 838.303 Expressly dividing employee annuity. (a) A court order directed at employee annuity is not a court order acceptable for processing unless it expressly divides the employee annuity as...

Ciliated cells in vitamin A-deprived cultured hamster tracheal epithelium do divide

International Nuclear Information System (INIS)

Rutten, A.A.; Beems, R.B.; Wilmer, J.W.; Feron, V.J.

1988-01-01

The pseudostratified tracheal epithelium, composed of a heterogeneous phenotypically varying cell population, was studied with respect to the in vitro cell proliferative activity of differentiated epithelial cells. Ciliated tracheal epithelial cells so far have been considered to be terminally differentiated, nonproliferating cells. Tracheal organ cultures obtained from vitamin A-deprived Syrian Golden hamsters were cultured in a vitamin A-deficient, serum-free, hormone-supplemented medium. In vitamin A-deprived tracheal epithelium treated with physiologically active all-trans retinol and low cigarette-smoke condensate concentrations it is possible to stimulate the cell proliferation of both basal and columnar cells. Therefore, the probability of finding proliferating columnar cells was increased compared with the in vivo and the vitamin A-deprived situation in which cell proliferative activity is relatively low. In the presence of cigarette-smoke condensate in a noncytotoxic concentration, basal, small mucous granule, ciliated, and indifferent tracheal epithelial cells incorporated [methyl-3H]-thymidine into the DNA during the S phase. The finding that ciliated cells were labeled was supported by serial sections showing the same labeled ciliated cell in two section planes separated by 2 to 3 micron, without labeled epithelial cells next to the ciliated cell. Furthermore, a ciliated tracheal epithelial cell incorporating [methyl- 3 H]thymidine into DNA was also seen in tracheal cultures of vitamin A-deprived hamsters treated with all-trans retinol in a physiologic concentration

False Operation of Static Random Access Memory Cells under Alternating Current Power Supply Voltage Variation

Science.gov (United States)

Sawada, Takuya; Takata, Hidehiro; Nii, Koji; Nagata, Makoto

2013-04-01

Static random access memory (SRAM) cores exhibit susceptibility against power supply voltage variation. False operation is investigated among SRAM cells under sinusoidal voltage variation on power lines introduced by direct RF power injection. A standard SRAM core of 16 kbyte in a 90 nm 1.5 V technology is diagnosed with built-in self test and on-die noise monitor techniques. The sensitivity of bit error rate is shown to be high against the frequency of injected voltage variation, while it is not greatly influenced by the difference in frequency and phase against SRAM clocking. It is also observed that the distribution of false bits is substantially random in a cell array.

Random blebbing motion: A simple model linking cell structural properties to migration characteristics

Science.gov (United States)

Woolley, Thomas E.; Gaffney, Eamonn A.; Goriely, Alain

2017-07-01

If the plasma membrane of a cell is able to delaminate locally from its actin cortex, a cellular bleb can be produced. Blebs are pressure-driven protrusions, which are noteworthy for their ability to produce cellular motion. Starting from a general continuum mechanics description, we restrict ourselves to considering cell and bleb shapes that maintain approximately spherical forms. From this assumption, we obtain a tractable algebraic system for bleb formation. By including cell-substrate adhesions, we can model blebbing cell motility. Further, by considering mechanically isolated blebbing events, which are randomly distributed over the cell, we can derive equations linking the macroscopic migration characteristics to the microscopic structural parameters of the cell. This multiscale modeling framework is then used to provide parameter estimates, which are in agreement with current experimental data. In summary, the construction of the mathematical model provides testable relationships between the bleb size and cell motility.

Random blebbing motion: A simple model linking cell structural properties to migration characteristics.

Science.gov (United States)

Woolley, Thomas E; Gaffney, Eamonn A; Goriely, Alain

2017-07-01

If the plasma membrane of a cell is able to delaminate locally from its actin cortex, a cellular bleb can be produced. Blebs are pressure-driven protrusions, which are noteworthy for their ability to produce cellular motion. Starting from a general continuum mechanics description, we restrict ourselves to considering cell and bleb shapes that maintain approximately spherical forms. From this assumption, we obtain a tractable algebraic system for bleb formation. By including cell-substrate adhesions, we can model blebbing cell motility. Further, by considering mechanically isolated blebbing events, which are randomly distributed over the cell, we can derive equations linking the macroscopic migration characteristics to the microscopic structural parameters of the cell. This multiscale modeling framework is then used to provide parameter estimates, which are in agreement with current experimental data. In summary, the construction of the mathematical model provides testable relationships between the bleb size and cell motility.

Sequentially switching cell assemblies in random inhibitory networks of spiking neurons in the striatum.

Science.gov (United States)

Ponzi, Adam; Wickens, Jeff

2010-04-28

The striatum is composed of GABAergic medium spiny neurons with inhibitory collaterals forming a sparse random asymmetric network and receiving an excitatory glutamatergic cortical projection. Because the inhibitory collaterals are sparse and weak, their role in striatal network dynamics is puzzling. However, here we show by simulation of a striatal inhibitory network model composed of spiking neurons that cells form assemblies that fire in sequential coherent episodes and display complex identity-temporal spiking patterns even when cortical excitation is simply constant or fluctuating noisily. Strongly correlated large-scale firing rate fluctuations on slow behaviorally relevant timescales of hundreds of milliseconds are shown by members of the same assembly whereas members of different assemblies show strong negative correlation, and we show how randomly connected spiking networks can generate this activity. Cells display highly irregular spiking with high coefficients of variation, broadly distributed low firing rates, and interspike interval distributions that are consistent with exponentially tailed power laws. Although firing rates vary coherently on slow timescales, precise spiking synchronization is absent in general. Our model only requires the minimal but striatally realistic assumptions of sparse to intermediate random connectivity, weak inhibitory synapses, and sufficient cortical excitation so that some cells are depolarized above the firing threshold during up states. Our results are in good qualitative agreement with experimental studies, consistent with recently determined striatal anatomy and physiology, and support a new view of endogenously generated metastable state switching dynamics of the striatal network underlying its information processing operations.

Syringe needle skull penetration reduces brain injuries and secondary inflammation following intracerebral neural stem cell transplantation

OpenAIRE

Gao, Mou; Dong, Qin; Zhang, Hongtian; Yang, Yang; Zhu, Jianwei; Yang, Zhijun; Xu, Minhui; Xu, Ruxiang

2017-01-01

Intracerebral neural stem cell (NSC) transplantation is beneficial for delivering stem cell grafts effectively, however, this approach may subsequently result in brain injury and secondary inflammation. To reduce the risk of promoting brain injury and secondary inflammation, two methods were compared in the present study. Murine skulls were penetrated using a drill on the left side and a syringe needle on the right. Mice were randomly divided into three groups (n=84/group): Group A, receiving...

Microtubule networks for plant cell division

NARCIS (Netherlands)

Keijzer, de Jeroen; Mulder, B.M.; Janson, M.E.

2014-01-01

During cytokinesis the cytoplasm of a cell is divided to form two daughter cells. In animal cells, the existing plasma membrane is first constricted and then abscised to generate two individual plasma membranes. Plant cells on the other hand divide by forming an interior dividing wall, the so-called

Weak Ergodicity Breaking of Receptor Motion in Living Cells Stemming from Random Diffusivity

Science.gov (United States)

Manzo, Carlo; Torreno-Pina, Juan A.; Massignan, Pietro; Lapeyre, Gerald J.; Lewenstein, Maciej; Garcia Parajo, Maria F.

2015-01-01

Molecular transport in living systems regulates numerous processes underlying biological function. Although many cellular components exhibit anomalous diffusion, only recently has the subdiffusive motion been associated with nonergodic behavior. These findings have stimulated new questions for their implications in statistical mechanics and cell biology. Is nonergodicity a common strategy shared by living systems? Which physical mechanisms generate it? What are its implications for biological function? Here, we use single-particle tracking to demonstrate that the motion of dendritic cell-specific intercellular adhesion molecule 3-grabbing nonintegrin (DC-SIGN), a receptor with unique pathogen-recognition capabilities, reveals nonergodic subdiffusion on living-cell membranes In contrast to previous studies, this behavior is incompatible with transient immobilization, and, therefore, it cannot be interpreted according to continuous-time random-walk theory. We show that the receptor undergoes changes of diffusivity, consistent with the current view of the cell membrane as a highly dynamic and diverse environment. Simulations based on a model of an ordinary random walk in complex media quantitatively reproduce all our observations, pointing toward diffusion heterogeneity as the cause of DC-SIGN behavior. By studying different receptor mutants, we further correlate receptor motion to its molecular structure, thus establishing a strong link between nonergodicity and biological function. These results underscore the role of disorder in cell membranes and its connection with function regulation. Because of its generality, our approach offers a framework to interpret anomalous transport in other complex media where dynamic heterogeneity might play a major role, such as those found, e.g., in soft condensed matter, geology, and ecology.

Matrix analysis of the digital divide in eHealth services using awareness, want, and adoption gap.

Science.gov (United States)

Liang, Te-Hsin

2012-02-13

The digital divide usually refers to access or usage, but some studies have identified two other divides: awareness and demand (want). Given that the hierarchical stages of the innovation adoption process of a customer are interrelated, it is necessary and meaningful to analyze the digital divide in eHealth services through three main stages, namely, awareness, want, and adoption. By following the three main integrated stages of the innovation diffusion theory, from the customer segment viewpoint, this study aimed to propose a new matrix analysis of the digital divide using the awareness, want, and adoption gap ratio (AWAG). I compared the digital divide among different groups. Furthermore, I conducted an empirical study on eHealth services to present the practicability of the proposed methodology. Through a review and discussion of the literature, I proposed hypotheses and a new matrix analysis. To test the proposed method, 3074 Taiwanese respondents, aged 15 years and older, were surveyed by telephone. I used the stratified simple random sampling method, with sample size allocation proportioned by the population distribution of 23 cities and counties (strata). This study proposed the AWAG segment matrix to analyze the digital divide in eHealth services. First, awareness and want rates were divided into two levels at the middle point of 50%, and then the 2-dimensional cross of the awareness and want segment matrix was divided into four categories: opened group, desire-deficiency group, perception-deficiency group, and closed group. Second, according to the degrees of awareness and want, each category was further divided into four subcategories. I also defined four possible strategies, namely, hold, improve, evaluate, and leave, for different regions in the proposed matrix. An empirical test on two recently promoted eHealth services, the digital medical service (DMS) and the digital home care service (DHCS), was conducted. Results showed that for both e

Monitoring the digital divide

International Nuclear Information System (INIS)

Canessa, E.; Cerdeira, H.A.; Matthews, W.; Cottrell, R.L.

2003-05-01

It is increasingly important to support the large numbers of scientists working in remote areas and having low-bandwidth access to the Internet. This will continue to be the case for years to come since there is evidence from PingER performance measurements that the, so-called, digital divide is not decreasing. In this work, we review the collaborative work of The Abdus Salam International Center for Theoretical Physics (ICTP) in Trieste - a leading organization promoting science dissemination in the developing world- and SLAC in Stanford, to monitor by PingER, Universities and Research Institutions all over the developing world following the recent 'Recommendations of Trieste' to help bridge the digital divide. As a result, PingER's deployment now covers the real-time monitoring of worldwide Internet performance and, in particular, West and Central Africa for the first time. We report on the results from the ICTP sites and quantitatively identify regions with poor performance, identify trends, discuss experiences and future work. (author)

Monitoring the Digital Divide

International Nuclear Information System (INIS)

Cottrell, Les

2003-01-01

It is increasingly important to support the large numbers of scientists working in remote areas and having low bandwidth access to the Internet. This will continue to be the case for years to come since there is evidence from PingER performance measurements that the, so-called, digital divide is not decreasing. In this work, we review the collaborative work of The Abdus Salam International Center for Theoretical Physics (ICTP) in Trieste, a leading organization promoting science dissemination in the developing world- and SLAC in Stanford, to monitor by PingER, Universities and Research Institutions all over the developing world following the recent ''Recommendations of Trieste'' to help bridge the digital divide. As a result, PingER's deployment now covers the real-time monitoring of worldwide Internet performance and, in particular, West and Central Africa for the first time. We report on the results from the ICTP sites and quantitatively identify regions with poor performance, identify trends, discuss experiences and future work

Cytokine-primed bone marrow stem cells vs. peripheral blood stem cells for autologous transplantation: a randomized comparison of GM-CSF vs. G-CSF.

Science.gov (United States)

Weisdorf, D; Miller, J; Verfaillie, C; Burns, L; Wagner, J; Blazar, B; Davies, S; Miller, W; Hannan, P; Steinbuch, M; Ramsay, N; McGlave, P

1997-10-01

Autologous transplantation for non-Hodgkins lymphoma and Hodgkin's disease is widely used as standard therapy for those with high-risk or relapsed tumor. Peripheral blood stem cell (PBSC) collections have nearly completely replaced bone marrow stem cell (BMSC) harvests because of the perceived advantages of more rapid engraftment, less tumor contamination in the inoculum, and better survival after therapy. The advantage of PBSC, however, may derive from the hematopoietic stimulating cytokines used for PBSC mobilization. Therefore, we tested a randomized comparison of GM-CSF vs. G-CSF used to prime either BMSC or PBSC before collection for use in autologous transplantation. Sixty-two patients receiving transplants (31 PBSC; 31 BMSC) for non-Hodgkin's lymphoma (n = 51) or Hodgkin's disease (n = 11) were treated. All patients received 6 days of randomly assigned cytokine. Those with cellular marrow in morphologic remission underwent BMSC harvest, while those with hypocellular marrow or microscopic marrow tumor involvement had PBSC collected. Neutrophil recovery was similarly rapid in all groups (median 14 days; range 10-23 days), though two patients had delayed neutrophil recovery using GM-CSF primed PBSC (p = 0.01). Red cell and platelet recovery were significantly quicker after BMSC mobilized with GM-CSF or PBSC mobilized with G-CSF. This speedier hematologic recovery resulted in earlier hospital discharge as well. However, in multivariate analysis, neither the stem cell source nor randomly assigned G-CSF vs. GM-CSF was independently associated with earlier multilineage hematologic recovery or shorter hospital stay. Relapse-free survival was not independently affected by either the assigned stem cell source or the randomly assigned priming cytokine, though malignant relapse was more frequent in those assigned to PBSC (RR of relapse 3.15, p = 0.03). These data document that BMSC, when collected following cytokine priming, can yield a similarly rapid hematologic

A Randomized Clinical Trial of Red Blood Cell Transfusion Triggers in Cardiac Surgery.

Science.gov (United States)

Koch, Colleen G; Sessler, Daniel I; Mascha, Edward J; Sabik, Joseph F; Li, Liang; Duncan, Andra I; Zimmerman, Nicole M; Blackstone, Eugene H

2017-10-01

Class I evidence supporting a threshold for transfusion in the cardiac surgical setting is scarce. We randomly allocated patients to a transfusion hematocrit trigger of 24% versus 28% to compare morbidity, mortality, and resource use. From March 2007 to August 2014, two centers randomly assigned 722 adults undergoing coronary artery bypass graft surgery or valve procedures to a 24% hematocrit trigger (n = 363, low group) or 28% trigger (n = 354, high group). One unit of red blood cells was transfused if the hematocrit fell below the designated threshold. The primary endpoint was a composite of postoperative morbidities and mortality. Treatment effect was primarily assessed using an average relative effect generalized estimating equation model. At the second planned interim analysis, the a priori futility boundary was crossed, and the study was stopped. There was no detected treatment effect on the composite outcome (average relative effect odds ratio, low versus high, 0.86, 95% confidence interval: 0.29 to 2.54, p = 0.71). However, the low group received fewer red blood cell transfusions than the high group (54% versus 75%, p < 0.001), mostly administered in the operating room (low group, 112 [31%]; high group, 208 [59%]), followed by intensive care unit (low, 105 [31%]; high, 115 [34%]) and floor (low, 41 [12%]; high, 42 [13%]). The low group was exposed to lower hematocrits: median before transfusion, 22% (Q1 = 21%, Q3 = 23%) versus 24% (Q1 = 22%, Q3 = 25%). Negative exposures differed between treatment groups, with lower hematocrit in the 24% trigger group and more red blood cells used in the 28% group, but adverse outcomes did not differ. Because red blood cell use was less with a 24% trigger without adverse effects, our randomized trial results support aggressive blood conservation efforts in cardiac surgery. Copyright © 2017 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

Facebook's gender divide

OpenAIRE

Garcia, David; Kassa, Yonas Mitike; Cuevas, Angel; Cebrian, Manuel; Moro, Esteban; Rahwan, Iyad; Cuevas, Ruben

2017-01-01

Online social media are information resources that can have a transformative power in society. While the Web was envisioned as an equalizing force that allows everyone to access information, the digital divide prevents large amounts of people from being present online. Online social media in particular are prone to gender inequality, an important issue given the link between social media use and employment. Understanding gender inequality in social media is a challenging task due to the neces...

The contribution of working memory to divided attention.

Science.gov (United States)

Santangelo, Valerio; Macaluso, Emiliano

2013-01-01

Previous studies have indicated that increasing working memory (WM) load can affect the attentional selection of signals originating from one object/location. Here we assessed whether WM load affects also the selection of multiple objects/locations (divided attention). Participants monitored either two object-categories (vs. one category; object-based divided attention) or two locations (vs. one location; space-based divided attention) while maintaining in WM either a variable number of objects (object-based WM load) or locations (space-based WM load). Behavioural results showed that WM load affected attentional performance irrespective of divided or focused attention. However, fMRI results showed that the activity associated with object-based divided attention increased linearly with increasing object-based WM load in the left and right intraparietal sulcus (IPS); while, in the same areas, activity associated with space-based divided attention was not affected by any type of WM load. These findings support the hypothesis that WM contributes to the maintenance of resource-demanding attentional sets in a domain-specific manner. Moreover, the dissociable impact of WM load on performance and brain activity suggests that increased IPS activation reflects a recruitment of additional, domain-specific processing resources that enable dual-task performance under conditions of high WM load and high attentional demand. Copyright © 2011 Wiley Periodicals, Inc.

Comparison of cell behavior on pva/pva-gelatin electrospun nanofibers with random and aligned configuration

Science.gov (United States)

Huang, Chen-Yu; Hu, Keng-Hsiang; Wei, Zung-Hang

2016-12-01

Electrospinning technique is able to create nanofibers with specific orientation. Poly(vinyl alcohol) (PVA) have good mechanical stability but poor cell adhesion property due to the low affinity of protein. In this paper, extracellular matrix, gelatin is incorporated into PVA solution to form electrospun PVA-gelatin nanofibers membrane. Both randomly oriented and aligned nanofibers are used to investigate the topography-induced behavior of fibroblasts. Surface morphology of the fibers is studied by optical microscopy and scanning electron microscopy (SEM) coupled with image analysis. Functional group composition in PVA or PVA-gelatin is investigated by Fourier Transform Infrared (FTIR). The morphological changes, surface coverage, viability and proliferation of fibroblasts influenced by PVA and PVA-gelatin nanofibers with randomly orientated or aligned configuration are systematically compared. Fibroblasts growing on PVA-gelatin fibers show significantly larger projected areas as compared with those cultivated on PVA fibers which p-value is smaller than 0.005. Cells on PVA-gelatin aligned fibers stretch out extensively and their intracellular stress fiber pull nucleus to deform. Results suggest that instead of the anisotropic topology within the scaffold trigger the preferential orientation of cells, the adhesion of cell membrane to gelatin have substantial influence on cellular behavior.

Neural Correlates of Divided Attention in Natural Scenes.

Science.gov (United States)

Fagioli, Sabrina; Macaluso, Emiliano

2016-09-01

Individuals are able to split attention between separate locations, but divided spatial attention incurs the additional requirement of monitoring multiple streams of information. Here, we investigated divided attention using photos of natural scenes, where the rapid categorization of familiar objects and prior knowledge about the likely positions of objects in the real world might affect the interplay between these spatial and nonspatial factors. Sixteen participants underwent fMRI during an object detection task. They were presented with scenes containing either a person or a car, located on the left or right side of the photo. Participants monitored either one or both object categories, in one or both visual hemifields. First, we investigated the interplay between spatial and nonspatial attention by comparing conditions of divided attention between categories and/or locations. We then assessed the contribution of top-down processes versus stimulus-driven signals by separately testing the effects of divided attention in target and nontarget trials. The results revealed activation of a bilateral frontoparietal network when dividing attention between the two object categories versus attending to a single category but no main effect of dividing attention between spatial locations. Within this network, the left dorsal premotor cortex and the left intraparietal sulcus were found to combine task- and stimulus-related signals. These regions showed maximal activation when participants monitored two categories at spatially separate locations and the scene included a nontarget object. We conclude that the dorsal frontoparietal cortex integrates top-down and bottom-up signals in the presence of distractors during divided attention in real-world scenes.

Random walk of passive tracers among randomly moving obstacles

OpenAIRE

Gori, Matteo; Donato, Irene; Floriani, Elena; Nardecchia, Ilaria; Pettini, Marco

2016-01-01

Background: This study is mainly motivated by the need of understanding how the diffusion behaviour of a biomolecule (or even of a larger object) is affected by other moving macromolecules, organelles, and so on, inside a living cell, whence the possibility of understanding whether or not a randomly walking biomolecule is also subject to a long-range force field driving it to its target. Method: By means of the Continuous Time Random Walk (CTRW) technique the topic of random walk in random en...

Bridging the Digital Divide--An Australian Story

Science.gov (United States)

Broadbent, Robyn; Papadopoulos, Theo

2013-01-01

There is increasing evidence that the lack of access to information and communication technology (ICT) or the "digital divide" severely limits education, employment and economic prospects. This paper reports on the evaluation of a project that aims to bridge the digital divide. In particular, the case study data has been used to bring to…

The Digital Divide Revisited: What Is Next?

Science.gov (United States)

Huffman, Stephanie

2018-01-01

As soon as the Internet came into existence and the World Wide Web was introduced to make Internet utilization much easier, leaders have been worried about the "digital divide." The digital divide refers to the inequality of access to information services. There has been marked improvements over the last 20 years, however the poorest…

Social Welfare Implications of the Digital Divide

Science.gov (United States)

Kim, Eunjin; Lee, Byungtae; Menon, Nirup M.

2009-01-01

The Internet plays a critical role in informing individuals about society, politics, business, and the environment. So much so that it has been said that the digital divide makes the segment of society on the ''right side'' of the divide (the digitally endowed group) better off and that on the ''wrong side'' (the digitally challenged group) worse…

Effects of preemptive analgesia with flurbiprofen ester on lymphocytes and natural killer cells in patients undergoing esophagectomy: A randomized controlled pilot study.

Science.gov (United States)

Zhou, Yi; Huang, Jinxi; Bai, Yu; Li, Changsheng; Lu, Xihua

2017-11-01

Tumors may induce systemic immune dysfunction, which can be aggravated by surgery and anesthesia/analgesia. Data on the effect of flurbiprofen preemptive analgesia on immune dysfunction is limited. The aim of this study was to investigate the effect of flurbiprofen preemptive analgesia on lymphocytes and natural killer (NK) cells in patients undergoing thoracotomy and thoracoscopy radical esophagectomy, and to explore the analgesic methods suitable for tumor patients. This was a randomized controlled pilot study of 89 patients with esophageal cancer treated with surgery at the Henan Cancer Hospital between January 1, 2015 and December 31, 2016. The patients were divided into three groups: group 1, thoracotomy; group 2, thoracoscopy and laparoscopic surgery; and group 3, flurbiprofen, thoracoscopy, and laparoscopic surgery. CD3+, CD19+, NK, CD4+, and CD8+ cells in whole blood were measured by flow cytometry 30 minutes before surgery (T0), at the end of the thoracic section of the procedure (T1), and at the end of the operation (T2). There were no significant differences in CD3+, CD19+, CD8+, NK, and CD4+ cells between the three groups or regarding the time points during the procedure (all P > 0.05). Thoracotomy and thoracoscopy surgery resulted in similar immunological outcomes. Flurbiprofen ester preemptive analgesia did not suppress the immune function in patients and could be a safe analgesic method for patients with esophageal cancer undergoing surgery. © 2017 The Authors. Thoracic Cancer published by China Lung Oncology Group and John Wiley & Sons Australia, Ltd.

The digital health divide: evaluating online health information access and use among older adults.

Science.gov (United States)

Hall, Amanda K; Bernhardt, Jay M; Dodd, Virginia; Vollrath, Morgan W

2015-04-01

Innovations in health information technology (HIT) provide opportunities to reduce health care spending, improve quality of care, and improve health outcomes for older adults. However, concerns relating to older adults' limited access and use of HIT, including use of the Internet for health information, fuel the digital health divide debate. This study evaluated the potential digital health divide in relation to characteristic and belief differences between older adult users and nonusers of online health information sources. A cross-sectional survey design was conducted using a random sample of older adults. A total of 225 older adults (age range = 50-92 years, M = 68.9 years, SD = 10.4) participated in the study. Seventy-six percent of all respondents had Internet access. Users and nonusers of online health information differed significantly on age (M = 66.29 vs. M = 71.13), education, and previous experience with the health care system. Users and nonusers of online health information also differed significantly on Internet and technology access, however, a large percentage of nonusers had Internet access (56.3%), desktop computers (55.9%), and laptop computers or netbooks (43.2%). Users of online health information had higher mean scores on the Computer Self-Efficacy Measure than nonusers, t(159) = -7.29, p information. Findings suggest strategies for reducing this divide and implications for health education programs to promote HIT use among older adults. © 2014 Society for Public Health Education.

Bridging the digital divide: with special reference to Nigeria ...

African Journals Online (AJOL)

This paper describes the digital divide in Africa with special reference to Nigeria. It presents the causes of digital divided such as; the general poor economic conditions in Africa; local content; telecommunications constraints; lack of investment in ICT infrastructure, etc. Benefits derivable from bridging the digital divide such ...

The digital divide as a complex and dynamic phenomenon

NARCIS (Netherlands)

van Dijk, Johannes A.G.M.; Hacker, Kenneth

2003-01-01

The purpose of this article is to propose a fruitful analytical framework for data supposedly related to the concept of the socalled “digital divide.” The extent and the nature of this divide depend on the kind of access defined. Considering the possession of hardware, growing divides among

The New Frontier of Digital Inequality. The Participatory Divide

Directory of Open Access Journals (Sweden)

José M. Robles Morales

2016-01-01

Full Text Available This article focuses on the relationship between digital participation and the digital participation divide. The first concept refers to the use of the Internet to produce cultural goods that are subsequently shared on a global scale; the latter, refers to the inequalities generated by the uneven distribution of these creative uses of the Internet in a given population. Empirically, our work focuses on the role of digital skills and sociopolitical attitudes toward the Internet in explaining the digital participation divide, as they are considered precursors of digital participation. Results suggest that the same mechanisms that previously sustained digital divide are now fostering digital participation divide; however, we argue that the negative social consequences of this divide exceed those of its predecessor.

Uneven Distribution of Microgranules in Divided Lansoprazole Tablets.

Science.gov (United States)

Teitelbaum, Gillian A; Teitelbaum, Jonathan E

2015-10-01

Lansoprazole is a proton pump inhibitor commonly used in children lansoprazole-containing microgranules within each half of a divided tablet. Clinicians must determine whether this difference is clinically relevant when prescribing "divided" medication to children.

Quantum random access memory

OpenAIRE

Giovannetti, Vittorio; Lloyd, Seth; Maccone, Lorenzo

2007-01-01

A random access memory (RAM) uses n bits to randomly address N=2^n distinct memory cells. A quantum random access memory (qRAM) uses n qubits to address any quantum superposition of N memory cells. We present an architecture that exponentially reduces the requirements for a memory call: O(log N) switches need be thrown instead of the N used in conventional (classical or quantum) RAM designs. This yields a more robust qRAM algorithm, as it in general requires entanglement among exponentially l...

[Promoting nursing competitiveness: introduction to the digital divide].

Science.gov (United States)

Lin, Chun-Hsu; Lee, Ting-Ting

2010-02-01

Increasingly sophisticated information technology (IT) has widened the gap (the so-called "digital divide") between those with effective access to IT resources and those without. Problems related to the digital divide exist in every country. In addition to level of familiarity with technology, the divide can also be influenced by factors of race, gender, age, education, economic status and area of residence. The digital divide may be ameliorated through technology innovations in terms of access to information, information application and information literacy. As IT is an increasingly significant component of modern healthcare, it may be expected that the "width" of the potential gap widens as IT applications increase in sophistication. Nursing professionals must keep abreast of advancing technologies in order to narrow the digital divide. To cope with this challenge, nursing professionals should enhance their understanding of new technologies beyond what is taught in formal education curricula. This knowledge enhancement may be attained through self learning or on-the-job training in nursing informatics. Content could cover hospital information system (IS) usage, security, applications and web access. This will improve the ability of nursing staff to face the current IT challenge.

Spaceflight enhances cell aggregation and random budding in Candida albicans.

Directory of Open Access Journals (Sweden)

Aurélie Crabbé

Full Text Available This study presents the first global transcriptional profiling and phenotypic characterization of the major human opportunistic fungal pathogen, Candida albicans, grown in spaceflight conditions. Microarray analysis revealed that C. albicans subjected to short-term spaceflight culture differentially regulated 452 genes compared to synchronous ground controls, which represented 8.3% of the analyzed ORFs. Spaceflight-cultured C. albicans-induced genes involved in cell aggregation (similar to flocculation, which was validated by microscopic and flow cytometry analysis. We also observed enhanced random budding of spaceflight-cultured cells as opposed to bipolar budding patterns for ground samples, in accordance with the gene expression data. Furthermore, genes involved in antifungal agent and stress resistance were differentially regulated in spaceflight, including induction of ABC transporters and members of the major facilitator family, downregulation of ergosterol-encoding genes, and upregulation of genes involved in oxidative stress resistance. Finally, downregulation of genes involved in actin cytoskeleton was observed. Interestingly, the transcriptional regulator Cap1 and over 30% of the Cap1 regulon was differentially expressed in spaceflight-cultured C. albicans. A potential role for Cap1 in the spaceflight response of C. albicans is suggested, as this regulator is involved in random budding, cell aggregation, and oxidative stress resistance; all related to observed spaceflight-associated changes of C. albicans. While culture of C. albicans in microgravity potentiates a global change in gene expression that could induce a virulence-related phenotype, no increased virulence in a murine intraperitoneal (i.p. infection model was observed under the conditions of this study. Collectively, our data represent an important basis for the assessment of the risk that commensal flora could play during human spaceflight missions. Furthermore, since the

Effect of cotransplantation of hematopoietic stem cells and embryonic AGM stromal cells on hematopoietic reconstitution in mice after bone marrow transplantation

International Nuclear Information System (INIS)

Tao Si; Sun Hanying; Liu Wenli

2007-01-01

Objective: To explore the effects of cotransplantation of hematopoietic stem cells and stromal cells derived from aorta-gonad-mesonephros (AGM) region on hematopoietic reconstitution in mice after bone marrow transplantation (BMT). Methods: The typical mice model of syngeneic BMT was established and the mice were randomly divided into 4 groups: the control group, the BMT group, the group of cotransplantation of HSC with AGM stromal cells (the cotransplantation group) and the ligustrazine group (the LT group). On days 3, 7, 10, 14, 21 and 28 after BMT, the peripheral blood cells and bone marrow mononuclear cells (BMMNC) were counted, and histology changes of bone marrow were detected. Results: The levels of peripheral WBC, RBC, platelet, and BMMNC in the contransplantation group were significantly higher than those in the single BMT group and the LT group (P<0.05). Conclusions: Cotransplantation with AGM stromal cells could significantly promote hematopoietic reconstruction in mice after BMT. (authors)

[Effect of Sijunzi Decoction and enteral nutrition on T-cell subsets and nutritional status in patients with gastric cancer after operation: a randomized controlled trial].

Science.gov (United States)

Cai, Jun; Wang, Hua; Zhou, Sheng; Wu, Bin; Song, Hua-Rong; Xuan, Zheng-Rong

2008-01-01

To observe the effect of perioperative application of Sijunzi Decoction and enteral nutrition on T-cell subsets and nutritional status in patients with gastric cancer after operation. In this prospective, single-blinded, controlled clinical trial, fifty-nine patients with gastric cancer were randomly divided into three groups: control group (n=20) and two study groups (group A, n=21; group B, n=18). Sjunzi Decoction (100 ml) was administered via nasogastric tube to the patients in the study group B from the second postoperation day to the 9th postoperation day. Patients in the two study groups were given an isocaloric and isonitrogonous enteral diet, which was started on the second day after operation, and continued for eight days. Patients in the control group were given an isocaloric and isonitrogonous parenteral diet for 9 days. All variables of nutritional status such as serum albumin (ALB), prealbumin (PA), transferrin (TRF) and T-cell subsets were measured one day before operation, and one day and 10 days after operation. All the nutritional variables and the levels of CD3(+), CD4(+), CD4(+)/CD8(+) were decreased significantly after operation. Ten days after operation, T-cell subsets and nutritional variables in the two study groups were increased as compare with the control group. The levels of ALB, TRF and T-cell subsets in the study group B were increased significantly as compared with the study group A (Pnutrition assisted with Sijunzi Decoction can positively improve and optimize cellular immune function and nutritional status in the patients with gastric cancer after operation.

Conjunctival Goblet Cell Density Following Cataract Surgery With Diclofenac Versus Diclofenac and Rebamipide: A Randomized Trial.

Science.gov (United States)

Kato, Kumiko; Miyake, Kensaku; Kondo, Nagako; Asano, Sayaka; Takeda, Junko; Takahashi, Akiko; Takashima, Yuko; Kondo, Mineo

2017-09-01

To determine the effects of topical diclofenac or betamethasone with concomitant application of topical rebamipide on the conjunctival goblet cell density in eyes after cataract surgery. Randomized clinical trial. Eighty patients who were scheduled for cataract surgery. Patients were randomized into 4 groups according to the postoperative topical drugs to be given; Group A, diclofenac alone; Group B, diclofenac and rebamipide; Group C, betamethasone alone; and Group D, betamethasone and rebamipide. Impression cytology was performed before and at 1 month after the surgery, and the mean density of goblet cells was determined. The mean (± SD) density of goblet cells before the surgery in Group A was 257.0 ± 188.7 cells/mm 2 , and it decreased significantly to 86.5 ± 76.7 cells/mm 2 at 1 month after the surgery (P = .002). In Group B, the goblet cell density was not statistically different between before (238.5 ± 116.6 cells/mm 2 ) and at 1 month after the surgery (211.3 ± 184.4 cells/mm 2 , P = .55). In Groups C and D, the mean density of goblet cells was decreased at 1 month after the surgery, but the decreases were not significant (P = .11 and P = .52, respectively). After cataract surgery with postoperative topical diclofenac, the conjunctival goblet cell density was significantly reduced, and this reduction was blocked by the concomitant use of topical rebamipide. These results suggest that the concomitant use of topical rebamipide with nonsteroidal anti-inflammatory drugs is beneficial, especially in cases with postoperative dry eyes. Copyright © 2017 The Author(s). Published by Elsevier Inc. All rights reserved.

Divided attention: an undesirable difficulty in memory retention.

Science.gov (United States)

Gaspelin, Nicholas; Ruthruff, Eric; Pashler, Harold

2013-10-01

How can we improve memory retention? A large body of research has suggested that difficulty encountered during learning, such as when practice sessions are distributed rather than massed, can enhance later memory performance (see R. A. Bjork & E. L. Bjork, 1992). Here, we investigated whether divided attention during retrieval practice can also constitute a desirable difficulty. Following two initial study phases and one test phase with Swahili-English word pairs (e.g., vuvi-snake), we manipulated whether items were tested again under full or divided attention. Two days later, participants were brought back for a final cued-recall test (e.g., vuvi-?). Across three experiments (combined N = 122), we found no evidence that dividing attention while practicing retrieval enhances memory retention. This finding raises the question of why many types of difficulty during practice do improve long-term retention, but dividing attention does not.

High Power Combiner/Divider with Coupled Lines for Broadband Applications

Science.gov (United States)

2017-03-20

novel isolation structure will also be presented. I. INTRODUCTION Power divider/combiners are traditionally used in the development of high power ...a novel Gysel divider/combiner structure have been demonstrated. The divider/combiner are applicable to various high- power , broadband radar, EW...Gysel Power Divider With Arbitrary Power Ratios and Filtering Responses Using Coupling Structure ,” IEEE Transactions on Microwave Theory and Tech., vol

A randomized, double blind trial of prophylactic fibrinogen to reduce bleeding in cardiac surgery

Directory of Open Access Journals (Sweden)

Mostafa Sadeghi

2014-07-01

Full Text Available BACKGROUND AND OBJECTIVES: Postoperative bleeding has a great clinical importance and can contribute to increased mortality and morbidity in patients undergoing coronary artery bypass graft surgery. In this prospective, randomized, double-blind study, we evaluated the effect of prophylactic administration of fibrinogen concentrate on post-coronary artery bypass graft surgery bleeding. METHODS: A total of 60 patients undergoing coronary artery bypass surgery were randomly divided into two groups. Patients in the fibrinogen group received 1 g of fibrinogen concentrate 30 min prior to the operation, while patients in the control group received placebo. Post-operative bleeding volumes, prothrombin time, partial thromboplastin time, INR, hemoglobin and transfused blood products in both groups were recorded. A strict red blood cell transfusion protocol was used in all patients. RESULTS: There were no significant differences between intra-operative packed red blood cells infusion in the studied groups (1.0 ± 1.4 in fibrinogen group, and 1.3 ± 1.1 in control group. Less postoperative bleeding was observed in the fibrinogen group (477 ± 143 versus 703 ± 179, p = 0.0001. Fifteen patients in the fibrinogen group and 21 in the control group required post-op packed red blood cells infusion (p = 0.094. No thrombotic event was observed through 72 h after surgery. CONCLUSION: Prophylactic fibrinogen reduces post-operative bleeding in patients undergoing coronary artery bypass graft.

Simulation of Material Flow Through a Sample Divider

Directory of Open Access Journals (Sweden)

Jiří Rozbroj

2018-03-01

Full Text Available The prerequisite for a modern approach to innovative procedures of the development of current or even newly created equipment for the transport of particulate materials is the utilization of simulation methods, such as the Discrete Element Method (DEM. This article focuses on the basic, or initial, validation of movement of material through the sample divider. The mechanical-physical properties of brown coal were measured. Based on these parameters the preliminary input values for EDEM Academic were selected, and a simulation of the dividing process was run. The key monitored parameters included density and friction coefficient. Experiments on a realistic model of the equipment were performed and assessed. The total weights of brown coal at the exit from the divider were determined for a specific speed of the divider. The aim of this task was to simulate the realistically determined weight division of the brown coal sample. The result from the DEM was compared with the results of measurement on a realistic model.

Romania's Digital Divide and the Failures of E-Government

Directory of Open Access Journals (Sweden)

Sorin Dan ŞANDOR

2006-02-01

Full Text Available This paper tries to measure the level of the digital divide existing in Romania and also to verify its relationship with e-government. At the country level, Romania is one of the least digitally developed countries in Europe, but it has shown a sharp increase in recent years. At the social level, based on data from public opinion surveys, digital divide is analyzed at two levels: lack of access and lack of knowledge. The results are similar to those in other countries: digital divide appears along the same dimensions: rural/urban, age, education, wealth and, to a lesser extent, gender. E-government services, while presumed to be at an adequate level, are used only by a very small number of citizens, thus having no impact upon the digital divide. Confronted with a serious divide, and with great possibility of its increasing, Romania needs to promote policies designed to increase access and knowledge. Also, e-government is not possible, unless administrative culture and procedures change.

A Divided Attention Experiment with Pervasively Hyperactive Children.

Science.gov (United States)

van der Meere, Jaap; Sergeant, Joseph

1987-01-01

Task performance of 12 pervasive hyperactives and controls (ages 8-13) was studied in a divided attention reaction time experiment. Hyperactives were slower than controls, had more variable reaction times, and made more frequent errors. Task inefficiency in hyperactives could not be explained by a divided attention deficiency or impulsive…

Introducing the RadBioStat Educational Software: Computer-Assisted Teaching of the Random Nature of Cell Killing

Directory of Open Access Journals (Sweden)

Safari A

2014-06-01

Full Text Available The interaction of radiation with cells and tissues has a random nature. Therefore, understanding the random nature of cell killing that is determined by Poisson distribution statistics is an essential point in education of radiation biology. RadBioStat is a newly developed educational MATLAB-based software designed for computer-assisted learning of the target theory in radiation biology. Although its potential applications is developing rapidly, currently RadBioStat software can be a useful tool in computerassisted education of radiobiological models such as single target single hit, multiple target single hit and multiple target multiple hit. Scholars’ feedback is valuable to the producers of this software and help them continuously improve this product, add new features and increase its desirability and functionality.

The Apply of Frequency Divider Circuit in Nuclear Electronics

International Nuclear Information System (INIS)

LIU Hefan; Zeng Bing; Zhang Ziliang; Ge Liangquan

2009-01-01

Different components in a digital system often need different working frequencies, the way we often used is clock division from the system clock. Through the analysis of frequency divider principle, a applied integer frequency dividing circuit with SE120A is proposed. It can divide the frequency multiple from 2 to 64. It's usually used in nuclear electronics. It's testing and analysis is displayed that it has no noise, good frequency division effect and stability. (authors)

Asymptotic Properties of Multistate Random Walks. II. Applications to Inhomogeneous Periodic and Random Lattices

NARCIS (Netherlands)

Roerdink, J.B.T.M.; Shuler, K.E.

1985-01-01

The previously developed formalism for the calculation of asymptotic properties of multistate random walks is used to study random walks on several inhomogeneous periodic lattices, where the periodically repeated unit cell contains a number of inequivalent sites, as well as on lattices with a random

A pulse amplitude dividing circuit for nuclear applications

International Nuclear Information System (INIS)

Ediss, C.; McQuarrie, S.A.

1981-01-01

A pulse dividing circuit has been developed to provide analogue and digital outputs proportional to the ratio of the amplitudes of two nuclear pulses. Input pulses ranging from 200 mV to 10 V may be processed by the device. The pulse dividing circuit has been successfully incorporated as part of a small gamma camera. (orig.)

Digital Divide Measurement in Lembata Regency Using SIBIS

Science.gov (United States)

Gabriel, Cecilia Dai Payon Binti; Setyohadi, Djoko Budiyanto; Suyoto

2018-02-01

Along with technological development in Indonesia, digital divide occurs in various regions, which were behind in terms of information on how to use, access and utilize ICT in collecting information from internet. One of the regions is Lembata Regency in East Nusa Tenggara, where digital divide among the people should be measured. The purpose of this study was to determine the level of digital divide among the people of Lembata Regency. To determine the level of digital divide, we used SIBIS GPS (General Population Survey) method, which consisted of several indicators or aspect, i.e. internet usage behavior, internet utilization, and e-government. We also performed two tests, i.e. validity test and reliability test to obtain value of index of digital divide measurement among the people of Lembata Regency. The results of validity test which is processed using SPSS program are categorized valid for each variable indicator and the reliability test results show reliable status. According to the test results on digital discrepancy in Lembata people, the internet usage attitude indicator is categorized low which is 63.1%, the internet usage function indicator is categorized low which is 64%, and the digital discrepancy of e-government indicator is categorized medium which is 40.4%. Therefore, the result of this study because consideration for the government of Lembata Regency in improving ICT services in e-government and in distributing ICT access and ability equally to the people.

Research of the method of pseudo-random number generation based on asynchronous cellular automata with several active cells

Directory of Open Access Journals (Sweden)

Bilan Stepan

2017-01-01

Full Text Available To date, there are many tasks that are aimed at studying the dynamic changes in physical processes. These tasks do not give advance known result. The solution of such problems is based on the construction of a dynamic model of the object. Successful structural and functional implementation of the object model can give a positive result in time. This approach uses the task of constructing artificial biological objects. To solve such problems, pseudo-random number generators are used, which also find wide application for information protection tasks. Such generators should have good statistical properties and give a long repetition period of the generated pseudo-random bit sequence. This work is aimed at improving these characteristics. The paper considers the method of forming pseudo-random sequences of numbers on the basis of aperiodic cellular automata with two active cells. A pseudo-random number generator is proposed that generates three bit sequences. The first two bit sequences are formed by the corresponding two active cells in the cellular automaton. The third bit sequence is the result of executing the XOR function over the bits of the first two sequences and it has better characteristics compared to them. The use of cellular automata with two active cells allowed to improve the statistical properties of the formed bit sequence, as well as its repetition period. This is proved by using graphical tests for generators built based on cellular automata using the neighborhoods of von Neumann and Moore. The tests showed high efficiency of the generator based on an asynchronous cellular automaton with the neighborhood of Moore. The proposed pseudo-random number generators have good statistical properties, which makes it possible to use them in information security systems, as well as for simulation tasks of various dynamic processes.

