WorldWideScience

Sample records for stronger crowding effects

  1. Crowding effects in vehicular traffic.

    Directory of Open Access Journals (Sweden)

    Jay Samuel L Combinido

    Full Text Available While the impact of crowding on the diffusive transport of molecules within a cell is widely studied in biology, it has thus far been neglected in traffic systems where bulk behavior is the main concern. Here, we study the effects of crowding due to car density and driving fluctuations on the transport of vehicles. Using a microscopic model for traffic, we found that crowding can push car movement from a superballistic down to a subdiffusive state. The transition is also associated with a change in the shape of the probability distribution of positions from a negatively-skewed normal to an exponential distribution. Moreover, crowding broadens the distribution of cars' trap times and cluster sizes. At steady state, the subdiffusive state persists only when there is a large variability in car speeds. We further relate our work to prior findings from random walk models of transport in cellular systems.

  2. Effects of macromolecular crowding on protein conformational changes.

    Directory of Open Access Journals (Sweden)

    Hao Dong

    2010-07-01

    Full Text Available Many protein functions can be directly linked to conformational changes. Inside cells, the equilibria and transition rates between different conformations may be affected by macromolecular crowding. We have recently developed a new approach for modeling crowding effects, which enables an atomistic representation of "test" proteins. Here this approach is applied to study how crowding affects the equilibria and transition rates between open and closed conformations of seven proteins: yeast protein disulfide isomerase (yPDI, adenylate kinase (AdK, orotidine phosphate decarboxylase (ODCase, Trp repressor (TrpR, hemoglobin, DNA beta-glucosyltransferase, and Ap(4A hydrolase. For each protein, molecular dynamics simulations of the open and closed states are separately run. Representative open and closed conformations are then used to calculate the crowding-induced changes in chemical potential for the two states. The difference in chemical-potential change between the two states finally predicts the effects of crowding on the population ratio of the two states. Crowding is found to reduce the open population to various extents. In the presence of crowders with a 15 A radius and occupying 35% of volume, the open-to-closed population ratios of yPDI, AdK, ODCase and TrpR are reduced by 79%, 78%, 62% and 55%, respectively. The reductions for the remaining three proteins are 20-44%. As expected, the four proteins experiencing the stronger crowding effects are those with larger conformational changes between open and closed states (e.g., as measured by the change in radius of gyration. Larger proteins also tend to experience stronger crowding effects than smaller ones [e.g., comparing yPDI (480 residues and TrpR (98 residues]. The potentials of mean force along the open-closed reaction coordinate of apo and ligand-bound ODCase are altered by crowding, suggesting that transition rates are also affected. These quantitative results and qualitative trends will

  3. Crowdedness Mediates the Effect of Social Identification on Positive Emotion in a Crowd: A Survey of Two Crowd Events

    Science.gov (United States)

    Novelli, David; Drury, John; Reicher, Stephen; Stott, Clifford

    2013-01-01

    Exposure to crowding is said to be aversive, yet people also seek out and enjoy crowded situations. We surveyed participants at two crowd events to test the prediction of self-categorization theory that variable emotional responses to crowding are a function of social identification with the crowd. In data collected from participants who attended a crowded outdoor music event (n = 48), identification with the crowd predicted feeling less crowded; and there was an indirect effect of identification with the crowd on positive emotion through feeling less crowded. Identification with the crowd also moderated the relation between feeling less crowded and positive emotion. In data collected at a demonstration march (n = 112), identification with the crowd predicted central (most dense) location in the crowd; and there was an indirect effect of identification with the crowd on positive emotion through central location in the crowd. Positive emotion in the crowd also increased over the duration of the crowd event. These findings are in line with the predictions of self-categorization theory. They are inconsistent with approaches that suggest that crowding is inherently aversive; and they cannot easily be explained through the concept of ‘personal space’. PMID:24236079

  4. Crowdedness mediates the effect of social identification on positive emotion in a crowd: a survey of two crowd events.

    Directory of Open Access Journals (Sweden)

    David Novelli

    Full Text Available Exposure to crowding is said to be aversive, yet people also seek out and enjoy crowded situations. We surveyed participants at two crowd events to test the prediction of self-categorization theory that variable emotional responses to crowding are a function of social identification with the crowd. In data collected from participants who attended a crowded outdoor music event (n = 48, identification with the crowd predicted feeling less crowded; and there was an indirect effect of identification with the crowd on positive emotion through feeling less crowded. Identification with the crowd also moderated the relation between feeling less crowded and positive emotion. In data collected at a demonstration march (n = 112, identification with the crowd predicted central (most dense location in the crowd; and there was an indirect effect of identification with the crowd on positive emotion through central location in the crowd. Positive emotion in the crowd also increased over the duration of the crowd event. These findings are in line with the predictions of self-categorization theory. They are inconsistent with approaches that suggest that crowding is inherently aversive; and they cannot easily be explained through the concept of 'personal space'.

  5. Associative Interactions in Crowded Solutions of Biopolymers Counteract Depletion Effects.

    Science.gov (United States)

    Groen, Joost; Foschepoth, David; te Brinke, Esra; Boersma, Arnold J; Imamura, Hiromi; Rivas, Germán; Heus, Hans A; Huck, Wilhelm T S

    2015-10-14

    The cytosol of Escherichia coli is an extremely crowded environment, containing high concentrations of biopolymers which occupy 20-30% of the available volume. Such conditions are expected to yield depletion forces, which strongly promote macromolecular complexation. However, crowded macromolecule solutions, like the cytosol, are very prone to nonspecific associative interactions that can potentially counteract depletion. It remains unclear how the cytosol balances these opposing interactions. We used a FRET-based probe to systematically study depletion in vitro in different crowded environments, including a cytosolic mimic, E. coli lysate. We also studied bundle formation of FtsZ protofilaments under identical crowded conditions as a probe for depletion interactions at much larger overlap volumes of the probe molecule. The FRET probe showed a more compact conformation in synthetic crowding agents, suggesting strong depletion interactions. However, depletion was completely negated in cell lysate and other protein crowding agents, where the FRET probe even occupied slightly more volume. In contrast, bundle formation of FtsZ protofilaments proceeded as readily in E. coli lysate and other protein solutions as in synthetic crowding agents. Our experimental results and model suggest that, in crowded biopolymer solutions, associative interactions counterbalance depletion forces for small macromolecules. Furthermore, the net effects of macromolecular crowding will be dependent on both the size of the macromolecule and its associative interactions with the crowded background.