Flexible conductive-bridging random-access-memory cell vertically stacked with top Ag electrode, PEO, PVK, and bottom Pt electrode

Science.gov (United States)

Seung, Hyun-Min; Kwon, Kyoung-Cheol; Lee, Gon-Sub; Park, Jea-Gun

2014-10-01

Flexible conductive-bridging random-access-memory (RAM) cells were fabricated with a cross-bar memory cell stacked with a top Ag electrode, conductive polymer (poly(n-vinylcarbazole): PVK), electrolyte (polyethylene oxide: PEO), bottom Pt electrode, and flexible substrate (polyethersulfone: PES), exhibiting the bipolar switching behavior of resistive random access memory (ReRAM). The cell also exhibited bending-fatigue-free nonvolatile memory characteristics: i.e., a set voltage of 1.0 V, a reset voltage of -1.6 V, retention time of >1 × 105 s with a memory margin of 9.2 × 105, program/erase endurance cycles of >102 with a memory margin of 8.4 × 105, and bending-fatigue-free cycles of ˜1 × 103 with a memory margin (Ion/Ioff) of 3.3 × 105.

Getting Past the "Digital Divide"

Science.gov (United States)

McCollum, Sean

2011-01-01

In the last decade, "digital divide" has become a catchphrase for the stubborn disparity in IT resources between communities, especially in regard to education. Low-income, rural and minority populations have received special scrutiny as the technological "have-nots." This article presents success stories of educators who can work around obstacles…

The digital divide as a complex and dynamic phenomenon

OpenAIRE

van Dijk, Johannes A.G.M.; Hacker, Kenneth

2003-01-01

The purpose of this article is to propose a fruitful analytical framework for data supposedly related to the concept of the socalled “digital divide.” The extent and the nature of this divide depend on the kind of access defined. Considering the possession of hardware, growing divides among different categories of income, employment, education, age, and ethnicity can be proved to have existed in the 1980s and 1990s according to official American and Dutch statistics. If only by effects of sat...

Joint estimation and contention-resolution protocol for wireless random access

DEFF Research Database (Denmark)

Stefanovic, Cedomir; Trillingsgaard, Kasper Fløe; Kiilerich Pratas, Nuno

2013-01-01

We propose a contention-based random-access protocol, designed for wireless networks where the number of users is not a priori known. The protocol operates in rounds divided into equal-duration slots, performing at the same time estimation of the number of users and resolution of their transmissi......We propose a contention-based random-access protocol, designed for wireless networks where the number of users is not a priori known. The protocol operates in rounds divided into equal-duration slots, performing at the same time estimation of the number of users and resolution...... successive interference cancellation which, coupled with the use of the optimized access probabilities, enables throughputs that are substantially higher than the traditional slotted ALOHA-like protocols. The key feature of the proposed protocol is that the round durations are not a priori set...

Dividing traffic cluster into parts by signal control

Science.gov (United States)

Nagatani, Takashi

2018-02-01

When a cluster of vehicles with various speeds moves through the series of signals, the cluster breaks down by stopping at signals and results in smaller groups of vehicles. We present the nonlinear-map model of the motion of vehicles controlled by the signals. We study the breakup of a cluster of vehicles through the series of signals. The cluster of vehicles is divided into various groups by controlling the cycle time of signals. The vehicles within each group move with the same mean velocity. The breakup of the traffic cluster depends highly on the signal control. The dependence of dividing on both cycle time and vehicular speed is clarified. Also, we investigate the effect of the irregular interval between signals on dividing.

Adipose-derived stem cells transfected with pEGFP-OSX enhance bone formation during distraction osteogenesis*

OpenAIRE

Lai, Qing-guo; Sun, Shao-long; Zhou, Xiao-hong; Zhang, Chen-ping; Yuan, Kui-feng; Yang, Zhong-jun; Luo, Sheng-lei; Tang, Xiao-peng; Ci, Jiang-bo

2014-01-01

This study was designed to investigate the effects of local delivery of adipose-derived stem cells (ADSCs) transfected with transcription factor osterix (OSX) on bone formation during distraction osteogenesis. New Zealand white rabbits (n=54) were randomly divided into three groups (18 rabbits per group). A directed cloning technique was used for the construction of recombinant plasmid pEGFP-OSX, where EGFP is the enhanced green fluorescence protein. After osteodistraction of the right mandib...

New mechanism to cross the phantom divide

OpenAIRE

Du, Yunshuang; Zhang, Hongsheng; Li, Xin-Zhou

2010-01-01

Recently, type Ia supernovae data appear to support a dark energy whose equation of state $w$ crosses -1, which is a much more amazing problem than the acceleration of the universe. We show that it is possible for the equation of state to cross the phantom divide by a scalar field in the gravity with an additional inverse power-law term of Ricci scalar in the Lagrangian. The necessary and sufficient condition for a universe in which the dark energy can cross the phantom divide is obtained. So...

Capacitive divider for output voltage measurement of intense electron beam accelerator

International Nuclear Information System (INIS)

Ding Desheng; Yi Lingzhi; Yu Binxiong; Hong Zhiqiang; Liu Jinliang

2012-01-01

A kind of simple-mechanism, easy-disassembly self-integrating capacitive divider used for measuring diode output voltage of intense electron beam accelerator (IEBA) is developed. The structure of the capacitive divider is described, and the capacitance value of the capacitive divider is calculated by theoretical analysis and electromagnetic simulation. The dependence of measurement voltage on electrical parameters such as stray capacitance, earth capacitance of front resistance is obtained by PSpice simulation. Measured waveforms appear overshoot phenomenon when stray capacitance of front resistance is larger, and the wavefront will be affected when earth capacitance of front resistance is larger. The diode output voltage waveforms of intense electron beam accelerator, are measured by capacitive divider and calibrated by water resistance divider, which is accordance with that measured by a resistive divider, the division ratio is about 563007. The designed capacitive divider can be used to measure high-voltage pulse with 100 ns full width at half maximum. (authors)

Evaluation of the divided attention condition during functional analyses.

Science.gov (United States)

Fahmie, Tara A; Iwata, Brian A; Harper, Jill M; Querim, Angie C

2013-01-01

A common condition included in most functional analyses (FAs) is the attention condition, in which the therapist ignores the client by engaging in a solitary activity (antecedent event) but delivers attention to the client contingent on problem behavior (consequent event). The divided attention condition is similar, except that the antecedent event consists of the therapist conversing with an adult confederate. We compared the typical and divided attention conditions to determine whether behavior in general (Study 1) and problem behavior in particular (Study 2) were more sensitive to one of the test conditions. Results showed that the divided attention condition resulted in faster acquisition or more efficient FA results for 2 of 9 subjects, suggesting that the divided attention condition could be considered a preferred condition when resources are available. © Society for the Experimental Analysis of Behavior.

Harmonic-suppressed quadrature-input frequency divider for OFDM systems

International Nuclear Information System (INIS)

Fu Haipeng; Ren Junyan; Li Wei; Li Ning

2011-01-01

A fully balanced harmonic-suppressed quadrature-input frequency divider is proposed. The frequency divider improves the quadrature phase accuracy at the output by using both input I/Q signals. Compared with conventional dividers, the circuit achieves an output I/Q phase sequence that is independent of the input I/Q phase sequence. Moreover, the third harmonic is effectively suppressed by employing a double degeneration technique. The design is fabricated in TSMC 0.13-μm CMOS and operated at 1.2 V. While locked at 8.5 GHz, the proposed divider measures a maximum third harmonic rejection of 45 dB and a phase noise of −124 dBc/Hz at a 10 MHz offset. The circuit achieves a locking range of 15% while consuming a total current of 4.5 mA. (semiconductor integrated circuits)

Divided attention deficits in patients with chronic fatigue syndrome.

Science.gov (United States)

Ross, S; Fantie, B; Straus, S F; Grafman, J

2001-01-01

Chronic fatigue syndrome (CFS) patients and controls were compared on a variety of mood state, personality, and neuropsychological measures, including memory, word finding, and attentional tasks that required participants to focus, sustain, or divide their attention, or to perform a combination of these functions. CFS patients demonstrated a selective deficit on 3 measures of divided attention. Their performance on the other neuropsychological tests of intelligence, fluency, and memory was no different than that of normal controls despite their reports of generally diminished cognitive capacity. There was an inverse relation between CFS patient fatigue severity and performance on 1 of the divided attention measures. Given these findings, it is probable that CFS patients will report more cognitive difficulties in real-life situations that cause them to divide their effort or rapidly reallocate cognitive resources between 2 response channels (vision and audition).

Amplification of neural stem cell proliferation by intermediate progenitor cells in Drosophila brain development

Directory of Open Access Journals (Sweden)

Bello Bruno C

2008-02-01

Full Text Available Abstract Background In the mammalian brain, neural stem cells divide asymmetrically and often amplify the number of progeny they generate via symmetrically dividing intermediate progenitors. Here we investigate whether specific neural stem cell-like neuroblasts in the brain of Drosophila might also amplify neuronal proliferation by generating symmetrically dividing intermediate progenitors. Results Cell lineage-tracing and genetic marker analysis show that remarkably large neuroblast lineages exist in the dorsomedial larval brain of Drosophila. These lineages are generated by brain neuroblasts that divide asymmetrically to self renew but, unlike other brain neuroblasts, do not segregate the differentiating cell fate determinant Prospero to their smaller daughter cells. These daughter cells continue to express neuroblast-specific molecular markers and divide repeatedly to produce neural progeny, demonstrating that they are proliferating intermediate progenitors. The proliferative divisions of these intermediate progenitors have novel cellular and molecular features; they are morphologically symmetrical, but molecularly asymmetrical in that key differentiating cell fate determinants are segregated into only one of the two daughter cells. Conclusion Our findings provide cellular and molecular evidence for a new mode of neurogenesis in the larval brain of Drosophila that involves the amplification of neuroblast proliferation through intermediate progenitors. This type of neurogenesis bears remarkable similarities to neurogenesis in the mammalian brain, where neural stem cells as primary progenitors amplify the number of progeny they generate through generation of secondary progenitors. This suggests that key aspects of neural stem cell biology might be conserved in brain development of insects and mammals.

Dividing Fractions: A Pedagogical Technique

Science.gov (United States)

Lewis, Robert

2016-01-01

When dividing one fraction by a second fraction, invert, that is, flip the second fraction, then multiply it by the first fraction. To multiply fractions, simply multiply across the denominators, and multiply across the numerators to get the resultant fraction. So by inverting the division of fractions it is turned into an easy multiplication of…

Cell-cycle regulation in green algae dividing by multiple fission

Czech Academy of Sciences Publication Activity Database

Bišová, Kateřina; Zachleder, Vilém

2014-01-01

Roč. 65, č. 10 (2014), s. 2585-2602 ISSN 0022-0957 R&D Projects: GA ČR M200201205; GA MŠk LH12145 Grant - others:Centre for Algal Biotechnologies (Algatech)(CZ) CZ.1.05/2.1.00/03.0110 Institutional support: RVO:61388971 Keywords : cell cycle * regulation * growth * light Subject RIV: EE - Microbiology, Virology Impact factor: 5.526, year: 2014

EXERCISE in pediatric autologous stem cell transplant patients: a randomized controlled trial protocol

Directory of Open Access Journals (Sweden)

Chamorro-Viña Carolina

2012-09-01

Full Text Available Abstract Background Hematopoietic stem cell transplantation is an intensive therapy used to improve survivorship and cure various oncologic diseases. However, this therapy is associated with high mortality rates and numerous negative side-effects. The recovery of the immune system is a special concern and plays a key role in the success of this treatment. In healthy populations it is known that exercise plays an important role in immune system regulation, but little is known about the role of exercise in the hematological and immunological recovery of children undergoing hematopoietic stem cell transplant. The primary objective of this randomized-controlled trial (RCT is to study the effect of an exercise program (in- and outpatient on immune cell recovery in patients undergoing an autologous stem cell transplantation. The secondary objective is to determine if an exercise intervention diminishes the usual deterioration in quality of life, physical fitness, and the acquisition of a sedentary lifestyle. Methods This RCT has received approval from The Conjoint Health Research Ethics Board (CHREB of the University of Calgary (Ethics ID # E-24476. Twenty-four participants treated for a malignancy with autologous stem cell transplant (5 to 18 years in the Alberta Children’s Hospital will be randomly assigned to an exercise or control group. The exercise group will participate in a two-phase exercise intervention (in- and outpatient from hospitalization until 10 weeks after discharge. The exercise program includes strength, flexibility and aerobic exercise. During the inpatient phase this program will be performed 5 times/week and will be supervised. The outpatient phase will combine a supervised session with two home-based exercise sessions with the use of the Wii device. The control group will follow the standard protocol without any specific exercise program. A range of outcomes, including quantitative and functional recovery of immune system

A novel water resistor divider with a coaxial low-voltage arm.

Science.gov (United States)

Jia, Wei; Chen, Weiqing; Mao, Congguang; Zeng, Jiangtao

2010-03-01

A new style high voltage resistor divider made of saline solution has been constructed and tested. A coaxial construction is used on the low-voltage arm, as the signal extraction electrode, which can increase the attenuation ratio of the divider. The time response of divider limited by the stray parameter also can be improved. Comparing the results of calibrated experiment with the commonly used equal size copper sulfate dividers, the new probe has nearly five times increase in the attenuation ratio. The time response of the new style divider in the dimension of 30 mm in diameter and 400 mm in length can reach to 1 ns.

Investigation on Locking and Pulling Modes in Analog Frequency Dividers

Directory of Open Access Journals (Sweden)

Antonio Buonomo

2013-01-01

Full Text Available We compare the main analytical results available to estimate the locking range, which is the key figure-of-merit of LC frequency dividers based on the injection locking phenomenon. Starting from the classical result by Adler concerning injection-locked oscillators, we elucidate the merits and the shortcomings of the different approaches to study injection-locked frequency dividers, with particular emphasis on divider-by-2. In particular, we show the potential of a perturbation approach which enables a more complete analysis of frequency dividers, making it possible to calculate not only the amplitude and the phase of the locked oscillation, but also the region where it exists and is stable, which defines the locking region. Finally, we analyze the dynamical behaviour of the dividers in the vicinity of the boundary of the locking region, showing that there exists a border region where the occurrence of the locking or the pulling operation mode is possible, depending on the initial conditions of the system.

Bifurcation in asymmetric plasma divided by a magnetic filter

International Nuclear Information System (INIS)

Ohi, K.; Naitou, H.; Tauchi, Y.; Fukumasa, O.

2001-05-01

A magnetic filter (MF) reflecting electrons from both sides can separate a low-temperature and low-density subplasma from a high-temperature and high-density main plasma. The one-dimensional numerical simulation by the particle-in-cell code revealed that, depending on the asymmetry, the plasma divided by the MF behaves dynamically or statically [K. Ohi et al., Physics of Plasmas 8, 23 (2001)]. The transition between the two bifurcated states is discontinuous. In the dynamic state, the autonomous potential oscillation in the subplasma is synchronized with the passage of the shock wave structure generated by the modulated ion beam from the main plasma. The stationary phase of the dynamic state appears after the amplitude of the potential oscillation in the subplasma grows exponentially from the thermal noise. In the static state, the system is stable to the growth of the potential oscillation in the subplasma. (author)

Shaping the spectrum of random-phase radar waveforms

Science.gov (United States)

Doerry, Armin W.; Marquette, Brandeis

2017-05-09

The various technologies presented herein relate to generation of a desired waveform profile in the form of a spectrum of apparently random noise (e.g., white noise or colored noise), but with precise spectral characteristics. Hence, a waveform profile that could be readily determined (e.g., by a spoofing system) is effectively obscured. Obscuration is achieved by dividing the waveform into a series of chips, each with an assigned frequency, wherein the sequence of chips are subsequently randomized. Randomization can be a function of the application of a key to the chip sequence. During processing of the echo pulse, a copy of the randomized transmitted pulse is recovered or regenerated against which the received echo is correlated. Hence, with the echo energy range-compressed in this manner, it is possible to generate a radar image with precise impulse response.

Digital Divide between Teachers and Students in Urban Bangladesh

DEFF Research Database (Denmark)

Khalid, Md. Saifuddin

2011-01-01

Telecom boom since 2000 and ‘Digital Bangladesh’ campaign since late 2008 created significant nationwide hype, resulting rapid increase in the use of digital devices. While studies are being conducted to use the ability of “power users of technology” for reducing digital divide, there is hardly a...... into digital divide and associated reasons in four different educations systems in Bangladesh.......Telecom boom since 2000 and ‘Digital Bangladesh’ campaign since late 2008 created significant nationwide hype, resulting rapid increase in the use of digital devices. While studies are being conducted to use the ability of “power users of technology” for reducing digital divide, there is hardly any...... data available on them in Bangladesh context. A study was conducted to study the digital divide and ICT usage pattern among the urban students and teachers of schools and colleges in Dhaka, the capital of Bangladesh. About 75 students enrolled in probability and statistics course of Independent...

Performance of inverted polymer solar cells with randomly oriented ZnO nanorods coupled with atomic layer deposited ZnO

Energy Technology Data Exchange (ETDEWEB)

Zafar, Muhammad [School of Chemical Engineering, Chonnam National University, 300 Youngbong-dong, Gwangju 500-757 (Korea, Republic of); Yun, Ju-Young [Center for Vacuum, Korea Research Institute of Standards and Science, 267 Gajeong-ro, Daejeon 305-600 (Korea, Republic of); Kim, Do-Heyoung, E-mail: kdhh@chonnam.ac.kr [School of Chemical Engineering, Chonnam National University, 300 Youngbong-dong, Gwangju 500-757 (Korea, Republic of)

2017-03-15

Highlights: • Hydrothermally grown, randomly oriented, and low areal density ZnO nanorods have been successfully adopted as the electron transport layer in inverted organic solar cells. • The addition of atomic layer deposited ZnO on the ZnO nanorods effectively enhance the photovoltaic performances of inverted organic solar cells. • The inverted organic solar cells with 5 nm thick-ALD ZnO showed the highest power conversion efficiency of 3.08%, which is an enhancement of approximately 80% compared to the cells without the ALD ZnO layer (PCE = 1.67%). - Abstract: Nanostructuring of the electron transport layer (ETL) in organic photovoltaic cells (OPV) is of great interest because it increases the surface area of the cell and electron transport. In this work, hydrothermally grown, randomly oriented, and low areal density ZnO nanorods (NRs) have been adopted as the ETL, and the effect of adding atomic layer deposited (ALD) ZnO on the ZnO NRs on the inverted organic solar cell performance has been investigated. The fabricated inverted organic solar cell with 5-nm-thick ALD-ZnO grown on the ZnO NRs showed the highest power conversion efficiency (PCE) of 3.08%, which is an enhancement of 85% from that of the cell without ALD-ZnO (PCE = 1.67%). The ultrathin ALD-ZnO was found to act as a curing layer of the surface defects on the hydrothermally grown ZnO NRs, resulting in an improvement in photovoltaic performance.

Performance of inverted polymer solar cells with randomly oriented ZnO nanorods coupled with atomic layer deposited ZnO

International Nuclear Information System (INIS)

Zafar, Muhammad; Yun, Ju-Young; Kim, Do-Heyoung

2017-01-01

Highlights: • Hydrothermally grown, randomly oriented, and low areal density ZnO nanorods have been successfully adopted as the electron transport layer in inverted organic solar cells. • The addition of atomic layer deposited ZnO on the ZnO nanorods effectively enhance the photovoltaic performances of inverted organic solar cells. • The inverted organic solar cells with 5 nm thick-ALD ZnO showed the highest power conversion efficiency of 3.08%, which is an enhancement of approximately 80% compared to the cells without the ALD ZnO layer (PCE = 1.67%). - Abstract: Nanostructuring of the electron transport layer (ETL) in organic photovoltaic cells (OPV) is of great interest because it increases the surface area of the cell and electron transport. In this work, hydrothermally grown, randomly oriented, and low areal density ZnO nanorods (NRs) have been adopted as the ETL, and the effect of adding atomic layer deposited (ALD) ZnO on the ZnO NRs on the inverted organic solar cell performance has been investigated. The fabricated inverted organic solar cell with 5-nm-thick ALD-ZnO grown on the ZnO NRs showed the highest power conversion efficiency (PCE) of 3.08%, which is an enhancement of 85% from that of the cell without ALD-ZnO (PCE = 1.67%). The ultrathin ALD-ZnO was found to act as a curing layer of the surface defects on the hydrothermally grown ZnO NRs, resulting in an improvement in photovoltaic performance.

The Digital Divide in Health Education: Myth or Reality?

Science.gov (United States)

Stellefson, Michael; Chaney, Beth; Chaney, Don

2008-01-01

Although e-health interventions provide new opportunities for health education, there has been cause for concern regarding the purported information technology gap between those who have access to digital applications and those who do not--termed the "digital divide." The literature suggests, however, that this divide may now be illusory, driven…

Red blood cell transfusion triggers in acute leukemia: a randomized pilot study.

Science.gov (United States)

DeZern, Amy E; Williams, Katherine; Zahurak, Marianna; Hand, Wesley; Stephens, R Scott; King, Karen E; Frank, Steven M; Ness, Paul M

2016-07-01

Red blood cell (RBC) transfusion thresholds have yet to be examined in large randomized trials in hematologic malignancies. This pilot study in acute leukemia uses a restrictive compared to a liberal transfusion strategy. A randomized (2:1) study was conducted of restrictive (LOW) hemoglobin (Hb) trigger (7 g/dL) compared to higher (HIGH) Hb trigger (8 g/dL). The primary outcome was feasibility of conducting a larger trial. The four requirements for success required that more than 50% of the eligible patients could be consented, more than 75% of the patients randomized to the LOW arm tolerated the transfusion trigger, fewer than 15% of patients crossed over from the LOW arm to the HIGH arm, and no indication for the need to pause the study for safety concerns. Secondary outcomes included fatigue, bleeding, and RBCs and platelets transfused. Ninety patients were consented and randomly assigned to LOW to HIGH. The four criteria for the primary objective of feasibility were met. When the number of units transfused was compared, adjusting for baseline Hb, the LOW arm was transfused on average 8.0 (95% confidence interval [CI], 6.9-9.1) units/patient while the HIGH arm received 11.7 (95% CI, 10.1-13.2) units (p = 0.0003). There was no significant difference in bleeding events or neutropenic fevers between study arms. This study establishes feasibility for trial of Hb thresholds in leukemia through demonstration of success in all primary outcome metrics and a favorable safety profile. This population requires further study to evaluate the equivalence of liberal and restrictive transfusion thresholds in this unique clinical setting. © 2016 AABB.

Effects of total sleep deprivation on divided attention performance.

Science.gov (United States)

Chua, Eric Chern-Pin; Fang, Eric; Gooley, Joshua J

2017-01-01

Dividing attention across two tasks performed simultaneously usually results in impaired performance on one or both tasks. Most studies have found no difference in the dual-task cost of dividing attention in rested and sleep-deprived states. We hypothesized that, for a divided attention task that is highly cognitively-demanding, performance would show greater impairment during exposure to sleep deprivation. A group of 30 healthy males aged 21-30 years was exposed to 40 h of continuous wakefulness in a laboratory setting. Every 2 h, subjects completed a divided attention task comprising 3 blocks in which an auditory Go/No-Go task was 1) performed alone (single task); 2) performed simultaneously with a visual Go/No-Go task (dual task); and 3) performed simultaneously with both a visual Go/No-Go task and a visually-guided motor tracking task (triple task). Performance on all tasks showed substantial deterioration during exposure to sleep deprivation. A significant interaction was observed between task load and time since wake on auditory Go/No-Go task performance, with greater impairment in response times and accuracy during extended wakefulness. Our results suggest that the ability to divide attention between multiple tasks is impaired during exposure to sleep deprivation. These findings have potential implications for occupations that require multi-tasking combined with long work hours and exposure to sleep loss.

Effects of total sleep deprivation on divided attention performance.

Directory of Open Access Journals (Sweden)

Eric Chern-Pin Chua

Full Text Available Dividing attention across two tasks performed simultaneously usually results in impaired performance on one or both tasks. Most studies have found no difference in the dual-task cost of dividing attention in rested and sleep-deprived states. We hypothesized that, for a divided attention task that is highly cognitively-demanding, performance would show greater impairment during exposure to sleep deprivation. A group of 30 healthy males aged 21-30 years was exposed to 40 h of continuous wakefulness in a laboratory setting. Every 2 h, subjects completed a divided attention task comprising 3 blocks in which an auditory Go/No-Go task was 1 performed alone (single task; 2 performed simultaneously with a visual Go/No-Go task (dual task; and 3 performed simultaneously with both a visual Go/No-Go task and a visually-guided motor tracking task (triple task. Performance on all tasks showed substantial deterioration during exposure to sleep deprivation. A significant interaction was observed between task load and time since wake on auditory Go/No-Go task performance, with greater impairment in response times and accuracy during extended wakefulness. Our results suggest that the ability to divide attention between multiple tasks is impaired during exposure to sleep deprivation. These findings have potential implications for occupations that require multi-tasking combined with long work hours and exposure to sleep loss.

Isolating dividing neural and brain tumour cells for gene expression profiling

Czech Academy of Sciences Publication Activity Database

Endaya, B.; Cavanagh, B.; Alowaidi, F.; Walker, T.; de Pennington, N.; Ng, J.-M.; Lam, P.Y.P.; Mackay-Sim, A.; Neužil, Jiří; Meedeniya, A.C.B.

2016-01-01

Roč. 257, JAN 15 2016 (2016), s. 121-133 ISSN 0165-0270 Institutional support: RVO:86652036 Keywords : Cell division * Click chemistry * FACS Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 2.554, year: 2016

Is there a second level divide in students Internet skills?

DEFF Research Database (Denmark)

Dau, Susanne; Purushothaman, Aparna

2015-01-01

The concept of digital divide have moved beyond physical disparities in usage and also encompasses issues impending access like human (skills) social, cultural, and psychological barriers that affect the usage of existing available technologies apart from ownership. This paper focuses on the insu......The concept of digital divide have moved beyond physical disparities in usage and also encompasses issues impending access like human (skills) social, cultural, and psychological barriers that affect the usage of existing available technologies apart from ownership. This paper focuses...... on the insufficient level of skills which students have in making the best use of available Internet technology. Varying online skills of the students in higher education from two countrywide scenarios - Denmark and India are discussed. The paper emphasizes on the reflective and conceptual issues which the students...... face to take information from the Internet that brings a second level of divide. Through a cross-national comparison the paper hopes to contribute to the literature to learn from each other´s experiences and giving insights to researchers on digital divide. The digital divide in Internet skills...

Primitive human hematopoietic cells give rise to differentially specified daughter cells upon their initial cell division.

NARCIS (Netherlands)

Giebel, B.; Zhang, T.; Beckmann, J.; Spanholtz, J.; Wernet, P.; Ho, A.; Punzel, M.

2006-01-01

It is often predicted that stem cells divide asymmetrically, creating a daughter cell that maintains the stem-cell capacity, and 1 daughter cell committed to differentiation. While asymmetric stem-cell divisions have been proven to occur in model organisms (eg, in Drosophila), it remains illusive

Reduced Osteogenesis of Human Osteogenic Precursors' Cells Cultured in the Random Positioning Machine

Science.gov (United States)

Gershovich, J. G.; Buravkova, L. B.

2008-06-01

Recent studies have shown that simulated microgravity (SMG) results in altered proliferation and differentiation not only osteoblasts but also affects on osteogenic capacity of mesenchymal stem cells (MSCs) from various sources. For present study we used system that simulates effects of microgravity produced by the Random Positioning Machine (RPM). Cultured MCSs from human bone marrow and human osteoblasts (OBs) were exposed to SMG at RPM for 10-40 days. Induced osteogenesis of these progenitor cells was compared with the appropriate static (1g) and dynamic (horizontal shaker) controls. Clinorotated OBs and MSCs showed proliferation rate lower than static and dynamic control groups of cells in the early terms of SMG. Significant reduction of ALP activity was detected after 10 days of clinorotation of MSCs. There was no such dramatic difference in ALP activity of MSCs derived cells between SMG and control groups after 20 days of clinorotation but the expression of ALP was still reduced. However, virtually no matrix mineralization was found in OBs cultured under SMG conditions in the presence of differentiation stimuli. The similar effect was observed when we assayed matrix calcification of MSCs derived cultures. Thus, our results confirm low gravity mediated reduction of osteogenesis of different osteogenic precursors' cells and can clarify the mechanisms of bone loss during spaceflight.

Connecting across Many Divides: Digital, Racial, and Socio-Economic.

Science.gov (United States)

Hinson, Janice; Daniel, Cathy

As Internet usage increases nationally, it becomes more apparent that the Digital Divide (the gap between those who have information access and those who do not) is related to demographics. Although the number of low income and ethnic households that have Internet access is increasing, the Digital Divide is expected to widen because access…

REGENERATIVE GAS TURBINES WITH DIVIDED EXPANSION

DEFF Research Database (Denmark)

Elmegaard, Brian; Qvale, Einar Bjørn

2004-01-01

Recuperated gas turbines are currently drawing an increased attention due to the recent commercialization of micro gas turbines with recuperation. This system may reach a high efficiency even for the small units of less than 100 kW. In order to improve the economics of the plants, ways to improve...... their efficiency are always of interest. Recently, two independent studies have proposed recuperated gas turbines to be configured with the turbine expansion divided, in order to obtain higher efficiency. The idea is to operate the system with a gas generator and a power turbine, and use the gas from the gas...... divided expansion can be advantageous under certain circumstances. But, in order for todays micro gas turbines to be competitive, the thermodynamic efficiencies will have to be rather high. This requires that all component efficiencies including the recuperator effectiveness will have to be high...

The Digital Divide: A Global View

Science.gov (United States)

Ntoko, Alexander

2011-04-01

Huge progress was made in bridging the digital divide in first decade of 21^st century. This was largely due to the explosive growth of mobile, which saw numbers rise from under 500 million to over five billion mobile cellular subscriptions in just ten years. With household mobile penetration rates of over 50% even in rural areas of developing countries, we have achieved the dream of bringing all the world's people within reach of communications technology. We must now, however, replicate the mobile miracle for the Internet, and especially broadband, if we are to avoid creating a new broadband breach to replace the digital divide. Three things need to happen for this to be achieved: firstly, broadband needs to be brought to the top of the development agenda; secondly, broadband needs to become much more affordable and thirdly, security needs to be part of the strategy.

On interfaces between cell populations with different mobilities

KAUST Repository

Lorenzi, Tommaso

2016-11-18

Partial differential equations describing the dynamics of cell population densities from a fluid mechanical perspective can model the growth of avascular tumours. In this framework, we consider a system of equations that describes the interaction between a population of dividing cells and a population of non-dividing cells. The two cell populations are characterised by different mobilities. We present the results of numerical simulations displaying two-dimensional spherical waves with sharp interfaces between dividing and non-dividing cells. Furthermore, we numerically observe how different ratios between the mobilities change the morphology of the interfaces, and lead to the emergence of finger-like patterns of invasion above a threshold. Motivated by these simulations, we study the existence of one-dimensional travelling wave solutions.

Confronting the Digital Divide: Debunking Brave New World Discourses

Science.gov (United States)

Rowsell, Jennifer; Morrell, Ernest; Alvermann, Donna E.

2017-01-01

There is far more to the digital divide than meets the eye. In this article, the authors consolidate existing research on the digital divide to offer some tangible ways for educators to bridge the gap between the haves and have-nots, or the cans and cannots. Drawing on Aldous Huxley's notion of a "brave new world," some digital divide…

Accounting for randomness in measurement and sampling in studying cancer cell population dynamics.

Science.gov (United States)

Ghavami, Siavash; Wolkenhauer, Olaf; Lahouti, Farshad; Ullah, Mukhtar; Linnebacher, Michael

2014-10-01

Knowing the expected temporal evolution of the proportion of different cell types in sample tissues gives an indication about the progression of the disease and its possible response to drugs. Such systems have been modelled using Markov processes. We here consider an experimentally realistic scenario in which transition probabilities are estimated from noisy cell population size measurements. Using aggregated data of FACS measurements, we develop MMSE and ML estimators and formulate two problems to find the minimum number of required samples and measurements to guarantee the accuracy of predicted population sizes. Our numerical results show that the convergence mechanism of transition probabilities and steady states differ widely from the real values if one uses the standard deterministic approach for noisy measurements. This provides support for our argument that for the analysis of FACS data one should consider the observed state as a random variable. The second problem we address is about the consequences of estimating the probability of a cell being in a particular state from measurements of small population of cells. We show how the uncertainty arising from small sample sizes can be captured by a distribution for the state probability.

Cell division requirement for activation of murine leukemia virus in cell culture by irradiation

International Nuclear Information System (INIS)

Otten, J.A.; Quarles, J.M.; Tennant, R.W.

1976-01-01

Actively dividing cultures of AKR mouse cells were exposed to relatively low dose-rates of γ radiation and tested for activation of endogenous leukemia viruses. Efficient and reproducible induction of virus was obtained with actively dividing cells, but cultures deprived of serum to inhibit cell division before and during γ irradiation were not activated, even when medium with serum was added immediately after irradiation. These results show that cell division was required for virus induction but that a stable intermediate similar to the state induced by halogenated pyrimidines was not formed. In actively dividing AKR cell cultures, virus activation appeared to be proportional to the dose of γ radiation; the estimated frequency of activation was 1-8 x 10 - 5 per exposed cell and the efficiency of activation was approximately 0.012 inductions per cell per rad. Other normal primary and established mouse cell cultures tested were not activated by γ radiation. The requirement of cell division for radiation and chemical activation may reflect some common mechanism for initiation of virus expression

Analysing the role of ICT in bridging the digital divide amongst ...

African Journals Online (AJOL)

This digital divide can be seen as an educational divide and thus we examine how ICT is influencing education. We also investigate the nature of this digital divide while focusing on the local perspective. A short pilot study was done at four schools and one adult education centre in South Africa regarding their access to ICT.

Three-dimensional scanning near field optical microscopy (3D-SNOM) imaging of random arrays of copper nanoparticles: implications for plasmonic solar cell enhancement.

Science.gov (United States)

Ezugwu, Sabastine; Ye, Hanyang; Fanchini, Giovanni

2015-01-07

In order to investigate the suitability of random arrays of nanoparticles for plasmonic enhancement in the visible-near infrared range, we introduced three-dimensional scanning near-field optical microscopy (3D-SNOM) imaging as a useful technique to probe the intensity of near-field radiation scattered by random systems of nanoparticles at heights up to several hundred nm from their surface. We demonstrated our technique using random arrays of copper nanoparticles (Cu-NPs) at different particle diameter and concentration. Bright regions in the 3D-SNOM images, corresponding to constructive interference of forward-scattered plasmonic waves, were obtained at heights Δz ≥ 220 nm from the surface for random arrays of Cu-NPs of ∼ 60-100 nm in diameter. These heights are too large to use Cu-NPs in contact of the active layer for light harvesting in thin organic solar cells, which are typically no thicker than 200 nm. Using a 200 nm transparent spacer between the system of Cu-NPs and the solar cell active layer, we demonstrate that forward-scattered light can be conveyed in 200 nm thin film solar cells. This architecture increases the solar cell photoconversion efficiency by a factor of 3. Our 3D-SNOM technique is general enough to be suitable for a large number of other applications in nanoplasmonics.

Similar disturbances in B cell activity and regulatory T cell function in Henoch-Schonlein purpura and systemic lupus erythematosus

International Nuclear Information System (INIS)

Beale, M.G.; Nash, G.S.; Bertovich, M.J.; MacDermott, R.P.

1982-01-01

The immunoglobulin synthesizing activities of peripheral mononuclear cells (MNC) from five patients with Henoch-Schonlein purpura (HSP) and eight patients with active systemic lupus erythematosus (SLE) were compared. Cumulative amounts of IgM, IgG, and IgA synthesized and secreted by unstimulated and PWM-stimulated patient cells over a 12-day period were determied in a solid-phase radioimmunoassay. In unstimulated control cultures mean rates of IgM, IgG, and IgA synthesis were less than 250 ng/ml. The synthetic activities of patient MNC were markedly increased. In HSP cultures IgA was the major immunoglobulin class produced (2810 x/divide 1.33 ng/ml) followed by IgG (1754 x/divide 1.32 ng/ml) and IgM (404 x/divide 1.16 ng/ml). In SLE cultures IgA and IgG syntheses were equally elevated (4427 x/divide 1.20 and 4438 x/divide 1.49 ng/ml, respectively) whereas IgM synthesis averaged 967 x/divide 1.66 ng/ml. PWM stimulation of pateient MNC caused a sharp decline in the synthesis of all three immunoglobulin classes. After T cell depletion B cell-enriched fractions from HSP and SLE patients maintained high levels of IgA and IgG synthesis that were inhibited by PWM and by normal allogeneic but not autologous T cells. In PWM-stimulted co-cultures, patient T cells nonspecifically suppressed the synthetic activities of autologous and control B cells. in contrast patient B cells achieved normal levels of immunoglobulin synthesis when cultured with control T cells plus PWM. In longitudinal studies patient B and T cell disturbances persisted despite clinical improvement

Random walk of passive tracers among randomly moving obstacles.

Science.gov (United States)

Gori, Matteo; Donato, Irene; Floriani, Elena; Nardecchia, Ilaria; Pettini, Marco

2016-04-14

This study is mainly motivated by the need of understanding how the diffusion behavior of a biomolecule (or even of a larger object) is affected by other moving macromolecules, organelles, and so on, inside a living cell, whence the possibility of understanding whether or not a randomly walking biomolecule is also subject to a long-range force field driving it to its target. By means of the Continuous Time Random Walk (CTRW) technique the topic of random walk in random environment is here considered in the case of a passively diffusing particle among randomly moving and interacting obstacles. The relevant physical quantity which is worked out is the diffusion coefficient of the passive tracer which is computed as a function of the average inter-obstacles distance. The results reported here suggest that if a biomolecule, let us call it a test molecule, moves towards its target in the presence of other independently interacting molecules, its motion can be considerably slowed down.

Divided attention in computer game play: analysis utilizing unobtrusive health monitoring.

Science.gov (United States)

McKanna, James A; Jimison, Holly; Pavel, Misha

2009-01-01

Divided attention is a vital cognitive ability used in important daily activities (e.g., driving), which tends to deteriorate with age. As with Alzheimer's and other neural degenerative conditions, treatment for divided attention problems is likely to be more effective the earlier it is detected. Thus, it is important that a method be found to detect changes in divided attention early on in the process, for both safety and health care reasons. We present here a new method for detecting divided attention unobtrusively, using performance on a computer game designed to force players to attend to different dimensions simultaneously in order to succeed. Should this model prove to predict scores on a standard test for divided attention, it could help to detect cognitive decline earlier in our increasingly computer-involved aging population, providing treatment efficacy benefits to those who will experience cognitive decline.

Bridging the Digital Divide for urban seniors: community partnership.

Science.gov (United States)

Cresci, M Kay; Jarosz, Patricia A

2010-01-01

Computers and the Internet offer older adults resources for improving health. For many older adults, the "Digital Divide" (the social, economic, and demographic factors that exist between individuals who use computers and those who do not) is a barrier to taking advantage of these resources. Bridging the Digital Divide by making computers and the Internet more accessible and making online health information more usable for older adults has the potential to improve health of older adults. This article describes a strategy for closing the Digital Divide for urban seniors through the formation of a community- university partnership with the goal of improving health and well-being through the use of online health information. Copyright © 2010 Mosby, Inc. All rights reserved.

Combining polyamine depletion with radiation therapy for rapidly dividing head and neck tumors: Strategies for improved locoregional control

International Nuclear Information System (INIS)

Petereit, D.G.; Harari, P.M.; Contreras, L.; Pickart, M.A.; Verma, A.K.; Kinsella, T.J.; Gerner, E.W.

1994-01-01

Locoregional control is adversely affected as clonogens from rapidly proliferating tumors repopulate during a course of radiation therapy. The cytostatic agent α-difluoromethylornithine (DFMO) was investigated for its capacity to slow proliferation kinetics in human squamous cell carcinomas (SSC) of the head and neck (H ampersand N), with the ultimate objective of improving locoregional control in rapidly dividing tumors treated with radiation therapy. Three human SSC cell lines established from primary H ampersand N tumors were evaluated in vitro (cell culture) and in vivo (SSC tumor xenografts in athymic mice) for the capacity of DFMO to induce growth inhibition. Flow cytometry analysis of SCC tumor growth kinetics and quantitative assessment of polyamine biosynthesis inhibition was performed to verify DFMO activity. DFMO effects on in vitro SSC radiosensitivity using clonogenic survival were also studied. A noncytotoxic exposure to DFMO (5mM x 72 hours) induced pronounced growth inhibition in all three SSC cell lines (70-90% at 7 days), and induced a 2-3 fold delay in volume doubling time for SCC tumor xenografts when administered orally in the drinking water (1.5%) to athymic mice. Kinetic analysis via flow cytometry confirmed that DFMO produced a lengthening of SCC cell cycle times, but did not alter in vitro radiosensitivity. Inhibition of ornithine decarboxylase (ODC) activity and depletion of endogenous polyamines (putrescine and spermidine), were confirmed in normal tissue (mouse skin) and in human SSC tumor xenografts of athymic mice receiving continuous oral DFMO. These data indicate that antiproliferative agents, such as DFMO, are capable of altering human SSC growth kinetics without altering intrinsic radiosensitivity. Such kinetic modulation may therefore provide a strategy to reduce the adverse impact of tumor cell proliferation during a radiotherapy treatment course for rapidly dividing tumors such as those in the H ampersand N. 33 refs., 5 figs

The Testing Effect under Divided Attention

Science.gov (United States)

Buchin, Zachary L.; Mulligan, Neil W.

2017-01-01

Memory retrieval often enhances later memory compared with restudying (i.e., the testing effect), indicating that retrieval does not simply reveal but also modifies memory representations. Dividing attention (DA) during encoding greatly disrupts later memory performance while DA during retrieval typically has modest effects--but what of the…

Random graph states, maximal flow and Fuss-Catalan distributions

International Nuclear Information System (INIS)

Collins, BenoIt; Nechita, Ion; Zyczkowski, Karol

2010-01-01

For any graph consisting of k vertices and m edges we construct an ensemble of random pure quantum states which describe a system composed of 2m subsystems. Each edge of the graph represents a bipartite, maximally entangled state. Each vertex represents a random unitary matrix generated according to the Haar measure, which describes the coupling between subsystems. Dividing all subsystems into two parts, one may study entanglement with respect to this partition. A general technique to derive an expression for the average entanglement entropy of random pure states associated with a given graph is presented. Our technique relies on Weingarten calculus and flow problems. We analyze the statistical properties of spectra of such random density matrices and show for which cases they are described by the free Poissonian (Marchenko-Pastur) distribution. We derive a discrete family of generalized, Fuss-Catalan distributions and explicitly construct graphs which lead to ensembles of random states characterized by these novel distributions of eigenvalues.

Fluctuations of the transcription factor ATML1 generate the pattern of giant cells in the Arabidopsis sepal

Science.gov (United States)

Meyer, Heather M; Teles, José; Formosa-Jordan, Pau; Refahi, Yassin; San-Bento, Rita; Ingram, Gwyneth; Jönsson, Henrik; Locke, James C W; Roeder, Adrienne H K

2017-01-01

Multicellular development produces patterns of specialized cell types. Yet, it is often unclear how individual cells within a field of identical cells initiate the patterning process. Using live imaging, quantitative image analyses and modeling, we show that during Arabidopsis thaliana sepal development, fluctuations in the concentration of the transcription factor ATML1 pattern a field of identical epidermal cells to differentiate into giant cells interspersed between smaller cells. We find that ATML1 is expressed in all epidermal cells. However, its level fluctuates in each of these cells. If ATML1 levels surpass a threshold during the G2 phase of the cell cycle, the cell will likely enter a state of endoreduplication and become giant. Otherwise, the cell divides. Our results demonstrate a fluctuation-driven patterning mechanism for how cell fate decisions can be initiated through a random yet tightly regulated process. DOI: http://dx.doi.org/10.7554/eLife.19131.001 PMID:28145865

Modeling random combustion of lycopodium particles and gas

Directory of Open Access Journals (Sweden)

M Bidabadi

2016-06-01

Full Text Available The random modeling combustion of lycopodium particles has been researched by many authors. In this paper, we extend this model and we also generate a different method by analyzing the effect of random distributed sources of combustible mixture. The flame structure is assumed to consist of a preheat-vaporization zone, a reaction zone and finally a post flame zone. We divide the preheat zone to different parts. We assumed that there is different distribution of particles in sections which are really random. Meanwhile, it is presumed that the fuel particles vaporize first to yield gaseous fuel. In other words, most of the fuel particles are vaporized at the end of the preheat zone. It is assumed that the Zel’dovich number is large; therefore, the reaction term in preheat zone is negligible. In this work, the effect of random distribution of particles in the preheat zone on combustion characteristics such as burning velocity, flame temperature for different particle radius is obtained.

Dividing Streamline Formation Channel Confluences by Physical Modeling

Directory of Open Access Journals (Sweden)

Minarni Nur Trilita

2010-02-01

Full Text Available Confluence channels are often found in open channel network system and is the most important element. The incoming flow from the branch channel to the main cause various forms and cause vortex flow. Phenomenon can cause erosion of the side wall of the channel, the bed channel scour and sedimentation in the downstream confluence channel. To control these problems needed research into the current width of the branch channel. The incoming flow from the branch channel to the main channel flow bounded by a line distributors (dividing streamline. In this paper, the wide dividing streamline observed in the laboratory using a physical model of two open channels, a square that formed an angle of 30º. Observations were made with a variety of flow coming from each channel. The results obtained in the laboratory observation that the width of dividing streamline flow is influenced by the discharge ratio between the channel branch with the main channel. While the results of a comparison with previous studies showing that the observation in the laboratory is smaller than the results of previous research.

Negotiating Digital Divides: Perspectives from the New Zealand Schooling System

Science.gov (United States)

Starkey, Louise; Sylvester, Allan; Johnstone, David

2017-01-01

This article explores digital divides identified in research literature and considers educational policy directions that may mitigate or enhance future inequities. A review of literature identified three categories of digital divides in society; access, capability, and participation. To explore the strategic focus in schooling, data were gathered…

Analyzing Broadband Divide in the Farming Sector

DEFF Research Database (Denmark)

Jensen, Michael; Gutierrez Lopez, Jose Manuel; Pedersen, Jens Myrup

2013-01-01

, upstream and downstream connection. The main constraint is that farms are naturally located in rural areas where the required access broadband data rates are not available. This paper studies the broadband divide in relation to the Danish agricultural sector. Results show how there is an important......Agriculture industry has been evolving for centuries. Currently, the technological development of Internet oriented farming tools allows to increase the productivity and efficiency of this sector. Many of the already available tools and applications require high bandwidth in both directions...... difference between the broadband availability for farms and the rest of the households/buildings the country. This divide may be slowing down the potential technological development of the farming industry, in order to keep their competitiveness in the market. Therefore, broadband development in rural areas...

Divider plate leak inspections using an acoustic tool 'ALIS'

International Nuclear Information System (INIS)

Kowalewski, J.; Colbert, M.

1998-01-01

Divider plate leakage in the primary head of steam generators may be a contributor to high Reactor Inlet Header Temperature (RIHT) which can have a negative effect on the operation of a plant. A method to provide quick information of divider plate leakage can be very useful in helping operators to make timely and cost effective repair and maintenance decisions. As part of a CANDU Owners Group (COG) funded program, a novel acoustic tool for performing inspections in empty steam generators during a shutdown has been developed and successfully demonstrated by Ontario Hydro Technologies (OHT). The basic principle of this technique utilizes sound transmission through the leakage paths of a divider plate assembly for creating a graphic image which reveals the locations and relative sizes of leaks. This is accomplished by injecting one side of the primary head with a series of airborne, ultrasonic sound bursts while scanning the divider plates from the opposite side and collecting transmitted sound pressure levels. Once a scan is completed the results are processed and displayed graphically as a color mapping of the entire divider plate assembly showing an image of the leakage locations and relative severity. The special transducers of the acoustic leak inspection system (ALIS) are installed through the manways of the steam generator at both sides of the primary head. These are clamped to the tube sheet and operated from a convenient remote location within the containment building. This process minimizes radiation exposure of the workers, as well, it reduces risk of contamination of the ALIS equipment. The current version of this tool performs the scans by remote manual control. (author)

Divided attention and driving. The effects of aging and brain injury

OpenAIRE

Withaar, Frederiec Kunna

2000-01-01

In this thesis, divided attention was investigated in four groups of subjects: closed head injury (CHI) patients, young control and healthy older subjects, and older subjects with cognitive impairments. It was studied how diffuse brain injury and normal and abnormal aging affect cognitive processes involved in divided attention tasks. Furthermore, it was investigated how deficits in divided attention relate to performance of instrumental activities of daily living (IADL), with an emphasis on ...

Digital divide research, achievements and shortcomings

NARCIS (Netherlands)

van Dijk, Johannes A.G.M.

2006-01-01

From the end of the 1990s onwards the digital divide, commonly defined as the gap between those who have and do not have access to computers and the Internet, has been a central issue on the scholarly and political agenda of new media development. This article makes an inventory of 5 years of

Improved process for contacting finely divided solid particles with gases

Energy Technology Data Exchange (ETDEWEB)

1952-07-30

A process of contacting solids and gases of the type in which finely divided solids are maintained in a dense fluidized state in a treating zone by means of an upflowing gaseous fluidizing medium wherein solid packing in the form of a body static contiguous elements is maintained in the treating zone. The size, shape, and arrangement of the elements constituting the packing being such as to define a labyrinth of passageways in which the finely divided solids are maintained in a fluidized state, and the finely divided solids are adapted to flow freely downwardly through the passageways in the absence of a gaseous fluidizing medium.

Randomized study: small cell anaplastic lung cancer treated by combination chemotherapy and adjuvant radiotherapy

International Nuclear Information System (INIS)

Fox, R.M.; Woods, R.L.; Brodie, G.N.; Tattersall, M.H.N.

1980-01-01

Chemotherapy and primary site radiation therapy were compared to chemotherapy alone in a randomized study of 125 patients with small cell cancer of the lung. The sites of initial relapse, as well as disease free and overall survival were analyzed. Radiotherapy to the primary site reduced the rate of local relapse, but median survival was not prolonged in patients with either limited or extensive disease, when the radiation therapy-chemotherapy group was compared to the group that received chemotherapy alone

The Digital Divide and Health Outcomes: A Teleretinal Imaging Study

Science.gov (United States)

Connolly, Kathleen Kihmm

2013-01-01

The purpose of this research project was to understand, explore and describe the digital divide and the relationship between technology utilization and health outcomes. Diabetes and diabetic eye disease was used as the real-life context for understanding change and exploring the digital divide. As an investigational framework, a telemedicine…

Are changes in the digital divide consistent with global equality or inequality?

NARCIS (Netherlands)

James, M.J.

2011-01-01

To answer the question in the title, the author divides a sample of developing countries according to whether they have experienced a rise or fall of the (absolute) digital divide in the Internet. He suggests that in countries where the divide is falling, incomes will tend to be relatively high, and

Landslide-driven drainage divide migration and quantifying progress toward topographic steady state

Science.gov (United States)

Dahlquist, M. P.; West, A. J.; Li, G.

2017-12-01

Drainage divide migration is a critical process in landscape evolution. It reorganizes river basins, redistributing fluvial erosive energy to facilitate mass balance, and contributes to feedbacks between tectonics, erosion, and climate. However, it leaves little straightforward evidence in the geologic or geomorphic record, and has been subject to minimal field study, hampering understanding its role in landscape evolution. Landslides link river channels, hillslopes, and ridges in steep landscapes, and thus play a central role in divide migration. In this study, we examine landslides triggered by three events: the 2008 Wenchuan Earthquake in central China, the 2015 Gorkha Earthquake in Nepal, and the 2009 Typhoon Morakot in southern Taiwan, seeking new insight into the controls on divide migration. Of the 100,000 landslides triggered, we mapped 367 which caused a divide to migrate, resulting in a total exchange of about 2 km2 between basins. We use this database of divide migrations to explore relationships between the geometry of rivers and the exchange of drainage area, comparing metrics which have been proposed as indicators of divide stability across mobile divides. We find that upstream-averaged local relief and upstream-averaged channel gradient predict the We propose a new metric to describe divide mobility and the overall influence of a reorganizing event on a landscape, using it to estimate the impact of events similar to the 2009 Typhoon Morakot on the progress of Taiwan's Central Range toward topographic steady state.

Large-size, high-uniformity, random silver nanowire networks as transparent electrodes for crystalline silicon wafer solar cells.

Science.gov (United States)

Xie, Shouyi; Ouyang, Zi; Jia, Baohua; Gu, Min

2013-05-06

Metal nanowire networks are emerging as next generation transparent electrodes for photovoltaic devices. We demonstrate the application of random silver nanowire networks as the top electrode on crystalline silicon wafer solar cells. The dependence of transmittance and sheet resistance on the surface coverage is measured. Superior optical and electrical properties are observed due to the large-size, highly-uniform nature of these networks. When applying the nanowire networks on the solar cells with an optimized two-step annealing process, we achieved as large as 19% enhancement on the energy conversion efficiency. The detailed analysis reveals that the enhancement is mainly caused by the improved electrical properties of the solar cells due to the silver nanowire networks. Our result reveals that this technology is a promising alternative transparent electrode technology for crystalline silicon wafer solar cells.

Wave propagation and scattering in random media

CERN Document Server

Ishimaru, Akira

1978-01-01

Wave Propagation and Scattering in Random Media, Volume 2, presents the fundamental formulations of wave propagation and scattering in random media in a unified and systematic manner. The topics covered in this book may be grouped into three categories: waves in random scatterers, waves in random continua, and rough surface scattering. Random scatterers are random distributions of many particles. Examples are rain, fog, smog, hail, ocean particles, red blood cells, polymers, and other particles in a state of Brownian motion. Random continua are the media whose characteristics vary randomly an

Digital Natives and Digital Divide: Analysing Perspective for Emerging Pedagogy

Science.gov (United States)

Onye, Uriel U.; Du, Yunfei

2016-01-01

This paper addresses the concepts of digital natives and digital divide from the perspective of the digital outsiders (part of digital natives). It takes a critical look at the implications of available ICT in both developed and underdeveloped countries in the fight against digital divide. The major contribution to literature is by drawing…

The effects of divided attention on auditory priming.

Science.gov (United States)

Mulligan, Neil W; Duke, Marquinn; Cooper, Angela W

2007-09-01

Traditional theorizing stresses the importance of attentional state during encoding for later memory, based primarily on research with explicit memory. Recent research has begun to investigate the role of attention in implicit memory but has focused almost exclusively on priming in the visual modality. The present experiments examined the effect of divided attention on auditory implicit memory, using auditory perceptual identification, word-stem completion and word-fragment completion. Participants heard study words under full attention conditions or while simultaneously carrying out a distractor task (the divided attention condition). In Experiment 1, a distractor task with low response frequency failed to disrupt later auditory priming (but diminished explicit memory as assessed with auditory recognition). In Experiment 2, a distractor task with greater response frequency disrupted priming on all three of the auditory priming tasks as well as the explicit test. These results imply that although auditory priming is less reliant on attention than explicit memory, it is still greatly affected by at least some divided-attention manipulations. These results are consistent with research using visual priming tasks and have relevance for hypotheses regarding attention and auditory priming.

A digital divider with extension bits for position-sensitive detectors

International Nuclear Information System (INIS)

Koike, Masaki; Hasegawa, Ken-ichi

1988-01-01

Digitizing errors produced in a digital divider for position-sensitive detectors have been reduced by adding extension bits to data bits. A relation between the extension bits and the data bits to obtain perfect position uniformity is also given. A digital divider employing 10 bit ADCs and 6 bit extension circuits has been constructed. (orig.)

Computation of restoration of ligand response in the random kinetics of a prostate cancer cell signaling pathway.

Science.gov (United States)

Dana, Saswati; Nakakuki, Takashi; Hatakeyama, Mariko; Kimura, Shuhei; Raha, Soumyendu

2011-01-01

Mutation and/or dysfunction of signaling proteins in the mitogen activated protein kinase (MAPK) signal transduction pathway are frequently observed in various kinds of human cancer. Consistent with this fact, in the present study, we experimentally observe that the epidermal growth factor (EGF) induced activation profile of MAP kinase signaling is not straightforward dose-dependent in the PC3 prostate cancer cells. To find out what parameters and reactions in the pathway are involved in this departure from the normal dose-dependency, a model-based pathway analysis is performed. The pathway is mathematically modeled with 28 rate equations yielding those many ordinary differential equations (ODE) with kinetic rate constants that have been reported to take random values in the existing literature. This has led to us treating the ODE model of the pathways kinetics as a random differential equations (RDE) system in which the parameters are random variables. We show that our RDE model captures the uncertainty in the kinetic rate constants as seen in the behavior of the experimental data and more importantly, upon simulation, exhibits the abnormal EGF dose-dependency of the activation profile of MAP kinase signaling in PC3 prostate cancer cells. The most likely set of values of the kinetic rate constants obtained from fitting the RDE model into the experimental data is then used in a direct transcription based dynamic optimization method for computing the changes needed in these kinetic rate constant values for the restoration of the normal EGF dose response. The last computation identifies the parameters, i.e., the kinetic rate constants in the RDE model, that are the most sensitive to the change in the EGF dose response behavior in the PC3 prostate cancer cells. The reactions in which these most sensitive parameters participate emerge as candidate drug targets on the signaling pathway. 2011 Elsevier Ireland Ltd. All rights reserved.

Divided attention in young drivers under the influence of alcohol.

Science.gov (United States)

Freydier, C; Berthelon, C; Bastien-Toniazzo, M; Gineyt, G

2014-06-01

The present research evaluates driving impairment linked to divided attention task and alcohol and determines whether it is higher for novice drivers than for experienced drivers. Novice and experienced drivers participated in three experimental sessions in which blood alcohol concentrations (BACs) were 0.0 g/L, 0.2 g/L, and 0.5 g/L. They performed a divided attention task with a main task of car-following task and an additional task of number parity identification. Driving performance, response time and accuracy on the additional task were measured. ANOVA showed a driving impairment and a decrease in additional task performance from a BAC of 0.5 g/L, particularly for novice drivers. Indeed, the latter adopt more risky behavior such as tailgating. In the divided attention task, driving impairment was found for all drivers and impairment on information processing accuracy was highlighted, notably in peripheral vision. The divided attention task used here provides a relevant method for identifying the effects of alcohol on cognitive functions and could be used in psychopharmacological research. Copyright © 2014 Elsevier Ltd. All rights reserved.

Acoustic tool for leak inspections in steam generator divider plates

International Nuclear Information System (INIS)

Kowalewski, J.; Maak, P.; Colbert, M.

1997-01-01

Cross flow leakage through divider plates in the primary head of steam generators, may be a contributor to RIHT rise which can have a negative effect on the operation of a plant. A method to provide quick and reliable inspection of divider plate leakage can be very useful in helping make timely and effective maintenance decisions. A novel acoustic tool for performing inspections in drained steam generators during shutdowns has been developed by OH Technologies and successfully demonstrated in a field application. The technique, referred as ALIS (acoustic leak inspection system), performs a scan of the divider plate face and presents a graphic image of the leakage paths and an estimate of the total leakage area. (author)

Safety and effects of two red blood cell transfusion strategies in pediatric cardiac surgery patients: a randomized controlled trial

NARCIS (Netherlands)

de Gast-Bakker, D. H.; de Wilde, R. B. P.; Hazekamp, M. G.; Sojak, V.; Zwaginga, J. J.; Wolterbeek, R.; de Jonge, E.; Gesink-van der Veer, B. J.

2013-01-01

To investigate the safety and effects of a restrictive red blood cell (RBC) transfusion strategy in pediatric cardiac surgery patients. Randomized controlled trial. Pediatric ICU in an academic tertiary care center, Leiden University Medical Center, Leiden, The Netherlands. One hundred seven

RANdom SAmple Consensus (RANSAC) algorithm for material-informatics: application to photovoltaic solar cells.

Science.gov (United States)

Kaspi, Omer; Yosipof, Abraham; Senderowitz, Hanoch

2017-06-06

An important aspect of chemoinformatics and material-informatics is the usage of machine learning algorithms to build Quantitative Structure Activity Relationship (QSAR) models. The RANdom SAmple Consensus (RANSAC) algorithm is a predictive modeling tool widely used in the image processing field for cleaning datasets from noise. RANSAC could be used as a "one stop shop" algorithm for developing and validating QSAR models, performing outlier removal, descriptors selection, model development and predictions for test set samples using applicability domain. For "future" predictions (i.e., for samples not included in the original test set) RANSAC provides a statistical estimate for the probability of obtaining reliable predictions, i.e., predictions within a pre-defined number of standard deviations from the true values. In this work we describe the first application of RNASAC in material informatics, focusing on the analysis of solar cells. We demonstrate that for three datasets representing different metal oxide (MO) based solar cell libraries RANSAC-derived models select descriptors previously shown to correlate with key photovoltaic properties and lead to good predictive statistics for these properties. These models were subsequently used to predict the properties of virtual solar cells libraries highlighting interesting dependencies of PV properties on MO compositions.

Proteome Analysis of Thyroid Cancer Cells After Long-Term Exposure to a Random Positioning Machine

Science.gov (United States)

Pietsch, Jessica; Bauer, Johann; Weber, Gerhard; Nissum, Mikkel; Westphal, Kriss; Egli, Marcel; Grosse, Jirka; Schönberger, Johann; Eilles, Christoph; Infanger, Manfred; Grimm, Daniela

2011-11-01

Annulling gravity during cell culturing triggers various types of cells to change their protein expression in a time dependent manner. We therefore decided to determine gravity sensitive proteins and their period of sensitivity to the effects of gravity. In this study, thyroid cancer cells of the ML-1 cell line were cultured under normal gravity (1 g) or in a random positioning machine (RPM), which simulated near weightlessness for 7 and 11 days. Cells were then sonicated and proteins released into the supernatant were separated from those that remained attached to the cell fragments. Subsequently, both types of proteins were fractionated by free-flow isoelectric focussing (FF-IEF). The fractions obtained were further separated by sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) to which comparable FF-IEF fractions derived from cells cultured either under 1 g or on the RPM had been applied side by side. The separation resulted in pairs of lanes, on which a number of identical bands were observed. Selected gel pieces were excised and their proteins determined by mass spectrometry. Equal proteins from cells cultured under normal gravity and the RPM, respectively, were detected in comparable gel pieces. However, many of these proteins had received different Mascot scores. Quantifying heat shock cognate 71 kDa protein, glutathione S-transferase P, nucleoside diphosphate kinase A and annexin-2 by Western blotting using whole cell lysates indicated usefulness of Mascot scores for selecting the most efficient antibodies.

Two types of photomultiplier voltage dividers for high and changing count rates

International Nuclear Information System (INIS)

Reiter, W.L.; Stengl, G.

1980-01-01

We report on the design of two types of voltage distribution circuits for high stability photomultiplier operation. 'Type A' voltage divider is an ohmic voltage divider with high bleeder current (up to 10 mA) and the resistor chain split at one of the last dynodes, usually the dynode where the analog signal is derived from. This simple constructive measure improves the stability of the dynode voltage by a factor of 5 compared with an unsplit conventional resistor chain. 'Type B' is a novel active voltage divider using cold cathode tubes ar regulating elements. This voltage divider exhibits excellent temperature stability (about 10 -4 / 0 C). With 'type B' an equal stability compared with conventional ohmic dividers can be achieved at a bleeder current smaller by one order of magnitude. Of course both concepts, 'type A' and 'type B', can be combined. (orig.)

Randomness determines practical security of BB84 quantum key distribution

Science.gov (United States)

Li, Hong-Wei; Yin, Zhen-Qiang; Wang, Shuang; Qian, Yong-Jun; Chen, Wei; Guo, Guang-Can; Han, Zheng-Fu

2015-11-01

Unconditional security of the BB84 quantum key distribution protocol has been proved by exploiting the fundamental laws of quantum mechanics, but the practical quantum key distribution system maybe hacked by considering the imperfect state preparation and measurement respectively. Until now, different attacking schemes have been proposed by utilizing imperfect devices, but the general security analysis model against all of the practical attacking schemes has not been proposed. Here, we demonstrate that the general practical attacking schemes can be divided into the Trojan horse attack, strong randomness attack and weak randomness attack respectively. We prove security of BB84 protocol under randomness attacking models, and these results can be applied to guarantee the security of the practical quantum key distribution system.

Randomize Trial of Cisplatin plus Gemcitabine with either Sorafenib or Placebo as First-line Therapy for Non-small Cell Lung Cancer

OpenAIRE

Yan WANG; Lin WANG; Yutao LIU; Shufei YU; Xiangru ZHANG; Yuankai SHI; Yan SUN

2011-01-01

Background and objective Platinum-based chemotherapy doublets reached an efficacy plateau in nonsmall-cell lung cancer (NSCLC). This randomized controlled study prospectively assessed the efficacy and safety of cisplatin plus gemcitabine with either Sorafenib or placebo as first-line therapy for NSCLC. Methods Thirty patients, which were confirmed advanced NSCLC histologically or cytologically, were randomly assigned to receive up to six cycles of cisplatin plus gemcitabine with sorafenib or ...

Selectively Distracted: Divided Attention and Memory for Important Information.

Science.gov (United States)

Middlebrooks, Catherine D; Kerr, Tyson; Castel, Alan D

2017-08-01

Distractions and multitasking are generally detrimental to learning and memory. Nevertheless, people often study while listening to music, sitting in noisy coffee shops, or intermittently checking their e-mail. The current experiments examined how distractions and divided attention influence one's ability to selectively remember valuable information. Participants studied lists of words that ranged in value from 1 to 10 points while completing a digit-detection task, while listening to music, or without distractions. Though participants recalled fewer words following digit detection than in the other conditions, there were no significant differences between conditions in terms of selectively remembering the most valuable words. Similar results were obtained across a variety of divided-attention tasks that stressed attention and working memory to different degrees, which suggests that people may compensate for divided-attention costs by selectively attending to the most valuable items and that factors that worsen memory do not necessarily impair the ability to selectively remember important information.

Combination N-Way Power Divider/Combiner and Noninvasive Reflected Power Detection

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — An N-way RF/microwave power divider/combiner utilizes one input and N outputs, or conversely N inputs and one output to divide (or combine) RF/microwave power while...

"Is There a Second Level Divide in Student’s Internet Skills?

DEFF Research Database (Denmark)

Purushothaman, Aparna; Dau, Susanne

2015-01-01

The concept of a digital divide has moved beyond only physical disparities in technology usage and now also encompasses issues impeding access such as human social, cultural, and psychological barriers that affect the usage of existing available technologies. This paper focuses on students......’ insufficient skill levels in making the best use of available Internet technology, discussing students in higher education in scenarios in Denmark and India. The paper emphasizes the reflective and conceptual issues which the students face in retrieving information from the Internet, which result in a second......-level divide. Through a cross-national comparison, the paper hopes to contribute to the literature through experiences of students in the two countries, providing researchers with insights into the digital divide. This divide in Internet skills is illuminated from different perspectives in the context of two...

The electronic health record: a digital divide?

Science.gov (United States)

Glaser, John

2007-10-01

The gap between EHR adoption among larger providers versus adoption by smaller or rural providers has caused a "digital divide" that could threaten smaller providers' survival in the years ahead. Closing this gap will require the collective action of providers, payers, and government.

New mechanism to cross the phantom divide

International Nuclear Information System (INIS)

Du, Yunshuang; Zhang, Hongsheng; Li, Xin-Zhou

2011-01-01

Recently, type Ia supernova data appear to support a dark energy whose equation of state w crosses -1, which is a much more amazing problem than the acceleration of the universe. We show that it is possible for the equation of state to cross the phantom divide by a scalar field in gravity with an additional inverse power-law term of the Ricci scalar in the Lagrangian. The necessary and sufficient condition for a universe in which the dark energy can cross the phantom divide is obtained. Some analytical solutions with w -1 are obtained. A minimally coupled scalar with different potentials, including quadratic, cubic, quantic, exponential and logarithmic potentials are investigated via numerical methods, respectively. All these potentials lead to the crossing behavior. We show that it is a robust result which is hardly dependent on the concrete form of the potential of the scalar. (orig.)

Hybrid lentivirus-phiC31-int-NLS vector allows site-specific recombination in murine and human cells but induces DNA damage.

Directory of Open Access Journals (Sweden)

Nicolas Grandchamp

Full Text Available Gene transfer allows transient or permanent genetic modifications of cells for experimental or therapeutic purposes. Gene delivery by HIV-derived lentiviral vector (LV is highly effective but the risk of insertional mutagenesis is important and the random/uncontrollable integration of the DNA vector can deregulate the cell transcriptional activity. Non Integrative Lentiviral Vectors (NILVs solve this issue in non-dividing cells, but they do not allow long term expression in dividing cells. In this context, obtaining stable expression while avoiding the problems inherent to unpredictable DNA vector integration requires the ability to control the integration site. One possibility is to use the integrase of phage phiC31 (phiC31-int which catalyzes efficient site-specific recombination between the attP site in the phage genome and the chromosomal attB site of its Streptomyces host. Previous studies showed that phiC31-int is active in many eukaryotic cells, such as murine or human cells, and directs the integration of a DNA substrate into pseudo attP sites (pattP which are homologous to the native attP site. In this study, we combined the efficiency of NILV for gene delivery and the specificity of phiC31-int for DNA substrate integration to engineer a hybrid tool for gene transfer with the aim of allowing long term expression in dividing and non-dividing cells preventing genotoxicity. We demonstrated the feasibility to target NILV integration in human and murine pattP sites with a dual NILV vectors system: one which delivers phiC31-int, the other which constitute the substrate containing an attB site in its DNA sequence. These promising results are however alleviated by the occurrence of significant DNA damages. Further improvements are thus required to prevent chromosomal rearrangements for a therapeutic use of the system. However, its use as a tool for experimental applications such as transgenesis is already applicable.

Evaluation of Fatih Project in the Frame of Digital Divide

Science.gov (United States)

Karabacak, Kerim

2016-01-01

The aim of this research realized at the general survey model is to evaluate "FATIH Project" in the frame of digital divide by determining the effects of the distributed tablets to the students being educated at K-12 schools on digital divide. Sample is taking from the 9th grade students in Sakarya city in the 2013-2014 academic session.…

Divided attention interferes with fulfilling activity-based intentions.

Science.gov (United States)

Brewer, Gene A; Ball, B Hunter; Knight, Justin B; Dewitt, Michael R; Marsh, Richard L

2011-09-01

Two experiments were conducted to examine the effects of divided attention on activity-based prospective memory. After establishing a goal to fulfill an intention upon completion of an ongoing activity, successful completion of the intention generally suffered when attention was being devoted to an additional task (Experiment 1). Forming an implementation intention at encoding ameliorated the negative effects of divided attention (Experiment 2). The results from the present experiments demonstrate that activity-based prospective memory is susceptible to distraction and that implementing encoding strategies that enhance prospective memory performance can reduce this interference. The current work raises interesting questions about the similarities and differences between event- and activity-based prospective memories. Published by Elsevier B.V.

A novel multiplexer-based structure for random access memory cell in quantum-dot cellular automata

Science.gov (United States)

Naji Asfestani, Mazaher; Rasouli Heikalabad, Saeed

2017-09-01

Quantum-dot cellular automata (QCA) is a new technology in scale of nano and perfect replacement for CMOS circuits in the future. Memory is one of the basic components in any digital system, so designing the random access memory (RAM) with high speed and optimal in QCA is important. In this paper, by employing the structure of multiplexer, a novel RAM cell architecture is proposed. The proposed architecture is implemented without the coplanar crossover approach. The proposed architecture is simulated using the QCADesigner version 2.0.3 and QCAPro. The simulation results demonstrate that the proposed QCA RAM architecture has the best performance in terms of delay, circuit complexity, area, cell count and energy consumption in comparison with other QCA RAM architectures.

Randomized trial of stopping or continuing ART among postpartum women with pre-ART CD4 ≥ 400 cells/mm3.

Science.gov (United States)

Currier, Judith S; Britto, Paula; Hoffman, Risa M; Brummel, Sean; Masheto, Gaerolwe; Joao, Esau; Santos, Breno; Aurpibul, Linda; Losso, Marcelo; Pierre, Marie F; Weinberg, Adriana; Gnanashanmugam, Devasena; Chakhtoura, Nahida; Klingman, Karin; Browning, Renee; Coletti, Anne; Mofenson, Lynne; Shapiro, David; Pilotto, Jose

2017-01-01

Health benefits of postpartum antiretroviral therapy (ART) for human immunodeficiency virus (HIV) positive women with high CD4+ T-counts have not been assessed in randomized trials. Asymptomatic, HIV-positive, non-breastfeeding women with pre-ART CD4+ T-cell counts ≥ 400 cells/mm3 started on ART during pregnancy were randomized up to 42 days after delivery to continue or discontinue ART. Lopinavir/ritonavir plus tenofovir/emtricitabine was the preferred ART regimen. The sample size was selected to provide 88% power to detect a 50% reduction from an annualized primary event rate of 2.07%. A post-hoc analysis evaluated HIV/AIDS-related and World Health Organization (WHO) Stage 2 and 3 events. All analyses were intent to treat. 1652 women from 52 sites in Argentina, Botswana, Brazil, China, Haiti, Peru, Thailand and the US were enrolled (1/2010-11/2014). Median age was 28 years and major racial categories were Black African (28%), Asian (25%) White (15%). Median entry CD4 count was 696 cells/mm3 (IQR 575-869), median ART exposure prior to delivery was 19 weeks (IQR 13-24) and 94% had entry HIV-1 RNA women randomized to continue ART, 189/827 (23%) had virologic failure; of the 155 with resistance testing, 103 (66%) failed without resistance to their current regimen, suggesting non-adherence. Overall, serious clinical events were rare among young HIV-positive post-partum women with high CD4 cell counts. Continued ART was safe and was associated with a halving of the rate of WHO 2/3 conditions. Virologic failure rates were high, underscoring the urgent need to improve adherence in this population. ClinicalTrials.gov NCT00955968.

Divided attention capacity in adults with autism spectrum disorders and without intellectual disability

NARCIS (Netherlands)

Bogte, H; Flamma, B; Van der Meere, J.J.; van Engeland, H.

Earlier research showed that divided attention, an aspect of executive function, is limited in both children and adults with autism spectrum disorders (ASDs). The current study explored divided attention capacity in adults with ASD and without intellectual disability (n = 36). Divided attention was

Randomized placebo-controlled phase II trial of autologous mesenchymal stem cells in multiple sclerosis.

Directory of Open Access Journals (Sweden)

Sara Llufriu

Full Text Available Uncontrolled studies of mesenchymal stem cells (MSCs in multiple sclerosis suggested some beneficial effect. In this randomized, double-blind, placebo-controlled, crossover phase II study we investigated their safety and efficacy in relapsing-remitting multiple sclerosis patients. Efficacy was evaluated in terms of cumulative number of gadolinium-enhancing lesions (GEL on magnetic resonance imaging (MRI at 6 months and at the end of the study.Patients unresponsive to conventional therapy, defined by at least 1 relapse and/or GEL on MRI scan in past 12 months, disease duration 2 to 10 years and Expanded Disability Status Scale (EDSS 3.0-6.5 were randomized to receive IV 1-2×10(6 bone-marrow-derived-MSCs/Kg or placebo. After 6 months, the treatment was reversed and patients were followed-up for another 6 months. Secondary endpoints were clinical outcomes (relapses and disability by EDSS and MS Functional Composite, and several brain MRI and optical coherence tomography measures. Immunological tests were explored to assess the immunomodulatory effects.At baseline 9 patients were randomized to receive MSCs (n = 5 or placebo (n = 4. One patient on placebo withdrew after having 3 relapses in the first 5 months. We did not identify any serious adverse events. At 6 months, patients treated with MSCs had a trend to lower mean cumulative number of GEL (3.1, 95% CI = 1.1-8.8 vs 12.3, 95% CI = 4.4-34.5, p = 0.064, and at the end of study to reduced mean GEL (-2.8±5.9 vs 3±5.4, p = 0.075. No significant treatment differences were detected in the secondary endpoints. We observed a non-significant decrease of the frequency of Th1 (CD4+ IFN-γ+ cells in blood of MSCs treated patients.Bone-marrow-MSCs are safe and may reduce inflammatory MRI parameters supporting their immunomodulatory properties. ClinicalTrials.gov NCT01228266.

Outcome of loop versus divided colostomy in the management of anorectal malformations.

Science.gov (United States)

Almosallam, Osama Ibrahim; Aseeri, Ali; Shanafey, Saud Al

2016-01-01

Colostomy is a common part of the management of high anorectal malformation (ARM) in the pediatric population. To evaluate whether the type of colostomy (loop vs divided) has an impact on outcome in patients with ARM. A retrospective study. King Faisal Specialist Hospital and Research Center, a tertiary care center. All patients who were managed with colostomy for ARM and had definitive repair during the period of January 2000 to December 2014. Outcomes relative to the type of the colostomy were compared. Morbidities associated with each type of colostomy. There were 104 patients managed for ARM with colostomy as staged procedures, 63 males and 41 females. Patients had a colostomy at a median age of 6 days and were closed at a median of 11 months. Definitive repair was at a median age of 17 months. Type of fistula was 8 perineal, 21 rectovestibular, 35 rectourethral, 11 rectovesical and there were 16 without fistula and 13 cloaca anomalies. There were 55 loop and 49 divided colostomies. There were 91 descending/sigmoid and 13 transverse colostomies. Operative time for loop colostomy closure was shorter than with divided colo6stomy (76 minutes vs 94 minutes, P=.002). Three patients among the divided group had reversed orientation of the colostomy that had affected bowel preparations negatively prior to its repair. There was no differences in complications of creation and closure of loop and divided colostomies except in occurrence of skin excoriation. There was more skin excoriation with divided colostomy compared to loop colostomy (17 vs 10, P=.04). Loop colostomy has a shorter closure operative time and relatively fewer complications compared to the divided colostomy. Our data suggests that loop colostomy may be more favorable than divided colostomy for ARM patients. Retrospective nature of the study and some colostomies performed at other hospitals.

Details Matter: Noise and Model Structure Set the Relationship between Cell Size and Cell Cycle Timing

Directory of Open Access Journals (Sweden)

Felix Barber

2017-11-01

Full Text Available Organisms across all domains of life regulate the size of their cells. However, the means by which this is done is poorly understood. We study two abstracted “molecular” models for size regulation: inhibitor dilution and initiator accumulation. We apply the models to two settings: bacteria like Escherichia coli, that grow fully before they set a division plane and divide into two equally sized cells, and cells that form a bud early in the cell division cycle, confine new growth to that bud, and divide at the connection between that bud and the mother cell, like the budding yeast Saccharomyces cerevisiae. In budding cells, delaying cell division until buds reach the same size as their mother leads to very weak size control, with average cell size and standard deviation of cell size increasing over time and saturating up to 100-fold higher than those values for cells that divide when the bud is still substantially smaller than its mother. In budding yeast, both inhibitor dilution or initiator accumulation models are consistent with the observation that the daughters of diploid cells add a constant volume before they divide. This “adder” behavior has also been observed in bacteria. We find that in bacteria an inhibitor dilution model produces adder correlations that are not robust to noise in the timing of DNA replication initiation or in the timing from initiation of DNA replication to cell division (the C+D period. In contrast, in bacteria an initiator accumulation model yields robust adder correlations in the regime where noise in the timing of DNA replication initiation is much greater than noise in the C + D period, as reported previously (Ho and Amir, 2015. In bacteria, division into two equally sized cells does not broaden the size distribution.

A low-power digital frequency divider for system-on-a-chip applications

KAUST Repository

Omran, Hesham

2011-08-01

In this paper, an idea for a new frequency divider architecture is proposed. The divider is based on a coarse-fine architecture. The coarse block operates at a low frequency to save power consumption and it selectively enables the fine block which operates at the high input frequency. The proposed divider has the advantages of synchronous divider, but with lower power consumption and higher operation speed. The design can achieve a wide division range with a minor effect on power consumption and speed. The architecture was implemented on a complex programmable logic device (CPLD) to verify its operation. Experimental measurements validate system operation with power reduction greater than 40%. © 2011 IEEE.

Media Literacy in Times of Media Divides

Directory of Open Access Journals (Sweden)

Kaja Žuran

2013-12-01

Full Text Available We live in a post-modern society, an information society, a society based around knowledge and participation, and above all in a media society. In a media culture where media holds a dominant position, we cannot overlook the emerging idea of a ‘media divide’ within the frame of media education, media literate individuals and the expansion of the traditional concept of media literacy. Firstly, we are in an era of technological revolution, and it is time to consider the meaning and function of media and how we experience it in our everyday life. Secondly, as a society we are subject to intense media invasion and we all need to learn how to use it to our benefit and apply a critical and autonomous perspective towards selecting media content. Otherwise the media divide between the media literate and illiterate will widen; but is there even a chance to overcome the supposed divide between those who are formally media educated and those who are not?

The Effect of Divided Attention on Emotion-Induced Memory Narrowing

Science.gov (United States)

Steinmetz, Katherine R. Mickley; Waring, Jill D.; Kensinger, Elizabeth A.

2014-01-01

Individuals are more likely to remember emotional than neutral information, but this benefit does not always extend to the surrounding background information. This memory narrowing is theorized to be linked to the availability of attentional resources at encoding. In contrast to the predictions of this theoretical account, altering participants’ attentional resources at encoding, by dividing attention, did not affect the emotion-induced memory narrowing. Attention was divided using three separate manipulations: a digit ordering task (Experiment 1), an arithmetic task (Experiment 2), and an auditory discrimination task (Experiment 3). Across all three experiments, divided attention decreased memory across-the-board but did not affect the degree of memory narrowing. These findings suggest that theories to explain memory narrowing must be expanded to include other potential mechanisms beyond limitations of attentional resources. PMID:24295041

The effect of divided attention on emotion-induced memory narrowing.

Science.gov (United States)

Mickley Steinmetz, Katherine R; Waring, Jill D; Kensinger, Elizabeth A

2014-01-01

Individuals are more likely to remember emotional than neutral information, but this benefit does not always extend to the surrounding background information. This memory narrowing is theorised to be linked to the availability of attentional resources at encoding. In contrast to the predictions of this theoretical account, altering participants' attentional resources at encoding by dividing attention did not affect emotion-induced memory narrowing. Attention was divided using three separate manipulations: a digit ordering task (Experiment 1), an arithmetic task (Experiment 2) and an auditory discrimination task (Experiment 3). Across all three experiments, divided attention decreased memory across the board but did not affect the degree of memory narrowing. These findings suggest that theories to explain memory narrowing must be expanded to include other potential mechanisms beyond the limitations of attentional resources.

Discovery of cell-type specific DNA motif grammar in cis-regulatory elements using random Forest.

Science.gov (United States)

Wang, Xin; Lin, Peijie; Ho, Joshua W K

2018-01-19

It has been observed that many transcription factors (TFs) can bind to different genomic loci depending on the cell type in which a TF is expressed in, even though the individual TF usually binds to the same core motif in different cell types. How a TF can bind to the genome in such a highly cell-type specific manner, is a critical research question. One hypothesis is that a TF requires co-binding of different TFs in different cell types. If this is the case, it may be possible to observe different combinations of TF motifs - a motif grammar - located at the TF binding sites in different cell types. In this study, we develop a bioinformatics method to systematically identify DNA motifs in TF binding sites across multiple cell types based on published ChIP-seq data, and address two questions: (1) can we build a machine learning classifier to predict cell-type specificity based on motif combinations alone, and (2) can we extract meaningful cell-type specific motif grammars from this classifier model. We present a Random Forest (RF) based approach to build a multi-class classifier to predict the cell-type specificity of a TF binding site given its motif content. We applied this RF classifier to two published ChIP-seq datasets of TF (TCF7L2 and MAX) across multiple cell types. Using cross-validation, we show that motif combinations alone are indeed predictive of cell types. Furthermore, we present a rule mining approach to extract the most discriminatory rules in the RF classifier, thus allowing us to discover the underlying cell-type specific motif grammar. Our bioinformatics analysis supports the hypothesis that combinatorial TF motif patterns are cell-type specific.

The Influence of Selective and Divided Attention on Audiovisual Integration in Children.

Science.gov (United States)

Yang, Weiping; Ren, Yanna; Yang, Dan Ou; Yuan, Xue; Wu, Jinglong

2016-01-24

This article aims to investigate whether there is a difference in audiovisual integration in school-aged children (aged 6 to 13 years; mean age = 9.9 years) between the selective attention condition and divided attention condition. We designed a visual and/or auditory detection task that included three blocks (divided attention, visual-selective attention, and auditory-selective attention). The results showed that the response to bimodal audiovisual stimuli was faster than to unimodal auditory or visual stimuli under both divided attention and auditory-selective attention conditions. However, in the visual-selective attention condition, no significant difference was found between the unimodal visual and bimodal audiovisual stimuli in response speed. Moreover, audiovisual behavioral facilitation effects were compared between divided attention and selective attention (auditory or visual attention). In doing so, we found that audiovisual behavioral facilitation was significantly difference between divided attention and selective attention. The results indicated that audiovisual integration was stronger in the divided attention condition than that in the selective attention condition in children. Our findings objectively support the notion that attention can modulate audiovisual integration in school-aged children. Our study might offer a new perspective for identifying children with conditions that are associated with sustained attention deficit, such as attention-deficit hyperactivity disorder. © The Author(s) 2016.

Statistical and numerical methods to improve the transient divided bar method

DEFF Research Database (Denmark)

Bording, Thue Sylvester; Nielsen, S.B.; Balling, N.

The divided bar method is a commonly used method to measure thermal conductivity of rock samples in laboratory. We present improvements to this method that allows for simultaneous measurements of both thermal conductivity and thermal diffusivity. The divided bar setup is run in a transient mode...

Full versus divided attention and implicit memory performance.

Science.gov (United States)

Wolters, G; Prinsen, A

1997-11-01

Effects of full and divided attention during study on explicit and implicit memory performance were investigated in two experiments. Study time was manipulated in a third experiment. Experiment 1 showed that both similar and dissociative effects can be found in the two kinds of memory test, depending on the difficulty of the concurrent tasks used in the divided-attention condition. In this experiment, however, standard implicit memory tests were used and contamination by explicit memory influences cannot be ruled out. Therefore, in Experiments 2 and 3 the process dissociation procedure was applied. Manipulations of attention during study and of study time clearly affected the controlled (explicit) memory component, but had no effect on the automatic (implicit) memory component. Theoretical implications of these findings are discussed.

Bridging the Digital Divide

DEFF Research Database (Denmark)

Frølunde, Lisbeth

2002-01-01

The article concerns the digital divide, meaning the social inequity in the access and the opportunities for gaining competencies with ICT (information and communication technologies). Problematic issues are highlighted in relation to experiences during visits to several Computer Clubhouses......, a network of multimedia workshops for youth in the USA. There are references to the learning philosophy Constructionism, which originates from MIT Media Lab and is the basis for the Computer Clubhouse project. Abstract : The consortium for Math and Science at Learning Lab Denmark and the Ministry...... of Education have published the white book 'Life of Science - White Book on Educational Initiatives in the Natural Sciences and Technology', inconnection with a conference for EIST (Initiatives in Science and Technology). The purpose of the EIST project is to make a qualitative overview of a number...

The Effect of Divided Attention on Emotion-Induced Memory Narrowing

OpenAIRE

Steinmetz, Katherine R. Mickley; Waring, Jill D.; Kensinger, Elizabeth A.

2013-01-01

Individuals are more likely to remember emotional than neutral information, but this benefit does not always extend to the surrounding background information. This memory narrowing is theorized to be linked to the availability of attentional resources at encoding. In contrast to the predictions of this theoretical account, altering participants’ attentional resources at encoding, by dividing attention, did not affect the emotion-induced memory narrowing. Attention was divided using three sepa...

Randomized combined modality trial in small cell carcinoma of the lung

International Nuclear Information System (INIS)

Maurer, L.H.; Tulloh, M.; Weiss, R.B.; Blom, J.; Leone, L.; Glidewell, O.; Pajak, T.F.