  6. The contrasting effect of macromolecular crowding on amyloid fibril formation.

    Directory of Open Access Journals (Sweden)

    Qian Ma

    Full Text Available Amyloid fibrils associated with neurodegenerative diseases can be considered biologically relevant failures of cellular quality control mechanisms. It is known that in vivo human Tau protein, human prion protein, and human copper, zinc superoxide dismutase (SOD1 have the tendency to form fibril deposits in a variety of tissues and they are associated with different neurodegenerative diseases, while rabbit prion protein and hen egg white lysozyme do not readily form fibrils and are unlikely to cause neurodegenerative diseases. In this study, we have investigated the contrasting effect of macromolecular crowding on fibril formation of different proteins.As revealed by assays based on thioflavin T binding and turbidity, human Tau fragments, when phosphorylated by glycogen synthase kinase-3β, do not form filaments in the absence of a crowding agent but do form fibrils in the presence of a crowding agent, and the presence of a strong crowding agent dramatically promotes amyloid fibril formation of human prion protein and its two pathogenic mutants E196K and D178N. Such an enhancing effect of macromolecular crowding on fibril formation is also observed for a pathological human SOD1 mutant A4V. On the other hand, rabbit prion protein and hen lysozyme do not form amyloid fibrils when a crowding agent at 300 g/l is used but do form fibrils in the absence of a crowding agent. Furthermore, aggregation of these two proteins is remarkably inhibited by Ficoll 70 and dextran 70 at 200 g/l.We suggest that proteins associated with neurodegenerative diseases are more likely to form amyloid fibrils under crowded conditions than in dilute solutions. By contrast, some of the proteins that are not neurodegenerative disease-associated are unlikely to misfold in crowded physiological environments. A possible explanation for the contrasting effect of macromolecular crowding on these two sets of proteins (amyloidogenic proteins and non-amyloidogenic proteins has been

  7. Modulation of calmodulin plasticity by the effect of macromolecular crowding.

    Science.gov (United States)

    Homouz, Dirar; Sanabria, Hugo; Waxham, M Neal; Cheung, Margaret S

    2009-09-04

    In vitro biochemical reactions are most often studied in dilute solution, a poor mimic of the intracellular space of eukaryotic cells, which are crowded with mobile and immobile macromolecules. Such crowded conditions exert volume exclusion and other entropic forces that have the potential to impact chemical equilibria and reaction rates. In this article, we used the well-characterized and ubiquitous molecule calmodulin (CaM) and a combination of theoretical and experimental approaches to address how crowding impacts CaM's conformational plasticity. CaM is a dumbbell-shaped molecule that contains four EF hands (two in the N-lobe and two in the C-lobe) that each could bind Ca(2+), leading to stabilization of certain substates that favor interactions with other target proteins. Using coarse-grained molecular simulations, we explored the distribution of CaM conformations in the presence of crowding agents. These predictions, in which crowding effects enhance the population of compact structures, were then confirmed in experimental measurements using fluorescence resonance energy transfer techniques of donor- and acceptor-labeled CaM under normal and crowded conditions. Using protein reconstruction methods, we further explored the folding-energy landscape and examined the structural characteristics of CaM at free-energy basins. We discovered that crowding stabilizes several different compact conformations, which reflects the inherent plasticity in CaM's structure. From these results, we suggest that the EF hands in the C-lobe are flexible and can be thought of as a switch, while those in the N-lobe are stiff, analogous to a rheostat. New combinatorial signaling properties may arise from the product of the differential plasticity of the two distinct lobes of CaM in the presence of crowding. We discuss the implications of these results for modulating CaM's ability to bind Ca(2+) and target proteins.

  8. Two's a crowd? Crowding effect in a parasitic castrator drives differences in reproductive resource allocation in single vs double infections.

    Science.gov (United States)

    Fong, Caitlin R; Moron, Nancy A; Kuris, Armand M

    2017-04-01

    The 'crowding effect' is a result of competition by parasites within a host for finite resources. Typically, the severity of this effect increases with increasing numbers of parasites within a host and manifests in reduced body size and thus fitness. Evidence for the crowding effect is mixed - while some have found negative effects, others have found a positive effect of increased parasite load on parasite fitness. Parasites are consumers with diverse trophic strategies reflected in their life history traits. These distinctions are useful to predict the effects of crowding. We studied a parasitic castrator, a parasite that usurps host reproductive energy and renders the host sterile. Parasitic castrators typically occur as single infections within hosts. With multiple parasitic castrators, we expect strong competition and evidence of crowding. We directly assess the effect of crowding on reproductive success in a barnacle population infected by a unique parasitic castrator, Hemioniscus balani, an isopod parasite that infects and blocks reproduction of barnacles. We find (1) strong evidence of crowding in double infections, (2) increased frequency of double infections in larger barnacle hosts with more resources and (3) perfect compensation in egg production, supporting strong space limitation. Our results document that the effects of crowding are particularly severe for this parasitic castrator, and may be applicable to other castrators that are also resource or space limited.

  9. The Crowding out Effect on the Labor Market in Romania

    Directory of Open Access Journals (Sweden)

    Mihaela Hrisanta DOBRE

    2011-01-01

    Full Text Available Discrimination expresses any distinction, exclusion, restriction, preference or different treatment that disadvantages a person or group, in comparison with others in similar situations. The crowding out effect was first formulated by Bergmann (1974 and explains that an individual can obtain lower returns if he belongs to a branch dominated by the members of another group. The difference in pay between women and men is also reinforced by the segregation in the labor market, which may explain the crowding out effect. In this article we analyzed the level of segregation in the Romanian labor market starting from the workers professional status and their distribution by branch from 2003 to 2008. Crowding out effect was analyzed based on the gain function of the two groups (women and men.

  10. How social influence can undermine the wisdom of crowd effect

    Science.gov (United States)

    Lorenz, Jan; Rauhut, Heiko; Schweitzer, Frank; Helbing, Dirk

    2011-01-01

    Social groups can be remarkably smart and knowledgeable when their averaged judgements are compared with the judgements of individuals. Already Galton [Galton F (1907) Nature 75:7] found evidence that the median estimate of a group can be more accurate than estimates of experts. This wisdom of crowd effect was recently supported by examples from stock markets, political elections, and quiz shows [Surowiecki J (2004) The Wisdom of Crowds]. In contrast, we demonstrate by experimental evidence (N = 144) that even mild social influence can undermine the wisdom of crowd effect in simple estimation tasks. In the experiment, subjects could reconsider their response to factual questions after having received average or full information of the responses of other subjects. We compare subjects’ convergence of estimates and improvements in accuracy over five consecutive estimation periods with a control condition, in which no information about others’ responses was provided. Although groups are initially “wise,” knowledge about estimates of others narrows the diversity of opinions to such an extent that it undermines the wisdom of crowd effect in three different ways. The “social influence effect” diminishes the diversity of the crowd without improvements of its collective error. The “range reduction effect” moves the position of the truth to peripheral regions of the range of estimates so that the crowd becomes less reliable in providing expertise for external observers. The “confidence effect” boosts individuals’ confidence after convergence of their estimates despite lack of improved accuracy. Examples of the revealed mechanism range from misled elites to the recent global financial crisis. PMID:21576485

  11. Social identification moderates the effect of crowd density on safety at the Hajj.

    Science.gov (United States)

    Alnabulsi, Hani; Drury, John

    2014-06-24

    Crowd safety is a major concern for those attending and managing mass gatherings, such as the annual Hajj or pilgrimage to Mecca (also called Makkah). One threat to crowd safety at such events is crowd density. However, recent research also suggests that psychological membership of crowds can have positive benefits. We tested the hypothesis that the effect of density on safety might vary depending on whether there is shared social identification in the crowd. We surveyed 1,194 pilgrims at the Holy Mosque, Mecca, during the 2012 Hajj. Analysis of the data showed that the negative effect of crowd density on reported safety was moderated by social identification with the crowd. Whereas low identifiers reported reduced safety with greater crowd density, high identifiers reported increased safety with greater crowd density. Mediation analysis suggested that a reason for these moderation effects was the perception that other crowd members were supportive. Differences in reported safety across national groups (Arab countries and Iran compared with the rest) were also explicable in terms of crowd identification and perceived support. These findings support a social identity account of crowd behavior and offer a novel perspective on crowd safety management.

  12. The effect of music tempo on perceived crowding in retailing

    OpenAIRE

    Fiksdal, Taisiya; Hua, Wen

    2016-01-01

    Masteroppgave(MSc) in Master of Science in Strategic Marketing Management - Handelshøyskolen BI, 2016 In the marketing field the influence of in-store atmospherics on consumers’ shopping behavior is widely accepted. We seek to understand the effects of instore music tempo on perceived crowding and how music tempo can affect emotions, arousal and perceived control occurring in retail stores. Hence, our research questions are the following: Does music tempo influence the perce...

  13. The Behavioral Effects of Crowding: Definitions and Methods.

    Science.gov (United States)

    Dean, Larry M.; And Others

    1978-01-01

    Crews of 18 U.S. Navy combat vessels rated their living and working conditions aboard ship, including degree of crowding. Three different types of measures corresponding to different definitions of crowding were constructed. These separate crowding measures correlated uniquely with satisfaction and illness criteria. (Author/MA)

  14. A behavioral economics perspective on the overjustification effect: Crowding-in and crowding-out of intrinsic motivation.

    OpenAIRE

    Weibel, Antoinette; Wiemann, Meike; Osterloh, Margit

    2014-01-01

    In the last two decades, economic motivation research has undergone a paradigm shift when it comes to the effect of incentive schemes on individual performance and motivation. Inspired by self-determination theory, a new branch in economics evolved called behavioral economics. Especially by evidencing the negative effect of “pay-for-performance” on intrinsic motivation, called the “crowding-out” or “overjustification” effect, it challenges the economic paradigm of the relative price-effect an...

  15. Effect of form of obstacle on speed of crowd evacuation

    Science.gov (United States)

    Yano, Ryosuke

    2018-03-01

    This paper investigates the effect of the form of an obstacle on the time that a crowd takes to evacuate a room, using a toy model. Pedestrians are modeled as active soft matter moving toward a point with intended velocities. An obstacle is placed in front of the exit, and it has one of four shapes: a cylindrical column, a triangular prism, a quadratic prism, or a diamond prism. Numerical results indicate that the evacuation-completion time depends on the shape of the obstacle. Obstacles with a circular cylinder (C.C.) shape yield the shortest evacuation-completion time in the proposed model.

  16. Effects of Soundscapes on Perceived Crowding and Encounter Norms

    Science.gov (United States)

    Kim, Sang-Oh; Shelby, Bo

    2011-07-01

    Soundscapes in recreation settings are becoming an important issue, but there are few studies of the effects of sounds on recreation experiences, especially crowding perceptions and encounter norms. This study compared effects of six types of sounds (an airplane, a truck engine, children playing, birds, water, and a control) on perceived crowding (PC) and encounter norms for hikers. Data were collected from 47 college students through lab experiments using simulated images, with moving hikers inserted in the original photo taken in the Jungmeori area of Mudeungsan Provincial Park in Korea. Overall, the motor-made sounds of the airplane and truck engine increased PC and decreased acceptability ratings, and the natural sounds of birds and water decreased PC and increased acceptability ratings. Ratings of the sound of children playing were similar to those in the control (i.e., no sound). In addition, as numbers of hikers increased, the overall effects of sounds decreased, and there were few significant differences in PC or acceptability ratings at the highest encounter levels. Theoretical and methodological implications are discussed.

  17. Effective and Innovative Practices for Stronger Facilities Management.

    Science.gov (United States)

    Banick, Sarah

    2002-01-01

    Describes the five winners of the APPA's Effective & Innovative Practices Award. These facilities management programs and processes were recognized for enhancing service delivery, lowering costs, increasing productivity, improving customer service, generating revenue, or otherwise benefiting the educational institution. (EV)

  18. Effect of Households' Socio-Economic Condition on Crowding in ...

    African Journals Online (AJOL)

    The results indicate a preponderance of gentrification, with attendant policy implications. The results also show that there is no significant difference in the degree of crowding among the different socio-economic classifications. This is inconsistent with the generally held understanding in urban housing studies that crowding ...

  19. Stability analysis of predator-prey interaction with a crowding effect ...

    African Journals Online (AJOL)

    The mathematical modeling of species interactions usually relies on competition models. However, it is known that species interactions may exhibit more complicated patterns with a crowding effect and this can be particularly important in benign environments. In this paper we discuss competition models with a crowding ...

  20. Nonlinear Effects in Examples of Crowd Evacuation Scenarios

    DEFF Research Database (Denmark)

    Starke, Jens; Berg Thomsen, Kristian; Sørensen, Asger

    2014-01-01

    Severe accidents with many fatalities have occurred when too many pedestrians had to maneuver in too tight surroundings, as during evacuations of mass events. This demonstrates the importance of a better general understanding of pedestrians and emergent complex behavior in crowds. To this end, we...

  1. Social dynamics in emergency evacuations: Disentangling crowd's attraction and repulsion effects

    Science.gov (United States)

    Haghani, Milad; Sarvi, Majid

    2017-06-01

    The social dynamics of crowds in emergency escape scenarios have been conventionally modelled as the net effect of virtual forces exerted by the crowd on each individual (as self-driven particles), with the magnitude of the influence formulated as decreasing functions of inter-individual distances and the direction of effect assumed to be transitioning from repulsion to attraction by distance. Here, we revisit this conventional assumption using laboratory experimental data. We show based on robust econometric hypothesis-testing methods that individuals' perception of other escapees differs based on whether those individuals are jamming around exit destinations or are on the move towards the destinations. Also, for moving crowds, it differs based on whether the escape destination chosen by the moving flow is visible or invisible to the individual. The presence of crowd jams around a destination, also the movement of crowd flows towards visible destinations are both perceived on average as repulsion (or disutility) effects (with the former showing significantly larger magnitude than the latter). The movement of crowd flows towards an invisible destination, however, is on average perceived as attraction (or utility) effect. Yet, further hypothesis testing showed that neither of those effects in isolation determines adequately whether an individual would merge with or diverge from the crowd. Rather, the social interaction factors act (at significant levels) in conjunction with the physical factors of the environments (including spatial distances to exit destinations and destinations' visibility). In brief, our finding disentangles the conditions under which individuals are more likely to show mass behaviour from the situations where they are more likely to break from the herd. It identifies two factors that moderate the perception of social interactions, ;crowds' jam/movement status; and ;environmental setup;. Our results particularly challenge the taxonomy of

  2. Intracellular crowding effects on the self-association of the bacterial cell division protein FtsZ.

    Science.gov (United States)

    Naddaf, Lamis; Sayyed-Ahmad, Abdallah

    2014-12-15

    The dimerization rate of the bacterial cell division protein FtsZ is strongly affected by the intracellular crowding. Yet the complexity of the intracellular environment makes it difficult to investigate via all-atom molecular dynamics or other detailed theoretical methods. We study the crowding effect on FtsZ dimerization which is the first step of an oligomerization process that results in more elaborate supramolecular structures. In particular, we consider the effect of intracellular crowding on the reaction rates, and their dependence on the different concentrations of crowding agents. We achieved this goal by using Brownian dynamics (BD) simulation techniques and a modified post-processing approach in which we decompose the rate constant in crowded media as a product of the rate constant in the dilute solution times a factor that incorporates the crowding effect. The latter factor accounts for the diffusion reduction and crowder induced energy. In addition we include the crowding effects on water viscosity in the BD simulations of crowded media. We finally show that biomolecular crowding has a considerable effect on the FtsZ dimerization by increasing the dimerization rate constant from 2.6×10(7)M(-1)s(-1) in the absence of crowders to 1.0×10(8)M(-1)s(-1) at crowding level of 0.30. Copyright © 2014 Elsevier Inc. All rights reserved.