1980-01-01

A randomized trial of combined modality therapy employing combination chemotherapy (cyclophosphamide (CTX) and methotrexate (MTX), CTX, MTX and Vincristine (VCR) and CTX, VCR, and high-dose MTX with citrovorum rescue), and radiation therapy was compared to cyclophosphamide and radiation therapy in 258 patients with pulmonary small cell carcinoma. Patients were also randomized: (1) to determine the effects of prophylactic whole brain irradiation; (2) to establish the effects of maintenance chemotherapy. Survival, frequency of response, and site of relapse were different in patients with limited disease (LD) (disease confined to lung, mediastinum, and supraclavicular lymph nodes) when compared with disease spread beyond these sites (extensive disease) (ED). No survival advantage was seen in LD when combination chemotherapy was employed, although the frequency of complete remission was greater with three drugs than with one or two drugs (48% vs 32%). In ED frequency of response was greater for three drugs than for one and two drugs (60% vs 40%), but there was no survival advantage. The median survival time for complete responders was similar for limited or extensive disease (12.1 months), but 23.8% were alive at 24 months with LD compared to none with ED. Maintenance chemotherapy significantly prolonged survival by 16.8 months with 33% alive at 24 months compared to 9% who were unmaintained. Prophylactic whole brain irradiation prevented brain metastases with only 4% developing this complication as compared to 18% of control subjects, but did not influence survival

Divided Attention Capacity in Adults with Autism Spectrum Disorders and without Intellectual Disability

Science.gov (United States)

Bogte, Hans; Flamma, Bert; Van Der Meere, Jaap; Van Engeland, Herman

2009-01-01

Earlier research showed that divided attention, an aspect of executive function, is limited in both children and adults with autism spectrum disorders (ASDs). The current study explored divided attention capacity in adults with ASD and without intellectual disability (n = 36). Divided attention was tested using a computerized variant of a…

Divided versus selective attention: evidence for common processing mechanisms.

Science.gov (United States)

Hahn, Britta; Wolkenberg, Frank A; Ross, Thomas J; Myers, Carol S; Heishman, Stephen J; Stein, Dan J; Kurup, Pradeep K; Stein, Elliot A

2008-06-18

The current study revisited the question of whether there are brain mechanisms specific to divided attention that differ from those used in selective attention. Increased neuronal activity required to simultaneously process two stimulus dimensions as compared with each separate dimension has often been observed, but rarely has activity induced by a divided attention condition exceeded the sum of activity induced by the component tasks. Healthy participants performed a selective-divided attention paradigm while undergoing functional Magnetic Resonance Imaging (fMRI). The task required participants to make a same-different judgment about either one of two simultaneously presented stimulus dimensions, or about both dimensions. Performance accuracy was equated between tasks by dynamically adjusting the stimulus display time. Blood Oxygenation Level Dependent (BOLD) signal differences between tasks were identified by whole-brain voxel-wise comparisons and by region-specific analyses of all areas modulated by the divided attention task (DIV). No region displayed greater activation or deactivation by DIV than the sum of signal change by the two selective attention tasks. Instead, regional activity followed the tasks' processing demands as reflected by reaction time. Only a left cerebellar region displayed a correlation between participants' BOLD signal intensity and reaction time that was selective for DIV. The correlation was positive, reflecting slower responding with greater activation. Overall, the findings do not support the existence of functional brain activity specific to DIV. Increased activity appears to reflect additional processing demands by introducing a secondary task, but those demands do not appear to qualitatively differ from processes of selective attention.

Preferential processing of tactile events under conditions of divided attention: Effects of divided attention on reaction time

OpenAIRE

Hanson, James V. M.; Whitaker, David; Heron, James

2009-01-01

Differences in transduction and transmission latencies of visual, auditory and tactile events cause corresponding differences in simple reaction time. As reaction time is usually measured in unimodal blocks, it is unclear whether such latency differences also apply when observers monitor multiple sensory channels. We investigate this by comparing reaction time when attention is focussed on a single modality, and when attention is divided between multiple modalities. Results show that tactile ...

Effects of valence and divided attention on cognitive reappraisal processes.

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Morris, John A; Leclerc, Christina M; Kensinger, Elizabeth A

2014-12-01

Numerous studies have investigated the neural substrates supporting cognitive reappraisal, identifying the importance of cognitive control processes implemented by prefrontal cortex (PFC). This study examined how valence and attention affect the processes used for cognitive reappraisal by asking participants to passively view or to cognitively reappraise positive and negative images with full or divided attention. When participants simply viewed these images, results revealed few effects of valence or attention. However, when participants engaged in reappraisal, there was a robust effect of valence, with the reappraisal of negative relative to positive images associated with more widespread activation, including within regions of medial and lateral PFC. There also was an effect of attention, with more lateral PFC recruitment when regulating with full attention and more medial PFC recruitment when regulating with divided attention. Within two regions of medial PFC and one region of ventrolateral PFC, there was an interaction between valence and attention: in these regions, divided attention reduced activity during reappraisal of positive but not negative images. Critically, participants continued to report reappraisal success even during the Divided Attention condition. These results suggest multiple routes to successful cognitive reappraisal, depending upon image valence and the availability of attentional resources. © The Author (2014). Published by Oxford University Press. For Permissions, please email: journals.permissions@oup.com.

Effects of valence and divided attention on cognitive reappraisal processes

Science.gov (United States)

Leclerc, Christina M.; Kensinger, Elizabeth A.

2014-01-01

Numerous studies have investigated the neural substrates supporting cognitive reappraisal, identifying the importance of cognitive control processes implemented by prefrontal cortex (PFC). This study examined how valence and attention affect the processes used for cognitive reappraisal by asking participants to passively view or to cognitively reappraise positive and negative images with full or divided attention. When participants simply viewed these images, results revealed few effects of valence or attention. However, when participants engaged in reappraisal, there was a robust effect of valence, with the reappraisal of negative relative to positive images associated with more widespread activation, including within regions of medial and lateral PFC. There also was an effect of attention, with more lateral PFC recruitment when regulating with full attention and more medial PFC recruitment when regulating with divided attention. Within two regions of medial PFC and one region of ventrolateral PFC, there was an interaction between valence and attention: in these regions, divided attention reduced activity during reappraisal of positive but not negative images. Critically, participants continued to report reappraisal success even during the Divided Attention condition. These results suggest multiple routes to successful cognitive reappraisal, depending upon image valence and the availability of attentional resources. PMID:24493837

The Role of IT Literacy in Defining Digital Divide Policy Needs

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Ferro, Enrico; Helbig, Natalie C.; Gil-Garcia, J. Ramon

2011-01-01

This article expands our current understanding of the digital divide by examining differences in individuals' IT skills acquisition. In the last two decades scholars have gradually refined the conceptualization of the digital divide, moving from a dichotomous model mainly based on access, to a multidimensional model accounting for differences in…

Knowledge Reduction Based on Divide and Conquer Method in Rough Set Theory

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Feng Hu

2012-01-01

Full Text Available The divide and conquer method is a typical granular computing method using multiple levels of abstraction and granulations. So far, although some achievements based on divided and conquer method in the rough set theory have been acquired, the systematic methods for knowledge reduction based on divide and conquer method are still absent. In this paper, the knowledge reduction approaches based on divide and conquer method, under equivalence relation and under tolerance relation, are presented, respectively. After that, a systematic approach, named as the abstract process for knowledge reduction based on divide and conquer method in rough set theory, is proposed. Based on the presented approach, two algorithms for knowledge reduction, including an algorithm for attribute reduction and an algorithm for attribute value reduction, are presented. Some experimental evaluations are done to test the methods on uci data sets and KDDCUP99 data sets. The experimental results illustrate that the proposed approaches are efficient to process large data sets with good recognition rate, compared with KNN, SVM, C4.5, Naive Bayes, and CART.

Effects of DNA double-strand and single-strand breaks on intrachromosomal recombination events in cell-cycle-arrested yeast cells

International Nuclear Information System (INIS)

Galli, A.; Schiestl, R.H.

1998-01-01

Intrachromosomal recombination between repeated elements can result in deletion (DEL recombination) events. We investigated the inducibility of such intrachromosomal recombination events at different stages of the cell cycle and the nature of the primary DNA lesions capable of initiating these events. Two genetic systems were constructed in Saccharomyces cerevisiae that select for DEL recombination events between duplicated alleles of CDC28 and TUB2. We determined effects of double-strand breaks (DSBs) and single-strand breaks (SSBs) between the duplicated alleles on DEL recombination when induced in dividing cells or cells arrested in G1 or G2. Site-specific DSBs and SSBs were produced by overexpression of the I-Sce I endonuclease and the gene II protein (gIIp), respectively. I-Sce I-induced DSBs caused an increase in DEL recombination frequencies in both dividing and cell-cycle-arrested cells, indicating that G1- and G2-arrested cells are capable of completing DSB repair. In contrast, gIIp-induced SSBs caused an increase in DEL recombination frequency only in dividing cells. To further examine these phenomena we used both γ-irradiation, inducing DSBs as its most relevant lesion, and UV, inducing other forms of DNA damage. UV irradiation did not increase DEL recombination frequencies in G1 or G2, whereas γ-rays increased DEL recombination frequencies in both phases. Both forms of radiation, however, induced DEL recombination in dividing cells. The results suggest that DSBsbut not SSBs induce DEL recombination, probably via the single-strand annealing pathway. Further, DSBs in dividing cells may result from the replication of a UV or SSB-damaged template. Alternatively, UV induced events may occur by replication slippage after DNA polymerase pausing in front of the damage. (author)

Efficient Divide-And-Conquer Classification Based on Feature-Space Decomposition

OpenAIRE

Guo, Qi; Chen, Bo-Wei; Jiang, Feng; Ji, Xiangyang; Kung, Sun-Yuan

2015-01-01

This study presents a divide-and-conquer (DC) approach based on feature space decomposition for classification. When large-scale datasets are present, typical approaches usually employed truncated kernel methods on the feature space or DC approaches on the sample space. However, this did not guarantee separability between classes, owing to overfitting. To overcome such problems, this work proposes a novel DC approach on feature spaces consisting of three steps. Firstly, we divide the feature ...

Afterword. Internet Freedom, Nuanced Digital Divide, and the Internet Craftsman

OpenAIRE

Meinrath, Sascha D; Losey, James; Lennett, Benjamin

2013-01-01

This book provides an in-depth comparative analysis of inequality and the stratification of the digital sphere. Grounded in classical sociological theories of inequality, as well as empirical evidence, this book defines 'the digital divide' as the unequal access and utility of internet communications technologies and explores how it has the potential to replicate existing social inequalities, as well as create new forms of stratification. The Digital Divide examines how various demographic an...

Neural mechanisms of human perceptual choice under focused and divided attention

Science.gov (United States)

Wyart, Valentin; Myers, Nicholas E.; Summerfield, Christopher

2015-01-01

Perceptual decisions occur after evaluation and integration of momentary sensory inputs, and dividing attention between spatially disparate sources of information impairs decision performance. However, it remains unknown whether dividing attention degrades the precision of sensory signals, precludes their conversion into decision signals, or dampens the integration of decision information towards an appropriate response. Here we recorded human electroencephalographic (EEG) activity whilst participants categorised one of two simultaneous and independent streams of visual gratings according to their average tilt. By analyzing trial-by-trial correlations between EEG activity and the information offered by each sample, we obtained converging behavioural and neural evidence that dividing attention between left and right visual fields does not dampen the encoding of sensory or decision information. Under divided attention, momentary decision information from both visual streams was encoded in slow parietal signals without interference but was lost downstream during their integration as reflected in motor mu- and beta-band (10–30 Hz) signals, resulting in a ‘leaky’ accumulation process which conferred greater behavioural influence to more recent samples. By contrast, sensory inputs that were explicitly cued as irrelevant were not converted into decision signals. These findings reveal that a late cognitive bottleneck on information integration limits decision performance under divided attention, and place new capacity constraints on decision-theoretic models of information integration under cognitive load. PMID:25716848

Broadband Millimeter-Wave In-Phase and Out-of-Phase Waveguide Dividers with High Isolation

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Dong, Jun; Liu, Yu; Yang, Ziqiang; Peng, Hao; Yang, Tao

2015-11-01

In this paper, two novel broadband in-phase and out-of-phase waveguide power dividers with high isolation are presented. Based on the substrate-integrated waveguide (SIW) divider and SIW-to-waveguide transition circuit, two kinds of E-plane waveguide dividers have been implemented. Due to the features of in-phase and out-of-phase performances, the proposed waveguide dividers can provide much more flexibilities than that of conventional E-plane waveguide T-junction. A broadband phase and amplitude performances are achieved across the whole Ka-band owing to the wideband characteristic of the SIW divider and transition circuits. To minimize the size and loss of the divider, a compact and low-loss SIW-to-waveguide transition circuit has been developed using the antisymmetric tapered probes. Two prototypes of the Ka-band waveguide dividers, including the in-phase and out-of-phase types, have been fabricated and measured. Measured results show that the isolation, input return loss, output return loss, amplitude imbalance, and phase imbalance of the in-phase divider are better than 15.5, 13.1, 10.8, 0.4 dB, and 3.50, while those of the out-of-phase divider are better than 15.0, 13.4, 10.4, 0.5 dB, and 3.60, respectively, over the frequency range from 26.5 to 40 GHz. The measured results agree well with the simulated ones. Considering their wide bandwidth, high isolation, good port matching performance, and compact configuration, the two types of waveguide dividers can be good candidates for broadband applications in millimeter-wave waveguide systems.

Yogurt supplemented with probiotics can protect the healthy elderly from respiratory infections: A randomized controlled open-label trial.

Science.gov (United States)

Pu, Fangfang; Guo, Yue; Li, Ming; Zhu, Hong; Wang, Shijie; Shen, Xi; He, Miao; Huang, Chengyu; He, Fang

2017-01-01

To evaluate whether yogurt supplemented with a probiotic strain could protect middle-aged and elderly people from acute upper respiratory tract infections (URTI) using a randomized, blank-controlled, parallel-group design. Two hundred and five volunteers aged ≥45 years were randomly divided into two groups. The subjects in the intervention group were orally administered 300 mL/d of yogurt supplemented with a probiotic strain, Lactobacillus paracasei N1115 (N1115), 3.6×10 7 CFU/mL for 12 weeks, while those in the control group retained their normal diet without any probiotic supplementation. The primary outcome was the incidence of URTI, and changes in serum protein, immunoglobulins, and the profiles of the T-lymphocyte subsets (total T-cells [CD3 + ], T-helper cells [CD4 + ], and T-cytotoxic-suppressor cells [CD8 + ]) during the intervention were the secondary outcomes. Compared to the control group, the number of persons diagnosed with an acute URTI and the number of URTI events significantly decreased in the intervention group ( P =0.038, P =0.030, respectively). The risk of URTI in the intervention group was evaluated as 55% of that in the control group (relative risk =0.55, 95% CI: 0.307-0.969). The change in the percentage of CD3 + cells in the intervention group was significantly higher than in the control group ( P =0.038). However, no significant differences were observed in the total protein, albumin, globulin, and prealbumin levels in both groups ( P >0.05). The study suggested that yogurt with selected probiotic strains such as N1115 may reduce the risk of acute upper tract infections in the elderly. The enhancement of the T-cell-mediated natural immune defense might be one of the important underlying mechanisms for probiotics to express their anti-infective effects.

Proton induced single event upset cross section prediction for 0.15 μm six-transistor (6T) silicon-on-insulator static random access memories

International Nuclear Information System (INIS)

Li Lei; Zhou Wanting; Liu Huihua

2012-01-01

In this paper, an efficient physics-based method to estimate the saturated proton upset cross section for six-transistor (6T) silicon-on-insulator (SOI) static random access memory (SRAM) cells using layout and technology parameters is proposed. This method calculates the effects of radiation based on device physics. The simple method handles the problem with ease by SPICE simulations, which can be divided into two stages. At first, it uses a standard SPICE program to predict the cross section for recoiling heavy ions with linear energy transfer (LET) of 14 MeV-cm 2 /mg. Then, the predicted cross section for recoiling heavy ions with LET of 14 MeV-cm 2 /mg is used to estimate the saturated proton upset cross section for 6T SOI SRAM cells with a simple model. The calculated proton induced upset cross section based on this method is in good agreement with the test results of 6T SOI SRAM cells processed using 0.15 μm technology. (author)

Regulation of spindle orientation and neural stem cell fate in the Drosophila optic lobe

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Brand Andrea H

2007-01-01

Full Text Available Abstract Background The choice of a stem cell to divide symmetrically or asymmetrically has profound consequences for development and disease. Unregulated symmetric division promotes tumor formation, whereas inappropriate asymmetric division affects organ morphogenesis. Despite its importance, little is known about how spindle positioning is regulated. In some tissues cell fate appears to dictate the type of cell division, whereas in other tissues it is thought that stochastic variation in spindle position dictates subsequent sibling cell fate. Results Here we investigate the relationship between neural progenitor identity and spindle positioning in the Drosophila optic lobe. We use molecular markers and live imaging to show that there are two populations of progenitors in the optic lobe: symmetrically dividing neuroepithelial cells and asymmetrically dividing neuroblasts. We use genetically marked single cell clones to show that neuroepithelial cells give rise to neuroblasts. To determine if a change in spindle orientation can trigger a neuroepithelial to neuroblast transition, we force neuroepithelial cells to divide along their apical/basal axis by misexpressing Inscuteable. We find that this does not induce neuroblasts, nor does it promote premature neuronal differentiation. Conclusion We show that symmetrically dividing neuroepithelial cells give rise to asymmetrically dividing neuroblasts in the optic lobe, and that regulation of spindle orientation and division symmetry is a consequence of cell type specification, rather than a mechanism for generating cell type diversity.

Problems Related to the Abolition of Divided Real Estate Ownership

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Dinsberga Jolanta

2016-12-01

Full Text Available Legal relationship between apartment owners in residential buildings and the land owners, that is, divided real estate ownership, was created in the Republic of Latvia in 1990, within the framework of the Land Reform, restoring property rights of the former owners or their heirs or privatising apartments in multi-apartment residential buildings. The existence of such legal relationship created different lease problems and restrictions on the property rights to the owners of both the building and the land. To abolish the legal relationship related to divided real estate ownership, the Ministry of Justice of the Republic of Latvia has developed a draft law Regarding the Abolition of Mandatory Divided Real Estate Ownership in Multi-Apartment Buildings (hereinafter referred to as Draft Law. Unfortunately, in the opinion of authors of this article, there are serious shortcomings to the Draft Law which must be corrected. The aim of the research is to identify the problematic issues by selecting and analysing the legislation on the abolition of the divided real estate ownership, which is related to the calculation of redemption price, payment method and consequences of non-payment, which are not regulated by the new Draft Law. The article reflects research on the determination and calculation of redemption price reglamented by the Draft Law and also analyses the Law of December 8, 1938, On the Abolition of Divided Real Estate Ownership and its practical implementation, which may significantly influence the redemption price and the method of its calculation; however, the mentioned law has been disregarded in developing the Draft Law. Thus the research has both theoretical and practical significance. For the research purposes general research methods, such as historical, analytical, inductive, deductive, logical-constructive and descriptive methods, are used. For the interpretation of legislation norms, grammatical, systemic, teleological and historical

Carbon fuel particles used in direct carbon conversion fuel cells

Science.gov (United States)

Cooper, John F.; Cherepy, Nerine

2012-10-09

A system for preparing particulate carbon fuel and using the particulate carbon fuel in a fuel cell. Carbon particles are finely divided. The finely dividing carbon particles are introduced into the fuel cell. A gas containing oxygen is introduced into the fuel cell. The finely divided carbon particles are exposed to carbonate salts, or to molten NaOH or KOH or LiOH or mixtures of NaOH or KOH or LiOH, or to mixed hydroxides, or to alkali and alkaline earth nitrates.

Carbon Fuel Particles Used in Direct Carbon Conversion Fuel Cells

Science.gov (United States)

Cooper, John F.; Cherepy, Nerine

2008-10-21

A system for preparing particulate carbon fuel and using the particulate carbon fuel in a fuel cell. Carbon particles are finely divided. The finely dividing carbon particles are introduced into the fuel cell. A gas containing oxygen is introduced into the fuel cell. The finely divided carbon particles are exposed to carbonate salts, or to molten NaOH or KOH or LiOH or mixtures of NaOH or KOH or LiOH, or to mixed hydroxides, or to alkali and alkaline earth nitrates.

Ocean-Bottom Topography: The Divide between the Sohm and Hatteras Abyssal Plains.

Science.gov (United States)

Pratt, R M

1965-06-18

A compilation of precision echo soundings has delineated the complex topography between the Sohm and Hatteras abyssal plains off the Atlantic coast of the United States. At present the divide between the two plains is a broad, flat area about 4950 meters deep; however, the configuration of channels and depressions suggests spillage of turbidity currents from the Sohm Plain into the Hatteras Plain and a shifting of the divide toward the northeast. Hudson Canyon terminates in the divide area and has probably fed sediment into both plains.

Preferential solvation: dividing surface vs excess numbers.

Science.gov (United States)

Shimizu, Seishi; Matubayasi, Nobuyuki

2014-04-10

How do osmolytes affect the conformation and configuration of supramolecular assembly, such as ion channel opening and actin polymerization? The key to the answer lies in the excess solvation numbers of water and osmolyte molecules; these numbers are determinable solely from experimental data, as guaranteed by the phase rule, as we show through the exact solution theory of Kirkwood and Buff (KB). The osmotic stress technique (OST), in contrast, purposes to yield alternative hydration numbers through the use of the dividing surface borrowed from the adsorption theory. However, we show (i) OST is equivalent, when it becomes exact, to the crowding effect in which the osmolyte exclusion dominates over hydration; (ii) crowding is not the universal driving force of the osmolyte effect (e.g., actin polymerization); (iii) the dividing surface for solvation is useful only for crowding, unlike in the adsorption theory which necessitates its use due to the phase rule. KB thus clarifies the true meaning and limitations of the older perspectives on preferential solvation (such as solvent binding models, crowding, and OST), and enables excess number determination without any further assumptions.

A randomized double-blind study of testosterone replacement therapy or placebo in testicular cancer survivors with mild Leydig cell insufficiency (Einstein-intervention).

Science.gov (United States)

Bandak, Mikkel; Jørgensen, Niels; Juul, Anders; Lauritsen, Jakob; Kreiberg, Michael; Oturai, Peter Sandor; Helge, Jørn Wulff; Daugaard, Gedske

2017-07-03

Elevated serum levels of luteinizing hormone and slightly decreased serum levels of testosterone (mild Leydig cell insufficiency) is a common hormonal disturbance in testicular cancer (TC) survivors. A number of studies have shown that low serum levels of testosterone is associated with low grade inflammation and increased risk of metabolic syndrome. However, so far, no studies have evaluated whether testosterone substitution improves metabolic dysfunction in TC survivors with mild Leydig cell insufficiency. This is a single-center, randomized, double-blind, placebo-controlled study, designed to evaluate the effect of testosterone replacement therapy in TC survivors with mild Leydig cell insufficiency. Seventy subjects will be randomized to receive either testosterone replacement therapy or placebo. The subjects will be invited for an information meeting where informed consent will be obtained. Afterwards, a 52-weeks treatment period begins in which study participants will receive a daily dose of transdermal testosterone or placebo. Dose adjustment will be made three times during the initial 8 weeks of the study to a maximal daily dose of 40 mg of testosterone in the intervention arm. Evaluation of primary and secondary endpoints will be performed at baseline, 26 weeks post-randomization, at the end of treatment (52 weeks) and 3 months after completion of treatment (week 64). This study is the first to investigate the effect of testosterone substitution in testicular cancer survivors with mild Leydig cell insufficiency. If positive, it may change the clinical handling of testicular cancer survivors with borderline low levels of testosterone. ClinicalTrials.gov : NCT02991209 (November 25, 2016).

The effect of the melatonin on cryopreserved mouse testicular cells

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Ghasem Saki

2016-01-01

Full Text Available Background: After improvements in various cancer treatments, life expectancy has been raised, but success in treatment causes loss of fertility in many of the survived young men. Cryopreservation of immature testicular tissues or cells introduced as the only way to preserve fertility. However, freezing has some harmful effects. Melatonin, a pineal gland hormone, has receptors in reproductive systems of different species. It is assumed that melatonin has free radical scavenger properties. Objective: The aim of this study was to evaluate the effects of melatonin on the cryopreserved testicular cells in mouse. Materials and Methods: Cells from 7- 10 days old NMRI mice testes were isolated using two step enzymatic digestion. The testicular cells were divided into two groups randomly and cryopreserved in two different freezing media with and without the addition of 100 μm melatonin. Finally, apoptosis of the cells was assayed by flow cytometry. Also, lactate dehydrogenase activity test was performed to assess the cytotoxicity. Results: The results of lactate dehydrogenase showed the nearly cytotoxic effect of melatonin. The results of flow cytometry showed increase in apoptosis in the cryopreserved cells in the media containing melatonin compared to the control group. Conclusion: The present study shows that melatonin has an apoptotic effect on cryopreserved mouse testicular cells.

Concept of rewritable organic ferroelectric random access memory in two lateral transistors-in-one cell architecture

International Nuclear Information System (INIS)

Kim, Min-Hoi; Lee, Gyu Jeong; Keum, Chang-Min; Lee, Sin-Doo

2014-01-01

We propose a concept of rewritable ferroelectric random access memory (RAM) with two lateral organic transistors-in-one cell architecture. Lateral integration of a paraelectric organic field-effect transistor (OFET), being a selection transistor, and a ferroelectric OFET as a memory transistor is realized using a paraelectric depolarizing layer (PDL) which is patterned on a ferroelectric insulator by transfer-printing. For the selection transistor, the key roles of the PDL are to reduce the dipolar strength and the surface roughness of the gate insulator, leading to the low memory on–off ratio and the high switching on–off current ratio. A new driving scheme preventing the crosstalk between adjacent memory cells is also demonstrated for the rewritable operation of the ferroelectric RAM. (paper)

Bruce NGS A Unit 4 preheater divider plate failure

International Nuclear Information System (INIS)

Landridge, M.; McInnes, D.

1995-01-01

On May 19, 1995, without any prior operational indications, Bruce A discovered preheater divider plate damage in Unit 4 that had the potential to have a major impact on the continued safe operation of the station. Further investigations indicated that Unit 4 may have been operating with this damage for as long as ten years. In the two months following the discovery, Bruce A has procured and replaced the 4 divider plates, located most of the missing pieces, retrieved pieces from the PHT system, investigated historical operational information, performed detailed analytical investigations, investigated root cause, performed in-situ and mock-up testing, updated operational procedures and installed DP monitoring equipment

Modulation of early cortical processing during divided attention to non-contiguous locations.

Science.gov (United States)

Frey, Hans-Peter; Schmid, Anita M; Murphy, Jeremy W; Molholm, Sophie; Lalor, Edmund C; Foxe, John J

2014-05-01

We often face the challenge of simultaneously attending to multiple non-contiguous regions of space. There is ongoing debate as to how spatial attention is divided under these situations. Whereas, for several years, the predominant view was that humans could divide the attentional spotlight, several recent studies argue in favor of a unitary spotlight that rhythmically samples relevant locations. Here, this issue was addressed by the use of high-density electrophysiology in concert with the multifocal m-sequence technique to examine visual evoked responses to multiple simultaneous streams of stimulation. Concurrently, we assayed the topographic distribution of alpha-band oscillatory mechanisms, a measure of attentional suppression. Participants performed a difficult detection task that required simultaneous attention to two stimuli in contiguous (undivided) or non-contiguous parts of space. In the undivided condition, the classic pattern of attentional modulation was observed, with increased amplitude of the early visual evoked response and increased alpha amplitude ipsilateral to the attended hemifield. For the divided condition, early visual responses to attended stimuli were also enhanced, and the observed multifocal topographic distribution of alpha suppression was in line with the divided attention hypothesis. These results support the existence of divided attentional spotlights, providing evidence that the corresponding modulation occurs during initial sensory processing time-frames in hierarchically early visual regions, and that suppressive mechanisms of visual attention selectively target distracter locations during divided spatial attention. © 2014 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

Effects of prolonged wakefulness combined with alcohol and hands-free cell phone divided attention tasks on simulated driving.

Science.gov (United States)

Iudice, A; Bonanni, E; Gelli, A; Frittelli, C; Iudice, G; Cignoni, F; Ghicopulos, I; Murri, L

2005-03-01

Simulated driving ability was assessed following administration of alcohol, at an estimated blood level of 0.05%, and combined prolonged wakefulness, while participants were undertaking divided attention tasks over a hands-free mobile phone. Divided attention tasks were structured to provide a sustained cognitive workload to the subjects. Twenty three young healthy individuals drove 10 km simulated driving under four conditions in a counterbalanced, within-subject design: alcohol, alcohol and 19 h wakefulness, alcohol and 24 h wakefulness, and while sober. Study measures were: simulated driving, self-reported sleepiness, critical flicker fusion threshold (CFFT), Stroop word-colour interference test (Stroop) and simple visual reaction times (SVRT). As expected, subjective sleepiness was highly correlated with both sleep restriction and alcohol consumption. The combination of alcohol and 24 h sustained wakefulness produced the highest driving impairment, significantly beyond the alcohol effect itself. Concurrent alcohol and 19 h wakefulness significantly affected only driving time-to-collision. No significant changes of study measures occurred following alcohol intake in unrestricted sleep conditions. CFFT, SVRT and Stroop results showed a similar trend in the four study conditions. Thus apparently 'safe' blood alcohol levels in combination with prolonged wakefulness resulted in significant driving impairments. In normal sleep conditions alcohol effects on driving were partially counteracted by the concomitant hands-free phone based psychometric tasks. 2005 John Wiley & Sons, Ltd.

Neural mechanisms of human perceptual choice under focused and divided attention.

Science.gov (United States)

Wyart, Valentin; Myers, Nicholas E; Summerfield, Christopher

2015-02-25

Perceptual decisions occur after the evaluation and integration of momentary sensory inputs, and dividing attention between spatially disparate sources of information impairs decision performance. However, it remains unknown whether dividing attention degrades the precision of sensory signals, precludes their conversion into decision signals, or dampens the integration of decision information toward an appropriate response. Here we recorded human electroencephalographic (EEG) activity while participants categorized one of two simultaneous and independent streams of visual gratings according to their average tilt. By analyzing trial-by-trial correlations between EEG activity and the information offered by each sample, we obtained converging behavioral and neural evidence that dividing attention between left and right visual fields does not dampen the encoding of sensory or decision information. Under divided attention, momentary decision information from both visual streams was encoded in slow parietal signals without interference but was lost downstream during their integration as reflected in motor mu- and beta-band (10-30 Hz) signals, resulting in a "leaky" accumulation process that conferred greater behavioral influence to more recent samples. By contrast, sensory inputs that were explicitly cued as irrelevant were not converted into decision signals. These findings reveal that a late cognitive bottleneck on information integration limits decision performance under divided attention, and places new capacity constraints on decision-theoretic models of information integration under cognitive load. Copyright © 2015 the authors 0270-6474/15/353485-14$15.00/0.

Dose and Fractionation in Radiation Therapy of Curative Intent for Non-Small Cell Lung Cancer: Meta-Analysis of Randomized Trials

Energy Technology Data Exchange (ETDEWEB)

Ramroth, Johanna; Cutter, David J.; Darby, Sarah C. [Nuffield Department of Population Health, University of Oxford, Oxford, Oxfordshire (United Kingdom); Higgins, Geoff S. [Department of Oncology, University of Oxford, Oxford, Oxfordshire (United Kingdom); McGale, Paul [Nuffield Department of Population Health, University of Oxford, Oxford, Oxfordshire (United Kingdom); Partridge, Mike [CRUK/MRC Oxford Institute for Radiation Oncology, Oxford, Oxfordshire (United Kingdom); Taylor, Carolyn W., E-mail: carolyn.taylor@ndph.ox.ac.uk [Nuffield Department of Population Health, University of Oxford, Oxford, Oxfordshire (United Kingdom)

2016-11-15

Purpose: The optimum dose and fractionation in radiation therapy of curative intent for non-small cell lung cancer remains uncertain. We undertook a published data meta-analysis of randomized trials to examine whether radiation therapy regimens with higher time-corrected biologically equivalent doses resulted in longer survival, either when given alone or when given with chemotherapy. Methods and Materials: Eligible studies were randomized comparisons of 2 or more radiation therapy regimens, with other treatments identical. Median survival ratios were calculated for each comparison and pooled. Results: 3795 patients in 25 randomized comparisons of radiation therapy dose were studied. The median survival ratio, higher versus lower corrected dose, was 1.13 (95% confidence interval [CI] 1.04-1.22) when radiation therapy was given alone and 0.83 (95% CI 0.71-0.97) when it was given with concurrent chemotherapy (P for difference=.001). In comparisons of radiation therapy given alone, the survival benefit increased with increasing dose difference between randomized treatment arms (P for trend=.004). The benefit increased with increasing dose in the lower-dose arm (P for trend=.01) without reaching a level beyond which no further survival benefit was achieved. The survival benefit did not differ significantly between randomized comparisons where the higher-dose arm was hyperfractionated and those where it was not. There was heterogeneity in the median survival ratio by geographic region (P<.001), average age at randomization (P<.001), and year trial started (P for trend=.004), but not for proportion of patients with squamous cell carcinoma (P=.2). Conclusions: In trials with concurrent chemotherapy, higher radiation therapy doses resulted in poorer survival, possibly caused, at least in part, by high levels of toxicity. Where radiation therapy was given without chemotherapy, progressively higher radiation therapy doses resulted in progressively longer survival, and no

Dose and Fractionation in Radiation Therapy of Curative Intent for Non-Small Cell Lung Cancer: Meta-Analysis of Randomized Trials

International Nuclear Information System (INIS)

Ramroth, Johanna; Cutter, David J.; Darby, Sarah C.; Higgins, Geoff S.; McGale, Paul; Partridge, Mike; Taylor, Carolyn W.

2016-01-01

Purpose: The optimum dose and fractionation in radiation therapy of curative intent for non-small cell lung cancer remains uncertain. We undertook a published data meta-analysis of randomized trials to examine whether radiation therapy regimens with higher time-corrected biologically equivalent doses resulted in longer survival, either when given alone or when given with chemotherapy. Methods and Materials: Eligible studies were randomized comparisons of 2 or more radiation therapy regimens, with other treatments identical. Median survival ratios were calculated for each comparison and pooled. Results: 3795 patients in 25 randomized comparisons of radiation therapy dose were studied. The median survival ratio, higher versus lower corrected dose, was 1.13 (95% confidence interval [CI] 1.04-1.22) when radiation therapy was given alone and 0.83 (95% CI 0.71-0.97) when it was given with concurrent chemotherapy (P for difference=.001). In comparisons of radiation therapy given alone, the survival benefit increased with increasing dose difference between randomized treatment arms (P for trend=.004). The benefit increased with increasing dose in the lower-dose arm (P for trend=.01) without reaching a level beyond which no further survival benefit was achieved. The survival benefit did not differ significantly between randomized comparisons where the higher-dose arm was hyperfractionated and those where it was not. There was heterogeneity in the median survival ratio by geographic region (P<.001), average age at randomization (P<.001), and year trial started (P for trend=.004), but not for proportion of patients with squamous cell carcinoma (P=.2). Conclusions: In trials with concurrent chemotherapy, higher radiation therapy doses resulted in poorer survival, possibly caused, at least in part, by high levels of toxicity. Where radiation therapy was given without chemotherapy, progressively higher radiation therapy doses resulted in progressively longer survival, and no

Effect of benazepril on the transdifferentiation of renal tubular epithelial cells from diabetic rats.

Science.gov (United States)

Peng, Tao; Wang, Jie; Zhen, Junhui; Hu, Zhao; Yang, Xiangdong

2014-07-01

The aim of this study was to investigate the effect of benazepril on the transdifferentiation of renal tubular epithelial cells from diabetic rats. Thirty male Sprague-Dawley rats were included in the present study. Eight of the 30 rats were randomly selected and served as the normal control group (N group), while the remaining 22 rats, injected with streptozotocin (STZ), comprised the diabetic rat model. Rats with diabetes were randomly divided into the diabetic (DM group) and benazepril (B group) groups. The total course was conducted over 12 weeks. Blood glucose, body weight, kidney/body weight, 24-h urinary protein, serum creatinine and blood urea nitrogen were measured at the start and end of the study. We observed the tubulointerstitial pathological changes, and applied immunohistochemistry and western blotting to detect the expression of α-smooth muscle actin (α-SMA) in renal tissue. The levels of blood glucose, kidney/body weight, 24-h urinary protein, serum creatinine, blood urea nitrogen and tubulointerstitial damage index (TII) in the DM group were significantly higher than that in the N group (pbenazepril significantly reduced the expression of α-SMA in renal tubular epithelial cells obtained from diabetic rats, inhibited the transdifferentiation of renal tubular epithelial cells and played an important role in kidney protection.

Divided attention in young drivers under the influence of alcohol

OpenAIRE

FREYDIER, Chloé; BERTHELON, Catherine; BASTIEN-TONIAZZO, Mireille; GINEYT, Guy

2014-01-01

Aim: The present research evaluates driving impairment linked to two crashes factors, divided attention task and alcohol, and determines whether it is higher for novice drivers than for experienced drivers. Method: Novice and experienced drivers participated in three experimental sessions in which blood alcohol concentrations (BACs) were 0.0 g/L, 0.2 g/L and 0.5 g/L. They performed a divided attention task with a main task of car-following task and an additional task of number parity identif...

The New Digital Divide For Digital BioMarkers.

Science.gov (United States)

Torous, John; Rodriguez, Jorge; Powell, Adam

2017-09-01

As smartphone and sensors continue to become more ubiquitous across the world, digital biomarkers have emerged as a scalable and practical tool to explore disease states and advance health. But as the digital divide of access and ownership begins to fade, a new digital divide is emerging. Who are the types of people that own smartphones or smart watches, who are the types of people that download health apps or partake in digital biomarker studies, and who are the types of people that are actually active with digital biomarkers apps and sensors - the people providing the high quality and longitudinal data that this field is being founded upon? Understanding the people behind digital biomarkers, the very people this emerging field aims to help, may actually be the real challenge as well as opportunity for digital biomarkers.

Selected CD133⁺ progenitor cells to promote angiogenesis in patients with refractory angina: final results of the PROGENITOR randomized trial.

Science.gov (United States)

Jimenez-Quevedo, Pilar; Gonzalez-Ferrer, Juan Jose; Sabate, Manel; Garcia-Moll, Xavier; Delgado-Bolton, Roberto; Llorente, Leopoldo; Bernardo, Esther; Ortega-Pozzi, Aranzazu; Hernandez-Antolin, Rosana; Alfonso, Fernando; Gonzalo, Nieves; Escaned, Javier; Bañuelos, Camino; Regueiro, Ander; Marin, Pedro; Fernandez-Ortiz, Antonio; Neves, Barbara Das; Del Trigo, Maria; Fernandez, Cristina; Tejerina, Teresa; Redondo, Santiago; Garcia, Eulogio; Macaya, Carlos

2014-11-07

Refractory angina constitutes a clinical problem. The aim of this study was to assess the safety and the feasibility of transendocardial injection of CD133(+) cells to foster angiogenesis in patients with refractory angina. In this randomized, double-blinded, multicenter controlled trial, eligible patients were treated with granulocyte colony-stimulating factor, underwent an apheresis and electromechanical mapping, and were randomized to receive treatment with CD133(+) cells or no treatment. The primary end point was the safety of transendocardial injection of CD133(+) cells, as measured by the occurrence of major adverse cardiac and cerebrovascular event at 6 months. Secondary end points analyzed the efficacy. Twenty-eight patients were included (n=19 treatment; n=9 control). At 6 months, 1 patient in each group had ventricular fibrillation and 1 patient in each group died. One patient (treatment group) had a cardiac tamponade during mapping. There were no significant differences between groups with respect to efficacy parameters; however, the comparison within groups showed a significant improvement in the number of angina episodes per month (median absolute difference, -8.5 [95% confidence interval, -15.0 to -4.0]) and in angina functional class in the treatment arm but not in the control group. At 6 months, only 1 simple-photon emission computed tomography (SPECT) parameter: summed score improved significantly in the treatment group at rest and at stress (median absolute difference, -1.0 [95% confidence interval, -1.9 to -0.1]) but not in the control arm. Our findings support feasibility and safety of transendocardial injection of CD133(+) cells in patients with refractory angina. The promising clinical results and favorable data observed in SPECT summed score may set up the basis to test the efficacy of cell therapy in a larger randomized trial. © 2014 American Heart Association, Inc.

Errors in causal inference: an organizational schema for systematic error and random error.

Science.gov (United States)

Suzuki, Etsuji; Tsuda, Toshihide; Mitsuhashi, Toshiharu; Mansournia, Mohammad Ali; Yamamoto, Eiji

2016-11-01

To provide an organizational schema for systematic error and random error in estimating causal measures, aimed at clarifying the concept of errors from the perspective of causal inference. We propose to divide systematic error into structural error and analytic error. With regard to random error, our schema shows its four major sources: nondeterministic counterfactuals, sampling variability, a mechanism that generates exposure events and measurement variability. Structural error is defined from the perspective of counterfactual reasoning and divided into nonexchangeability bias (which comprises confounding bias and selection bias) and measurement bias. Directed acyclic graphs are useful to illustrate this kind of error. Nonexchangeability bias implies a lack of "exchangeability" between the selected exposed and unexposed groups. A lack of exchangeability is not a primary concern of measurement bias, justifying its separation from confounding bias and selection bias. Many forms of analytic errors result from the small-sample properties of the estimator used and vanish asymptotically. Analytic error also results from wrong (misspecified) statistical models and inappropriate statistical methods. Our organizational schema is helpful for understanding the relationship between systematic error and random error from a previously less investigated aspect, enabling us to better understand the relationship between accuracy, validity, and precision. Copyright © 2016 Elsevier Inc. All rights reserved.

Crossing the phantom divide: Dark energy internal degrees of freedom

International Nuclear Information System (INIS)

Hu, Wayne

2005-01-01

Dark energy constraints have forced viable alternatives that differ substantially from a cosmological constant Λ to have an equation of state w that evolves across the phantom divide set by Λ. Naively, crossing this divide makes the dark energy gravitationally unstable, a problem that is typically finessed by unphysically ignoring the perturbations. While this procedure does not affect constraints near the favored cosmological constant model it can artificially enhance the confidence with which alternative models are rejected. Similar to the general problem of stability for w<0, the solution lies in the internal degrees of freedom in the dark energy sector. We explicitly show how to construct a two scalar field model that crosses the phantom divide and mimics the single field behavior on either side to substantially better than 1% in all observables. It is representative of models where the internal degrees of freedom keep the dark energy smooth out to the horizon scale independently of the equation of state

Kinematic Identification of Parallel Mechanisms by a Divide and Conquer Strategy

DEFF Research Database (Denmark)

Durango, Sebastian; Restrepo, David; Ruiz, Oscar

2010-01-01

using the inverse calibration method. The identification poses are selected optimizing the observability of the kinematic parameters from a Jacobian identification matrix. With respect to traditional identification methods the main advantages of the proposed Divide and Conquer kinematic identification...... strategy are: (i) reduction of the kinematic identification computational costs, (ii) improvement of the numerical efficiency of the kinematic identification algorithm and, (iii) improvement of the kinematic identification results. The contributions of the paper are: (i) The formalization of the inverse...... calibration method as the Divide and Conquer strategy for the kinematic identification of parallel symmetrical mechanisms and, (ii) a new kinematic identification protocol based on the Divide and Conquer strategy. As an application of the proposed kinematic identification protocol the identification...

Chemoprevention of Basal and Squamous Cell Carcinoma With a Single Course of Fluorouracil, 5%, Cream: A Randomized Clinical Trial.

Science.gov (United States)

Weinstock, Martin A; Thwin, Soe Soe; Siegel, Julia A; Marcolivio, Kimberly; Means, Alexander D; Leader, Nicholas F; Shaw, Fiona M; Hogan, Daniel; Eilers, David; Swetter, Susan M; Chen, Suephy C; Jacob, Sharon E; Warshaw, Erin M; Stricklin, George P; Dellavalle, Robert P; Sidhu-Malik, Navjeet; Konnikov, Nellie; Werth, Victoria P; Keri, Jonette E; Robinson-Bostom, Leslie; Ringer, Robert J; Lew, Robert A; Ferguson, Ryan; DiGiovanna, John J; Huang, Grant D

2018-02-01

Keratinocyte carcinoma (ie, cutaneous basal and squamous cell carcinoma) is the most common cancer in the United States. To determine whether topical fluorouracil could prevent surgically treated keratinocyte carcinoma. The Veterans Affairs Keratinocyte Carcinoma Chemoprevention Trial was a randomized, double-blind, placebo-controlled trial of topical fluorouracil for chemoprevention of keratinocyte carcinoma. Participants were recruited from May 2009 to September 2011 from 12 Veterans Affairs medical centers and followed until June 30, 2013. Participants were veterans (n = 932) with a history of at least 2 keratinocyte carcinomas in the past 5 years; almost all were white males and the median age was 70 years. Application of fluorouracil, 5%, (n = 468) or vehicle control cream (n = 464) to the face and ears twice daily for 2 to 4 weeks upon randomization. Surgically treated keratinocyte, basal cell, and squamous cell carcinoma risk on the face and ears in the first year after enrollment; and time to first surgically treated keratinocyte, basal cell, and squamous cell carcinoma. The a priori hypothesis was that fluorouracil would be effective in preventing these cancers. Of 932 participants (916 men [98%]; 926 white [99%]; median age, 70 years), 299 developed a basal cell carcinoma end point (95 in year 1) and 108 developed a squamous cell carcinoma end point (25 in year 1) over 4 years (median follow-up, 2.8 years). Over the entire study, there was no difference between treatment groups in time to first keratinocyte, basal cell, or squamous cell carcinoma. During the first year, however, 5 participants (1%) in the fluorouracil group developed a squamous cell carcinoma vs 20 (4%) in the control group, a 75% (95% CI, 35%-91%) risk reduction (P = .002). The 11% reduction in basal cell carcinoma risk during year 1 (45 [10%] in the fluorouracil group vs 50 [11%] in the control group) was not statistically significant (95% CI, 39% reduction to 31

Dynamic crossmodal links revealed by steady-state responses in auditory-visual divided attention.