  3. The Crowd in Mind and Crowded Minds: An Experimental Investigation of Crowding Effects on Students' Views Regarding Tuition Fees in Germany

    Science.gov (United States)

    Hellmann, Jens H.; Jucks, Regina

    2017-01-01

    In higher education, just amounts of tuition fees are often a topic of heated debate among different groups such as students, university teachers, administrative staff, and policymakers. We investigated whether unpleasant situations that students often experience at university due to social crowding can affect students' views on the justified…

  4. A simple quantitative model of macromolecular crowding effects on protein folding: Application to the murine prion protein(121-231)

    Science.gov (United States)

    Bergasa-Caceres, Fernando; Rabitz, Herschel A.

    2013-06-01

    A model of protein folding kinetics is applied to study the effects of macromolecular crowding on protein folding rate and stability. Macromolecular crowding is found to promote a decrease of the entropic cost of folding of proteins that produces an increase of both the stability and the folding rate. The acceleration of the folding rate due to macromolecular crowding is shown to be a topology-dependent effect. The model is applied to the folding dynamics of the murine prion protein (121-231). The differential effect of macromolecular crowding as a function of protein topology suffices to make non-native configurations relatively more accessible.

  5. Predatory blue crabs induce stronger nonconsumptive effects in eastern oysters Crassostrea virginica than scavenging blue crabs

    Directory of Open Access Journals (Sweden)

    Avery E. Scherer

    2017-02-01

    Full Text Available By influencing critical prey traits such as foraging or habitat selection, predators can affect entire ecosystems, but the nature of cues that trigger prey reactions to predators are not well understood. Predators may scavenge to supplement their energetic needs and scavenging frequency may vary among individuals within a species due to preferences and prey availability. Yet prey reactions to consumers that are primarily scavengers versus those that are active foragers have not been investigated, even though variation in prey reactions to scavengers or predators might influence cascading nonconsumptive effects in food webs. Oysters Crassostrea virginica react to crab predators by growing stronger shells. We exposed oysters to exudates from crabs fed live oysters or fed aged oyster tissue to simulate scavenging, and to controls without crab cues. Oysters grew stronger shells when exposed to either crab exudate, but their shells were significantly stronger when crabs were fed live oysters. The stronger response to predators than scavengers could be due to inherent differences in diet cues representative of reduced risk in the presence of scavengers or to degradation of conspecific alarm cues in aged treatments, which may mask risk from potential predators subsisting by scavenging.

  6. Double Crowding-Out Effects of Means-Tested Public Provision for Long-Term Care

    Directory of Open Access Journals (Sweden)

    Christophe Courbage

    2015-02-01

    Full Text Available Publicly provided long-term care (LTC insurance with means-tested benefits is suspected to crowd out either private saving or informal care. This contribution predicts crowding-out effects for both private saving and informal care for policy measures designed to relieve the public purse from LTC expenditure such as more stringent means testing and increased taxation of inheritance. These effects result from the interaction of a parent who decides on the amount of saving in retirement and a caregiver who decides on the effort devoted to informal care which lowers the probability of admission to a nursing home. Double crowding-out effects are also found to be the consequence of exogenous influences, notably a higher opportunity cost of caregiving.

  7. Accelerated recovery of Atlantic salmon (Salmo salar) from effects of crowding by swimming.

    Science.gov (United States)

    Veiseth, Eva; Fjaera, Svein Olav; Bjerkeng, Bjørn; Skjervold, Per Olav

    2006-07-01

    The effects of post-crowding swimming velocity (0, 0.35, and 0.70 m/s) and recovery time (1.5, 6, and 12 h) on physiological recovery and processing quality parameters of adult Atlantic salmon (Salmo salar) were determined. Atlantic salmon crowded to a density similar to that of a commercial slaughter process (>200 kg/m(3), 40 min) were transferred to a swimming chamber for recovery treatment. Osmolality and concentrations of cortisol, glucose and lactate in blood plasma were used as physiological stress indicators, whereas image analyses of extent and duration of rigor contraction, and fillet gaping were used as measures of processing quality. Crowded salmon had a 5.8-fold higher plasma cortisol concentration than control salmon (Prigor mortis contraction. However, subjecting crowded salmon to active swimming for 6 h before slaughter delayed the onset of rigor mortis contraction from 2.5 to 7.5 h post mortem. The extent of rigor mortis contraction was also affected by crowding and post-stress swimming activity (Prigor mortis contraction, which has a positive technological implication for the salmon processing industry.

  8. Effect of macromolecular crowding on the rate of diffusion-limited ...

    Indian Academy of Sciences (India)

    The enzymatic reaction rate has been shown to be affected by the presence of such macromolecules. A simple numerical model is proposed here based on percolation and diffusion in disordered systems to study the effect of macromolecular crowding on the enzymatic reaction rates. The model qualitatively explains some ...

  9. Effects of Crowding Combined with Mood on Working Memory Performance among College Students

    Science.gov (United States)

    Daniel, Lisa

    2012-01-01

    This study investigated the effects of crowding combined with mood on working memory performance among college students. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web…

  10. Prominent effects and neural correlates of visual crowding in a neurodegenerative disease population.

    Science.gov (United States)

    Yong, Keir X X; Shakespeare, Timothy J; Cash, Dave; Henley, Susie M D; Nicholas, Jennifer M; Ridgway, Gerard R; Golden, Hannah L; Warrington, Elizabeth K; Carton, Amelia M; Kaski, Diego; Schott, Jonathan M; Warren, Jason D; Crutch, Sebastian J

    2014-12-01

    Crowding is a breakdown in the ability to identify objects in clutter, and is a major constraint on object recognition. Crowding particularly impairs object perception in peripheral, amblyopic and possibly developing vision. Here we argue that crowding is also a critical factor limiting object perception in central vision of individuals with neurodegeneration of the occipital cortices. In the current study, individuals with posterior cortical atrophy (n=26), typical Alzheimer's disease (n=17) and healthy control subjects (n=14) completed centrally-presented tests of letter identification under six different flanking conditions (unflanked, and with letter, shape, number, same polarity and reverse polarity flankers) with two different target-flanker spacings (condensed, spaced). Patients with posterior cortical atrophy were significantly less accurate and slower to identify targets in the condensed than spaced condition even when the target letters were surrounded by flankers of a different category. Importantly, this spacing effect was observed for same, but not reverse, polarity flankers. The difference in accuracy between spaced and condensed stimuli was significantly associated with lower grey matter volume in the right collateral sulcus, in a region lying between the fusiform and lingual gyri. Detailed error analysis also revealed that similarity between the error response and the averaged target and flanker stimuli (but not individual target or flanker stimuli) was a significant predictor of error rate, more consistent with averaging than substitution accounts of crowding. Our findings suggest that crowding in posterior cortical atrophy can be regarded as a pre-attentive process that uses averaging to regularize the pathologically noisy representation of letter feature position in central vision. These results also help to clarify the cortical localization of feature integration components of crowding. More broadly, we suggest that posterior cortical atrophy

  11. Crowding and experience-use history: a study of the moderating effect of place attachment among water-based recreationists.