Science.gov (United States)

de Jong, Ritske; Toffanin, Paolo; Harbers, Marten

2010-01-01

Frequency tagging has been often used to study intramodal attention but not intermodal attention. We used EEG and simultaneous frequency tagging of auditory and visual sources to study intermodal focused and divided attention in detection and discrimination performance. Divided-attention costs were smaller, but still significant, in detection than in discrimination. The auditory steady-state response (SSR) showed no effects of attention at frontocentral locations, but did so at occipital locations where it was evident only when attention was divided between audition and vision. Similarly, the visual SSR at occipital locations was substantially enhanced when attention was divided across modalities. Both effects were equally present in detection and discrimination. We suggest that both effects reflect a common cause: An attention-dependent influence of auditory information processing on early cortical stages of visual information processing, mediated by enhanced effective connectivity between the two modalities under conditions of divided attention. Copyright (c) 2009 Elsevier B.V. All rights reserved.

The effects of lead exposure on the expression of HMGB1 and HO-1 in rats and PC12 cells.

Science.gov (United States)

Yang, Meiyuan; Li, Yaobin; Wang, Ying; Cheng, Nuo; Zhang, Yi; Pang, Shimin; Shen, Qiwei; Zhao, Lijuan; Li, Guilin; Zhu, Gaochun

2018-05-15

Lead (Pb) is an environmental neurotoxic metal. Chronic exposure to Pb causes deficits of learning and memory in children and spatial learning deficits in developing rats. In this study we investigated the effects of Pb exposure on the expression of HMGB1 and HO-1 in rats and PC12 cells. The animals were randomly divided to three groups: control group; low lead exposure group; high lead exposure group; PC12 cells were divided into 3 groups: 0 μM (control group), 1 μM and 100 μM Pb acetate. The results showed that Pb levels in blood and brain of Pb exposed groups were significantly higher than that of the control group (p < 0.05). The expression of HMGB1 and HO-1 were increased in Pb exposed groups than that of the control group (p < 0.05). Moreover, we found that the up-regulation of HO-1 in Pb exposure environment inhibited the expression of HMGB1. Copyright © 2018 Elsevier B.V. All rights reserved.

Spectral Classification of Asteroids by Random Forest

Science.gov (United States)

Huang, C.; Ma, Y. H.; Zhao, H. B.; Lu, X. P.

2016-09-01

With the increasing asteroid spectral and photometric data, a variety of classification methods for asteroids have been proposed. This paper classifies asteroids based on the observations of Sloan Digital Sky Survey (SDSS) Moving Object Catalogue (MOC) by using the random forest algorithm. With the training data derived from the taxonomies of Tholen, Bus, Lazzaro, DeMeo, and Principal Component Analysis, we classify 48642 asteroids according to g, r, i, and z SDSS magnitudes. In this way, asteroids are divided into 8 spectral classes (C, X, S, B, D, K, L, and V).

A prototype splitter apparatus for dividing large catches of small fish

Science.gov (United States)

Stapanian, Martin A.; Edwards, William H.

2012-01-01

Due to financial and time constraints, it is often necessary in fisheries studies to divide large samples of fish and estimate total catch from the subsample. The subsampling procedure may involve potential human biases or may be difficult to perform in rough conditions. We present a prototype gravity-fed splitter apparatus for dividing large samples of small fish (30–100 mm TL). The apparatus features a tapered hopper with a sliding and removable shutter. The apparatus provides a comparatively stable platform for objectively obtaining subsamples, and it can be modified to accommodate different sizes of fish and different sample volumes. The apparatus is easy to build, inexpensive, and convenient to use in the field. To illustrate the performance of the apparatus, we divided three samples (total N = 2,000 fish) composed of four fish species. Our results indicated no significant bias in estimating either the number or proportion of each species from the subsample. Use of this apparatus or a similar apparatus can help to standardize subsampling procedures in large surveys of fish. The apparatus could be used for other applications that require dividing a large amount of material into one or more smaller subsamples.

The High/Scope Perry Preschool Study: A Case Study in Random Assignment.

Science.gov (United States)

Schweinhart, Lawrence J.

2000-01-01

Studied the long-term benefits of preschool programs for young children living in poverty in the High/Scope Perry Preschool Study, which examined the lives of 123 African Americans randomly divided into a preschool treatment group and a no-preschool comparison group. Cost-benefit analyses of data on these students to age 27 show beneficial effects…

Do bacterial cell numbers follow a theoretical Poisson distribution? Comparison of experimentally obtained numbers of single cells with random number generation via computer simulation.

Science.gov (United States)

Koyama, Kento; Hokunan, Hidekazu; Hasegawa, Mayumi; Kawamura, Shuso; Koseki, Shigenobu

2016-12-01

We investigated a bacterial sample preparation procedure for single-cell studies. In the present study, we examined whether single bacterial cells obtained via 10-fold dilution followed a theoretical Poisson distribution. Four serotypes of Salmonella enterica, three serotypes of enterohaemorrhagic Escherichia coli and one serotype of Listeria monocytogenes were used as sample bacteria. An inoculum of each serotype was prepared via a 10-fold dilution series to obtain bacterial cell counts with mean values of one or two. To determine whether the experimentally obtained bacterial cell counts follow a theoretical Poisson distribution, a likelihood ratio test between the experimentally obtained cell counts and Poisson distribution which parameter estimated by maximum likelihood estimation (MLE) was conducted. The bacterial cell counts of each serotype sufficiently followed a Poisson distribution. Furthermore, to examine the validity of the parameters of Poisson distribution from experimentally obtained bacterial cell counts, we compared these with the parameters of a Poisson distribution that were estimated using random number generation via computer simulation. The Poisson distribution parameters experimentally obtained from bacterial cell counts were within the range of the parameters estimated using a computer simulation. These results demonstrate that the bacterial cell counts of each serotype obtained via 10-fold dilution followed a Poisson distribution. The fact that the frequency of bacterial cell counts follows a Poisson distribution at low number would be applied to some single-cell studies with a few bacterial cells. In particular, the procedure presented in this study enables us to develop an inactivation model at the single-cell level that can estimate the variability of survival bacterial numbers during the bacterial death process. Copyright © 2016 Elsevier Ltd. All rights reserved.

Recent Advances in Intestinal Stem Cells.

Science.gov (United States)

McCabe, Laura R; Parameswaran, Narayanan

2017-09-01

The intestine is a dynamic organ with rapid stem cell division generating epithelial cells that mature and apoptose in 3-5 days. Rapid turnover maintains the epithelial barrier and homeostasis. Current insights on intestinal stem cells (ISCs) and their regulation are discussed here. The Lgr5+ ISCs maintain intestinal homeostasis by dividing asymmetrically, but also divide symmetrically to extinguish or replace ISCs. Following radiation or mucosal injury, reserve BMI1+ ISCs as well as other crypt cells can de-differentiate into Lgr5+ ISCs. ISC niche cells, including Paneth, immune and myofibroblast cells secrete factors that regulate ISC proliferation. Finally, several studies indicate that the microbiome metabolites regulate ISC growth. ISC cells can be plastic and integrate a complexity of environmental/niche cues to trigger or suppress proliferation as needed.

Aneuploidy in immortalized human mesenchymal stem cells with non-random loss of chromosome 13 in culture.

Science.gov (United States)

Takeuchi, Masao; Takeuchi, Kikuko; Ozawa, Yutaka; Kohara, Akihiro; Mizusawa, Hiroshi

2009-01-01

Aneuploidy (an abnormal number of chromosomes) is commonly observed in most human cancer cells, highlighting the need to examine chromosomal instability in tumorigenesis. Previously, the immortalized human mesenchymal stem cell line UE6E7T-3 was shown to undergo a preferential loss of one copy of chromosome 13 after prolonged culture. Here, the loss of chromosome 13 was found to be caused by chromosome missegregation during mitosis, which involved unequal segregation, exclusion of the misaligned chromosome 13 on the metaphase plate, and trapping of chromosome 13 in the midbody region, as observed by fluorescence in situ hybridization. Near-diploid aneuploidy, not tetraploidy, was the direct result. The loss of chromosome 13 was non-random, and was detected by analysis of microsatellites and single nucleotide polymorphism-based loss of heterozygosity (LOH). Of the five microsatellite loci on chromosome 13, four loci showed microsatellite instability at an early stage in culture, and LOH was apparent at a late stage in culture. These results suggest that the microsatellite mutations cause changes in centromere integrity provoking loss of this chromosome in the UE6E7T-3 cell line. Thus, these results support the use of this cell line as a useful model for understanding the mechanism of aneuploid formation in cell cultures.

Cytokine Release and Focal Adhesion Proteins in Normal Thyroid Cells Cultured on the Random Positioning Machine

Directory of Open Access Journals (Sweden)

Elisabeth Warnke

2017-08-01

Full Text Available Background/Aims: Spaceflight impacts on the function of the thyroid gland in vivo. In vitro normal and malignant thyrocytes assemble in part to multicellular spheroids (MCS after exposure to the random positioning machine (RPM, while a number of cells remain adherent (AD. We aim to elucidate possible differences between AD and MCS cells compared to 1g-controls of normal human thyroid cells. Methods: Cells of the human follicular epithelial thyroid cell line Nthy-ori 3-1 were incubated for up to 72 h on the RPM. Afterwards, they were investigated by phase-contrast microscopy, quantitative real-time PCR and by determination of cytokines released in their supernatants. Results: A significant up-regulation of IL6, IL8 and CCL2 gene expression was found after a 4h RPM-exposure, when the whole population was still growing adherently. MCS and AD cells were detected after 24 h on the RPM. At this time, a significantly reduced gene expression in MCS compared to 1g-controls was visible for IL6, IL8, FN1, ITGB1, LAMA1, CCL2, and TLN1. After a 72 h RPM-exposure, IL-6, IL-8, and TIMP-1 secretion rates were increased significantly. Conclusion: Normal thyrocytes form MCS within 24 h. Cytokines seem to be involved in the initiation of MCS formation via focal adhesion proteins.

Loop versus divided colostomy for the management of anorectal malformations.

Science.gov (United States)

Oda, Omar; Davies, Dafydd; Colapinto, Kimberly; Gerstle, J Ted

2014-01-01

The purpose of this study was to compare the clinical outcomes of loop and divided colostomies in patients with anorectal malformations (ARM). We performed a retrospective cohort study reviewing the medical records of all patients with ARM managed with diverting colostomies between 2000 and 2010 at our institution. Independent variables and outcomes of stoma complications were analyzed by parametric measures and logistic regression. One hundred forty-four patients managed with a colostomy for ARM were evaluated (37.5% females, 50.7% loop, 49.3% divided). The incidence of patients with loop and divided colostomies who developed stoma-related complications was 31.5 and 15.5%, respectively (p=0.031). The incidence of prolapse was 17.8 and 2.8%, respectively (p=0.005). Multivariable-logistic regression controlling for other significant independent variables found loop colostomies to be positively associated with the development of a stoma complication (OR 3.13, 95%CI (1.09, 8.96), p=0.033). When individual complications were evaluated, it was only stoma prolapse that was more likely in patients with loop colostomies (OR 8.75, 95%CI (1.74, 44.16), p=0.009). Because of the higher incidence of prolapse, loop colostomies were found to be associated with a higher total incidence of complications than divided stomas. The development of other complications, including urinary tract infections (UTIs) and megarectum, were independent of the type of colostomy performed. © 2014.

Divided attention and mental effort after severe traumatic brain injury.

Science.gov (United States)

Azouvi, Philippe; Couillet, Josette; Leclercq, Michel; Martin, Yves; Asloun, Sybille; Rousseaux, Marc

2004-01-01

The aim of this study was to assess dual-task performance in TBI patients, under different experimental conditions, with or without explicit emphasis on one of two tasks. Results were compared with measurement of the subjective mental effort required to perform each task. Forty-three severe TBI patients at the subacute or chronic phase performed two tasks under single- and dual-task conditions: (a) random generation; (b) visual go-no go reaction time task. Three dual-task conditions were given, requiring either to consider both tasks as equally important or to focus preferentially on one of them. Patients were compared to matched controls. Subjective mental effort was rated on a visual analogic scale. TBI patients showed a disproportionate increase in reaction time in the go-no go task under the dual-task condition. However, they were just as able as controls to adapt performance to the specific instructions about the task to be emphasised. Patients reported significantly higher subjective mental effort, but the variation of mental effort according to task condition was similar to that of controls. These results suggest that the divided attention deficit of TBI patients is related to a reduction in available processing resources rather than an impairment of strategic processes responsible for attentional allocation and switching. The higher level of subjective mental effort may explain why TBI patients frequently complain of mental fatigue, although this subjective complaint seems to be relatively independent of cognitive impairment.

Randomized, Double-Blind, and Placebo-Controlled Clinic Report of Intranasal Low-Intensity Laser Therapy on Vascular Diseases

Directory of Open Access Journals (Sweden)

Timon Cheng-Yi Liu

2012-01-01

Full Text Available The intranasal low intensity GaInP/AlGaInP diode 650 nm laser therapy (ILGLT might improve blood lipid and hemorheologic behavior of patients in view of its previous research, but it should be further supported by a randomized, double-blind, and placebo-controlled clinical study. In this paper, 90 patients with coronary heart disease or cerebral infarction were randomly divided into two groups, 60 in the treatment group and 30 in the control group, and were blindly treated with ILGLT at 8.38 and 0 mW/cm2 for 30 min each time once a day ten days each session for two sessions between which there were three days for rest, respectively. Fasting blood lipid such as total cholesterol and low/high-density lipoprotein cholesterol and hemorheologic behavior such as blood viscosity, plasma viscosity, redox viscosity and red blood cell aggregation were assessed before the first treatment and after the two sessions and were found to be significantly improved by ILGLT. It was concluded that ILGLT may improve blood lipid and hemorheologic behavior of patients with coronary heart disease or cerebral infarction.

Google and the digital divide the bias of online knowledge

CERN Document Server

Segev, Elad

2010-01-01

Beneficial to scholars and students in the fields of media and communication, politics and technology, this book outlines the significant role of search engines in general and Google in particular in widening the digital divide between individuals, organisations and states. It uses innovative methods and research approaches to assess and illustrate the digital divide by comparing the popular search queries in Google and Yahoo in different countries as well as analysing the various biases in Google News and Google Earth. The different studies developed and presented in this book provide various

A randomized trial of preoperative oral carbohydrates in abdominal surgery

OpenAIRE

Sada, Fatos; Krasniqi, Avdyl; Hamza, Astrit; Gecaj-Gashi, Agreta; Bicaj, Besnik; Kavaja, Floren

2014-01-01

Background Carbohydrate-rich liquid drinks (CRLDs) have been recommended to attenuate insulin resistance by shortening the preoperative fasting interval. The aim of our study the effect of preoperative oral administration of CRLDs on the well-being and clinical status of patients. Methods A randomized, double blind, prospective study of patients undergoing open colorectal operations (CR) and open cholecyctectomy (CH) was conducted. Patients were divided into three groups: study, placebo, and ...

An automated three-dimensional detection and segmentation method for touching cells by integrating concave points clustering and random walker algorithm.

Directory of Open Access Journals (Sweden)

Yong He

Full Text Available Characterizing cytoarchitecture is crucial for understanding brain functions and neural diseases. In neuroanatomy, it is an important task to accurately extract cell populations' centroids and contours. Recent advances have permitted imaging at single cell resolution for an entire mouse brain using the Nissl staining method. However, it is difficult to precisely segment numerous cells, especially those cells touching each other. As presented herein, we have developed an automated three-dimensional detection and segmentation method applied to the Nissl staining data, with the following two key steps: 1 concave points clustering to determine the seed points of touching cells; and 2 random walker segmentation to obtain cell contours. Also, we have evaluated the performance of our proposed method with several mouse brain datasets, which were captured with the micro-optical sectioning tomography imaging system, and the datasets include closely touching cells. Comparing with traditional detection and segmentation methods, our approach shows promising detection accuracy and high robustness.

The protective effect of aqueous extracts of roselle (Hibiscus sabdariffa L. UKMR-2) against red blood cell membrane oxidative stress in rats with streptozotocin-induced diabetes

OpenAIRE

Mohamed, Jamaludin; Shing, Saw Wuan; Idris, Muhd Hanis Md; Budin, Siti Balkis; Zainalabidin, Satirah

2013-01-01

OBJECTIVES: The aim of this study was to investigate the protective effects of aqueous extracts of roselle (Hibiscus sabdariffa L. UKMR-2) against red blood cell (RBC) membrane oxidative stress in rats with streptozotocin-induced diabetes. METHODS: Forty male Sprague-Dawley rats weighing 230-250 g were randomly divided into four groups (n = 10 rats each): control group (N), roselle-treated control group, diabetic group, and roselle-treated diabetic group. Roselle was administered by force-f...

The information divide: publishing and access issues | Baker ...

African Journals Online (AJOL)

Some global and local developments in information access and the Open Access movement are highlighted, and the National Library of South Africa\\'s interim strategies to bridge the information and digital divide are identified. However, it becomes evident that unless librarians, information consumers, publishers, ...

Erasure and reestablishment of random allelic expression imbalance after epigenetic reprogramming.

Science.gov (United States)

Jeffries, Aaron Richard; Uwanogho, Dafe Aghogho; Cocks, Graham; Perfect, Leo William; Dempster, Emma; Mill, Jonathan; Price, Jack

2016-10-01

Clonal level random allelic expression imbalance and random monoallelic expression provides cellular heterogeneity within tissues by modulating allelic dosage. Although such expression patterns have been observed in multiple cell types, little is known about when in development these stochastic allelic choices are made. We examine allelic expression patterns in human neural progenitor cells before and after epigenetic reprogramming to induced pluripotency, observing that loci previously characterized by random allelic expression imbalance (0.63% of expressed genes) are generally reset to a biallelic state in induced pluripotent stem cells (iPSCs). We subsequently neuralized the iPSCs and profiled isolated clonal neural stem cells, observing that significant random allelic expression imbalance is reestablished at 0.65% of expressed genes, including novel loci not found to show allelic expression imbalance in the original parental neural progenitor cells. Allelic expression imbalance was associated with altered DNA methylation across promoter regulatory regions, with clones characterized by skewed allelic expression being hypermethylated compared to their biallelic sister clones. Our results suggest that random allelic expression imbalance is established during lineage commitment and is associated with increased DNA methylation at the gene promoter. © 2016 Jeffries et al.; Published by Cold Spring Harbor Laboratory Press for the RNA Society.

Cell-mediated immune suppression effect of rocket kerosene through dermal exposure in mice

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Bing-xin XU

2015-10-01

Full Text Available Objective　To study the effect of cell-mediated immune suppression effect of rocket kerosene (RK through dermal application in mice. Methods　Skin delayed type hypersensitivity (DTH was used to observe the relation of the RK amount the skin exposed and the cellular immune inhibitory function. Different amount of the undiluted fuel was smeared directly onto the dorsal skin of mice. Mice in negative and positive control groups were treated with acetone. After the last exposure, all the mice except those in negative control group were allergized by evenly smearing with 1% dinitrofluorobenzene (DNFB solution on their dorsum. Five days after allergy, 1% DNFB solution was smeared onto right ear of all mice to stimulate the allergic reaction. Twenty-four hours after attack, the auricle swelling, spleen index and thymus index in corresponding mice were determined. In the first series of experiments, different dosages of RK were applied once, and the ICR mice were randomly divided into negative control group, positive control group and experimental group (0.5ml/kg.BW×1, 1ml/kg.BW×1 and 2ml/kg.BW×1 group. In the second series of experiments, the certain and same dosage of RK was applied for different times, and the ICR mice were randomly divided into negative control group, positive control group and experimental group (0.5ml/kg.BW×1, 0.5mL/kg.BW×2, 0.5ml/kg.BW×3, 0.5ml/kg.BW×4 and 0.5mL/kg.BW×5 group. In the third series of experiments, the different dosages of RK were applied more than once, and the ICR mice were randomly divided into negative control group, positive control group and experimental group (0.5ml/kg.BW×5, 1ml/kg.BW×5 and 2ml/kg.BW×5 group. Lymphocyte proliferation experiment in vitrowas conducted to observe the persistent time of the cell-mediated immune suppression in mice by RK dermal exposure. The lymphocyte proliferation induced by concanavalin A (Con A was analyzed by MTT assay, and T lymphocyte subsets (CD3+, CD4+ and CD

On the design of henon and logistic map-based random number generator

Science.gov (United States)

Magfirawaty; Suryadi, M. T.; Ramli, Kalamullah

2017-10-01

The key sequence is one of the main elements in the cryptosystem. True Random Number Generators (TRNG) method is one of the approaches to generating the key sequence. The randomness source of the TRNG divided into three main groups, i.e. electrical noise based, jitter based and chaos based. The chaos based utilizes a non-linear dynamic system (continuous time or discrete time) as an entropy source. In this study, a new design of TRNG based on discrete time chaotic system is proposed, which is then simulated in LabVIEW. The principle of the design consists of combining 2D and 1D chaotic systems. A mathematical model is implemented for numerical simulations. We used comparator process as a harvester method to obtain the series of random bits. Without any post processing, the proposed design generated random bit sequence with high entropy value and passed all NIST 800.22 statistical tests.

The ICT development index and the digital divide : How are they related?

NARCIS (Netherlands)

James, M.J.

2012-01-01

Digital preparedness and the digital divide are two ways of measuring ICT performance across countries. Recently, the ITU has proposed that a new index of preparedness be used to measure the divide. My goal is to investigate the validity of this suggestion. I have argued that the ICT Development

Poverty, Literacy, and Social Transformation: An Interdisciplinary Exploration of the Digital Divide

Science.gov (United States)

Bach, Amy J.; Wolfson, Todd; Crowell, Jessica K.

2018-01-01

Harnessing scholarship focused on literacy and poverty, in this article we aim to complicate the common understanding of the digital divide. First, we argue that the dominant literature on the digital divide misses broader connections between technological exclusion and broader forms of economic and social exclusion. Accordingly, and following…

Bridging the digital divide with mobile services

CERN Document Server

Yelton, Andromeda

2013-01-01

In this issue of Library Technology Reports, Andromeda Yelton shows how libraries can build on the breadth of this population to help bridge the digital divide and provide even greater access to information. Yelton breaks down the demographics of mobile internet users, provides examples of how different libraries are reaching out to these populations, and suggests what the future may hold for this trend.

Measuring the Digital Divide with PingER

Energy Technology Data Exchange (ETDEWEB)

Cottrell, L.

2003-10-01

We introduce the PingER project/toolkit and show its relevance to monitoring sites in developing countries. We then show results from PingER that illustrate the extent of the Digital Divide in terms of Internet performance between developed and developing regions, which developing regions are catching up, keeping up, or falling behind and the magnitude of the differences in performance between developed regions and developing regions.

Cross-point-type spin-transfer-torque magnetoresistive random access memory cell with multi-pillar vertical body channel MOSFET

Science.gov (United States)

Sasaki, Taro; Endoh, Tetsuo

2018-04-01

In this paper, from the viewpoint of cell size and sensing margin, the impact of a novel cross-point-type one transistor and one magnetic tunnel junction (1T–1MTJ) spin-transfer-torque magnetoresistive random access memory (STT-MRAM) cell with a multi-pillar vertical body channel (BC) MOSFET is shown for high density and wide sensing margin STT-MRAM, with a 10 ns writing period and 1.2 V V DD. For that purpose, all combinations of n/p-type MOSFETs and bottom/top-pin MTJs are compared, where the diameter of MTJ (D MTJ) is scaled down from 55 to 15 nm and the tunnel magnetoresistance (TMR) ratio is increased from 100 to 200%. The results show that, benefiting from the proposed STT-MRAM cell with no back bias effect, the MTJ with a high TMR ratio (200%) can be used in the design of smaller STT-MRAM cells (over 72.6% cell size reduction), which is a difficult task for conventional planar MOSFET based design.

Subjective cognitive impairment: functional MRI during a divided attention task.

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Rodda, J; Dannhauser, T; Cutinha, D J; Shergill, S S; Walker, Z

2011-10-01

Individuals with subjective cognitive impairment (SCI) have persistent memory complaints but normal neurocognitive performance. For some, this may represent a pre-mild cognitive impairment (MCI) stage of Alzheimer's disease (AD). Given that attentional deficits and associated brain activation changes are present early in the course of AD, we aimed to determine whether SCI is associated with brain activation changes during attentional processing. Eleven SCI subjects and 10 controls completed a divided attention task during functional magnetic resonance imaging. SCI and control groups did not differ in sociodemographic, neurocognitive or behavioural measures. When group activation during the divided attention task was compared, the SCI group demonstrated increased activation in left medial temporal lobe, bilateral thalamus, posterior cingulate and caudate. This pattern of increased activation is similar to the pattern of decreased activation reported during divided attention in AD and may indicate compensatory changes. These findings suggest the presence of early functional changes in SCI; longitudinal studies will help to further elucidate the relationship between SCI and AD. Copyright © 2010 Elsevier Masson SAS. All rights reserved.

An InGaAs/InP 40 GHz CML static frequency divider

International Nuclear Information System (INIS)

Su Yongbo; Jin Zhi; Cheng Wei; Ge Ji; Wang Xiantai; Chen Gaopeng; Liu Xinyu; Xu Anhuai; Qi Ming

2011-01-01

Static frequency dividers are widely used as a circuit performance benchmark or figure-of-merit indicator to gauge a particular device technology's ability to implement high speed digital and integrated high performance mixed-signal circuits. We report a 2 : 1 static frequency divider in InGaAs/InP heterojunction bipolar transistor technology. This is the first InP based digital integrated circuit ever reported on the mainland of China. The divider is implemented in differential current mode logic (CML) with 30 transistors. The circuit operated at a peak clock frequency of 40 GHz and dissipated 650 mW from a single -5 V supply. (semiconductor integrated circuits)

A Nation under Joint Custody: How Conflicting Family Models Divide US Politics

Science.gov (United States)

Wehling, Eva Elisabeth

2013-01-01

Across the globe and throughout history, politics are regularly divided into "left-leaning" and "right-leaning" camps. Explaining the sources of this conservative-liberal divide has become a major quest in the cognitive and social sciences. Early attempts have focused on self-interest as a possible explanation. However, as the…

Effect of Amifostine on Response Rates in Locally Advanced Non-Small-Cell Lung Cancer Patients Treated on Randomized Controlled Trials: A Meta-Analysis

International Nuclear Information System (INIS)

Mell, Loren K.; Malik, Renuka; Komaki, Ritsuko; Movsas, Benjamin; Swann, R. Suzanne; Langer, Corey; Antonadou, Dosia; Koukourakis, Michael; Mundt, Arno J.

2007-01-01

Purpose: Amifostine can reduce the cytotoxic effects of chemotherapy and radiotherapy in patients with locally advanced non-small-cell lung cancer, but concerns remain regarding its possible tumor-protective effects. Studies with sufficient statistical power to address this question are lacking. Methods and Materials: We performed a meta-analysis of all published clinical trials involving locally advanced non-small-cell lung cancer patients treated with radiotherapy with or without chemotherapy, who had been randomized to treatment with amifostine vs. no amifostine or placebo. Random effects estimates of the relative risk of overall, partial, and complete response were obtained. Results: Seven randomized trials involving 601 patients were identified. Response rate data were available for six studies (552 patients). The pooled relative risk (RR) estimate was 1.07 (95% confidence interval, 0.97-1.18; p = 0.18), 1.21 (95% confidence interval, 0.83-1.78; p = 0.33), and 0.99 (95% confidence interval, 0.78-1.26; p = 0.95) for overall, complete, and partial response, respectively (a RR >1 indicates improvement in response with amifostine compared with the control arm). The results were similar after sensitivity analyses. No evidence was found of treatment effect heterogeneity across the studies. Conclusions: Amifostine has no effect on tumor response in patients with locally advanced non-small-cell lung cancer treated with radiotherapy with or without chemotherapy

Concentration Sensing by the Moving Nucleus in Cell Fate Determination: A Computational Analysis.

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Varun Aggarwal

Full Text Available During development of the vertebrate neuroepithelium, the nucleus in neural progenitor cells (NPCs moves from the apex toward the base and returns to the apex (called interkinetic nuclear migration at which point the cell divides. The fate of the resulting daughter cells is thought to depend on the sampling by the moving nucleus of a spatial concentration profile of the cytoplasmic Notch intracellular domain (NICD. However, the nucleus executes complex stochastic motions including random waiting and back and forth motions, which can expose the nucleus to randomly varying levels of cytoplasmic NICD. How nuclear position can determine daughter cell fate despite the stochastic nature of nuclear migration is not clear. Here we derived a mathematical model for reaction, diffusion, and nuclear accumulation of NICD in NPCs during interkinetic nuclear migration (INM. Using experimentally measured trajectory-dependent probabilities of nuclear turning, nuclear waiting times and average nuclear speeds in NPCs in the developing zebrafish retina, we performed stochastic simulations to compute the nuclear trajectory-dependent probabilities of NPC differentiation. Comparison with experimentally measured nuclear NICD concentrations and trajectory-dependent probabilities of differentiation allowed estimation of the NICD cytoplasmic gradient. Spatially polarized production of NICD, rapid NICD cytoplasmic consumption and the time-averaging effect of nuclear import/export kinetics are sufficient to explain the experimentally observed differentiation probabilities. Our computational studies lend quantitative support to the feasibility of the nuclear concentration-sensing mechanism for NPC fate determination in zebrafish retina.

Design and analysis of unequal split Bagley power dividers

Science.gov (United States)

Abu-Alnadi, Omar; Dib, Nihad; Al-Shamaileh, Khair; Sheta, Abdelfattah

2015-03-01

In this article, we propose a general design procedure to develop unequal split Bagley power dividers (BPDs). Based on the mathematical approach carried out in the insight of simple circuit and transmission line theories, exact design equations for 3-way and 5-way BPDs are derived. Utilising the developed equations leads to power dividers with the ability of offering different output power ratios through a suitable choice of the characteristic impedances of the interconnecting transmission lines. For verification purposes, a 1:2:1 3-way, 1:2:1:2:1 5-way and 1:3:1:3:1 5-way BPDs are designed and fabricated. The experimental and full-wave simulation results prove the validity of the designed unequal split BPDs.

Improved process for heating finely divided carbonaceous materials

Energy Technology Data Exchange (ETDEWEB)

1956-08-01

A process for heating finely divided carbonaceous particles by burning a proportion of the carbon consists of passing the carbonaceous material at a temperature above 800/sup 0/F into an upwardly disposed, slender, combustion zone, suspending the particles in an upwardly-moving gas containing free oxygen so that the suspension has a density from 0.1 to 5.0 lb/cu. ft., passing the suspension upwardly through the combustion zone at a velocity of from 5 to 100 ft./sec., and injecting at least one stream of a second gas containing free oxygen at a point in the combustion zone such that at least 50% of the oxygen in the first gas has been consumed by the time the suspension reaches this point. The total quantity of oxygen is chosen so that the finely divided carbonaceous material is heated to a temperature of not less than 1,050/sup 0/F.

Stem cell organization in Arabidopsis

NARCIS (Netherlands)

Wendrich, J.R.

2016-01-01

Growth of plant tissues and organs depends on continuous production of new cells, by niches of stem cells. Stem cells typically divide to give rise to one differentiating daughter and one non-differentiating daughter. This constant process of self-renewal ensures that the niches of stem cells or

Sub-1-V-60 nm vertical body channel MOSFET-based six-transistor static random access memory array with wide noise margin and excellent power delay product and its optimization with the cell ratio on static random access memory cell

Science.gov (United States)

Ogasawara, Ryosuke; Endoh, Tetsuo

2018-04-01

In this study, with the aim to achieve a wide noise margin and an excellent power delay product (PDP), a vertical body channel (BC)-MOSFET-based six-transistor (6T) static random access memory (SRAM) array is evaluated by changing the number of pillars in each part of a SRAM cell, that is, by changing the cell ratio in the SRAM cell. This 60 nm vertical BC-MOSFET-based 6T SRAM array realizes 0.84 V operation under the best PDP and up to 31% improvement of PDP compared with the 6T SRAM array based on a 90 nm planar MOSFET whose gate length and channel width are the same as those of the 60 nm vertical BC-MOSFET. Additionally, the vertical BC-MOSFET-based 6T SRAM array achieves an 8.8% wider read static noise margin (RSNM), a 16% wider write margin (WM), and an 89% smaller leakage. Moreover, it is shown that changing the cell ratio brings larger improvements of RSNM, WM, and write time in the vertical BC-MOSFET-based 6T SRAM array.

Antitumor activity and safety of tivozanib (AV-951) in a phase II randomized discontinuation trial in patients with renal cell carcinoma.

Science.gov (United States)

Nosov, Dmitry A; Esteves, Brooke; Lipatov, Oleg N; Lyulko, Alexei A; Anischenko, A A; Chacko, Raju T; Doval, Dinesh C; Strahs, Andrew; Slichenmyer, William J; Bhargava, Pankaj

2012-05-10

The antitumor activity and safety of tivozanib, which is a potent and selective vascular endothelial growth factor receptor-1, -2, and -3 inhibitor, was assessed in patients with advanced/metastatic renal cell carcinoma (RCC). In this phase II, randomized discontinuation trial, 272 patients received open-label tivozanib 1.5 mg/d (one cycle equaled three treatment weeks followed by a 1-week break) orally for 16 weeks. Thereafter, 78 patients who demonstrated ≥ 25% tumor shrinkage continued to take tivozanib, and 118 patients with less than 25% tumor change were randomly assigned to receive tivozanib or a placebo in a double-blind manner; patients with ≥ 25% tumor growth were discontinued. Primary end points included safety, the objective response rate (ORR) at 16 weeks, and the percentage of randomly assigned patients who remained progression free after 12 weeks of double-blind treatment; secondary end points included progression-free survival (PFS). Of 272 patients enrolled onto the study, 83% of patients had clear-cell histology, 73% of patients had undergone nephrectomy, and 54% of patients were treatment naive. The ORR after 16 weeks of tivozanib treatment was 18% (95% CI, 14% to 23%). Of the 118 randomized patients, significantly more patients who were randomly assigned to receive double-blind tivozanib remained progression free after 12 weeks versus patients who received the placebo (49% v 21%; P = .001). Throughout the study, the ORR was 24% (95% CI, 19% to 30%), and the median PFS was 11.7 months (95% CI, 8.3 to 14.3 months) in the overall study population. The most common grade 3 and 4 treatment-related adverse event was hypertension (12%). Tivozanib was active and well tolerated in patients with advanced RCC. These data support additional development of tivozanib in advanced RCC.

The pupil response is sensitive to divided attention during speech processing.

Science.gov (United States)

Koelewijn, Thomas; Shinn-Cunningham, Barbara G; Zekveld, Adriana A; Kramer, Sophia E

2014-06-01

Dividing attention over two streams of speech strongly decreases performance compared to focusing on only one. How divided attention affects cognitive processing load as indexed with pupillometry during speech recognition has so far not been investigated. In 12 young adults the pupil response was recorded while they focused on either one or both of two sentences that were presented dichotically and masked by fluctuating noise across a range of signal-to-noise ratios. In line with previous studies, the performance decreases when processing two target sentences instead of one. Additionally, dividing attention to process two sentences caused larger pupil dilation and later peak pupil latency than processing only one. This suggests an effect of attention on cognitive processing load (pupil dilation) during speech processing in noise. Copyright © 2014 The Authors. Published by Elsevier B.V. All rights reserved.

Dividing time: concurrent timing of auditory and visual events by young and elderly adults.

Science.gov (United States)

McAuley, J Devin; Miller, Jonathan P; Wang, Mo; Pang, Kevin C H

2010-07-01

This article examines age differences in individual's ability to produce the durations of learned auditory and visual target events either in isolation (focused attention) or concurrently (divided attention). Young adults produced learned target durations equally well in focused and divided attention conditions. Older adults, in contrast, showed an age-related increase in timing variability in divided attention conditions that tended to be more pronounced for visual targets than for auditory targets. Age-related impairments were associated with a decrease in working memory span; moreover, the relationship between working memory and timing performance was largest for visual targets in divided attention conditions.

Pitfall of the Strongest Cells in Static Random Access Memory Physical Unclonable Functions

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Mingyang Gong

2018-06-01

Full Text Available Static Random Access Memory (SRAM Physical Unclonable Functions (PUFs are some of the most popular PUFs that provide a highly-secured solution for secret key storage. Given that PUF responses are noisy, the key reconstruction must use error correcting code (ECC to reduce the noise. Repetition code is widely used in resource constrained systems as it is concise and lightweight, however, research has shown that repetition codes can lead to information leakage. In this paper we found that the strongest cell distribution in a SRAM array may leak information of the responses of SRAM PUF when the repetition code is directly applied. Experimentally, on an ASIC platform with the HHGRACE 0.13 μm process, we recovered 8.3% of the measured response using the strongest cells revealed by the helper data, and we finally obtained a clone response 79% similar to weak response using the public helper data. We therefore propose Error Resistant Fuzzy Extractor (ERFE, a 4-bit error tolerant fuzzy extractor, that extracts the value of the sum of the responses as a unique key and reduces the failure rate to 1.8 × 10−8 with 256 bit entropy.

Fundamental criteria for the design of high-performance Josephson nondestructive readout random access memory cells and experimental confirmation

International Nuclear Information System (INIS)

Henkels, W.H.

1979-01-01

Fundamental design criteria for Josephson nondestructive readout random access memory (NDRO RAM) cells are presented, within the context of an LSI array environment. Emphasis is placed upon principles which are relevant to high performance. The criteria are elucidated via a specific design which is simulated and then experimentally evaluated in a technology with a smallest critical dimension of 5 μm. The specific cell differs from previously tested Josephson NDRO cells in several respects; namely, the cell stores only approx.8Phi 0 , employs interferometer gates and an external damping resistor, allows switching into device resonances, and eliminates the need for a special initialization cycle. The cell-selection scheme, employing triple coincidence, results in larger operating margins and smaller operating currents than have previously been achieved. The large operating margins and all basic cell design criteria were experimentally verified. The experimental interferometer gate characteristics were analyzed in detail and found to be describable by simple models. In addition, it was discovered that single flux quantum transitions in the interferometer gates could be exploited beneficially in order to enhance the insensitivity of operating margins to fabrication tolerances

Essays on the Digital Divide--Explorations through Global, National and Individual Lenses

Science.gov (United States)

Skaletsky, Maria

2013-01-01

The Digital Divide has emerged as an important research and policy issue during the past thirty years. The divide exists at different levels, such as global, regional and individual levels. While extensive research already exists on this subject, the complexity of the issue presents opportunities for further research. In particular, there is ample…

Communication in a Divided World: Opportunities and Constraints.

Science.gov (United States)

Lasswell, Harold

Communication systems in a divided world can perpetuate tension and violence or can be instrumental in developing unity. In response to this power, communicators must focus on generating worldwide recognition of interdependence in the shaping and sharing of values. Likewise, a responsible communication policy must stimulate the invention and…

SAMHD1 controls cell cycle status, apoptosis and HIV-1 infection in monocytic THP-1 cells

International Nuclear Information System (INIS)

Bonifati, Serena; Daly, Michele B.; St Gelais, Corine; Kim, Sun Hee; Hollenbaugh, Joseph A.; Shepard, Caitlin; Kennedy, Edward M.; Kim, Dong-Hyun; Schinazi, Raymond F.; Kim, Baek; Wu, Li

2016-01-01

SAMHD1 limits HIV-1 infection in non-dividing myeloid cells by decreasing intracellular dNTP pools. HIV-1 restriction by SAMHD1 in these cells likely prevents activation of antiviral immune responses and modulates viral pathogenesis, thus highlighting a critical role of SAMHD1 in HIV-1 physiopathology. Here, we explored the function of SAMHD1 in regulating cell proliferation, cell cycle progression and apoptosis in monocytic THP-1 cells. Using the CRISPR/Cas9 technology, we generated THP-1 cells with stable SAMHD1 knockout. We found that silencing of SAMHD1 in cycling cells stimulates cell proliferation, redistributes cell cycle population in the G_1/G_0 phase and reduces apoptosis. These alterations correlated with increased dNTP levels and more efficient HIV-1 infection in dividing SAMHD1 knockout cells relative to control. Our results suggest that SAMHD1, through its dNTPase activity, affects cell proliferation, cell cycle distribution and apoptosis, and emphasize a key role of SAMHD1 in the interplay between cell cycle regulation and HIV-1 infection.

SAMHD1 controls cell cycle status, apoptosis and HIV-1 infection in monocytic THP-1 cells

Energy Technology Data Exchange (ETDEWEB)

Bonifati, Serena [Center for Retrovirus Research, Department of Veterinary Biosciences, The Ohio State University, Columbus, OH (United States); Daly, Michele B. [Center for Drug Discovery, Department of Pediatrics, School of Medicine, Emory University, Atlanta, GA (United States); St Gelais, Corine; Kim, Sun Hee [Center for Retrovirus Research, Department of Veterinary Biosciences, The Ohio State University, Columbus, OH (United States); Hollenbaugh, Joseph A.; Shepard, Caitlin [Center for Drug Discovery, Department of Pediatrics, School of Medicine, Emory University, Atlanta, GA (United States); Kennedy, Edward M. [Department of Molecular Genetics and Microbiology, Duke University, Durham, NC (United States); Kim, Dong-Hyun [Department of Pharmacy, School of Pharmacy, Kyung-Hee University, Seoul (Korea, Republic of); Schinazi, Raymond F. [Center for Drug Discovery, Department of Pediatrics, School of Medicine, Emory University, Atlanta, GA (United States); Kim, Baek, E-mail: baek.kim@emory.edu [Center for Drug Discovery, Department of Pediatrics, School of Medicine, Emory University, Atlanta, GA (United States); Department of Pharmacy, School of Pharmacy, Kyung-Hee University, Seoul (Korea, Republic of); Wu, Li, E-mail: wu.840@osu.edu [Center for Retrovirus Research, Department of Veterinary Biosciences, The Ohio State University, Columbus, OH (United States)

2016-08-15

SAMHD1 limits HIV-1 infection in non-dividing myeloid cells by decreasing intracellular dNTP pools. HIV-1 restriction by SAMHD1 in these cells likely prevents activation of antiviral immune responses and modulates viral pathogenesis, thus highlighting a critical role of SAMHD1 in HIV-1 physiopathology. Here, we explored the function of SAMHD1 in regulating cell proliferation, cell cycle progression and apoptosis in monocytic THP-1 cells. Using the CRISPR/Cas9 technology, we generated THP-1 cells with stable SAMHD1 knockout. We found that silencing of SAMHD1 in cycling cells stimulates cell proliferation, redistributes cell cycle population in the G{sub 1}/G{sub 0} phase and reduces apoptosis. These alterations correlated with increased dNTP levels and more efficient HIV-1 infection in dividing SAMHD1 knockout cells relative to control. Our results suggest that SAMHD1, through its dNTPase activity, affects cell proliferation, cell cycle distribution and apoptosis, and emphasize a key role of SAMHD1 in the interplay between cell cycle regulation and HIV-1 infection.

Mast cell stabilizers as a potential treatment for Irritable bowel syndrome: A randomized placebo-controlled clinical trial

Directory of Open Access Journals (Sweden)

N Ebrahimi Daryani

2009-08-01

Full Text Available Objectives: Mast cells are believed to play a role in irritable bowel syndrome pathogenesis and symptom genesis due to their close neighborhood to gastrointestinal innervations. This study was designed to evaluate the efficacy of orally administered cromolyn for reduction of symptoms in patients with irritable bowel syndrome (IBS. Material and Methods s: A randomized placebo-controlled double-blinded 6×6 weeks cross-over study was performed in a private gastrointestinal clinic. 10 patients were allocated to group A and 6 patients to group B. Patients in group A received 150 mg cromolyn divided in three equal doses for the first 6 weeks and placebo for the next 6 weeks but patients in group B received placebo for the first 6 weeks and cromolyn in the next 6 weeks. Weekly evaluation was performed and visual analogue scale was used to determine severity of symptoms. Results: Sixteen patients completed the study. Mean age of the patients was 40.3 ± 10.9 years old [range: 24-57]. Eight patients had D-IBS (Diarrhea dominant and other 8 had C-IBS (Constipation dominant. Both cromolyn sodium and the placebo decreased the severity of bloating (Freidman test, p 0.001 and 0.006 respectively. The severity of the main symptom (diarrhea or constipation did not decrease in patients of group A and B who were treated with different sequences of the drug or placebo. The severity of pain decreased drastically after 6th week of treatment with cromolyn. Freidman test showed a significant difference between the pain levels of the former defined treatment spots (p 0.01, and 0.02 for patients in group A and B, respectively. No adverse drug reactions were observed during the study. Conclusion: In conclusion, long term administration of cromolyn seems to be partially effective for treatment of abdominal pain in patients with IBS while main symptoms (diarrhea or constipation might not decrease during this treatment.

S-1 plus cisplatin with concurrent radiotherapy versus cisplatin alone with concurrent radiotherapy for stage III non-small cell lung cancer: a pilot randomized controlled trial

International Nuclear Information System (INIS)

Yao, Lei; Xu, Shidong; Xu, Jianyu; Yang, Chaoyang; Wang, Junfeng; Sun, Dawei

2015-01-01

We investigated the efficacy and safety of S-1 and cisplatin with concurrent thoracic radiation (SCCR) over cisplatin alone plus concurrent thoracic radiation (CCR) for unresectable stage III non-small-cell lung cancer (NSCLC). Between January 2009 and November 2011, 40 eligible patients with NSCLC were included and divided randomly into two groups. Twenty patients received SCCR with S-1 (orally at 40 mg/m 2 per dose, b.i.d.) on days 1 through 14, cisplatin (60 mg/m 2 on day 1) every 4 weeks for two cycles, and radiotherapy (60 Gy/30 fractions over 6 weeks) beginning on day 1. Twenty subjects received CCR (cisplatin and radiotherapy, the same as for SCCR). The 3-year overall response rate was 59.3% and 52.4% for the SCCR and CCR groups, respectively, and the difference was statistically significant, while the median overall survival was 33 months (range, 4–41 months) and 24 months (range, 2–37 months), respectively (P = 0.048). The median progression-free survival was 31 months for SCCR (range, 5–39 months), whereas it was 20 months (range, 2–37 months) for CCR (P = 0.037). The toxicity profile was similar in both groups. In summary, we demonstrated that S-1 and cisplatin with concurrent thoracic radiation was more effective than cisplatin plus radiotherapy in NSCLC patients with acceptable toxicity

Non-Random Chromosome Segregation in Stem Cells

OpenAIRE

Conboy, Michael J; Karasov, Ariela O; Rando, Thomas A

2007-01-01

Decades ago, the "immortal strand hypothesis" was proposed as a means by which stem cells might limit acquiring mutations that could give rise to cancer, while continuing to proliferate for the life of an organism. Originally based on observations in embryonic cells, and later studied in terms of stem cell self-renewal, this hypothesis has remained largely unaccepted because of few additional reports, the rarity of the cells displaying template strand segregation, and alternative interpretati...

[Effects of perinatal exposure to bisphenol A inducing dopaminergic neuronal cell to apoptosis happening in midbrain of male rat offspring].

Science.gov (United States)

Lin, Yong; Zhang, Hao; Wang, Wen-dong; Wu, De-sheng; Jiang, Song-hui; Qu, Wei-dong

2006-07-01

To investigate the mechanism and effect of rat perinatal exposure to bisphenol A (BPA) resulting in midbrain dopaminergic neuronal cell apoptosis and tyrosine hydroxylase expression of male offspring. Rat dams were randomLy divided into 4 groups on gestational day(GD) 10 and given orally the bisphenol A doses as 0, 0.5, 5, 50 mg/kg x d from GD10 to weaning. The brains of male offspring were obtained for detecting, with immunohistochemistry protocol, the Caspase-3, Bcl-2 and tyrosine hydroxylase expression in the midbrain on postnatal day 21 or 30 respectively, and the midbrain apoptotic neuronal cell were detected by TUNEL on PND21. The expression of Caspase-3 in the midbrain of rat male offspring were increased but bcl-2 were decreased on PND21 and 30, respectively. On PND21, apoptotic neuronal cell were found in the midbrain of high and medium doses groups. TH protein expression was decreased. Perinatal exposure to bisphenol A can induce the apoptosis of midbrain dopaminergic neuron in the male rat offspring even after weaning, and concomitantly decrease the midbrain TH immunoreactivity, this may cause the abnormal function of dopaminergic pathway of rat male offspring.

Understanding gender bias in face recognition: effects of divided attention at encoding.

Science.gov (United States)

Palmer, Matthew A; Brewer, Neil; Horry, Ruth

2013-03-01

Prior research has demonstrated a female own-gender bias in face recognition, with females better at recognizing female faces than male faces. We explored the basis for this effect by examining the effect of divided attention during encoding on females' and males' recognition of female and male faces. For female participants, divided attention impaired recognition performance for female faces to a greater extent than male faces in a face recognition paradigm (Study 1; N=113) and an eyewitness identification paradigm (Study 2; N=502). Analysis of remember-know judgments (Study 2) indicated that divided attention at encoding selectively reduced female participants' recollection of female faces at test. For male participants, divided attention selectively reduced recognition performance (and recollection) for male stimuli in Study 2, but had similar effects on recognition of male and female faces in Study 1. Overall, the results suggest that attention at encoding contributes to the female own-gender bias by facilitating the later recollection of female faces. Copyright © 2013 Elsevier B.V. All rights reserved.

Analysis of chlorophyll fluorescence reveals stage specific patterns of chloroplast-containing cells during Arabidopsis embryogenesis

Directory of Open Access Journals (Sweden)

RICARDO I TEJOS

2010-01-01

Full Text Available The basic body plan of a plant is established early in embryogenesis when cells differentiate, giving rise to the apical and basal regions of the embryo. Using chlorophyll fluorescence as a marker for chloroplasts, we have detected specific patterns of chloroplast-containing cells at specific stages of embryogenesis. Non-randomly distributed chloroplast-containing cells are seen as early as the globular stage of embryogenesis in Arabidopsis. In the heart stage of embryogenesis, chloroplast containing cells are detected in epidermal cells as well as a central region of the heart stage embryo, forming a triangular septum of chloroplast-containing cells that divides the embryo into three equal sectors. Torpedo stage embryos have chloroplast-containing epidermal cells and a central band of chloroplast-containing cells in the cortex layer, just below the shoot apical meristem. In the walking-stick stage of embryogenesis, chloroplasts are present in the epidermal, cortex and endodermal cells. The chloroplasts appear reduced or absent from the provascular and columella cells of walking-stick stage embryos. These results suggest that there is a tight regulation of plastid differentiation during embryogenesis that generates specific patterns of chloroplast-containing cells in specific cell layers at specific stages of embryogenesis.

The Effect of Intravitreal Bevacizumab on Apoptosis of Rat Retina Cells

Directory of Open Access Journals (Sweden)

Özcan Kayıkçıoğlu

2013-01-01

Full Text Available Pur po se: To investigate the apoptotic effects of intravitreal bevacizumab on rat retinal cells. Ma te ri al and Met hod: Thirty-six male adult Swiss albino rats were randomly divided into two groups. The first group was applied 0.25 mg bevacizumab in 0.01 ml saline, and the second group received the same amount of saline intravitreally. Each group was divided into 3 subgroups. The animals were sacrificed and their globes were enucleated at the 3rd, 24th, and 72nd hours of the experiment. Enucleated eyes were preserved for histological analysis, immunohistochemical analysis of caspase-3, caspase-8, caspase-9, Fas/Fas L, VEGF and VEGF receptors (Flt-1, Flk-1, and TUNEL staining. Re sults: Histological evaluation showed no sign of retinal toxicity in both groups. In TUNEL staining, TUNEL(+ cells were detected in all subgroups, but the number of positive cells was relatively lower in bevacizumab treatment group that reached statistically significant level at 24 and 72 hours of treatment (p<0.001. Immunohistochemical analysis revealed that in saline-treated subgroups, immunoreactivity was more pronounced for all apoptosis-inducing proteins compared to bevacizumab-treated group. Also immunoreactivity of VEGF was prominent in saline treated group. For VEGF receptors, staining was only positive for Flt-1 at the 3rd hour in the control group. Dis cus si on: Bevacizumab did not have apoptosis-inducing potential compared to saline solution in short term, which was documented with TUNEL and immunohistochemical staining. (Turk J Ophthalmol 2013; 43: 39-44

XF-70 and XF-73, novel antibacterial agents active against slow-growing and non-dividing cultures of Staphylococcus aureus including biofilms.

Science.gov (United States)

Ooi, Nicola; Miller, Keith; Randall, Christopher; Rhys-Williams, William; Love, William; Chopra, Ian

2010-01-01

Slow-growing and non-dividing bacteria exhibit tolerance to many antibiotics. However, membrane-active agents may act against bacteria in all growth phases. We sought to examine whether the novel porphyrin antibacterial agents XF-70 and XF-73, which have rapid membrane-perturbing activity against Staphylococcus aureus, retained antistaphylococcal activity against growth-attenuated cells. The killing kinetics of XF-70, XF-73 and various comparator agents against exponential phase cultures of S. aureus SH1000 were compared with effects on cells held at 4 degrees C, non-growing cultures expressing the stringent response induced by mupirocin and bacteria in the stationary phase. Biofilms of S. aureus SH1000 were generated with the Calgary device to examine the activities of XF-70 and XF-73 under a further system exhibiting diminished bacterial growth. Cold culture, stringent response and stationary phase cultures remained susceptible to XF-70 and XF-73, which caused > or =5 log reductions in viability over 2 h. During this period the most active comparator agents (chlorhexidine and cetyltrimethylammonium bromide) only promoted a 3 log drop in viability. XF-70 and XF-73 were also highly active against biofilms, with both agents exhibiting low biofilm MICs (1 mg/L) and minimum biofilm eradication concentrations (2 mg/L). XF-70 and XF-73 remained highly active against various forms of slow-growing or non-dividing S. aureus. The results support the hypothesis that membrane-active agents may be particularly effective in eradicating slow- or non-growing bacteria and suggest that XF-70 and XF-73 could be utilized to treat staphylococcal infections where the organisms are only dividing slowly, such as biofilm-associated infections of prosthetic devices.

Effect of increased exercise in school children on physical fitness and endothelial progenitor cells: a prospective randomized trial.

Science.gov (United States)

Walther, Claudia; Gaede, Luise; Adams, Volker; Gelbrich, Götz; Leichtle, Alexander; Erbs, Sandra; Sonnabend, Melanie; Fikenzer, Kati; Körner, Antje; Kiess, Wieland; Bruegel, Mathias; Thiery, Joachim; Schuler, Gerhard

2009-12-01

The aim of this prospective, randomized study was to examine whether additional school exercise lessons would result in improved peak oxygen uptake (primary end point) and body mass index-standard deviation score, motor and coordinative abilities, circulating progenitor cells, and high-density lipoprotein cholesterol (major secondary end points). Seven sixth-grade classes (182 children, aged 11.1+/-0.7 years) were randomized to an intervention group (4 classes with 109 students) with daily school exercise lessons for 1 year and a control group (3 classes with 73 students) with regular school sports twice weekly. The significant effects of intervention estimated from ANCOVA adjusted for intraclass correlation were the following: increase of peak o(2) (3.7 mL/kg per minute; 95% confidence interval, 0.3 to 7.2) and increase of circulating progenitor cells evaluated by flow cytometry (97 cells per 1 x 10(6) leukocytes; 95% confidence interval, 13 to 181). No significant difference was seen for body mass index-standard deviation score (-0.08; 95% confidence interval, -0.28 to 0.13); however, there was a trend to reduction of the prevalence of overweight and obese children in the intervention group (from 12.8% to 7.3%). No treatment effect was seen for motor and coordinative abilities (4; 95% confidence interval, -1 to 8) and high-density lipoprotein cholesterol (0.03 mmol/L; 95% confidence interval, -0.08 to 0.14). Regular physical activity by means of daily school exercise lessons has a significant positive effect on physical fitness (o(2)max). Furthermore, the number of circulating progenitor cells can be increased, and there is a positive trend in body mass index-standard deviation score reduction and motor ability improvement. Therefore, we conclude that primary prevention by means of increasing physical activity should start in childhood. URL: http://www.clinicaltrials.gov. Identifier: NCT00176371.

The robotics divide a new frontier in the 21st century?

CERN Document Server

López Peláez, Antonio

2013-01-01

Analyzes how robotics will shape our societies in the twenty-first century; a time when industrial and service robotics, particularly for military and aerospace purposes, will become an essential technology Examines an emerging divide: the "robotics divide"; a phenomenon linked to the model to integrate advanced robotics in economic, social and military spheres Focuses on the main technological trends in the field of robotics, and the impact that robotics will have on different facets of social life

The relationship between divided attention and implicit memory: a meta-analysis.

Science.gov (United States)

Spataro, Pietro; Cestari, Vincenzo; Rossi-Arnaud, Clelia

2011-03-01

This article reports a meta-analysis comparing the size of repetition priming in full and divided-attention (DA) conditions. The main analysis included 38 effect sizes (ES) extracted from 21 empirical studies, for a total of 2074 (full-attention) and 2148 (divided-attention) participants. The mean weighted ES was 0.357 (95% CI=0.278-0.435), indicating that divided attention produced a small, but significant, negative effect on implicit memory. Overall, the distinction between identification and production priming provided the best fit to empirical data (with the effect of DA being greater for production tests), whereas there was no significant difference between perceptual and conceptual priming. A series of focused contrasts suggested that word-stem completion might be influenced by lexical-conceptual processes, and that perceptual identification might involve a productive component. Implications for current theories of implicit memory are discussed. Copyright © 2010 Elsevier B.V. All rights reserved.

Development of a new lower hybrid antenna module using a poloidal power divider

International Nuclear Information System (INIS)

Maebara, S.; Imai, T.; Seki, M.; Suganuma, K.; Goniche, M.; Bibet, Ph.; Berio, S.; Brossaud, J.; Rey, G.; Tonon, G.

1997-03-01

A realistic antenna module using a poloidal divider for lower hybrid current drive (LHCD) experiment, is modelled and fabricated. In this antenna module test II, three types of poloidal dividers, which split the power in 3, are tested. (author)

Research of ALA combined with HpD-PDT which induced s180 ascitic tumor cells, death or apoptosis on cytology

Science.gov (United States)

Zhu, Jing; Yan, Min; Zhang, Hui-Guo; Li, Enling; Luo, Hongyu

2005-07-01

To ascertain the adequate dosage of ALA combined with HpD-PDT which induced tumor cell death or apoptosis on cytology. And to study the different effect of ALA-PDT and HPD-PDT used only. Rat ascitic tumor cells(S180) were randomly divided into several groups and incubated with ALA（20μg/ml 、40μg/ml、80μg/ml 、160μg/ml）、HPD（2.5μg/ml、5μg/ml、10μg/ml）and their combination dosages. 630nm light (total output 2W) was delivered to tumor cells at a constant fluence rate: 200mw/cm2 and a constant irradiated time period: 20 minutes. We set 3 groups (no photosensitizers or no irradiation or neither) to be the control groups. We used inversion microscopy to observe the morphological change of tumor cells and flow cytometry technology to detect the death or apoptosis of tumor cells during the experiment. ..

Xenon Reduces Neuronal Hippocampal Damage and Alters the Pattern of Microglial Activation after Experimental Subarachnoid Hemorrhage: A Randomized Controlled Animal Trial

Directory of Open Access Journals (Sweden)

Michael Veldeman

2017-09-01

Full Text Available ObjectiveThe neuroprotective properties of the noble gas xenon have already been demonstrated using a variety of injury models. Here, we examine for the first time xenon’s possible effect in attenuating early brain injury (EBI and its influence on posthemorrhagic microglial neuroinflammation in an in vivo rat model of subarachnoid hemorrhage (SAH.MethodsSprague-Dawley rats (n = 22 were randomly assigned to receive either Sham surgery (n = 9; divided into two groups or SAH induction via endovascular perforation (n = 13, divided into two groups. Of those randomized for SAH, 7 animals were postoperatively ventilated with 50 vol% oxygen/50 vol% xenon for 1 h and 6 received 50 vol% oxygen/50 vol% nitrogen (control. The animals were sacrificed 24 h after SAH. Of each animal, a cerebral coronal section (−3.60 mm from bregma was selected for assessment of histological damage 24 h after SAH. A 5-point neurohistopathological severity score was applied to assess neuronal cell damage in H&E and NeuN stained sections in a total of four predefined anatomical regions of interest. Microglial activation was evaluated by a software-assisted cell count of Iba-1 stained slices in three cortical regions of interest.ResultsA diffuse cellular damage was apparent in all regions of the ipsilateral hippocampus 24 h after SAH. Xenon-treated animals presented with a milder damage after SAH. This effect was found to be particularly pronounced in the medial regions of the hippocampus, CA3 (p = 0.040, and dentate gyrus (DG p = 0.040. However, for the CA1 and CA2 regions, there were no statistical differences in neuronal damage according to our histological scoring. A cell count of activated microglia was lower in the cortex of xenon-treated animals. This difference was especially apparent in the left piriform cortex (p = 0.017.ConclusionIn animals treated with 50 vol% xenon (for 1 h after SAH, a less pronounced neuronal damage was

[Effects of Two Placement Ways for Storage of Blood Bag on Biochemical Indexes of Leukodepleted Red Blood Cells].

Science.gov (United States)

Zhang, Rui-Jun; Duan, Bing-Zheng; Ju, Chun-Mei; Sui, Su-Qin; Bai, Yan; Cao, Huan

2016-04-01

To investigate the effects of 2 different ways of storage bag placement on some biochemical indexes of leukodepleted red blood cells (LD-RBC) to as to ensure the efficacy and safety of clinical blood transfusion. The whole blood samples of 20 donors (400 ml/donor) were selected for preparating the LP-RBC, which were divided evenly into 10 bags. The 10 bags were randomly divided into 2 groups; the bags in 1 group were placed uprightly, while the bags in another group were placed horizontally. The bags of 2 groups were stored in the same conditions. One storage bag from each group was taken randomly on day 7, 14, 21, 28, 35 respectively, and then the biochemical indexes of samples were detected and analyzed. The values of K(+) and LAC on day 14, the value of LDH on day 28 in the uprightly placed group were higher than those in the horizontally placed group (P value of Na(+) on day 28, and the value of Glu on day 35 in the uprightly placed group were lower than those in horizontally placed group (P 0.05). The storage bags placed by different ways during the storage show different influence on some biochemical indexes of LD-RBC in the storage period.

Exploring Privilege in the Digital Divide: Implications for Theory, Policy, and Practice.

Science.gov (United States)

Fang, Mei Lan; Canham, Sarah L; Battersby, Lupin; Sixsmith, Judith; Wada, Mineko; Sixsmith, Andrew

2018-05-10

The digital revolution has resulted in innovative solutions and technologies that can support the well-being, independence, and health of seniors. Yet, the notion of the "digital divide" presents significant inequities in terms of who accesses and benefits from the digital landscape. To better understand the social and structural inequities of the digital divide, a realist synthesis was conducted to inform theoretical understandings of information and communication technologies (ICTs); to understand the practicalities of access and use inequities; to uncover practices that facilitate digital literacy and participation; and to recommend policies to mitigate the digital divide. A systematic search yielded 55 articles published between 2006 and 2016. Synthesis of existing knowledge, combined with user-experience elicited through a deliberative dialogue session with community stakeholders (n = 35), made visible a pattern of privilege that determined individual agency in ICT access and use. Though age is consistently centralized as the key determinant of the digital divide, our analyses, which encompassed both van Dijk's resources and appropriation theory and intersectionality, appraised this notion and revealed that age is not the sole determinant. Findings highlight the role of other factors that contribute to digital inequity among community-dwelling middle-aged (45-64) and older (65+) adults, including education, income, gender, and generational status. Informed by results of a realist synthesis that was guided by intersectional perspectives, a conceptual framework was developed outlining implications for theory, policy, and practice to address the wicked problem that is the digital divide.

X-ray and proton induced ultrastructural changes in Chlamydomonas reinhardi, with special reference to the dividing cell

International Nuclear Information System (INIS)

Gruber, H.E.

1976-01-01

Liquid cultures were exposed to 9000 R x-irradiation delivered at approximately 600 R/min. This produced 69 percent mortality in the 137c wild type strain and 71 percent mortality in the acetate-requiring strain ac-31. Irradiated and control cells were fixed for electron microscopic examination at intervals up to five days post exposure. Proton-irradiations using a positive ion Van de Graff accelerator were administered to monolayers of cells attached to Millipore filters. Irradiated and control cells were later resuspended and incubated in liquid culture medium. The dose rate was approximately 20 kilorad/second for thin targets with the dose monitored with a solid state detector. Distinctive fine structural responses were observed for the two kinds of radiation at the indicated exposure levels. Alterations affecting the nucleus were prominent after x-irradiation. Nuclei were observed in which non-nucleolar condensations and swollen nuclear envelopes were evident. Nuclear envelope rupture was noted when cells were in an advanced state of disorganization. Multiple nuclei per cell were also observed. Proton-irradiation often resulted in both live and dead daughter cells within the same mother cell wall. Changes in the chloroplast and mitochondria were seen after both types of irradiation. Two features absent in control cells were of special interest. Following x- and proton-irradiation, cells were observed which remained joined in configurations closely resembling division profiles or division conformations. Irradiated cells also possessed chromosomes and spindle fibers at a time not characteristic for such events in control cells

Spectral Classification of Asteroids by Random Forest

Science.gov (United States)

Huang, Chao; Ma, Yue-hua; Zhao, Hai-bin; Lu, Xiao-ping

2017-10-01

With the increasing spectral and photometric data of asteroids, a variety of classification methods for asteroids have been proposed. This paper classifies asteroids based on the observations in the Sloan Digital Sky Survey (SDSS) Moving Object Catalogue (MOC) by using the random forest algorithm. In combination with the present taxonomies of Tholen, Bus, Lazzaro, and DeMeo, and the principal component analysis, we have classified 48642 asteroids according to their SDSS magnitudes at the g, r, i, and z wavebands. In this way, these asteroids are divided into 8 (C, X, S, B, D, K, L, and V) classes.

Digital servo control of random sound test excitation. [in reverberant acoustic chamber

Science.gov (United States)

Nakich, R. B. (Inventor)

1974-01-01

A digital servocontrol system for random noise excitation of a test object in a reverberant acoustic chamber employs a plurality of sensors spaced in the sound field to produce signals in separate channels which are decorrelated and averaged. The average signal is divided into a plurality of adjacent frequency bands cyclically sampled by a time division multiplex system, converted into digital form, and compared to a predetermined spectrum value stored in digital form. The results of the comparisons are used to control a time-shared up-down counter to develop gain control signals for the respective frequency bands in the spectrum of random sound energy picked up by the microphones.

Asymmetric cell division and its role in cell fate determination in the ...

Indian Academy of Sciences (India)

Supplementary figure 1. Light micrograph of an asymmetrically dividing T. indica cell at various time intervals. Progress over a 12 hr period, showing that the larger component does not undergo further division. (A) 0 h, cell division at an early stage. (B) 5 h, lower half of cell undergoing further division. (C) 12 h, differentiated ...

Annan warns of 'content divide' between rich and poor

CERN Multimedia

Dickson, D

2003-01-01

"The Secretary-General of the United Nations, Kofi Annan, warned today (10 December) that a "content divide" is threatening to deprive developing countries of the full benefits offered by information and communications technologies (ICTs)" (1 page)

Geology of photo linear elements, Great Divide Basin, Wyoming

Science.gov (United States)

Blackstone, D. L., Jr.

1973-01-01

The author has identified the following significant results. Ground examination of photo linear elements in the Great Divide Basin, Wyoming indicates little if any tectonic control. Aeolian aspects are more widespread and pervasive than previously considered.

Digital divide and digital opportunity: Comparison, analysis and strategies for sustainable development in developing nations

International Nuclear Information System (INIS)

Bhunia, C.T.; Onime, C.

2007-07-01

The world is witnessing a new digital economic order which may be quantified by the diffusion of information technology and globalization process. The current information technology gap (digital divide) between developed countries and developing countries is huge. Improvements in information technology (measured by the digital opportunity index) usually open up an opportunity for national/regional growth and development. There is a need for scientific investigation on the digital divide, digital opportunity index and their consequences. This paper presents a critical analysis of existing digital divide and its trends, it also investigates the relationship between the digital divide and the digital opportunity index. A mathematical model based on analysis of the growing digital divide is presented as a possible tool for combating and eradicate the digital divide gap which is only possible if developing and poor nations take advantage of the digital opportunities that can transform them into global competitive partners in digital knowledge economy. (author)

Dynamic crossmodal links revealed by steady-state responses in auditory-visual divided attention

NARCIS (Netherlands)

de Jong, Ritske; Toffanin, Paolo; Harbers, Marten; Martens, Sander

Frequency tagging has been often used to study intramodal attention but not intermodal attention. We used EEG and simultaneous frequency tagging of auditory and visual sources to study intermodal focused and divided attention in detection and discrimination performance. Divided-attention costs were

An Improved Model of Nonuniform Coleochaete Cell Division.

Science.gov (United States)

Wang, Yuandi; Cong, Jinyu

2016-08-01

Cell division is a key biological process in which cells divide forming new daughter cells. In the present study, we investigate continuously how a Coleochaete cell divides by introducing a modified differential equation model in parametric equation form. We discuss both the influence of "dead" cells and the effects of various end-points on the formation of the new cells' boundaries. We find that the boundary condition on the free end-point is different from that on the fixed end-point; the former has a direction perpendicular to the surface. It is also shown that the outer boundaries of new cells are arc-shaped. The numerical experiments and theoretical analyses for this model to construct the outer boundary are given.

Divided attention reduces resistance to distraction at encoding but not retrieval.

Science.gov (United States)

Weeks, Jennifer C; Hasher, Lynn

2017-08-01

Older adults show implicit memory for previously seen distraction, an effect attributed to poor attentional control. It is unclear whether this effect results from lack of control over encoding during the distraction task, lack of retrieval constraint during the test task, or both. In the present study, we simulated poor distraction control in young adults using divided attention at encoding, at retrieval, at both times, or not at all. The encoding task was a 1-back task on pictures with distracting superimposed letter strings, some of which were words. The retrieval task was a word fragment completion task testing implicit memory for the distracting words. Attention was divided using an auditory odd digit detection task. Dividing attention at encoding, but not at retrieval, resulted in significant priming for distraction, which suggests that control over encoding processes is a primary determinant of distraction transfer in populations with low inhibitory control (e.g. older adults).

Calibration of the precision high voltage dividers of the KATRIN experiment

Energy Technology Data Exchange (ETDEWEB)

Rest, Oliver [Institut fuer Kernphysik, Westfaelische Wilhelms-Universitaet Muenster (Germany); Collaboration: KATRIN-Collaboration

2016-07-01

The KATRIN (KArlsruhe TRItium Neutrino) experiment will measure the endpoint region of the tritium β decay spectrum to determine the neutrino mass with a sensitivity of 200 meV/c{sup 2}. To achieve this sub-eV sensitivity the energy of the decay electrons will be analyzed using a MAC-E type spectrometer. The retarding potential of the MAC-E-filter (up to -35 kV) has to be monitored with a relative precision of 3 . 10{sup -6}. For this purpose the potential will be measured directly via two custom made precision high voltage dividers, which were developed and constructed in cooperation with the Physikalisch-Technische Bundesanstalt Braunschweig. In order to determine the absolute values and the stability of the scale factors of the voltage dividers, regular calibration measurements are essential. Such measurements have been performed during the last years using several different methods. The poster gives an overview of the methods and results of the calibration of the precision high voltage dividers.

The Political Divide Over Same-Sex Marriage: Mating Strategies in Conflict?

Science.gov (United States)

Pinsof, David; Haselton, Martie

2016-04-01

Although support for same-sex marriage has grown dramatically over the past decade, public opinion remains markedly divided. Here, we propose that the political divide over same-sex marriage represents a deeper divide between conflicting mating strategies. Specifically, we propose that opposition to same-sex marriage can be explained in terms of (a) individual differences in short-term mating orientation and (b) mental associations between homosexuality and sexual promiscuity. We created a novel Implicit Association Test to measure mental associations between homosexuality and promiscuity. We found that mental associations between homosexuality and promiscuity, at both the implicit and the explicit levels, interacted with short-term mating orientation to predict opposition to same-sex marriage. Our model accounted for 42.3% of the variation in attitudes toward same-sex marriage, and all predictors remained robust when we controlled for potential confounds. Our results reveal the centrality of mating psychology in attitudes toward same-sex marriage. © The Author(s) 2016.

Development of a new lower hybrid antenna module using a poloidal power divider

International Nuclear Information System (INIS)

Maebara, Sunao; Seki, Masami; Suganuma, Kazuaki

1996-07-01

The antenna using poloidal power divider is an effective method for simplification of Lower Hybrid Current Drive (LHCD) antenna system. This method should allow to reduce the power density in the antenna while maintaining a good flexibility of N parallel spectrum of waves. For this purpose, three types of poloidal power divider which split the power in three, and the 3 x 6 multi-junction module were developed. r.f. properties and outgassing of these components were evaluated using the CEA Cadarache RF Test Facility. A good power dividing ratio of 33 ± 4% was obtained for each of these poloidal dividers, and the reflection coefficient was lower value than 1.5%. For the 3 x 6 multi-junction, reflection coefficient was less than 1.3% and r.f. losses lower than 1.0% were measured. On the other hand, it was found in the scattering matrix analysis that reflection coefficient at plasma has to be less than a few % in order to operate these components under available conditions. In combination with two poloidal power dividers connected to the 3 x 6 multi-junction module, quasi stationary operation for r.f. injection time of 1000 sec at 300 kW was demonstrated under water cooling. In this case, it was found that the outgassing rate is in the lower range of 10 -7 Pam 3 s -1 m -2 within the maximum module temperature of ∼100degC. This report describes the experimental and analytical results of a new lower hybrid (LH) antenna module using the poloidal power divider. (author)

Quantifying and Mapping the Digital Divide from an Internet Point of View

Energy Technology Data Exchange (ETDEWEB)

Cottrell, R.Les; /SLAC; Khan, Shahryar; /NUST, Rawalpindi; Williams, Jerrod; /SLAC; Mehdi, Akbar; Kalim, Umar; Ali, Arshad; /NUST, Rawalpindi

2008-09-18

Quantitative knowledge of the magnitude, extent and trends of the Digital Divide are critical to understand and identify the regions most in need of help, to make rational decisions on how to address the problems and to make cases for executives, funding agencies and politicians. We report on a project (PingER) to measure the Digital Divide from the point of view of Internet performance. The PingER project has been measuring Internet performance since 1995 and with the increased emphasis on measuring and tracking the Digital Divide, it now covers over 700 hosts in over 150 countries that between them contain over 99% of the world's Internet connected population. In this paper we will describe the how PingER works, it deployment, the data analysis, and presentation. We also introduce a new PingER visualization tool (ViPER) that provides a more appealing interactive visualization of the PingER data and also works on mobile PDAs. We will also show results from PingER that illustrate the magnitude, extent and trends for the Digital Divide, and also compare PingER results with some human development and technology indices.

Dividing time: Concurrent timing of auditory and visual events by young and elderly adults

OpenAIRE

McAuley, J. Devin; Miller, Jonathan P.; Wang, Mo; Pang, Kevin C. H.

2010-01-01

This article examines age differences in individual’s ability to produce the durations of learned auditory and visual target events either in isolation (focused attention) or concurrently (divided attention). Young adults produced learned target durations equally well in focused and divided attention conditions. Older adults in contrast showed an age-related increase in timing variability in divided attention conditions that tended to be more pronounced for visual targets than for auditory ta...

Climate Change and North-South Divide. Between and Within

International Nuclear Information System (INIS)

2007-01-01

The traditional North-South divide has persisted through out the negotiations on climate change. Divergent state interests made striking a right balance between development and environmental protection an elusive endeavor as negotiators were striving to adopt a global climate regime. Four principles of international environmental law are of particular concern: the principle of common but differentiated responsibilities, the principle of equity, the precautionary principle, and the principle of sustainable development. With economic development being the overriding priority in developing countries, the negotiations leading to the Kyoto Protocol tend to prove that principles could be interpreted in different ways to fit particular interests. This study explains the confrontations between the North and the South and argues that climate change has by far strengthened the North-South divide both between and within. Accordingly, it concludes that there is a need to devise new principles

Can Attention be Divided Between Perceptual Groups?

Science.gov (United States)

McCann, Robert S.; Foyle, David C.; Johnston, James C.; Hart, Sandra G. (Technical Monitor)

1994-01-01

Previous work using Head-Up Displays (HUDs) suggests that the visual system parses the HUD and the outside world into distinct perceptual groups, with attention deployed sequentially to first one group and then the other. New experiments show that both groups can be processed in parallel in a divided attention search task, even though subjects have just processed a stimulus in one perceptual group or the other. Implications for models of visual attention will be discussed.

Defibrotide for the treatment of severe hepatic veno-occlusive disease and multiorgan failure after stem cell transplantation: a multicenter, randomized, dose-finding trial.

Science.gov (United States)

Richardson, Paul G; Soiffer, Robert J; Antin, Joseph H; Uno, Hajime; Jin, Zhezhen; Kurtzberg, Joanne; Martin, Paul L; Steinbach, Gideon; Murray, Karen F; Vogelsang, Georgia B; Chen, Allen R; Krishnan, Amrita; Kernan, Nancy A; Avigan, David E; Spitzer, Thomas R; Shulman, Howard M; Di Salvo, Donald N; Revta, Carolyn; Warren, Diane; Momtaz, Parisa; Bradwin, Gary; Wei, L J; Iacobelli, Massimo; McDonald, George B; Guinan, Eva C

2010-07-01

Therapeutic options for severe hepatic veno-occlusive disease (VOD) are limited and outcomes are dismal, but early phase I/II studies have suggested promising activity and acceptable toxicity using the novel polydisperse oligonucleotide defibrotide. This randomized phase II dose-finding trial determined the efficacy of defibrotide in patients with severe VOD following hematopoietic stem cell transplantation (HSCT) and identified an appropriate dose for future trials. Adult and pediatric patients received either lower-dose (arm A: 25 mg/kg/day; n = 75) or higher-dose (arm B: 40 mg/kg/day; n = 74) i.v. defibrotide administered in divided doses every 6 hours for > or =14 days or until complete response, VOD progression, or any unacceptable toxicity occurred. Overall complete response and day +100 post-HSCT survival rates were 46% and 42%, respectively, with no significant difference between treatment arms. The incidence of treatment-related adverse events was low (8% overall; 7% in arm A, 10% in arm B); there was no significant difference in the overall rate of adverse events between treatment arms. Early stabilization or decreased bilirubin was associated with better response and day +100 survival, and decreased plasminogen activator inhibitor type 1 (PAI-1) during treatment was associated with better outcome; changes were similar in both treatment arms. Defibrotide 25 or 40 mg/kg/day also appears effective in treating severe VOD following HSCT. In the absence of any differences in activity, toxicity or changes in PAI-1 level, defibrotide 25 mg/kg/day was selected for ongoing phase III trials in VOD.

From Fundamentalists to Structuralists: Bridging the Digital Divide

Science.gov (United States)

Kok, Ayse

2010-01-01

The purpose of this literature review is to provide information about several ICT initiatives undertaken in education on a global basis in order to overcome the digital divide and summarise the findings of these initiatives. Due to the limited scope of the study, the bulk of the review mainly concerns initiatives undertaken in secondary schools,…

The Digital Divide: The Special Case of Gender

Science.gov (United States)

Cooper, J.

2006-01-01

This paper examines the evidence for the digital divide based on gender. An overview of research published in the last 20 years draws to the conclusion that females are at a disadvantage relative to men when learning about computers or learning other material with the aid of computer-assisted software. The evidence shows that the digital divide…

Abelianization of the F-divided fundamental group scheme

Indian Academy of Sciences (India)

INDRANIL BISWAS

Abelianization of the F-divided fundamental group scheme. 283. Restrict the Poincaré bundle to X × Pic0 red(X). Viewing this restriction as a line bundle on Pic0 red(X) parametrized by X, we ... which gives rise to an exact sequence of the projective systems considered in Definition. 2.3. Applying the projective limit functor ...

Divided attention of adolescents related to lifestyles and academic and family conditions.

Science.gov (United States)

Mizuno, Kei; Tanaka, Masaaki; Fukuda, Sanae; Imai-Matsumura, Kyoko; Watanabe, Yasuyoshi

2013-05-01

Development of the ability to divide attention is of crucial importance in the transitional period from elementary to junior high school. The relationship between divided attention and the prevalence of fatigue or low academic motivation is observed in junior high school students. In order to clarify the factors underlying decreased ability to divide attention, we examined the relationships between divided attention, as assessed by the kana pick-out test, lifestyle factors, and academic and family conditions in junior high school students. The study group consisted of 158 healthy 1st-, 2nd-, and 3rd-grade level junior high school students. Each participant performed the kana pick-out test and questionnaires dealing with lifestyle factors (nocturnal sleeping hours on school days, breakfast, exercise, watching television, and spending time with family members), and academic and family conditions (good friendships at school and praise from family members when participants showed good academic performance). On multiple regression analyses adjusted for grade and gender, scores on the kana pick-out test were positively associated with spending time with family members. In addition, the comprehension score of the kana pick-out test was positively associated with having breakfast every day and praise by family members. The score was negatively associated with watching television. The present findings suggest that the ability to divide attention is independently associated with good lifestyles and academic and family conditions in junior high school students. Copyright © 2012 The Japanese Society of Child Neurology. Published by Elsevier B.V. All rights reserved.

Dll1 maintains quiescence of adult neural stem cells and segregates asymmetrically during mitosis

OpenAIRE

Kawaguchi, Daichi; Furutachi, Shohei; Kawai, Hiroki; Hozumi, Katsuto; Gotoh, Yukiko

2013-01-01

Stem cells often divide asymmetrically to produce one stem cell and one differentiating cell, thus maintaining the stem cell pool. Although neural stem cells (NSCs) in the adult mouse subventricular zone have been suggested to divide asymmetrically, intrinsic cell fate determinants for asymmetric NSC division are largely unknown. Stem cell niches are important for stem cell maintenance, but the niche for the maintenance of adult quiescent NSCs has remained obscure. Here we show that the Notch...

T-cell receptor gamma delta bearing cells in normal human skin

NARCIS (Netherlands)

Bos, J. D.; Teunissen, M. B.; Cairo, I.; Krieg, S. R.; Kapsenberg, M. L.; Das, P. K.; Borst, J.

1990-01-01

T-cell antigen receptors (TCR) are divided into common alpha beta and less common gamma delta types. In the murine skin, TCR gamma delta+ cells have been reported to form the great majority of epidermal T lymphocytes. We have examined the relative contribution of TCR alpha beta+ and TCR gamma delta+

The average crossing number of equilateral random polygons

International Nuclear Information System (INIS)

Diao, Y; Dobay, A; Kusner, R B; Millett, K; Stasiak, A

2003-01-01

In this paper, we study the average crossing number of equilateral random walks and polygons. We show that the mean average crossing number ACN of all equilateral random walks of length n is of the form (3/16)n ln n + O(n). A similar result holds for equilateral random polygons. These results are confirmed by our numerical studies. Furthermore, our numerical studies indicate that when random polygons of length n are divided into individual knot types, the for each knot type K can be described by a function of the form = a(n-n 0 )ln(n-n 0 ) + b(n-n 0 ) + c where a, b and c are constants depending on K and n 0 is the minimal number of segments required to form K. The profiles diverge from each other, with more complex knots showing higher than less complex knots. Moreover, the profiles intersect with the profile of all closed walks. These points of intersection define the equilibrium length of K, i.e., the chain length n e (K) at which a statistical ensemble of configurations with given knot type K-upon cutting, equilibration and reclosure to a new knot type K'-does not show a tendency to increase or decrease . This concept of equilibrium length seems to be universal, and applies also to other length-dependent observables for random knots, such as the mean radius of gyration g >

Effects of umbilical cord blood stem cells on healing factors for diabetic foot injuries.

Science.gov (United States)

Çil, N; Oğuz, E O; Mete, E; Çetinkaya, A; Mete, G A

2017-01-01

The use of stem or progenitor cells from bone marrow, or peripheral or umbilical cord blood is becoming more common for treatment of diabetic foot problems. These cells promote neovascularization by angiogenic factors and they promote epithelium formation by stimulating cell replication and migration under certain pathological conditions. We investigated the role of CD34 + stem cells from human umbilical cord blood in wound healing using a rat model. Rats were randomly divided into a control group and two groups with diabetes induced by a single dose of 55 mg/kg intraperitoneal streptozocin. Scarred areas 5 mm in diameter were created on the feet of all rats. The diabetic rats constituted the diabetes control group and a diabetes + stem cell group with local injection into the wound site of 0.5 × 106 CD34 + stem cells from human umbilical cord blood. The newly formed skin in the foot wounds following CD34 + stem cell treatment showed significantly improvement by immunohistochemistry and TUNEL staining, and were closer to the wound healing of the control group than the untreated diabetic animals. The increase in FGF expression that accompanied the local injection of CD34 + stem cells indicates that FGF stimulation helped prevent apoptosis. Our findings suggest a promising new treatment approach to diabetic wound healing.

Variable-geometry turbocharger with asymmetric divided volute for engine exhaust gas pulse optimization

Science.gov (United States)

Serres, Nicolas

2010-11-09

A turbine assembly for a variable-geometry turbocharger includes a turbine housing defining a divided volute having first and second scrolls, wherein the first scroll has a substantially smaller volume than the second scroll. The first scroll feeds exhaust gas to a first portion of a turbine wheel upstream of the throat of the wheel, while the second scroll feeds gas to a second portion of the wheel at least part of which is downstream of the throat. Flow from the second scroll is regulated by a sliding piston. The first scroll can be optimized for low-flow conditions such that the turbocharger can operate effectively like a small fixed-geometry turbocharger when the piston is closed. The turbine housing defines an inlet that is divided by a dividing wall into two portions respectively feeding gas to the two scrolls, a leading edge of the dividing wall being downstream of the inlet mouth.

Investigation about decoupling capacitors of PMT voltage divider effects on neutron-gamma discrimination

International Nuclear Information System (INIS)

Divani, Nazila; Firoozabadi, Mohammad M.; Bayat, Esmail

2014-01-01

Scintillators are almost used in any nuclear laboratory. These detectors combine of scintillation materials, PMT and a voltage divider. Voltage dividers are different in resistive ladder design. But the effect of decoupling capacitors and damping resistors haven’t discussed yet. In this paper at first a good equilibrium circuit designed for PMT, and it was used for investigating about capacitors and resistors in much manner. Results show that decoupling capacitors have great effect on PMT output pulses. In this research, it was tried to investigate the effect of Capacitor’s value and places on PMT voltage divider in Neutron-Gamma discrimination capability. Therefore, the voltage divider circuit for R329-02 Hamamatsu PMT was made and Zero Cross method used for neutron-gamma discrimination. The neutron source was a 20Ci Am-Be. Anode and Dynode pulses and discrimination spectrum were saved. The results showed that the pulse height and discrimination quality change with the value and setting of capacitors

Low-power wide-locking-range injection-locked frequency divider for OFDM UWB systems

Energy Technology Data Exchange (ETDEWEB)

Yin Jiangwei; Li Ning; Zheng Renliang; Li Wei; Ren Junyan, E-mail: lining@fudan.edu.c [State Key Laboratory of ASIC and System, Fudan University, Shanghai 201203 (China)

2009-05-01

This paper describes a divide-by-two injection-locked frequency divider (ILFD) for frequency synthesizers as used in multiband orthogonal frequency division multiplexing (OFDM) ultra-wideband (UWB) systems. By means of dual-injection technique and other conventional tuning techniques, such as DCCA and varactor tuning, the divider demonstrates a wide locking range while consuming much less power. The chip was fabricated in the Jazz 0.18 mum RF CMOS process. The measurement results show that the divider achieves a locking range of 4.85 GHz (6.23 to 11.08 GHz) at an input power of 8 dBm. The core circuit without the test buffer consumes only 3.7 mA from a 1.8 V power supply and has a die area of 0.38 x 0.28 mm{sup 2}. The wide locking range combined with low power consumption makes the ILFD suitable for its application in UWB systems.