    Science.gov (United States)

    Budruk, Megha; Wilhem Stanis, Sonja A; Schneider, Ingrid E; Heisey, Jennifer J

    2008-04-01

    Effective recreation resource management relies on understanding visitor perceptions and behaviors. Given current and increasing pressures on water resources, understanding crowding evaluations seems important. Beyond crowding, however, variables that possibly relate to or influence crowding are of interest and in particular, place attachment and experience-use history (EUH). As EUH is related to place attachment and likely affects crowding, this study explored the moderating effect of place attachment dimensions on the relationships between EUH and visitor crowding evaluations. Water based recreationists at a U.S. Army Corps of Engineers site were contacted onsite and asked questions related to experience-use history, crowding evaluations, place attachment, and activity participation. Anglers and campers at the site identified similar crowding perceptions and place attachments. Only one of eight models tested revealed a moderating effect. Specifically, place identity moderated the relationship between the total times visited in the past twelve months and expected crowding among anglers. As such, the quest continues to understand the relationship among these important variables.

  12. Stronger synergies

    CERN Multimedia

    Antonella Del Rosso

    2012-01-01

    CERN was founded 58 years ago under the auspices of UNESCO. Since then, both organisations have grown to become world leaders in their respective fields. The links between the two have always existed but today they are even stronger, with new projects under way to develop a more efficient way of exchanging information and devise a common strategy on topics of mutual interest.   CERN and UNESCO are a perfect example of natural partners: their common field is science and education is one of the pillars on which both are built. Historically, they share a common heritage. Both UNESCO and CERN were born of the desire to use scientific cooperation to rebuild peace and security in the aftermath of the Second World War. "Recently, building on our common roots and in close collaboration with UNESCO, we have been developing more structured links to ensure the continuity of the actions taken over the years," says Maurizio Bona, who is in charge of CERN relations with international orga...

  13. The Effect of Attractive Interactions and Macromolecular Crowding on Crystallins Association.

    Directory of Open Access Journals (Sweden)

    Jiachen Wei

    Full Text Available In living systems proteins are typically found in crowded environments where their effective interactions strongly depend on the surrounding medium. Yet, their association and dissociation needs to be robustly controlled in order to enable biological function. Uncontrolled protein aggregation often causes disease. For instance, cataract is caused by the clustering of lens proteins, i.e., crystallins, resulting in enhanced light scattering and impaired vision or blindness. To investigate the molecular origins of cataract formation and to design efficient treatments, a better understanding of crystallin association in macromolecular crowded environment is needed. Here we present a theoretical study of simple coarse grained colloidal models to characterize the general features of how the association equilibrium of proteins depends on the magnitude of intermolecular attraction. By comparing the analytic results to the available experimental data on the osmotic pressure in crystallin solutions, we identify the effective parameters regimes applicable to crystallins. Moreover, the combination of two models allows us to predict that the number of binding sites on crystallin is small, i.e. one to three per protein, which is different from previous estimates. We further observe that the crowding factor is sensitive to the size asymmetry between the reactants and crowding agents, the shape of the protein clusters, and to small variations of intermolecular attraction. Our work may provide general guidelines on how to steer the protein interactions in order to control their association.

  14. Flexibility damps macromolecular crowding effects on protein folding dynamics: Application to the murine prion protein (121-231)

    Science.gov (United States)

    Bergasa-Caceres, Fernando; Rabitz, Herschel A.

    2014-01-01

    A model of protein folding kinetics is applied to study the combined effects of protein flexibility and macromolecular crowding on protein folding rate and stability. It is found that the increase in stability and folding rate promoted by macromolecular crowding is damped for proteins with highly flexible native structures. The model is applied to the folding dynamics of the murine prion protein (121-231). It is found that the high flexibility of the native isoform of the murine prion protein (121-231) reduces the effects of macromolecular crowding on its folding dynamics. The relevance of these findings for the pathogenic mechanism are discussed.

  15. The Effect of Milk Constituents and Crowding Agents on Amyloid Fibril Formation by κ-Casein.

    Science.gov (United States)

    Liu, Jihua; Dehle, Francis C; Liu, Yanqin; Bahraminejad, Elmira; Ecroyd, Heath; Thorn, David C; Carver, John A

    2016-02-17

    When not incorporated into the casein micelle, κ-casein, a major milk protein, rapidly forms amyloid fibrils at physiological pH and temperature. In this study, the effects of milk components (calcium, lactose, lipids, and heparan sulfate) and crowding agents on reduced and carboxymethylated (RCM) κ-casein fibril formation was investigated using far-UV circular dichroism spectroscopy, thioflavin T binding assays, and transmission electron microscopy. Longer-chain phosphatidylcholine lipids, which form the lining of milk ducts and milk fat globules, enhanced RCM κ-casein fibril formation irrespective of whether the lipids were in a monomeric or micellar state, whereas shorter-chain phospholipids and triglycerides had little effect. Heparan sulfate, a component of the milk fat globule membrane and catalyst of amyloid deposition in extracellular tissue, had little effect on the kinetics of RCM κ-casein fibril formation. Major nutritional components such as calcium and lactose also had no significant effect. Macromolecular crowding enhances protein-protein interactions, but in contrast to other fibril-forming species, the extent of RCM κ-casein fibril formation was reduced by the presence of a variety of crowding agents. These data are consistent with a mechanism of κ-casein fibril formation in which the rate-determining step is dissociation from the oligomer to give the highly amyloidogenic monomer. We conclude that the interaction of κ-casein with membrane-associated phospholipids along its secretory pathway may contribute to the development of amyloid deposits in mammary tissue. However, the formation of spherical oligomers such as casein micelles is favored over amyloid fibrils in the crowded environment of milk, within which the occurrence of amyloid fibrils is low.

  16. The Effects of Family Size, Birth Order, Sibling Separation and Crowding on the Academic Achievement of Boys and Girls

    Science.gov (United States)

    Nuttall, Ena Vazquez; And Others

    1976-01-01

    Family constellation variables such as family size, birth order, spacing of children, and crowding were significantly associated with academic achievement when IQ was controlled. The effects of family constellation variables were found to be sex specific. (RC)

  17. Plant Identity Exerts Stronger Effect than Fertilization on Soil Arbuscular Mycorrhizal Fungi in a Sown Pasture.

    Science.gov (United States)

    Zheng, Yong; Chen, Liang; Luo, Cai-Yun; Zhang, Zhen-Hua; Wang, Shi-Ping; Guo, Liang-Dong

    2016-10-01

    Arbuscular mycorrhizal (AM) fungi play key roles in plant nutrition and plant productivity. AM fungal responses to either plant identity or fertilization have been investigated. However, the interactive effects of different plant species and fertilizer types on these symbiotic fungi remain poorly understood. We evaluated the effects of the factorial combinations of plant identity (grasses Avena sativa and Elymus nutans and legume Vicia sativa) and fertilization (urea and sheep manure) on AM fungi following 2-year monocultures in a sown pasture field study. AM fungal extraradical hyphal density was significantly higher in E. nutans than that in A. sativa and V. sativa in the unfertilized control and was significantly increased by urea and manure in A. sativa and by manure only in E. nutans, but not by either fertilizers in V. sativa. AM fungal spore density was not significantly affected by plant identity or fertilization. Forty-eight operational taxonomic units (OTUs) of AM fungi were obtained through 454 pyrosequencing of 18S rDNA. The OTU richness and Shannon diversity index of AM fungi were significantly higher in E. nutans than those in V. sativa and/or A. sativa, but not significantly affected by any fertilizer in all of the three plant species. AM fungal community composition was significantly structured directly by plant identity only and indirectly by both urea addition and plant identity through soil total nitrogen content. Our findings highlight that plant identity has stronger influence than fertilization on belowground AM fungal community in this converted pastureland from an alpine meadow.