Low-power wide-locking-range injection-locked frequency divider for OFDM UWB systems

International Nuclear Information System (INIS)

Yin Jiangwei; Li Ning; Zheng Renliang; Li Wei; Ren Junyan

2009-01-01

This paper describes a divide-by-two injection-locked frequency divider (ILFD) for frequency synthesizers as used in multiband orthogonal frequency division multiplexing (OFDM) ultra-wideband (UWB) systems. By means of dual-injection technique and other conventional tuning techniques, such as DCCA and varactor tuning, the divider demonstrates a wide locking range while consuming much less power. The chip was fabricated in the Jazz 0.18 μm RF CMOS process. The measurement results show that the divider achieves a locking range of 4.85 GHz (6.23 to 11.08 GHz) at an input power of 8 dBm. The core circuit without the test buffer consumes only 3.7 mA from a 1.8 V power supply and has a die area of 0.38 x 0.28 mm 2 . The wide locking range combined with low power consumption makes the ILFD suitable for its application in UWB systems.

Competing discourses on Europe: the divided case of Estonia

NARCIS (Netherlands)

Moes, Jeroen

2010-01-01

Historical and cultural context and individual experience are likely to influence the ‘imagination of Europe’. Such discourses exist according to specific social patterns that may critically divide societies into different and competing social constructions of Europe. Is there a transnational

A Phase Ib open label, randomized, safety study of SANGUINATE™ in patients with sickle cell anemia

Directory of Open Access Journals (Sweden)

Hemant Misra

Full Text Available Abstract Background: Treatment of sickle cell anemia is a challenging task and despite the well understood genetic and biochemical pathway of sickle hemoglobin, current therapy continues to be limited to the symptomatic treatment of pain, supplemental oxygen, antibiotics, red blood cell transfusions and hydroxyurea. SANGUINATE is a carbon monoxide releasing molecule and oxygen transfer agent under clinical development for the treatment of sickle cell anemia and comorbidities. Methods: An open-label randomized Phase Ib study was performed in adult sickle cell anemia patients. Two dose levels of SANGUINATE were compared to hydroxyurea in 24 homozygotes for Hb SS. Twelve subjects received either a low dose (160 mg/kg of SANGUINATE or 15 mg/kg hydroxyurea. Another 12 subjects received either a high dose (320 mg/kg of SANGUINATE or 15 mg/kg hydroxyurea. The primary endpoint was the safety of SANGUINATE versus hydroxyurea in sickle cell anemia patients. Secondary endpoints included determination of the plasma pharmacokinetics and assessment of hematologic measurements. Results: Musculoskeletal related adverse events were the most common. Transient troponin I levels increased in three patients, one of whom had an increase in tricuspid regurgitant velocity; however, no clinical signs were noted. Following an assessment of vital signs, tricuspid regurgitant velocity, electrocardiogram, serum biochemistry, hematology, urinalysis, and analysis of reported adverse events, SANGUINATE was found to be safe in stable sickle cell anemia patients. Conclusions: The clinical trial met its primary objective of demonstrating an acceptable safety profile for SANGUINATE in patients with sickle cell anemia. This trial established the safety of SANGUINATE at both dose levels and permitted its advance to Phase II trials.

Dividing wall column: Improving thermal efficiency, energy savings and economic performance

International Nuclear Information System (INIS)

Aurangzeb, Md; Jana, Amiya K.

2016-01-01

Highlights: • A rigorous model is developed for a dividing wall column. • Heat transfer model for metal wall is proposed. • Performance improvement is quantified for a ternary system. • Thermal efficiency, energy savings and cost are three used indices. - Abstract: This work aims at investigating the performance improvement of a dividing wall column (DWC) for the separation of a ternary system. It is true that for fractionating a ternary mixture, at least a sequence of two conventional distillation columns is required. To improve energetic and economic potential, and reduce space requirement, two columns are proposed to merge into one shell with a dividing wall. For developing the mathematical model of a distillation column, we consider the effect of heat transfer through the metal wall placed at an intermediated position inside the cylindrical column. The simulated DWC model is verified using the Aspen Plus flowsheet simulator with a wide variety of phase equilibrium models. The superiority of this proposed heat integrated configuration is shown for a ternary hydrocarbon system over a conventional distillation sequence (CDS) in terms of mainly three performance indexes, namely thermal efficiency, energy savings and total annual cost (TAC). It is investigated that the dividing wall distillation scheme can secure a 37.5% energy efficiency, and a 22.6% savings in energy consumption and 23.23% in TAC. The promising performance can also be quantified in terms of a reasonably low payback period of 2.11 years.

Environment, information divide and design

International Nuclear Information System (INIS)

Iwata, Shuichi

2007-01-01

Design of human environment is to be made with understanding human-human and human-environment relations and environmental behaviors of human beings, artifacts and natural things and overcoming their differences and contradictions. Information divide exists naturally due to various differences of human beings. Many problems in the area of nuclear energy seem to be derived from various differences and contradictions in central-local interests, between the particles concerned and unconcerned and also in human being-artifacts relations. In order to harmonize nuclear energy with the society, it is necessary to vanish differences and solve contradictions with redesigning environments of those problems in their context. Case studies are highly recommended with continuous efforts to develop more universal design methodology. Open access to information and data in science and technology is encouraged in the area of nuclear energy. (T. Tanaka)

High-resolution characterization of sequence signatures due to non-random cleavage of cell-free DNA.

Science.gov (United States)

Chandrananda, Dineika; Thorne, Natalie P; Bahlo, Melanie

2015-06-17

High-throughput sequencing of cell-free DNA fragments found in human plasma has been used to non-invasively detect fetal aneuploidy, monitor organ transplants and investigate tumor DNA. However, many biological properties of this extracellular genetic material remain unknown. Research that further characterizes circulating DNA could substantially increase its diagnostic value by allowing the application of more sophisticated bioinformatics tools that lead to an improved signal to noise ratio in the sequencing data. In this study, we investigate various features of cell-free DNA in plasma using deep-sequencing data from two pregnant women (>70X, >50X) and compare them with matched cellular DNA. We utilize a descriptive approach to examine how the biological cleavage of cell-free DNA affects different sequence signatures such as fragment lengths, sequence motifs at fragment ends and the distribution of cleavage sites along the genome. We show that the size distributions of these cell-free DNA molecules are dependent on their autosomal and mitochondrial origin as well as the genomic location within chromosomes. DNA mapping to particular microsatellites and alpha repeat elements display unique size signatures. We show how cell-free fragments occur in clusters along the genome, localizing to nucleosomal arrays and are preferentially cleaved at linker regions by correlating the mapping locations of these fragments with ENCODE annotation of chromatin organization. Our work further demonstrates that cell-free autosomal DNA cleavage is sequence dependent. The region spanning up to 10 positions on either side of the DNA cleavage site show a consistent pattern of preference for specific nucleotides. This sequence motif is present in cleavage sites localized to nucleosomal cores and linker regions but is absent in nucleosome-free mitochondrial DNA. These background signals in cell-free DNA sequencing data stem from the non-random biological cleavage of these fragments. This

Incorporation of mesoporous silica nanoparticles into random electrospun PLGA and PLGA/gelatin nanofibrous scaffolds enhances mechanical and cell proliferation properties

International Nuclear Information System (INIS)

Mehrasa, Mohammad; Asadollahi, Mohammad Ali; Nasri-Nasrabadi, Bijan; Ghaedi, Kamran; Salehi, Hossein; Dolatshahi-Pirouz, Alireza; Arpanaei, Ayyoob

2016-01-01

Poly(lactic-co-glycolic acid) (PLGA) and PLGA/gelatin random nanofibrous scaffolds embedded with different amounts of mesoporous silica nanoparticles (MSNPs) were fabricated using electrospinning method. To evaluate the effects of nanoparticles on the scaffolds, physical, chemical, and mechanical properties as well as in vitro degradation behavior of scaffolds were investigated. The mean diameters of nanofibers were 974 ± 68 nm for the pure PLGA scaffolds vs 832 ± 70, 764 ± 80, and 486 ± 64 for the PLGA/gelatin, PLGA/10 wt% MSNPs, and the PLGA/gelatin/10 wt% MSNPs scaffolds, respectively. The results suggested that the incorporation of gelatin and MSNPs into PLGA-based scaffolds enhances the hydrophilicity of scaffolds due to an increase of hydrophilic functional groups on the surface of nanofibers. With porosity examination, it was concluded that the incorporation of MSNPs and gelatin decrease the porosity of scaffolds. Nanoparticles also improved the tensile mechanical properties of scaffolds. Using in vitro degradation analysis, it was shown that the addition of nanoparticles to the nanofibers matrix increases the weight loss percentage of PLGA-based samples, whereas it decreases the weight loss percentage in the PLGA/gelatin composites. Cultivation of rat pheochromocytoma cell line (PC12), as precursor cells of dopaminergic neural cells, on the scaffolds demonstrated that the introduction of MSNPs into PLGA and PLGA/gelatin matrix leads to improved cell attachment and proliferation and enhances cellular processes. - Highlights: • PLGA-based random nanofibers embedded with mesoporous silica nanoparticles were fabricated using electrospinning method • Incorporation of gelatin and MSNPs into PLGA-based scaffolds increased the hydrophilicity of scaffold • Addition of nanoparticles also improved the tensile mechanical properties of scaffolds • Introduction of MSNPs led to improved cell attachment and proliferation

Incorporation of mesoporous silica nanoparticles into random electrospun PLGA and PLGA/gelatin nanofibrous scaffolds enhances mechanical and cell proliferation properties

Energy Technology Data Exchange (ETDEWEB)

Mehrasa, Mohammad [Department of Biotechnology, Faculty of Advanced Sciences and Technologies, University of Isfahan, Isfahan 81746-73441 (Iran, Islamic Republic of); Department of Industrial and Environmental Biotechnology, National Institute of Genetic Engineering and Biotechnology, Tehran (Iran, Islamic Republic of); Asadollahi, Mohammad Ali, E-mail: ma.asadollahi@ast.ui.ac.ir [Department of Biotechnology, Faculty of Advanced Sciences and Technologies, University of Isfahan, Isfahan 81746-73441 (Iran, Islamic Republic of); Nasri-Nasrabadi, Bijan [Department of Chemical Engineering, Isfahan University of Technology, Isfahan (Iran, Islamic Republic of); Ghaedi, Kamran [Department of Biology, Faculty of Science, University of Isfahan, Isfahan 81746-73441 (Iran, Islamic Republic of); Salehi, Hossein [Department of Anatomical Sciences, School of Medicine, Isfahan University of Medical Sciences, Isfahan (Iran, Islamic Republic of); Dolatshahi-Pirouz, Alireza [DTU Nanotech, Center for Nanomedicine and Theranostics, Technical University of Denmark (DTU), DK-2800 Kgs. Lyngby (Denmark); Arpanaei, Ayyoob, E-mail: arpanaei@yahoo.com [Department of Industrial and Environmental Biotechnology, National Institute of Genetic Engineering and Biotechnology, Tehran (Iran, Islamic Republic of)

2016-09-01

Poly(lactic-co-glycolic acid) (PLGA) and PLGA/gelatin random nanofibrous scaffolds embedded with different amounts of mesoporous silica nanoparticles (MSNPs) were fabricated using electrospinning method. To evaluate the effects of nanoparticles on the scaffolds, physical, chemical, and mechanical properties as well as in vitro degradation behavior of scaffolds were investigated. The mean diameters of nanofibers were 974 ± 68 nm for the pure PLGA scaffolds vs 832 ± 70, 764 ± 80, and 486 ± 64 for the PLGA/gelatin, PLGA/10 wt% MSNPs, and the PLGA/gelatin/10 wt% MSNPs scaffolds, respectively. The results suggested that the incorporation of gelatin and MSNPs into PLGA-based scaffolds enhances the hydrophilicity of scaffolds due to an increase of hydrophilic functional groups on the surface of nanofibers. With porosity examination, it was concluded that the incorporation of MSNPs and gelatin decrease the porosity of scaffolds. Nanoparticles also improved the tensile mechanical properties of scaffolds. Using in vitro degradation analysis, it was shown that the addition of nanoparticles to the nanofibers matrix increases the weight loss percentage of PLGA-based samples, whereas it decreases the weight loss percentage in the PLGA/gelatin composites. Cultivation of rat pheochromocytoma cell line (PC12), as precursor cells of dopaminergic neural cells, on the scaffolds demonstrated that the introduction of MSNPs into PLGA and PLGA/gelatin matrix leads to improved cell attachment and proliferation and enhances cellular processes. - Highlights: • PLGA-based random nanofibers embedded with mesoporous silica nanoparticles were fabricated using electrospinning method • Incorporation of gelatin and MSNPs into PLGA-based scaffolds increased the hydrophilicity of scaffold • Addition of nanoparticles also improved the tensile mechanical properties of scaffolds • Introduction of MSNPs led to improved cell attachment and proliferation.

Bridging the Digital Divide Creating Digital Dividend - The Investigation in Guizhou Province and the Analysis of GZNW

Directory of Open Access Journals (Sweden)

Linbo Jing

2007-12-01

Full Text Available This article begins with attention to the digital divide. It gives a brief overview of the digital divide on a global basis and analyzes specific aspects of the digital divide in our country. It also introduces the informationization construction of Guizhou Province and points out problems with the digital divide in that province. Then it focuses on the practice of Guizhou Province to bridge the digital divide ---- the practice and experience of GZNW. The final section gives a series of policy recommendations on how to bridge the digital divide, realize digital dividends, and how to build a new socialist countryside.

40 CFR 761.306 - Sampling 1 meter square surfaces by random selection of halves.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Sampling 1 meter square surfaces by...(b)(3) § 761.306 Sampling 1 meter square surfaces by random selection of halves. (a) Divide each 1 meter square portion where it is necessary to collect a surface wipe test sample into two equal (or as...

Multi-isotope imaging mass spectrometry quantifies stem cell division and metabolism.

Science.gov (United States)

Steinhauser, Matthew L; Bailey, Andrew P; Senyo, Samuel E; Guillermier, Christelle; Perlstein, Todd S; Gould, Alex P; Lee, Richard T; Lechene, Claude P

2012-01-15

Mass spectrometry with stable isotope labels has been seminal in discovering the dynamic state of living matter, but is limited to bulk tissues or cells. We developed multi-isotope imaging mass spectrometry (MIMS) that allowed us to view and measure stable isotope incorporation with submicrometre resolution. Here we apply MIMS to diverse organisms, including Drosophila, mice and humans. We test the 'immortal strand hypothesis', which predicts that during asymmetric stem cell division chromosomes containing older template DNA are segregated to the daughter destined to remain a stem cell, thus insuring lifetime genetic stability. After labelling mice with (15)N-thymidine from gestation until post-natal week 8, we find no (15)N label retention by dividing small intestinal crypt cells after a four-week chase. In adult mice administered (15)N-thymidine pulse-chase, we find that proliferating crypt cells dilute the (15)N label, consistent with random strand segregation. We demonstrate the broad utility of MIMS with proof-of-principle studies of lipid turnover in Drosophila and translation to the human haematopoietic system. These studies show that MIMS provides high-resolution quantification of stable isotope labels that cannot be obtained using other techniques and that is broadly applicable to biological and medical research.

Randomized Trial of Hypnosis as a Pain and Symptom Management Strategy in Adults with Sickle Cell Disease

Science.gov (United States)

Wallen, Gwenyth R; Middleton, Kimberly R; Ames, Nancy; Brooks, Alyssa T; Handel, Daniel

2014-01-01

Sickle cell disease (SCD) is the most common genetic disease in African-Americans, characterized by recurrent painful vaso-occlusive crises. Medical therapies for controlling or preventing crises are limited because of efficacy and/or toxicity. This is a randomized, controlled, single-crossover protocol of hypnosis for managing pain in SCD patients. Participants receive hypnosis from a trained hypnosis therapist followed by six weeks of self-hypnosis using digital media. Those in the control arm receive SCD education followed by a six-week waiting period before crossing over to the hypnosis arm of the study. Outcome measures include assessments of pain (frequency, intensity and quality), anxiety, coping strategies, sleep, depression, and health care utilization. To date, there are no published randomized, controlled trials evaluating the efficacy of hypnosis on SCD pain modulation in adults. Self-hypnosis for pain management may be helpful in modulating chronic pain, improving sleep quality, and decreasing use of narcotics in patients with SCD. TRIAL REGISTRATION ClinicalTrials.gov: NCT00393250 PMID:25520557

Randomized Trial of Hypnosis as a Pain and Symptom Management Strategy in Adults with Sickle Cell Disease

Directory of Open Access Journals (Sweden)

Gwenyth R. Wallen

2014-01-01

Full Text Available Sickle cell disease (SCD is the most common genetic disease in African-Americans, characterized by recurrent painful vaso-occlusive crises. Medical therapies for controlling or preventing crises are limited because of efficacy and/or toxicity. This is a randomized, controlled, single-crossover protocol of hypnosis for managing pain in SCD patients. Participants receive hypnosis from a trained hypnosis therapist followed by six weeks of self-hypnosis using digital media. Those in the control arm receive SCD education followed by a six-week waiting period before crossing over to the hypnosis arm of the study. Outcome measures include assessments of pain (frequency, intensity and quality, anxiety, coping strategies, sleep, depression, and health care utilization. To date, there are no published randomized, controlled trials evaluating the efficacy of hypnosis on SCD pain modulation in adults. Self-hypnosis for pain management may be helpful in modulating chronic pain, improving sleep quality, and decreasing use of narcotics in patients with SCD. TRIAL REGISTRATION: ClinicalTrials.gov: NCT00393250

MMS-induced primary aneuploidy and other genotoxic effects in mitotic cells of Aspergillus.

Science.gov (United States)

Käfer, E

1988-10-01

The possibility of more than 1 target for genotoxic effects of methyl methanesulphonate (MMS) was investigated, using mitotic test systems of the fungus Aspergillus. Haploid and diploid strains were exposed, either as dormant conidia or during mitosis, and analysed for induced aneuploidy and effects on genetic segregation. MMS treatment of haploid strains resulted in dose-dependent increases of stable mutants with altered phenotypes and semi-stable unbalanced aberrations (presumably duplications). In addition, but only in dividing cells, MMS induced unstable aneuploids. These mostly were hyperhaploid with few extra chromosomes and could be identified by comparison with standard disomic phenotypes. When well-marked diploids were treated 3 types of effect could be distinguished, using genetic and phenotypic criteria: (1) Clastogenic and mutagenic effects which caused dose-dependent increases of partial aneuploids with various abnormal phenotypes. These showed secondary genetic segregation of all types and produced euploid normal sectors by eliminating damaged chromosome segments. In addition, but only in dividing nuclei, MMS induced 2 types of segregation: (2) Reciprocal crossing-over at high frequency, recognisable as half or quarter colonies of mutant colour and in some cases as 'twin spots' (i.e., complementary pairs); (3) Trisomics and other aneuploids which showed characteristic phenotypes and expected segregation of markers: the types recovered indicate random malsegregation of chromosomes (occasional deviations resulted from coincidence with induced crossing-over). These results suggest that MMS may have 2 (or more) targets for genotoxic effects: DNA, as evident from induced mutations and aberrations, and from induced recombination in dividing cells; some non-DNA target (nucleotide or protein) essential for nuclear division and susceptible to alkylation, resulting in malsegregation and primary aneuploidy.

The Effect of a combination of 12% spirulina and 20% chitosan on macrophage, PMN, and lymphocyte cell expressions in post extraction wound

Directory of Open Access Journals (Sweden)

Nike Hendrijantini

2017-06-01

Full Text Available Background: Tooth extraction is the ultimate treatment option for defective teeth followed by the need for dentures. Inflammation is one phase of the healing process that should be minimized in order to preserve alveolar bone for denture support. Macrophage, PMN and lymphocyte cells are indicators of acute inflammation. Spirulina and chitosan are natural compounds with the potential to be anti-inflammatory agents. Purpose: This research aimed to determine macrophage, PMN and lymphocyte cells of animal models treated with a combination of 12% spirulina and 20% chitosan on the 1st, 2nd and 3rd post-extraction day. Methods: Animal models were randomly divided into control (K and treatment (P groups. Each group was further divided into three subgroups (KI, KII, KIII and PI, PII, PIII. The post-extraction sockets of the control group animals were then filled with CMC Na 3%. Meanwhile, the post-extraction sockets of the treatment group members were filled with a combination of 12% spirulina and 20% chitosan. Subsequently, the number of PMN, macrophage and lymphocyte cells was analyzed by means of HE analysis on the 1st., 2nd. and 3rd. days. Statistical analysis was then performed using a T-test. Results: There was a decrease in PMN cells and an increase in macrophage and lymphocyte cells on Days 1, 2, and 3. Conclusion: It can be concluded that a combination of 12% spirulina and 20% chitosan can not only decrease PMN cells, but can also increase macrophage and lymphocyte cells on Days 1, 2 and 3 after tooth extraction.

Reducing the Digital Divide among Children Who Received Desktop or Hybrid Computers for the Home

Science.gov (United States)

Zilka, Gila Cohen

2016-01-01

Researchers and policy makers have been exploring ways to reduce the digital divide. Parameters commonly used to examine the digital divide worldwide, as well as in this study, are: (a) the digital divide in the accessibility and mobility of the ICT infrastructure and of the content infrastructure (e.g., sites used in school); and (b) the digital…

Regulatory T cell activity in immunosuppresive mice model of pseudomonas aeruginosa pneumonia.

Science.gov (United States)

Li, Jun-Lu; Chen, Ting-Sang; Yuan, Cong-Cong; Zhao, Guo-Qiang; Xu, Min; Li, Xiao-Yan; Cao, Jie; Xing, Li-Hua

2017-08-01

Pseudomonas aeruginosa (PA) pneumonia is a refractory, even lethal complication in immunosuppressive individuals and immune disturbances may promote the pathological process. We aimed to investigate the regulatory T (Treg) cell activity in an immunosuppressive mice model of PA pneumonia by estimating levels of main transcription factor and the main effector of Treg cells, i.e., Forkhead box protein 3 (FOXP3) and interleukine-10 (IL-10). Seventy-two BALB/c mice were divided into four groups randomly: control (A), PA pneumonia (B), immunosuppression (C) and immunosuppression with PA pneumonia (D). Mice were sacrificed at 4, 8 and 24 h after establishing experimental models. The pathological changes of lung tissue were graded, and the FOXP3 mRNA and serum IL-10 levels were detected. Histological analysis of lung tissues showed there were no significantly pathological changes in groups A and C, but significantly pathological changes were found in groups B and D, especially in group D at 8 h (Ppneumonia in immunosuppressive individuals worsens rapidly, which may be associated with Treg cells function disturbance. And Treg cells may be promising as adjuvant therapeutics for PA pneumonia in immunosuppressive individuals.

Green and sustainable median on a divided multilane highway

Science.gov (United States)

Ambak, K.; Bajuri, F. A. A.; Yusoff, N. A.; Madun, A.; Prasetijo, J.

2017-11-01

The road system in Malaysia showed good growth with increasing number of vehicles on the road. However, statistic of road accident is still at an alarming rate. There are many factor can contribute to the occurrence of an accident. If the accident was caused by road facilities such as street furniture, it is shown that the street furniture was failed to improve the safety of the road users. In this study, a new concept of materials for the construction of road dividers was purpose. The sustainable materials such as laterite soil, Cow Grass, tires and PVC pipes was used to replace the cement and iron guardrails in road divider construction. The main objectives of this study is to design characteristics of a road divider using natural material such as laterite soil, sand, grass and recycle material like used a tyre. A series of experiments such as test liquid limit, plastic limit test, standard proctor test and observations of root growth in 30 days were conducted. The result shows that the plastic index value of 35% was obtained. From the proctor compaction test, the optimum water content was 23% and maximum dry density at 15.3 kN/m3. This value was used to build a prototype of green and sustainable raised road median. The suitability of sand used as the medium in irrigation system was approved. Permeability of sand is 10-2 mm/s to 10 mm/s which is having a high rate of flow. The growth of Cow Grass roots was increased by 4.9 cm in 30 days. This shows that, the grass is suitable to grow in laterite soil and can be used as vegetation material. Through the impact test conducted on a model with a scale of 1:7.5, indicate the initial damage occurred when a force reaches 10N. However, the condition of the model is still stable. From the impact test conducted, the prototype of green and sustainable raised road median has a good potential to be used as existing road divider as it can absorb the impact of an accident.

A Bimodel Algorithm with Data-Divider to Predict Stock Index

Directory of Open Access Journals (Sweden)

Zhaoyue Wang

2018-01-01

Full Text Available There is not yet reliable software for stock prediction, because most experts of this area have been trying to predict an exact stock index. Considering that the fluctuation of a stock index usually is no more than 1% in a day, the error between the forecasted and the actual values should be no more than 0.5%. It is too difficult to realize. However, forecasting whether a stock index will rise or fall does not need to be so exact a numerical value. A few scholars noted the fact, but their systems do not yet work very well because different periods of a stock have different inherent laws. So, we should not depend on a single model or a set of parameters to solve the problem. In this paper, we developed a data-divider to divide a set of historical stock data into two parts according to rising period and falling period, training, respectively, two neural networks optimized by a GA. Above all, the data-divider enables us to avoid the most difficult problem, the effect of unexpected news, which could hardly be predicted. Experiments show that the accuracy of our method increases 20% compared to those of traditional methods.

A 1T Dynamic Random Access Memory Cell Based on Gated Thyristor with Surrounding Gate Structure for High Scalability.

Science.gov (United States)

Kim, Hyungjin; Kim, Sihyun; Kim, Hyun-Min; Lee, Kitae; Kim, Sangwan; Pak, Byung-Gook

2018-09-01

In this study, we investigate a one-transistor (1T) dynamic random access memory (DRAM) cell based on a gated-thyristor device utilizing voltage-driven bistability to enable high-speed operations. The structural feature of the surrounding gate using a sidewall provides high scalability with regard to constructing an array architecture of the proposed devices. In addition, the operation mechanism, I-V characteristics, DRAM operations, and bias dependence are analyzed using a commercial device simulator. Unlike conventional 1T DRAM cells utilizing the floating body effect, excess carriers which are required to be stored to make two different states are not generated but injected from the n+ cathode region, giving the device high-speed operation capabilities. The findings here indicate that the proposed DRAM cell offers distinct advantages in terms of scalability and high-speed operations.

A millifluidic study of cell-to-cell heterogeneity in growth-rate and cell-division capability in populations of isogenic cells of Chlamydomonas reinhardtii.

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Shima P Damodaran

Full Text Available To address possible cell-to-cell heterogeneity in growth dynamics of isogenic cell populations of Chlamydomonas reinhardtii, we developed a millifluidic drop-based device that not only allows the analysis of populations grown from single cells over periods of a week, but is also able to sort and collect drops of interest, containing viable and healthy cells, which can be used for further experimentation. In this study, we used isogenic algal cells that were first synchronized in mixotrophic growth conditions. We show that these synchronized cells, when placed in droplets and kept in mixotrophic growth conditions, exhibit mostly homogeneous growth statistics, but with two distinct subpopulations: a major population with a short doubling-time (fast-growers and a significant subpopulation of slowly dividing cells (slow-growers. These observations suggest that algal cells from an isogenic population may be present in either of two states, a state of restricted division and a state of active division. When isogenic cells were allowed to propagate for about 1000 generations on solid agar plates, they displayed an increased heterogeneity in their growth dynamics. Although we could still identify the original populations of slow- and fast-growers, drops inoculated with a single progenitor cell now displayed a wider diversity of doubling-times. Moreover, populations dividing with the same growth-rate often reached different cell numbers in stationary phase, suggesting that the progenitor cells differed in the number of cell divisions they could undertake. We discuss possible explanations for these cell-to-cell heterogeneities in growth dynamics, such as mutations, differential aging or stochastic variations in metabolites and macromolecules yielding molecular switches, in the light of single-cell heterogeneities that have been reported among isogenic populations of other eu- and prokaryotes.

Examining the University-Profession Divide: An Inquiry into a Teacher Education Program's Practices

Science.gov (United States)

Sivia, Awneet; MacMath, Sheryl

2016-01-01

This paper focuses on the divide between the university as a site of teacher education and the profession of practicing teachers. We employed a theoretical inquiry methodology on a singular case study which included formulating questions about the phenomena of the university-profession divide (UPD), analysing constituents of the UPD, and…

The new technology of dividing wall in stope

International Nuclear Information System (INIS)

Li Zhiguo

1999-01-01

The author analyzes advantages and disadvantages of the ordinary separating methods between stopes at deep mine, points out the main problems of the original projects constructing dividing wall, presents an idea of new technology which can overcome the main problems, predicts effect adopting the new technology, and analyzes that feasibility applying the new technology to construct mortar pad in stope and dyke-dam

Disseminating relevant health information to underserved audiences: implications of the Digital Divide Pilot Projects.

Science.gov (United States)

Kreps, Gary L

2005-10-01

This paper examines the influence of the digital divide on disparities in health outcomes for vulnerable populations, identifying implications for medical and public libraries. The paper describes the results of the Digital Divide Pilot Projects demonstration research programs funded by the National Cancer Institute to test new strategies for disseminating relevant health information to underserved and at-risk audiences. The Digital Divide Pilot Projects field-tested innovative systemic strategies for helping underserved populations access and utilize relevant health information to make informed health-related decisions about seeking appropriate health care and support, resisting avoidable and significant health risks, and promoting their own health. The paper builds on the Digital Divide Pilot Projects by identifying implications for developing health communication strategies that libraries can adopt to provide digital health information to vulnerable populations.

[Relationship between sensitivity of tumor cells to chemotherapeutic agent in vivo and in vitro: experiment with mouse lymphoma cells].

Science.gov (United States)

Li, Chuan-gang; Li, Mo-lin; Shu, Xiao-hong; Jia, Yu-jie; Liu, Yong-ji; Li, Ming

2007-06-12

To study the relationship of the sensitivity of tumor cells to chemotherapeutic agent between in vivo and in vitro. Mouse lymphoma cells of the line E14 were cultured and melphalan resistant EL4 cell line (EL4/melphalan) was established by culturing EL4 cells with continuous low-concentration and intermittent gradually-increasing-concentration of melphalan in vitro. MTT assay was used to evaluate the drug sensitivity and the resistance index of the EL4/melphalan cells to melphalan was calculated. EL4/melphalan and EL4 cells of the concentration of 5 x 10(8)/L were inoculated separately into 20 C57BL/6 mice subcutaneously. 12 days later, the EL4 and EL4/melphalan tumor-bearing mice were randomly divided into 2 groups respectively, 5 mice in each group. Treatment groups were given 7.5 mg/kg melphalan intraperitoneally, and control groups were given the same volume of normal saline. The tumor size was observed every other day. Compared with the EL4 cells, the EL4/melphalan cells had no obvious changes morphologically. They could grow in RPMI 1640 medium containing 5 mg/ml melphalan. The resistance index was 2.87 against melphalan. After the treatment of melphalan of the dose 7.5 mg/kg, the tumor sizes of the treatment groups and control groups inoculated with both EL4 cells and the EL4/melphalan cells gradually decreased at the similar speed, and about one week later all tumors disappeared. However, the tumors of the control groups grew progressively and all the mice died at last. The chemotherapeutic effects of tumors in vivo have nothing to do with the effects of the chemotherapeutic agents on tumor cells in vitro. The tumor cells resistant to melphalan in vitro remain sensitive to the drug in vivo.

Effect of roscovitine treated donor cells and different activation methods on development of handmade cloned goat (Capra hircus) embryos.

Science.gov (United States)

Akshey, Y S; Malakar, D; De, A Kumar; Jena, M Kumar; Pawar, S Kumar; Dutta, R; Sahu, S

2011-05-01

The aim of the present investigation was to find out the effects of roscovitine treatment of donor cells and different activation methods on development of HMC goat embryos. Goat fetal fibroblast cells were cultured and divided into three treatment groups-contact inhibition group, roscovitine treatment group and serum starvation group. There was a significant decrease in blastocyst yield in serum starvation group (6.82%) compared to roscovitine treatment group (19.31%) and contact inhibition group (18.52%), however, no significant difference was found between roscovitine treatment group and contact inhibition group. To see the effect of different methods of activation, the reconstructed embryos were randomly divided into two groups and activated by two methods-one half by 2 μM Ca ionophore and another half by 2.31 kV/cm for 15 μSec electrical pulse. Subsequently, cloned embryos were cultured in TCM-199 based embryo development medium supplemented with 10 mg/mL bovine serum albumin in WOW culture system. There was a significant increase in the rate of cleavage and blastocyst production in electric pulse activation of 78.57% and 21.43% than Ca ionophore activation of 62.63% and 10.61% respectively. In conclusion, treatment of donor cells with roscovitine yields a significantly increased blastocyst than serum starved donor cells but equivalent blastocyst to contact inhibition group and electrical pulse activation (EPA) improves the production of HMC goat embryos. Copyright © 2011 Elsevier Inc. All rights reserved.

Lifestyle intervention using an internet-based curriculum with cell phone reminders for obese Chinese teens: a randomized controlled study.

Directory of Open Access Journals (Sweden)

Anisha A Abraham

Full Text Available Obesity is an increasing public health problem affecting young people. The causes of obesity are multi-factorial among Chinese youth including lack of physical activity and poor eating habits. The use of an internet curriculum and cell phone reminders and texting may be an innovative means of increasing follow up and compliance with obese teens. The objectives of this study were to determine the feasibility of using an adapted internet curriculum and existing nutritional program along with cell phone follow up for obese Chinese teens.This was a randomized controlled study involving obese teens receiving care at a paediatric obesity clinic of a tertiary care hospital in Hong Kong. Forty-eight subjects aged 12 to 18 years were randomized into three groups. The control group received usual care visits with a physician in the obesity clinic every three months. The first intervention (IT group received usual care visits every three months plus a 12-week internet-based curriculum with cell phone calls/texts reminders. The second intervention group received usual care visits every three months plus four nutritional counselling sessions.The use of the internet-based curriculum was shown to be feasible as evidenced by the high recruitment rate, internet log-in rate, compliance with completing the curriculum and responses to phone reminders. No significant differences in weight were found between IT, sLMP and control groups.An internet-based curriculum with cell phone reminders as a supplement to usual care of obesity is feasible. Further study is required to determine whether an internet plus text intervention can be both an effective and a cost-effective adjunct to changing weight in obese youth.Chinese Clinical Trial Registry ChiCTR-TRC-12002624.

Background fluorescence estimation and vesicle segmentation in live cell imaging with conditional random fields.

Science.gov (United States)

Pécot, Thierry; Bouthemy, Patrick; Boulanger, Jérôme; Chessel, Anatole; Bardin, Sabine; Salamero, Jean; Kervrann, Charles

2015-02-01

Image analysis applied to fluorescence live cell microscopy has become a key tool in molecular biology since it enables to characterize biological processes in space and time at the subcellular level. In fluorescence microscopy imaging, the moving tagged structures of interest, such as vesicles, appear as bright spots over a static or nonstatic background. In this paper, we consider the problem of vesicle segmentation and time-varying background estimation at the cellular scale. The main idea is to formulate the joint segmentation-estimation problem in the general conditional random field framework. Furthermore, segmentation of vesicles and background estimation are alternatively performed by energy minimization using a min cut-max flow algorithm. The proposed approach relies on a detection measure computed from intensity contrasts between neighboring blocks in fluorescence microscopy images. This approach permits analysis of either 2D + time or 3D + time data. We demonstrate the performance of the so-called C-CRAFT through an experimental comparison with the state-of-the-art methods in fluorescence video-microscopy. We also use this method to characterize the spatial and temporal distribution of Rab6 transport carriers at the cell periphery for two different specific adhesion geometries.

Heat control in HVDC resistive divider by PID and NN controllers

International Nuclear Information System (INIS)

Yilmaz, S.; Dincer, H.; Eksin, I.; Kalenderli, O.

2007-01-01

In this study, a control system is presented that is devised to increase measurement precisions within a prototype high voltage DC resistive divider (HVDC-RD). Since one of the major sources of measurement errors in such devices is the self heating effect, a system controlling the temperature within the high voltage DC resistive divider is devised so that suitable and stable temperature conditions are maintained that, in return, will decrease the measurement errors. The resistive divider system is cooled by oil, and PID and neural network (NN) controllers try to keep the temperature within the prescribed limits. The system to be controlled exhibits a nonlinear character, and therefore, a control approach based on NN controllers is proposed. Thus, a system that can fulfill the various requirements dictated by the designer is constructed. The performance of the NN controller is compared with that of the PID controller developed for the same purpose, and the values of the performance indices indicate the superiority of the NN controller over that of the classical PID controller

Layer dividing and zone dividing of physical property of crust and deep structure in Jiangxi province

International Nuclear Information System (INIS)

Li Chunhua; Yang Yaxin; Gong Yuling; Huang Linping

2001-01-01

On the base of summing experiences both at home and abroad, the Bugar gravitative anomalies are studied by major means of data processing. According to the anomalous character, three layer crust models (surface layer, middle layer in region and material layer under crust) are built up, depth of upper and bottom surfaces for every layer is calculated quantitatively, their varied characters of depth are studied and deep geological tectonics are outlined. The 'density' and 'mass' of every layer are calculated, and according to these two parameters, the shallow geological tectonics are researched. The relation-factor R between the surface altitude and Bugar gravitative anomalies are calculated and the stable or unstable crust zones are divided. The favorable mine zones for uranium deposit in Jiangxi Province are outlined

Leadership Analysis in K-12 Case Study: "Divided Loyalties"

Science.gov (United States)

Alsubaie, Merfat Ayesh

2016-01-01

This report mainly aims to provide a critical and in-depth analysis of the K-12 Case, "Divided Loyalty" by Holy and Tartar (2004). The case recounts how the manifestation of inadequate leadership skills in a school setting could affect negatively the performance of students.

Microcanonical rates, gap times, and phase space dividing surfaces

NARCIS (Netherlands)

Ezra, Gregory S.; Waalkens, Holger; Wiggins, Stephen

2009-01-01

The general approach to classical unimolecular reaction rates due to Thiele is revisited in light of recent advances in the phase space formulation of transition state theory for multidimensional systems. Key concepts, such as the phase space dividing surface separating reactants from products, the

Long-term sequential deferiprone-deferoxamine versus deferiprone alone for thalassaemia major patients: a randomized clinical trial

DEFF Research Database (Denmark)

Maggio, Aurelio; Vitrano, Angela; Capra, Marcello

2009-01-01

A multicentre randomized open-label trial was designed to assess the effectiveness of long-term sequential deferiprone-deferoxamine (DFO-DFP) versus DFP alone to treat thalassaemia major (TM). DFP at 75 mg/kg, divided into three oral daily doses, for 4 d/week and DFO by subcutaneous infusion (8-1...

Quasi-resonant converter with divided resonant capacitor on primary and secondary side

OpenAIRE

Shiroyama, Hironobu; Matsuo, Hirofumi; Ishizuka, Yoichi

2009-01-01

This paper presents a quasi-resonant converter with divided resonant capacitor on primary and secondary side of the isolation transformer. A conventional quasi-resonant converter using flyback topology can realize soft switching with simple circuit. However, relatively large surge voltage is generated in the switching device. To suppress such surge voltage, resonant capacitor is divided on primary side and secondary side in the proposed converter. In case of prototype 95W converter, the volta...

Cover times of random searches

Science.gov (United States)

Chupeau, Marie; Bénichou, Olivier; Voituriez, Raphaël

2015-10-01

How long must one undertake a random search to visit all sites of a given domain? This time, known as the cover time, is a key observable to quantify the efficiency of exhaustive searches, which require a complete exploration of an area and not only the discovery of a single target. Examples range from immune-system cells chasing pathogens to animals harvesting resources, from robotic exploration for cleaning or demining to the task of improving search algorithms. Despite its broad relevance, the cover time has remained elusive and so far explicit results have been scarce and mostly limited to regular random walks. Here we determine the full distribution of the cover time for a broad range of random search processes, including Lévy strategies, intermittent strategies, persistent random walks and random walks on complex networks, and reveal its universal features. We show that for all these examples the mean cover time can be minimized, and that the corresponding optimal strategies also minimize the mean search time for a single target, unambiguously pointing towards their robustness.

Gemcitabine and treatment of diffuse large B-cell lymphoma in relapsed or refractory elderly patients: A prospective randomized trial in Algeria

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Aribi Mourad

2010-01-01

Full Text Available Context: Support for non-Hodgkin′s lymphoma (NHL with large cells that is refractory or relapsed after first-line chemotherapy poses a greater therapeutic problem with bone marrow transplant therapy or when old age is a contra-indication for high-dose chemotherapy, especially among developing countries such as Algeria. Aim: To show that the regimen, including gemcitabine, could be more effective in treating elderly patients with diffuse large B-cell lymphoma (DLBCL in relapse / refractory, without complete remission, when compared with the ESHAP (etoposide, cisplatine, solumedrol, aracytine regimen. Materials and Methods: Ninety-six patients in the age group of 60-70 years were volunteers for a prospective randomized single-blind study, carried out for three years. Patients were divided into two groups by the drawing of lots. The first group (GA, n = 48, relapse; n = 27 [56.3%], refractory; n = 21 [43.7%] received treatment with ESHAP protocol and the second one (GB, n = 48, relapse; n = 28 [58%], refractory; n = 20 [42%] with GPD (gemcitabine, dexamethasone, cisplatine protocol. Results: The overall response rates and mean survival at three years were significantly higher among patients subjected to GPD treatment compared with those subjected to ESHAP treatment (63% vs. 55%, P = 0.01 and 20.5% [95% CI 16.5-24.5] vs. 11.8% [8.9-14.6], respectively. Additionally, three-year progression-free and event-free survival rates were 20.5% (16.3-24 and 19.7% (15.9-23.5, respectively, for the GPD regimen and 10.9% (8.2-13.7 and 11.1% (95% CI 8.5-13.7, respectively, for the ESHAP regimen. Moreover, the GPD regimen was associated with improving overall survival (RR=2.02, 95% CI 1.59-2.56; P = 0.000, event-free survival (2.03, 1.64-2.52; P < 0.001 and progression-free survival (1.86, 1.46-2.37; P < 0.001. Conclusion: In cases of contra-indication for high-dose chemotherapy for elderly patients with DLBCL, without complete remission, the Gemcitabine

Receptor-mediated endocytosis of low density lipoproteins in aortic endothelial cells

International Nuclear Information System (INIS)

Sanan, D.A.

1986-04-01

Lipoprotein binding and metabolism in actively-dividing (subconfluent) and quiescent (postconfluent) bovine aortic endothelial cells (ECs) were qualitatively investigated by fluorescence microscopy using dioctadecylindocarbocyanine-labelled lipoproteins and by indirect immunofluorescence microscopy. LDL and acetylated-LDL (AcLDL) were seen bound to the surfaces of subconfluent ECs (at 4 degrees C or at 37 degrees C), as a random distribution of punctate foci. ECs therefore closely resembled fibroblasts in the distribution of LDL receptors on their surfaces. No binding of LDL was seen on postconfluent EC surfaces by either direct or indirect fluorescence microscopy. The patterns of AcLDL binding on postconfluent ECs resembled those on subconfluent ECs. Intracellular LDL and AcLDL occurred as perinuclear accumulations of large fluorescent disc-shaped profiles in subconfluent ECs. These accumulations were shown to arise from surface-bound material by pulse-chase experiments. Intracellular LDL was absent in the majority of postconfluent ECs, while AcLDL accumulation was massive. 'Wounding' of cultures allowed simultaneous assessment of lipoprotein metabolism in quiescent and actively-dividing areas of the same culture. It is concluded that postconfluent quiescent bovine aortic ECs in vitro metabolise virtually no LDL via the LDL-receptor pathway due to a vanishingly low number of LDL receptors. This contrasts with the ability of postconfluent cells to metabolise relatively large amounts of AcLDL via a receptor-mediated mechanism. The significance of these conclusions is discussed with respect to the interaction of plasma lipoproteins with the endothelium in vivo. 301 refs

Radiomimetic effect of cisplatin on cucumber root development: the relationship between cell division and cell growth

Energy Technology Data Exchange (ETDEWEB)

Dubrovsky, J. G. [Division of Experimental Biology, Center for Biological Research (CIB), PO Box 128, La Paz, BCS 23000 (Mexico)

1993-07-01

Cisplatin [DDP, cis-dichlorodiammine platinum (II)], a strong cytostatic and antineoplastic agent, was tested on seedlings of cucumber Cucumis sativus L. for its general effect on root development and its particular effects on root cell division and cell growth. DDP was characterized as a radiomimetic compound since both DDP (1·3 × 10{sup -5} M) and γ-irradiation (2·5-10 kGy) drastically and irreversibly stopped development of embryonic lateral root primordia (LRPs) in the radicle by inhibiting both mitotic activity and cell growth. In 20% of the LRPs of DDP-treated roots, cells did not divide at all. Dividing cells completed no more than two cell cycles. These effects were specific because when DDP was available to the roots only at the onset of cell division, cell proliferation and cell growth were similar to that produced by constant incubation. Neither DDP nor γ-irradiation affected non-meristematic cell elongation. It was concluded that cell growth of meristematic cells is closely related to cell division. However, non-meristematic cell growth is independent of DNA damage. This suggests DDP as a tool to reveal these autonomous processes in plants development and to detect tissue compartments in mature plant embryos which contain potentially non-meristematic cells. (author)

Randomized phase II study of a bendamustine monotherapy schedule for relapsed or refractory low-grade B-cell non-Hodgkin lymphoma or mantle cell lymphoma (RABBIT-14).