  18. Daytime warming has stronger negative effects on soil nematodes than night-time warming

    Science.gov (United States)

    Yan, Xiumin; Wang, Kehong; Song, Lihong; Wang, Xuefeng; Wu, Donghui

    2017-03-01

    Warming of the climate system is unequivocal, that is, stronger warming during night-time than during daytime. Here we focus on how soil nematodes respond to the current asymmetric warming. A field infrared heating experiment was performed in the western of the Songnen Plain, Northeast China. Three warming modes, i.e. daytime warming, night-time warming and diurnal warming, were taken to perform the asymmetric warming condition. Our results showed that the daytime and diurnal warming treatment significantly decreased soil nematodes density, and night-time warming treatment marginally affected the density. The response of bacterivorous nematode and fungivorous nematode to experimental warming showed the same trend with the total density. Redundancy analysis revealed an opposite effect of soil moisture and soil temperature, and the most important of soil moisture and temperature in night-time among the measured environment factors, affecting soil nematode community. Our findings suggested that daily minimum temperature and warming induced drying are most important factors affecting soil nematode community under the current global asymmetric warming.

  19. An evaluation of self-esteem and quality of life in orthodontic patients: effects of crowding and protrusion.

    Science.gov (United States)

    Jung, Min-Ho

    2015-09-01

    To evaluate the effect of dental crowding and lip protrusion on self-esteem and quality of life (QOL) in female orthodontic patients with Class I malocclusion. The study sample consisted of 201 patients (mean age 22.6 ± 3.0 years) who sought orthodontic treatment. All the patients were evaluated before treatment in terms of their degree of dental crowding and lip protrusion. Rosenberg's Self-Esteem Scale and the Orthognathic Quality of Life Questionnaire (OQLQ) were used to determine self-esteem and QOL and to evaluate whether these values were related to malocclusion severity. The results indicated that severe crowding and severe protrusion can result in lower self-esteem and poorer QOL (P self-esteem and QOL scores than severe crowding or protrusion patients.

  20. Crowding as appropriation

    DEFF Research Database (Denmark)

    Thelle, Mikkel

    2016-01-01

    This article seeks to address the relation between crowds andpublic space as a question of appropriation. With the newliberal constitutions in Europe, several phenomena of crowdingemerge in major cities, of which Copenhagen is taken as anexample. By focusing on the crowd as an agglomeration...... ofbodies, it is assessed how the agency of the crowd works on animmediate level and in its more lasting effects on urban space.The notion of appropriation is related to the crowd’s claim,formal and informal, as resulting from a negotiation of this,mostly public, space, and articulated in empirical cases...

  1. The effects of crowding agents Dextran-70k and PEG-8k on actin structure and unfolding reaction

    Science.gov (United States)

    Gagarskaia, Iuliia A.; Povarova, Olga I.; Uversky, Vladimir N.; Kuznetsova, Irina M.; Turoverov, Konstantin K.

    2017-07-01

    Recently, an increasing number of studies on proteins' structure, stability and folding are trying to bring the experimental conditions closer to those existing in a living cell, namely to the conditions of macromolecular crowding. In vitro such conditions are typically imitated by the ;inert; highly water-soluble polymers with different hydrodynamic dimensions. In this work, the effects of crowded milieu on the structure and conformational stability of actin, which is a key component of the muscle contraction system, was examined. The crowded milieu was simulated by high concentrations of PEG-8k or Dextran-70k. It was revealed that both crowding agents decelerated but not inhibited actin unfolding and made a compact state of inactivated actin thermodynamically more favorable in comparison with the unfolded state. At the same time, the high viscosity of the solution of crowding agents slowed down all processes and especially inactivated actin formation, since it involves the interaction of 14-16 partially unfolded actin molecules. The effects of crowding agent were larger when its hydrodynamic dimensions were closer to the size of globular actin.

  2. Modeling and simulation of explosion effectiveness as a function of blast and crowd characteristics

    Science.gov (United States)

    Usmani, Zeeshan-Ul-Hassan

    Suicide bombing has become one of the most lethal and favorite modus operandi of terrorist organizations around the world. On average, there is a suicide bombing attack every six days somewhere in the world. While various attempts have been made to assess the impact of explosions on structures and military personnel, little has been done on modeling the impact of a blast wave on a crowd in civilian settings. The assessment of an explosion's effect on a crowd can lead to better management of disasters, triage of patients, locating blast victims under the debris, development of protective gear, and safe distance recommendations to reduce the casualties. The overall goal of this work is to predict the magnitude of injuries and lethality on humans from a blast-wave with various explosive and crowd characteristics, and to compare, contrast, and analyze the performance of explosive and injury models against the real-life data of suicide bombing incidents. This thesis introduces BlastSim---a physics based stationary multi-agent simulation platform to model and simulate a suicide bombing event. The agents are constrained by the physical characteristics and mechanics of the blast wave. The BlastSim is programmed to test, analyze, and validate the results of different model combinations under various conditions with different sets of parameters, such as the crowd and explosive characteristics, blockage and human shields, fragmentation and the bomber's position, in 2-dimensional and 3-dimensional environments. The suicide bombing event can be re-created for forensic analysis. The proposed model combinations show a significant performance---the Harold Brode explosive model with Catherine Lee injury model using the blockage stands out consistently to be the best with an overall cumulative accuracy of 87.6%. When comparing against actual data, overall, prediction accuracy can be increased by 71% using this model combination. The J. Clutter with Reflection explosive model using

  3. Effects of molecular confinement and crowding on horseradish peroxidase kinetics using a nanofluidic gradient mixer.

    Science.gov (United States)

    Wichert, William R A; Han, Donghoon; Bohn, Paul W

    2016-03-07

    The effects of molecular confinement and crowding on enzyme kinetics were studied at length scales and under conditions similar to those found in biological cells. These experiments were carried out using a nanofluidic network of channels constituting a nanofluidic gradient mixer, providing the basis for measuring multiple experimental conditions simultaneously. The 100 nm × 40 μm nanochannels were wet etched directly into borosilicate glass, then annealed and characterized with fluorescein emission prior to kinetic measurements. The nanofluidic gradient mixer was then used to measure the kinetics of the conversion of the horseradish peroxidase (HRP)-catalyzed conversion of non-fluorescent Amplex Red (AR) to the fluorescent product resorufin in the presence of hydrogen peroxide (H2O2). The design of the gradient mixer allows reaction kinetics to be studied under multiple (five) unique solution compositions in a single experiment. To characterize the efficiency of the device the effects of confinement on HRP-catalyzed AR conversion kinetics were studied by varying the starting ratio of AR : H2O2. Equimolar concentrations of Amplex Red and H2O2 yielded the highest reaction rates followed by 2 : 1, 1 : 2, 5 : 1, and finally 1 : 5 [AR] : [H2O2]. Under all conditions, initial reaction velocities were decreased by excess H2O2. Crowding effects on kinetics were studied by increasing solution viscosity in the nanochannels in the range 1.0-1.6 cP with sucrose. Increasing the solution viscosities in these confined geometries decreases the initial reaction velocity at the highest concentration from 3.79 μM min(-1) at 1.00 cP to 0.192 μM min(-1) at 1.59 cP. Variations in reaction velocity are interpreted in the context of models for HRP catalysis and for molecular crowding.

  4. Income inequality is associated with stronger social comparison effects: The effect of relative income on life satisfaction.

    Science.gov (United States)

    Cheung, Felix; Lucas, Richard E

    2016-02-01

    Previous research has shown that having rich neighbors is associated with reduced levels of subjective well-being, an effect that is likely due to social comparison. The current study examined the role of income inequality as a moderator of this relative income effect. Multilevel analyses were conducted on a sample of more than 1.7 million people from 2,425 counties in the United States. Results showed that higher income inequality was associated with stronger relative income effects. In other words, people were more strongly influenced by the income of their neighbors when income inequality was high. (c) 2016 APA, all rights reserved).

  5. Income Inequality Is Associated with Stronger Social Comparison Effects: The Effect of Relative Income on Life Satisfaction

    Science.gov (United States)

    Cheung, Felix; Lucas, Richard E.

    2015-01-01

    Previous research has shown that having rich neighbors is associated with reduced levels of subjective well-being, an effect that is likely due to social comparison. The current study examined the role of income inequality as a moderator of this relative income effect. Multilevel analyses were conducted on a sample of over 1.7 million people from 2,425 counties in the United States. Results showed that higher income inequality was associated with stronger relative income effects. In other words, people were more strongly influenced by the income of their neighbors when income inequality was high. PMID:26191957

  6. Daytime warming has stronger negative effects on soil nematodes than night-time warming

    OpenAIRE

    Yan, Xiumin; Wang, Kehong; Song, Lihong; Wang, Xuefeng; Wu, Donghui

    2017-01-01

    Warming of the climate system is unequivocal, that is, stronger warming during night-time than during daytime. Here we focus on how soil nematodes respond to the current asymmetric warming. A field infrared heating experiment was performed in the western of the Songnen Plain, Northeast China. Three warming modes, i.e. daytime warming, night-time warming and diurnal warming, were taken to perform the asymmetric warming condition. Our results showed that the daytime and diurnal warming treatmen...

  7. Improvement of imprinting effect of ionic liquid molecularly imprinted polymers by use of a molecular crowding agent.

    Science.gov (United States)

    Jia, Man; Yang, Jian; Sun, Ya Kun; Bai, Xi; Wu, Tao; Liu, Zhao Sheng; Aisa, Haji Akber

    2018-01-01

    We aimed to improve the imprinting effect of ionic liquid molecularly imprinted polymers (MIPs) by use of a molecular crowding agent. The ionic liquid 1-vinyl-3-ethylimidazolium tetrafluoroborate ([VEIm][BF 4 ]) was used as the functional monomer and aesculetin was used as the template molecule in a crowding environment, which was made up of a tetrahydrofuran solution of polystyrene. The ionic liquid MIPs that were prepared in the crowding environment displayed an enhanced imprinting effect. NMR peak shifts of active hydrogen of aesculetin suggested that interaction between the functional monomer and the template could be increased by the use of a crowding agent in the self-assembly process. The retention and selectivity of aesculetin were affected greatly by high molecular crowding, the amount of high molecular weight crowding agent, and the ratio of [VEIm][BF 4 ] to aesculetin. The optimal MIPs were used as solid-phase extraction sorbents to extract aesculetin from Cichorium glandulosum. A calibration curve was obtained with aesculetin concentrations from 0.0005 to 0.05 mg mL -1 (correlation coefficient R 2 of 0.9999, y = 1519x + 0.0923). The limit of quantification was 0.12 μg mL -1 , and the limit of detection was 0.05 μg mL -1 . The absolute recovery of aesculetin was (80 ± 2)% (n = 3), and the purity of aesculetin was (92 ± 0.5)% (n = 5). As a conclusion, molecular crowding is an effective approach to obtain ionic liquid MIPs with high selectivity even in a polar solvent environment.

  8. The Effects of Molecular Crowding on the Structure and Stability of G-Quadruplexes with an Abasic Site

    Science.gov (United States)

    Fujimoto, Takeshi; Nakano, Shu-ichi; Miyoshi, Daisuke; Sugimoto, Naoki

    2011-01-01

    Both cellular environmental factors and chemical modifications critically affect the properties of nucleic acids. However, the structure and stability of DNA containing abasic sites under cell-mimicking molecular crowding conditions remain unclear. Here, we investigated the molecular crowding effects on the structure and stability of the G-quadruplexes including a single abasic site. Structural analysis by circular dichroism showed that molecular crowding by PEG200 did not affect the topology of the G-quadruplex structure with or without an abasic site. Thermodynamic analysis further demonstrated that the degree of stabilization of the G-quadruplex by molecular crowding decreased with substitution of an abasic site for a single guanine. Notably, we found that the molecular crowding effects on the enthalpy change for G-quadruplex formation had a linear relationship with the abasic site effects depending on its position. These results are useful for predicting the structure and stability of G-quadruplexes with abasic sites in the cell-mimicking conditions. PMID:21949901

  9. Crowd Sourcing.

    Science.gov (United States)

    Baum, Neil

    2016-01-01

    The Internet has contributed new words and slang to our daily vernacular. A few terms, such as tweeting, texting, sexting, blogging, and googling, have become common in most vocabularies and in many languages, and are now included in the dictionary. A new buzzword making the rounds in industry is crowd sourcing, which involves outsourcing an activity, task, or problem by sending it to people or groups outside a business or a practice. Crowd sourcing allows doctors and practices to tap the wisdom of many instead of relying only on the few members of their close-knit group. This article defines "crowd sourcing," offers examples, and explains how to get started with this approach that can increase your ability to finish a task or solve problems that you don't have the time or expertise to accomplish.

  10. Effects of Polymer Hydrophobicity on Protein Structure and Aggregation Kinetics in Crowded Milieu.

    Science.gov (United States)

    Breydo, Leonid; Sales, Amanda E; Frege, Telma; Howell, Mark C; Zaslavsky, Boris Y; Uversky, Vladimir N

    2015-05-19

    We examined the effects of water-soluble polymers of various degrees of hydrophobicity on the folding and aggregation of proteins. The polymers we chose were polyethylene glycol (PEG) and UCON (1:1 copolymer of ethylene glycol and propylene glycol). The presence of additional methyl groups in UCON makes it more hydrophobic than PEG. Our earlier analysis revealed that similarly sized PEG and UCON produced different changes in the solvent properties of water in their solutions and induced morphologically different α-synuclein aggregates [Ferreira, L. A., et al. (2015) Role of solvent properties of aqueous media in macromolecular crowding effects. J. Biomol. Struct. Dyn., in press]. To improve our understanding of molecular mechanisms defining behavior of proteins in a crowded environment, we tested the effects of these polymers on secondary and tertiary structure and aromatic residue solvent accessibility of 10 proteins [five folded proteins, two hybrid proteins; i.e., protein containing ordered and disordered domains, and three intrinsically disordered proteins (IDPs)] and on the aggregation kinetics of insulin and α-synuclein. We found that effects of both polymers on secondary and tertiary structures of folded and hybrid proteins were rather limited with slight unfolding observed in some cases. Solvent accessibility of aromatic residues was significantly increased for the majority of the studied proteins in the presence of UCON but not PEG. PEG also accelerated the aggregation of protein into amyloid fibrils, whereas UCON promoted aggregation to amyloid oligomers instead. These results indicate that even a relatively small change in polymer structure leads to a significant change in the effect of this polymer on protein folding and aggregation. This is an indication that protein folding and especially aggregation are highly sensitive to the presence of other macromolecules, and an excluded volume effect is insufficient to describe their effect.