Science.gov (United States)

Itoh, Kuniaki; Igarashi, Tadahiko; Irisawa, Hiroyuki; Aotsuka, Nobuyuki; Masuda, Shinichi; Utsu, Yoshikazu; Tsujimura, Hideki; Tsukasaki, Kunihiro; Wakita, Hisashi

2017-10-30

The aim of this randomized phase II study was to improve the treatment delays and discontinuations associated with bendamustine use by comparing the effect of Benda-14 (intravenous bendamustine, 120 mg/m 2 on days 1 and 15, repeated every 4 weeks for a total of 6 cycles) with those of the standard treatment in relapsed indolent lymphoma and/or mantle cell lymphoma. Forty-six patients were randomly assigned to the treatments from September 2012 to February 2016. Treatment accomplishment rate and median relative dose intensity were similar in both arms: 38 and 63.4% in the Benda-14 arm and 41 and 66.3% in the standard treatment arm, respectively. The overall response rate and median progression-free survival, respectively, were 83% and 21.0 months for Benda-14, and 77% and 15.5 months for the standard treatment. Benda-14 induced favorable responses with less frequent hematological toxicities.

Disseminating relevant health information to underserved audiences: implications of the Digital Divide Pilot Projects*

Science.gov (United States)

Kreps, Gary L.

2005-01-01

Objective: This paper examines the influence of the digital divide on disparities in health outcomes for vulnerable populations, identifying implications for medical and public libraries. Method: The paper describes the results of the Digital Divide Pilot Projects demonstration research programs funded by the National Cancer Institute to test new strategies for disseminating relevant health information to underserved and at-risk audiences. Results: The Digital Divide Pilot Projects field-tested innovative systemic strategies for helping underserved populations access and utilize relevant health information to make informed health-related decisions about seeking appropriate health care and support, resisting avoidable and significant health risks, and promoting their own health. Implications: The paper builds on the Digital Divide Pilot Projects by identifying implications for developing health communication strategies that libraries can adopt to provide digital health information to vulnerable populations. PMID:16239960

Divided attention selectively impairs memory for self-relevant information.

Science.gov (United States)

Turk, David J; Brady-van den Bos, Mirjam; Collard, Philip; Gillespie-Smith, Karri; Conway, Martin A; Cunningham, Sheila J

2013-05-01

Information that is relevant to oneself tends to be remembered more than information that relates to other people, but the role of attention in eliciting this "self-reference effect" is unclear. In the present study, we assessed the importance of attention in self-referential encoding using an ownership paradigm, which required participants to encode items under conditions of imagined ownership by themselves or by another person. Previous work has established that this paradigm elicits a robust self-reference effect, with more "self-owned" items being remembered than "other-owned" items. Access to attentional resources was manipulated using divided-attention tasks at encoding. A significant self-reference effect emerged under full-attention conditions and was related to an increase in episodic recollection for self-owned items, but dividing attention eliminated this memory advantage. These findings are discussed in relation to the nature of self-referential cognition and the importance of attentional resources at encoding in the manifestation of the self-reference effect in memory.

Effect of tranexamic acid on gross hematuria: A pilot randomized clinical trial study.

Science.gov (United States)

Moharamzadeh, Payman; Ojaghihaghighi, Seyedhossein; Amjadi, Mohsen; Rahmani, Farzad; Farjamnia, Arezoo

2017-12-01

Local forms of the tranexamic acid have been effective in treating many haemorrhagic cases. So that the aim of the current study is to assess the effectiveness of local tranexamic acid in controlling painless hematuria in patients referred to the emergency department. This is a randomized, double-blind clinical trial study, which was conducted on 50 patients with complaints of painless lower urinary tract bleeding during June 2014 and August 2015. The patients were randomly divided into two groups of 25 people each, one group receiving tranexamic acid and the other given a placebo. During bladder irrigation, local tranexamic acid and the placebo were injected into the bladder via Foley catheter. Patients were examined over 24h in terms of the amount of normal saline serum used for irrigation, level of hemoglobin, and blood in urine. In this study it was observed that consumption of tranexamic acid significantly decreased the volume of used serum for bladder irrigation (P=0.041) and the microscopic status of urine decreased significantly in terms of the hematuria after 24h (P=0.026). However, the rate of packed cell transfusion and drop in hemoglobin levels showed no significant difference in both groups of patients (P˃0.05). The results of this study showed that tranexamic acid could significantly reduce the volume of required serum for bladder irrigation to clear urine, but it had no significant effect on the drop in serum hemoglobin levels. Copyright © 2017 Elsevier Inc. All rights reserved.

Listening to the Noise: Random Fluctuations Reveal Gene Network Parameters

Science.gov (United States)

Munsky, Brian; Trinh, Brooke; Khammash, Mustafa

2010-03-01

The cellular environment is abuzz with noise originating from the inherent random motion of reacting molecules in the living cell. In this noisy environment, clonal cell populations exhibit cell-to-cell variability that can manifest significant prototypical differences. Noise induced stochastic fluctuations in cellular constituents can be measured and their statistics quantified using flow cytometry, single molecule fluorescence in situ hybridization, time lapse fluorescence microscopy and other single cell and single molecule measurement techniques. We show that these random fluctuations carry within them valuable information about the underlying genetic network. Far from being a nuisance, the ever-present cellular noise acts as a rich source of excitation that, when processed through a gene network, carries its distinctive fingerprint that encodes a wealth of information about that network. We demonstrate that in some cases the analysis of these random fluctuations enables the full identification of network parameters, including those that may otherwise be difficult to measure. We use theoretical investigations to establish experimental guidelines for the identification of gene regulatory networks, and we apply these guideline to experimentally identify predictive models for different regulatory mechanisms in bacteria and yeast.

Healing the Physical/Spiritual Divide through a Holistic and Hermeneutic Approach to Education

Science.gov (United States)

Webster, R. Scott

2013-01-01

In this special edition of the journal, attention is being given to the two dimensions of spirituality and physicality. In this particular paper I argue that there is an unhelpful divide that is often assumed to exist between these two dimensions and that this divide can be transcended or "healed" through a holistic and hermeneutic approach to…

Age-dependent impairment of auditory processing under spatially focused and divided attention: an electrophysiological study.

Science.gov (United States)

Wild-Wall, Nele; Falkenstein, Michael

2010-01-01

By using event-related potentials (ERPs) the present study examines if age-related differences in preparation and processing especially emerge during divided attention. Binaurally presented auditory cues called for focused (valid and invalid) or divided attention to one or both ears. Responses were required to subsequent monaurally presented valid targets (vowels), but had to be suppressed to non-target vowels or invalidly cued vowels. Middle-aged participants were more impaired under divided attention than young ones, likely due to an age-related decline in preparatory attention following cues as was reflected in a decreased CNV. Under divided attention, target processing was increased in the middle-aged, likely reflecting compensatory effort to fulfill task requirements in the difficult condition. Additionally, middle-aged participants processed invalidly cued stimuli more intensely as was reflected by stimulus ERPs. The results suggest an age-related impairment in attentional preparation after auditory cues especially under divided attention and latent difficulties to suppress irrelevant information.

Effects of aging and divided attention on recognition memory processes for single and associative information.

Science.gov (United States)

Kinjo, Hikari

2011-04-01

In the divided attention paradigm to test age-related associative memory deficits, whether the effects of divided attention occur at encoding or retrieval has not been clarified, and the effect on retention has not been studied. This study explored whether and how much divided attention at either encoding, retention, or retrieval diminished accuracy in recognizing a single feature (object or location) and associated features (object+location) by 23 elderly people (13 women; M age = 70.6 yr., SD = 2.8) recruited from a neighborhood community circle, and 29 female college students (M age = 20.8 yr., SD = 1.1). The results showed a significant decline in memory performance for both age groups due to divided attention in location and associative memory at retention, suggesting that the retention process demands attentional resources. Overall, regardless of their relative deficiency in associative memory, older adults showed an effect of divided attention comparable to that of younger adults in a recognition task.

Evaluation of Periodontal Ligament Cell Viability in Three Different Storage Media: An in Vitro Study

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Meenakshi Sharma

2016-01-01

Full Text Available Objectives: This study was undertaken to evaluate the viability of periodontal ligament (PDL cells of avulsed teeth in three different storage media.Materials and Methods: Forty-five premolars extracted for orthodontic therapeutic purposes were randomly and equally divided into three groups based on storage media used [Group I: milk (control; Group II: aloe vera (experimental; Group III: egg white (experimental]. Following extractions, the teeth were placed in one of the three different storage media for 30 minutes, following which the scrapings of the PDL from these teeth were collected in Falcon tubes containing collagenase enzyme in 2.5 mL of phosphate buffered saline. The tubes were subsequently incubated for 30 minutes and centrifuged for five minutes at 800 rpm. The obtained PDL cells were stained with Trypan Blue and were observed under optical microscope. The percentage of viable cells was calculated.Results: Aloe vera showed the highest percentage of viable cells (114.3±8.0, followed by egg white (100.9±6.3 and milk (101.1±7.3.Conclusion: Within the limitations of this study, it appears that aloe vera maintains PDL cell viability better than egg white or milk.

Differential reinforcement and resistance to change of divided-attention performance.

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Podlesnik, Christopher A; Thrailkill, Eric; Shahan, Timothy A

2012-06-01

Behavioral momentum theory provides a framework for understanding how conditions of reinforcement influence instrumental response strength under conditions of disruption (i.e., resistance to change). The present experiment examined resistance to change of divided-attention performance when different overall probabilities of reinforcement were arranged across two components of a multiple schedule. Pigeons responded in a delayed-matching-to-sample procedure with compound samples (color + line orientation) and element comparisons (two colors or two line orientations). Reinforcement ratios of 1:9, 1:1, and 9:1 for accurate matches on the two types of comparison trials were examined across conditions using reinforcement probabilities (color/lines) of .9/.1, .5/.5, and .1/.9 in the rich component and .18/.02, .1/.1, and .02/.18 in the lean component. Relative accuracy with color and line comparisons was an orderly function of relative reinforcement, but this relation did not depend on the overall rate of reinforcement between components. The resistance to change of divided-attention performance was greater for both trial types in the rich component with presession feeding and extinction, but not with decreases in sample duration. These findings suggest promise for the applicability of quantitative models of operant behavior to divided-attention performance, but they highlight the need to further explore conditions impacting the resistance to change of attending.

Simple Cell Balance Circuit

Science.gov (United States)

Johnson, Steven D.; Byers, Jerry W.; Martin, James A.

2012-01-01

A method has been developed for continuous cell voltage balancing for rechargeable batteries (e.g. lithium ion batteries). A resistor divider chain is provided that generates a set of voltages representing the ideal cell voltage (the voltage of each cell should be as if the cells were perfectly balanced). An operational amplifier circuit with an added current buffer stage generates the ideal voltage with a very high degree of accuracy, using the concept of negative feedback. The ideal voltages are each connected to the corresponding cell through a current- limiting resistance. Over time, having the cell connected to the ideal voltage provides a balancing current that moves the cell voltage very close to that ideal level. In effect, it adjusts the current of each cell during charging, discharging, and standby periods to force the cell voltages to be equal to the ideal voltages generated by the resistor divider. The device also includes solid-state switches that disconnect the circuit from the battery so that it will not discharge the battery during storage. This solution requires relatively few parts and is, therefore, of lower cost and of increased reliability due to the fewer failure modes. Additionally, this design uses very little power. A preliminary model predicts a power usage of 0.18 W for an 8-cell battery. This approach is applicable to a wide range of battery capacities and voltages.

Nuclear vlimata and aneuploidy in embryonic cells is caused by meiosis. Behaviour and properties of meiotic cells

OpenAIRE

Logothetou-Rella, H.

1995-01-01

This study demonstrates that human embryonic cells divide by meiosis. The use of trophoblastic tissue cells (early embryo) and amniotic cells (late embryo) exhibited the following characteristic events of meiosis: nuclear (NVs) and nucleolar (NuVs) vlimata formation; NV invasion in host cells; extrusion of chromosomes; nuclear fusion; metaphase fusion; hybrid cell formation; nuclear, nucleolar and cytoplasmic bridges, chromosomal transfer, variablesized nuc...

The Design and Characterization of a Prototype Wideband Voltage Sensor Based on a Resistive Divider.

Science.gov (United States)

Garnacho, Fernando; Khamlichi, Abderrahim; Rovira, Jorge

2017-11-17

The most important advantage of voltage dividers over traditional voltage transformers is that voltage dividers do not have an iron core with non-linear hysteresis characteristics. The voltage dividers have a linear behavior with respect to over-voltages and a flat frequency response larger frequency range. The weak point of a voltage divider is the influence of external high-voltage (HV) and earth parts in its vicinity. Electrical fields arising from high voltages in neighboring phases and from ground conductors and structures are one of their main sources for systematic measurement errors. This paper describes a shielding voltage divider for a 24 kV medium voltage network insulated in SF6 composed of two resistive-capacitive dividers, one integrated within the other, achieving a flat frequency response up to 10 kHz for ratio error and up to 5 kHz for phase displacement error. The metal shielding improves its immunity against electric and magnetic fields. The characterization performed on the built-in voltage sensor shows an accuracy class of 0.2 for a frequency range from 20 Hz to 5 kHz and a class of 0.5 for 1 Hz up to 20 Hz. A low temperature effect is also achieved for operation conditions of MV power grids.

Unobtrusive monitoring of divided attention in a cognitive health coaching intervention for the elderly.

Science.gov (United States)

McKanna, James A; Pavel, Misha; Jimison, Holly

2010-11-13

Assessment of cognitive functionality is an important aspect of care for elders. Unfortunately, few tools exist to measure divided attention, the ability to allocate attention to different aspects of tasks. An accurate determination of divided attention would allow inference of generalized cognitive decline, as well as providing a quantifiable indicator of an important component of driving skill. We propose a new method for determining relative divided attention ability through unobtrusive monitoring of computer use. Specifically, we measure performance on a dual-task cognitive computer exercise as part of a health coaching intervention. This metric indicates whether the user has the ability to pay attention to both tasks at once, or is primarily attending to one task at a time (sacrificing optimal performance). The monitoring of divided attention in a home environment is a key component of both the early detection of cognitive problems and for assessing the efficacy of coaching interventions.

A plant U-box protein, PUB4, regulates asymmetric cell division and cell proliferation in the root meristem

NARCIS (Netherlands)

Kinoshita, A.; Hove, ten C.A.; Tabata, R.; Yamada, M.; Shimizu, N.; Ishida, T.; Yamaguchi, K.; Shigenobu, S.; Takebayashi, Y.; Luchies, J.; Kobayashi, M.; Kurata, T.; Wada, T.; Seo, M.; Hasebe, M.; Blilou, I.; Fukuda, H.; Scheres, B.; Heidstra, R.; Kamiya, Y.; Sawa, S.

2015-01-01

The root meristem (RM) is a fundamental structure that is responsible for postembryonic root growth. The RM contains the quiescent center (QC), stem cells and frequently dividing meristematic cells, in which the timing and the frequency of cell division are tightly regulated. In Arabidopsis

Isoflurane Preconditioning Increases Survival of Rat Skin Random-Pattern Flaps by Induction of HIF-1α Expression

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Yu Sun

2013-04-01

Full Text Available Background: Survival of random-pattern skin flaps is important for the success of plastic and reconstructive surgeries. This study investigates isoflurane-induced protection against ischemia of skin flap and the underlying molecular mechanism in this process. Methods: Human umbilical vein endothelial cells (HUVECs and human skin fibroblast cells were exposed to isoflurane for 4 h. Expression of hypoxia inducible factor-1α (HIF-1α, heme oxygenase-1 (HO-1 and vascular endothelial growth factor (VEGF were analyzed up to 24 h post isoflurane exposure using qRT-PCR and western blot, or ELISA analyses. PI3K inhibitors - LY 294002 and wortmannin, mTOR inhibitor - rapamycin, and GSK3β inhibitor - SB 216763 were used respectively to assess the effects of isoflurane treatment and HIF-1α expression. Furthermore, 40 rats were randomly divided into 5 groups (control, isoflurane, scrambled siRNA plus isoflurane, HIF-1α siRNA plus isoflurane, and DMOG and subjected to random-pattern skin flaps operation. Rats were prepared for evaluation of flap survival and full-feld laser perfusion imager (FLPI (at 7 day and microvessel density evaluation (at 10 day. Results: Isoflurane exposure induced expression of HIF-1α protein, HO-1 and VEGF mRNA and proteins in a time-dependent manner. Both LY 294002 and wortmannin inhibited phospho-Akt, phospho-mTOR, phospho-GSK 3β and HIF-1α expression after isoflurane exposure. Both wortmannin and rapamycin inhibited isoflurane-induced phospho-4E-BP1 (Ser 65 and phospho-P70s6k (Thr 389 and HIF-1α expression. SB 216763 pre-treatment could further enhance isoflurane-induced expression of phospho-GSK 3β (Ser 9 and HIF-1α protein compared to the isoflurane-alone cells. In animal experiments, isoflurane alone, scrambled siRNA plus isoflurane, or DMOG groups had significantly upregulated vascularity and increased survival of the skin flaps compared to the controls. However, HIF-1α knockdown abrogated the protective effect of

Random access memory immune to single event upset using a T-resistor

Science.gov (United States)

Ochoa, Jr., Agustin

1989-01-01

In a random access memory cell, a resistance "T" decoupling network in each leg of the cell reduces random errors caused by the interaction of energetic ions with the semiconductor material forming the cell. The cell comprises two parallel legs each containing a series pair of complementary MOS transistors having a common gate connected to the node between the transistors of the opposite leg. The decoupling network in each leg is formed by a series pair of resistors between the transistors together with a third resistor interconnecting the junction between the pair of resistors and the gate of the transistor pair forming the opposite leg of the cell.

A CO-FISH assay to assess sister chromatid segregation patterns in mitosis of mouse embryonic stem cells.

Science.gov (United States)

Sauer, Stephan; Burkett, Sandra S; Lewandoski, Mark; Klar, Amar J S

2013-05-01

Sister chromatids contain identical DNA sequence but are chiral with respect to both their helical handedness and their replication history. Emerging evidence from various model organisms suggests that certain stem cells segregate sister chromatids nonrandomly to either maintain genome integrity or to bias cellular differentiation in asymmetric cell divisions. Conventional methods for tracing of old vs. newly synthesized DNA strands generally lack resolution for individual chromosomes and employ halogenated thymidine analogs with profound cytotoxic effects on rapidly dividing cells. Here, we present a modified chromosome orientation fluorescence in situ hybridization (CO-FISH) assay, where identification of individual chromosomes and their replication history is achieved in subsequent hybridization steps with chromosome-specific DNA probes and PNA telomere probes. Importantly, we tackle the issue of BrdU cytotoxicity and show that our method is compatible with normal mouse ES cell biology, unlike a recently published related protocol. Results from our CO-FISH assay show that mitotic segregation of mouse chromosome 7 is random in ES cells, which contrasts previously published results from our laboratory and settles a controversy. Our straightforward protocol represents a useful resource for future studies on chromatid segregation patterns of in vitro-cultured cells from distinct model organisms.

Umbilical Cord Mesenchymal Stem Cell Treatment for Crohn’s Disease: A Randomized Controlled Clinical Trial

Science.gov (United States)

Zhang, Jian; Lv, Samei; Liu, Xiaojing; Song, Bin; Shi, Liping

2018-01-01

Background/Aims Stem cell therapy has been applied to treat a variety of autoimmune diseases, including Crohn’s disease (CD), but few studies have examined the use of umbilical cord mesenchymal stem cells (UC-MSCs). This trial sought to investigate the efficacy and safety of UC-MSCs for the treatment of CD. Methods Eighty-two patients who had been diagnosed with CD and had received steroid maintenance therapy for more than 6 months were included in this study. Forty-one patients were randomly selected to receive a total of four peripheral intravenous infusions of 1×106 UC-MSCs/kg, with one infusion per week. Patients were followed up for 12 months. The Crohn’s disease activity index (CDAI), Harvey-Bradshaw index (HBI), and corticosteroid dosage were assessed. Results Twelve months after treatment, the CDAI, HBI, and corticosteroid dosage had decreased by 62.5±23.2, 3.4±1.2, and 4.2±0.84 mg/day, respectively, in the UC-MSC group and by 23.6±12.4, 1.2±0.58, and 1.2±0.35 mg/day, respectively, in the control group (pUC-MSC vs control, respectively). Four patients developed a fever after cell infusion. No serious adverse events were observed. Conclusions UC-MSCs were effective in the treatment of CD and produced mild side effects. PMID:28873511

Are divided attention tasks useful in the assessment and management of sport-related concussion?

Science.gov (United States)

Register-Mihalik, Johna K; Littleton, Ashley C; Guskiewicz, Kevin M

2013-12-01

This article is a systematic review of the literature on divided attention assessment inclusive of a cognitive and motor task (balance or gait) for use in concussion management. The systematic review drew from published papers listed in PubMed, MEDLINE, EMBASE and CINAHL databases. The search identified 19 empirical research papers meeting the inclusion criteria. Study results were considered for the psychometric properties of the paradigms, the influence of divided attention on measures of cognition and postural control and the comparison of divided attention task outcomes between individuals with concussion and healthy controls (all samples were age 17 years or older). The review highlights that the reliability of the tasks under a divided attention paradigm presented ranges from low to high (ICC: 0.1-0.9); however, only 3/19 articles included psychometric information. Response times are greater, gait strategies are less efficient, and postural control deficits are greater in concussed participants compared with healthy controls both immediately and for some period following concussive injury, specifically under divided attention conditions. Dual task assessments in some cases were more reliable than single task assessments and may be better able to detect lingering effects following concussion. Few of the studies have been replicated and applied across various age groups. A key limitation of these studies is that many include laboratory and time-intensive measures. Future research is needed to refine a time and cost efficient divided attention assessment paradigm, and more work is needed in younger (pre-teens) populations where the application may be of greatest utility.

Design of Compact Wilkinson Power Divider with Harmonic Suppression using T-Shaped Resonators

Science.gov (United States)

Siahkamari, Hesam; Yasoubi, Zahra; Jahanbakhshi, Maryam; Mousavi, Seyed Mohammad Hadi; Siahkamari, Payam; Nouri, Mohammad Ehsan; Azami, Sajad; Azadi, Rasoul

2018-04-01

A novel scheme of a shrunken Wilkinson power divider with harmonic suppression, using two identical resonators in the conventional Wilkinson power divider is designed. Moreover, the LC equivalent circuit and its relevant formulas are provided. To substantiate the functionality and soundness of design, a microstrip implementation of this design operating at 1 GHz with the second to eighth harmonic suppression, is developed. The proposed circuit is relatively smaller than the conventional circuit, (roughly 55% of the conventional circuit). Simulation and measurement results for the proposed scheme, which are highly consistent with one another, indicate a good insertion loss about 3.1 dB, input return loss of 20 dB and isolation of 20 dB, while sustaining high-power handling capability over the Wilkinson power divider.

SIW based multilayer transition and power divider in LTCC technology

KAUST Repository

Abuzaid, Hattan

2013-06-01

A multilayer transition and balanced power divider are presented for millimeter-wave system-on-package (SoP). These two components operate at Ka-band and exploit the substrate integrate waveguide (SIW) technology with its shielding characteristics and the Low-temperature co-fired ceramics (LTCC) technology for its high density integration. A coupling slot has been used to perform vertical integration, which can be easily optimized through its length. The measured input return loss within the bandwidth of interest (32 GHz-38 GHz) is less than -15 dB and -18 dB for the multilayer transition and the power divider, respectively. The lateral dimensions of a multilayer system, such as a feed network of an array, can be greatly reduced by employing these 3D slot-coupled components. © 2013 IEEE.

Parental health information seeking and re-exploration of the 'digital divide'.

Science.gov (United States)

Malone, Mary; While, Alison; Roberts, Julia

2014-04-01

To describe patterns of 'online' and 'offline' health information seeking in families with children under five years of age and living in five socially, economically and culturally disparate local authority (LA) wards in one inner-city area. Earlier work analysed data from the five LA wards merged as one data set. A 'digital divide' in health information seeking was identified between parents who actively sought information from both internet websites and from 14 other health information sources (online health information seekers), and those who acquired information from a more limited range of sources excluding the internet. Of the two groups, the online health information seekers had higher levels of computer ownership and, therefore, internet access within the home. Re-analysis of data (questionnaires n = 224; five focus groups; two interviews with service providers; two opportunistic conversations with service providers). Additional data were retrieved after the original data analysis and between 2005 and 2007. These data were from service user-led discussions (n = 30) held with parents in child health clinics, informal interviews (n = 11) with health visitors and semi-structured interviews (n = 2) with health visitors. Information was also retrieved from the Office for National Statistics data set. In the re-analysis, data were disaggregated at LA ward level in order to explore local influences on patterns of health information seeking. Multiple layers of influence upon parental health information seeking emerged and revealed a non-digital second divide, which was independent of computer ownership and home internet access. This divide was based on preference for use of certain health information sources, which might be either 'online' or 'offline'. A spatial patterning of both digital and preferential divides was identified with an association between each of these and features of the physical, social, cultural and psychosocial environment, one of which was

Peculiarities of the Digital Divide in Sub-Saharan Africa

Science.gov (United States)

Mutula, Stephen M.

2005-01-01

Purpose: Seeks to argue that the peculiarities of sub-Saharan Africa, in terms of its socio-cultural diversity, low economic development, linguistic factors, HIV/AIDS pandemic, gender discrimination, low ICT awareness and so on, demand a new model of addressing the digital divide. Design/methodology/approach: Paper largely based on literature…

Luteolin inhibits the colon cancer HT-29 cell proliferation, migration and epithelial-mesenchymal transition: an experimental study

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Xin Meng

2017-11-01

Full Text Available Objective: To study the regulating effect of luteolin on colon cancer HT-29 cell proliferation, migration and epithelial-mesenchymal transition. Methods: Colon cancer HT-29 cells were cultured and randomly divided into two groups, control group were treated with serum-free medium without drugs and LUT group were treated with serum-free medium containing luteolin. After 24 h of treatment, cells were collected to extract RNA, and then fluorescent quantitative PCR method was used to determine the mRNA expression of proliferation genes, migration genes and epithelial-mesenchymal transition genes. Results: After 24 h of luteolin treatment, Lrig1, TSPYL5, Bim, SOX15 and DLC1 mRNA expression in LUT group were significantly higher than those in control group while RPS15a, Bad, TRPV5, TRPV6, PLD2, IBP, SphK1, FAK, Vimentin and N-cadherin mRNA expression were significantly lower than those in control group. Conclusion: Luteolin has inhibiting effect on colon cancer HT-29 cell proliferation, migration and epithelial-mesenchymal transition.

Omcg1 is critically required for mitosis in rapidly dividing mouse intestinal progenitors and embryonic stem cells.

Science.gov (United States)

Léguillier, Teddy; Vandormael-Pournin, Sandrine; Artus, Jérôme; Houlard, Martin; Picard, Christel; Bernex, Florence; Robine, Sylvie; Cohen-Tannoudji, Michel

2012-07-15

Recent studies have shown that factors involved in transcription-coupled mRNA processing are important for the maintenance of genome integrity. How these processes are linked and regulated in vivo remains largely unknown. In this study, we addressed in the mouse model the function of Omcg1, which has been shown to participate in co-transcriptional processes, including splicing and transcription-coupled repair. Using inducible mouse models, we found that Omcg1 is most critically required in intestinal progenitors. In absence of OMCG1, proliferating intestinal epithelial cells underwent abnormal mitosis followed by apoptotic cell death. As a consequence, the crypt proliferative compartment of the small intestine was quickly and totally abrogated leading to the rapid death of the mice. Lack of OMCG1 in embryonic stem cells led to a similar cellular phenotype, with multiple mitotic defects and rapid cell death. We showed that mutant intestinal progenitors and embryonic stem cells exhibited a reduced cell cycle arrest following irradiation, suggesting that mitotic defects may be consecutive to M phase entry with unrepaired DNA damages. These findings unravel a crucial role for pre-mRNA processing in the homeostasis of the small intestine and point to a major role of OMCG1 in the maintenance of genome integrity.

Omcg1 is critically required for mitosis in rapidly dividing mouse intestinal progenitors and embryonic stem cells

Directory of Open Access Journals (Sweden)

Teddy Léguillier

2012-05-01

Recent studies have shown that factors involved in transcription-coupled mRNA processing are important for the maintenance of genome integrity. How these processes are linked and regulated in vivo remains largely unknown. In this study, we addressed in the mouse model the function of Omcg1, which has been shown to participate in co-transcriptional processes, including splicing and transcription-coupled repair. Using inducible mouse models, we found that Omcg1 is most critically required in intestinal progenitors. In absence of OMCG1, proliferating intestinal epithelial cells underwent abnormal mitosis followed by apoptotic cell death. As a consequence, the crypt proliferative compartment of the small intestine was quickly and totally abrogated leading to the rapid death of the mice. Lack of OMCG1 in embryonic stem cells led to a similar cellular phenotype, with multiple mitotic defects and rapid cell death. We showed that mutant intestinal progenitors and embryonic stem cells exhibited a reduced cell cycle arrest following irradiation, suggesting that mitotic defects may be consecutive to M phase entry with unrepaired DNA damages. These findings unravel a crucial role for pre-mRNA processing in the homeostasis of the small intestine and point to a major role of OMCG1 in the maintenance of genome integrity.

Brain activity during divided and selective attention to auditory and visual sentence comprehension tasks.

Science.gov (United States)

Moisala, Mona; Salmela, Viljami; Salo, Emma; Carlson, Synnöve; Vuontela, Virve; Salonen, Oili; Alho, Kimmo

2015-01-01

Using functional magnetic resonance imaging (fMRI), we measured brain activity of human participants while they performed a sentence congruence judgment task in either the visual or auditory modality separately, or in both modalities simultaneously. Significant performance decrements were observed when attention was divided between the two modalities compared with when one modality was selectively attended. Compared with selective attention (i.e., single tasking), divided attention (i.e., dual-tasking) did not recruit additional cortical regions, but resulted in increased activity in medial and lateral frontal regions which were also activated by the component tasks when performed separately. Areas involved in semantic language processing were revealed predominantly in the left lateral prefrontal cortex by contrasting incongruent with congruent sentences. These areas also showed significant activity increases during divided attention in relation to selective attention. In the sensory cortices, no crossmodal inhibition was observed during divided attention when compared with selective attention to one modality. Our results suggest that the observed performance decrements during dual-tasking are due to interference of the two tasks because they utilize the same part of the cortex. Moreover, semantic dual-tasking did not appear to recruit additional brain areas in comparison with single tasking, and no crossmodal inhibition was observed during intermodal divided attention.

Brain activity during divided and selective attention to auditory and visual sentence comprehension tasks

Science.gov (United States)

Moisala, Mona; Salmela, Viljami; Salo, Emma; Carlson, Synnöve; Vuontela, Virve; Salonen, Oili; Alho, Kimmo

2015-01-01

Using functional magnetic resonance imaging (fMRI), we measured brain activity of human participants while they performed a sentence congruence judgment task in either the visual or auditory modality separately, or in both modalities simultaneously. Significant performance decrements were observed when attention was divided between the two modalities compared with when one modality was selectively attended. Compared with selective attention (i.e., single tasking), divided attention (i.e., dual-tasking) did not recruit additional cortical regions, but resulted in increased activity in medial and lateral frontal regions which were also activated by the component tasks when performed separately. Areas involved in semantic language processing were revealed predominantly in the left lateral prefrontal cortex by contrasting incongruent with congruent sentences. These areas also showed significant activity increases during divided attention in relation to selective attention. In the sensory cortices, no crossmodal inhibition was observed during divided attention when compared with selective attention to one modality. Our results suggest that the observed performance decrements during dual-tasking are due to interference of the two tasks because they utilize the same part of the cortex. Moreover, semantic dual-tasking did not appear to recruit additional brain areas in comparison with single tasking, and no crossmodal inhibition was observed during intermodal divided attention. PMID:25745395

Versatile element for free-space dividing and redirecting neutral-atom clouds

International Nuclear Information System (INIS)

Arakelyan, I. V.; Chattrapiban, N.; Mitra, S.; Hill, W. T. III

2007-01-01

We introduce a tunnel lock that can be exploited to divide, delay, and alter the direction of traveling clouds of cold atoms. This versatile free-space element is implemented by crossing two atom tunnels formed by low-intensity, blue-detuned dark-hollow (Bessel mode) laser beams. We show that clouds of cold Rb atoms initially moving within one tunnel can be transferred to the other without heating by gating the intensities of the two tunnels--a tunnel lock--with an efficiency limited by the overlap volume. The element also can be used to divide a single cloud into smaller clouds, each having a distinct momentum

Divided attention and driving: a pilot study using virtual reality technology.

Science.gov (United States)

Lengenfelder, Jean; Schultheis, Maria T; Al-Shihabi, Talal; Mourant, Ronald; DeLuca, John

2002-02-01

Virtual reality (VR) was used to investigate the influence of divided attention (simple versus complex) on driving performance (speed control). Three individuals with traumatic brain injury (TBI) and three healthy controls (HC), matched for age, education, and gender, were examined. Preliminary results revealed no differences on driving speed between TBI and HC. In contrast, TBI subjects demonstrated a greater number of errors on a secondary task performed while driving. The findings suggest that VR may provide an innovative medium for direct evaluation of basic cognitive functions (ie, divided attention) and its impact on everyday tasks (ie, driving) not previously available through traditional neuropsychological measures.

Complex Systems Analysis of Cell Cycling Models in Carcinogenesis:II. Cell Genome and Interactome, Neoplastic Non-random Transformation Models in Topoi with Lukasiewicz-Logic and MV Algebras

CERN Document Server

Baianu, I C

2004-01-01

Quantitative Biology, abstract q-bio.OT/0406045 From: I.C. Baianu Dr. [view email] Date (v1): Thu, 24 Jun 2004 02:45:13 GMT (164kb) Date (revised v2): Fri, 2 Jul 2004 00:58:06 GMT (160kb) Complex Systems Analysis of Cell Cycling Models in Carcinogenesis: II. Authors: I.C. Baianu Comments: 23 pages, 1 Figure Report-no: CC04 Subj-class: Other Carcinogenesis is a complex process that involves dynamically inter-connected modular sub-networks that evolve under the influence of micro-environmentally induced perturbations, in non-random, pseudo-Markov chain processes. An appropriate n-stage model of carcinogenesis involves therefore n-valued Logic treatments of nonlinear dynamic transformations of complex functional genomes and cell interactomes. Lukasiewicz Algebraic Logic models of genetic networks and signaling pathways in cells are formulated in terms of nonlinear dynamic systems with n-state components that allow for the generalization of previous, Boolean or "fuzzy", logic models of genetic activities in vivo....

SIW based multilayer transition and power divider in LTCC technology

KAUST Repository

Abuzaid, Hattan; Doghri, Ali; Wu, Ke; Shamim, Atif

2013-01-01

A multilayer transition and balanced power divider are presented for millimeter-wave system-on-package (SoP). These two components operate at Ka-band and exploit the substrate integrate waveguide (SIW) technology with its shielding characteristics

Characterization of TLX expression in neural stem cells and progenitor cells in adult brains.

Science.gov (United States)

Li, Shengxiu; Sun, Guoqiang; Murai, Kiyohito; Ye, Peng; Shi, Yanhong

2012-01-01

TLX has been shown to play an important role in regulating the self-renewal and proliferation of neural stem cells in adult brains. However, the cellular distribution of endogenous TLX protein in adult brains remains to be elucidated. In this study, we used immunostaining with a TLX-specific antibody to show that TLX is expressed in both neural stem cells and transit-amplifying neural progenitor cells in the subventricular zone (SVZ) of adult mouse brains. Then, using a double thymidine analog labeling approach, we showed that almost all of the self-renewing neural stem cells expressed TLX. Interestingly, most of the TLX-positive cells in the SVZ represented the thymidine analog-negative, relatively quiescent neural stem cell population. Using cell type markers and short-term BrdU labeling, we demonstrated that TLX was also expressed in the Mash1+ rapidly dividing type C cells. Furthermore, loss of TLX expression dramatically reduced BrdU label-retaining neural stem cells and the actively dividing neural progenitor cells in the SVZ, but substantially increased GFAP staining and extended GFAP processes. These results suggest that TLX is essential to maintain the self-renewing neural stem cells in the SVZ and that the GFAP+ cells in the SVZ lose neural stem cell property upon loss of TLX expression. Understanding the cellular distribution of TLX and its function in specific cell types may provide insights into the development of therapeutic tools for neurodegenerative diseases by targeting TLX in neural stem/progenitors cells.

Comparing Young and Elderly Serial Reaction Time Task Performance on Repeated and Random Conditions

Directory of Open Access Journals (Sweden)

Fatemeh Ehsani

2012-07-01

Full Text Available Objectives: Acquisition motor skill training in elderly is at great importance. The main purpose of this study was to compare young and elderly performance in serial reaction time task on different repeated and random conditions. Methods & Materials: A serial reaction time task by using software was applied for studying motor learning in 30 young and 30 elderly. Each group divided randomly implicitly and explicitly into subgroups. A task 4 squares with different colors appeared on the monitor and subjects were asked to press its defined key immediately after observing it. Subjects practiced 8 motor blocks (4 repeated blocks, then 2 random blocks and 2 repeated blocks. Block time that was dependent variable measured and Independent-samples t- test with repeated ANOVA measures were used in this test. Results: young groups performed both repeated and random sequences significantly faster than elderly (P0.05. Explicit older subgroup performed 7,8 blocks slower than 6 block with a significant difference (P<0.05. Conclusion: Young adults discriminate high level performance than elderly in both repeated and random practice. Elderly performed random practice better than repeated practice.

Patient reported outcomes following stereotactic ablative radiotherapy or surgery for stage IA non-small-cell lung cancer : Results from the ROSEL multicenter randomized trial

NARCIS (Netherlands)

Louie, Alexander V.; van Werkhoven, Erik; Chen, Hanbo; Smit, Egbert F.; Paul, Marinus A.; Widder, Joachim; Groen, Harry J. M.; van den Borne, Ben E. E. M.; De Jaeger, Katrien; Slotman, Ben J.; Senan, Suresh

2015-01-01

We report quality of life and indirect costs from patient reported outcomes from the ROSEL randomized control trial comparing stereotactic ablative radiotherapy (SABR, also known as stereotactic body radiotherapy or SBRT) versus surgical resection for medically operable stage IA non-small cell lung

The random projection method

CERN Document Server

Vempala, Santosh S

2005-01-01

Random projection is a simple geometric technique for reducing the dimensionality of a set of points in Euclidean space while preserving pairwise distances approximately. The technique plays a key role in several breakthrough developments in the field of algorithms. In other cases, it provides elegant alternative proofs. The book begins with an elementary description of the technique and its basic properties. Then it develops the method in the context of applications, which are divided into three groups. The first group consists of combinatorial optimization problems such as maxcut, graph coloring, minimum multicut, graph bandwidth and VLSI layout. Presented in this context is the theory of Euclidean embeddings of graphs. The next group is machine learning problems, specifically, learning intersections of halfspaces and learning large margin hypotheses. The projection method is further refined for the latter application. The last set consists of problems inspired by information retrieval, namely, nearest neig...

Digital Divide among Youth: Socio-Cultural Factors and Implications

Science.gov (United States)

Parycek, Peter; Sachs, Michael; Schossbock, Judith

2011-01-01

Purpose: This paper aims to examine socio-cultural differences in internet use (Digital Divide) among 14-year-old Austrian pupils, in particular usage scenarios and research competences. It is based on a paper presented at the International Association for the Development of the Information Society e-Society conference, 10-13 March 2011, Spain…

Determinants of Internet skills, use and outcomes : A systematic review of the second- and third-level digital divide

NARCIS (Netherlands)

Scheerder, Anique; van Deursen, Alexander; van Dijk, Jan

2017-01-01

Recently, several digital divide scholars suggested that a shift is needed from a focus on binary Internet access (first-level digital divide) and Internet skills and use (second-level digital divide) to a third-level digital divide in which the tangible outcomes of Internet use are highlighted. A

The Digital Divide

Science.gov (United States)

Hudson, Hannah Trierweiler

2011-01-01

Megan is a 14-year-old from Nebraska who just started ninth grade. She has her own digital camera, cell phone, Nintendo DS, and laptop, and one or more of these devices is usually by her side. Compared to the interactions and exploration she's engaged in at home, Megan finds the technology in her classroom falls a little flat. Most of the…

Coping with divided attention: the advantage of familiarity.

OpenAIRE

Griffiths, S. W.; Brockmark, S.; Höjesjö, J.; Johnsson, J. I.

2004-01-01

The ability of an animal to perform a task successfully is limited by the amount of attention being simultaneously focused on other activities. One way in which individuals might reduce the cost of divided attention is by preferentially focusing on the most beneficial tasks. In territorial animals where aggression is lower among familiar individuals, the decision to associate preferentially with familiar conspecifics may therefore confer advantages by allowing attention to be switched from ag...

Modulation of electromagnetic fields by a depolarizer of random polarizer array

DEFF Research Database (Denmark)

Ma, Ning; Hanson, Steen Grüner; Wang, Wei

2016-01-01

The statistical properties of the electric fields with random changes of the polarization state in space generated by a depolarizer are investigated on the basis of the coherence matrix. The depolarizer is a polarizer array composed of a multitude of contiguous square cells of polarizers with ran......The statistical properties of the electric fields with random changes of the polarization state in space generated by a depolarizer are investigated on the basis of the coherence matrix. The depolarizer is a polarizer array composed of a multitude of contiguous square cells of polarizers...... with randomly distributed polarization angles, where the incident fields experience a random polarization modulation after passing through the depolarizer. The propagation of the modulated electric fields through any quadratic optical system is examined within the framework of the complex ABCD matrix to show...

Internet use and the digital divide in the English longitudinal study of ageing.

Science.gov (United States)

Gilleard, Chris; Higgs, Paul

2008-09-01

This paper examines the digital divide in Internet use in later life. We hypothesise that the differential diffusion of domestic information and communication technologies between pre- and post-Second World War cohorts is primarily responsible for this divide rather than either age-associated structural inequalities or age-related intrinsic features of mental and/or physical infirmity. Using data from the English Longitudinal Study of Ageing we show that age/cohort differences in Internet use persist after income, education, employment and health status are controlled for. However, when engagement with domestic information and communication technology and cultural activities are taken into account, age/cohort influences on Internet use decline. These contingent 'age/cohort' effects suggest that 'generational' rather than 'structural' or 'stage of life' influences may be more salient explanations of the (age-based) digital divide.

Measuring and Bridging the Gender Digital Divide in Rural Pakistan ...

International Development Research Centre (IDRC) Digital Library (Canada)

Measuring and Bridging the Gender Digital Divide in Rural Pakistan ... to critically examining the gender-specific aspects of ICT use and its impact on development in ... In partnership with UNESCO's Organization for Women in Science for the ...

Reduction of Musical Noise in Spectral Subtraction Method Using Subframe Phase Randomization

Energy Technology Data Exchange (ETDEWEB)

Seok, J.W.; Bae, K.S. [Kyungpook National University, Taegu (Korea)

1999-06-01

The Subframe phase randomization method is applied to the spectral subtraction method to reduce the musical noise in nonvoicing region after speech enhancement. The musical noise in the spectral subtraction method is the result of the narrowband tonal components that appearing somewhat periodically in the spectrogram of unvoiced and silence regions. Thus each synthesis frame in nonvoicing region is divided into several subframes to broaden the narrowband spectrum, and then phases of silence and unvoiced regions are randomized to eliminate the tonal components in the spectrum while keeping the shape of the amplitude spectrum. Performance assessments based on visual inspection of spectrogram, objective measure, and informal subjective listening tests demonstrate the superiority of the proposed algorithm. (author). 7 refs., 5 figs.

The simulation model of growth and cell divisions for the root apex with an apical cell in application to Azolla pinnata.

Science.gov (United States)