  11. The effect of macromolecular crowding on the electrostatic component of barnase-barstar binding: a computational, implicit solvent-based study.

    Directory of Open Access Journals (Sweden)

    Helena W Qi

    Full Text Available Macromolecular crowding within the cell can impact both protein folding and binding. Earlier models of cellular crowding focused on the excluded volume, entropic effect of crowding agents, which generally favors compact protein states. Recently, other effects of crowding have been explored, including enthalpically-related crowder-protein interactions and changes in solvation properties. In this work, we explore the effects of macromolecular crowding on the electrostatic desolvation and solvent-screened interaction components of protein-protein binding. Our simple model enables us to focus exclusively on the electrostatic effects of water depletion on protein binding due to crowding, providing us with the ability to systematically analyze and quantify these potentially intuitive effects. We use the barnase-barstar complex as a model system and randomly placed, uncharged spheres within implicit solvent to model crowding in an aqueous environment. On average, we find that the desolvation free energy penalties incurred by partners upon binding are lowered in a crowded environment and solvent-screened interactions are amplified. At a constant crowder density (fraction of total available volume occupied by crowders, this effect generally increases as the radius of model crowders decreases, but the strength and nature of this trend can depend on the water probe radius used to generate the molecular surface in the continuum model. In general, there is huge variation in desolvation penalties as a function of the random crowder positions. Results with explicit model crowders can be qualitatively similar to those using a lowered "effective" solvent dielectric to account for crowding, although the "best" effective dielectric constant will likely depend on multiple system properties. Taken together, this work systematically demonstrates, quantifies, and analyzes qualitative intuition-based insights into the effects of water depletion due to crowding on the

  12. Chemical and physical effects of crowding on growth and survival of Penaeus monodon Fabricius post-larvae

    NARCIS (Netherlands)

    Nga, B.T.; Lürling, M.F.L.L.W.; Peeters, E.T.H.M.; Roijackers, R.M.M.; Scheffer, M.; Nghia, T.T.

    2005-01-01

    The hypothesis that crowding effects through physical and/or chemical interference may be an important factor in lowering the chance of survival and reducing growth of Penaeus monodon post-larvae under high stocking densities was tested. To separate physical interference from chemically-exerted

  13. Effect of Joule heating and current crowding on electromigration in mobile technology

    Science.gov (United States)

    Tu, K. N.; Liu, Yingxia; Li, Menglu

    2017-03-01

    In the present era of big data and internet of things, the use of microelectronic products in all aspects of our life is manifested by the ubiquitous presence of mobile devices as i-phones and wearable i-products. These devices are facing the need for higher power and greater functionality applications such as in i-health, yet they are limited by physical size. At the moment, software (Apps) is much ahead of hardware in mobile technology. To advance hardware, the end of Moore's law in two-dimensional integrated circuits can be extended by three-dimensional integrated circuits (3D ICs). The concept of 3D ICs has been with us for more than ten years. The challenge in 3D IC technology is dense packing by using both vertical and horizontal interconnections. Mass production of 3D IC devices is behind schedule due to cost because of low yield and uncertain reliability. Joule heating is serious in a dense structure because of heat generation and dissipation. A change of reliability paradigm has advanced from failure at a specific circuit component to failure at a system level weak-link. Currently, the electronic industry is introducing 3D IC devices in mainframe computers, where cost is not an issue, for the purpose of collecting field data of failure, especially the effect of Joule heating and current crowding on electromigration. This review will concentrate on the positive feedback between Joule heating and electromigration, resulting in an accelerated system level weak-link failure. A new driving force of electromigration, the electric potential gradient force due to current crowding, will be reviewed critically. The induced failure tends to occur in the low current density region.

  14. Diversity has stronger top-down than bottom-up effects on decomposition.

    Science.gov (United States)

    Srivastava, Diane S; Cardinale, Bradley J; Downing, Amy L; Duffy, J Emmett; Jouseau, Claire; Sankaran, Mahesh; Wright, Justin P

    2009-04-01

    The flow of energy and nutrients between trophic levels is affected by both the trophic structure of food webs and the diversity of species within trophic levels. However, the combined effects of trophic structure and diversity on trophic transfer remain largely unknown. Here we ask whether changes in consumer diversity have the same effect as changes in resource diversity on rates of resource consumption. We address this question by focusing on consumer-resource dynamics for the ecologically important process of decomposition. This study compares the top-down effect of consumer (detritivore) diversity on the consumption of dead organic matter (decomposition) with the bottom-up effect of resource (detrital) diversity, based on a compilation of 90 observations reported in 28 studies. We did not detect effects of either detrital or consumer diversity on measures of detrital standing stock, and effects on consumer standing stock were equivocal. However, our meta-analysis indicates that reductions in detritivore diversity result in significant reductions in the rate of decomposition. Detrital diversity has both positive and negative effects on decomposition, with no overall trend. This difference between top-down and bottom-up effects of diversity is robust to different effect size metrics and could not be explained by differences in experimental systems or designs between detritivore and detrital manipulations. Our finding that resource diversity has no net effect on consumption in "brown" (detritus-consumer) food webs contrasts with previous findings from "green" (plant-herbivore) food webs and suggests that effects of plant diversity on consumption may fundamentally change after plant death.

  15. Stronger effects of Roundup than its active ingredient glyphosate in damselfly larvae.

    Science.gov (United States)

    Janssens, Lizanne; Stoks, Robby

    2017-12-01

    Pesticides are causing strong decreases in aquatic biodiversity at concentrations assumed safe by legislation. One reason for the failing risk assessment may be strong differences in the toxicity of the active ingredient of pesticides and their commercial formulations. Sublethal effects, especially those on behaviour, have been largely ignored in this context, yet can be equally important as lethal effects at the population and ecosystem levels. Here, we compared the toxicity of the herbicide Roundup and its active ingredient glyphosate on survival, but also on ecologically relevant sublethal traits (life history, behaviour and physiology) in damselfly larvae. Roundup was more toxic than glyphosate with negative effects on survival, behaviour and most of the physiological traits being present at lower concentrations (food intake, escape swimming speed) or even only present (survival, sugar and total energy content and muscle mass) following Roundup exposure. This confirms the toxicity of the surfactant POEA. Notably, also glyphosate was not harmless: a realistic concentration of 2mg/l resulted in reduced growth rate, escape swimming speed and fat content. Our results therefore indicate that the toxicity of Roundup cannot be fully attributed to its surfactant, thereby suggesting that also the new generation of glyphosate-based herbicides with other mixtures of surfactants likely will have adverse effects on non-target aquatic organisms. Ecotoxicological studies comparing the toxicity of active ingredients and their commercial formulations typically ignore behaviour while the here observed differential effects on behaviour likely will negatively impact damselfly populations. Our data highlight that risk assessment of pesticides ignoring sublethal effects may contribute to the negative effects of pesticides on aquatic biodiversity. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. Stronger evidence for own-age effects in memory for older as compared to younger adults

    Czech Academy of Sciences Publication Activity Database

    Freund, A.M.; Kouřilová, Sylvie; Kuhl, P.

    2011-01-01

    Roč. 19, č. 5 (2011), s. 429-448 ISSN 0965-8211 Institutional research plan: CEZ:AV0Z70250504 Keywords : own- age effect * memory bias * age relevance * age ing Subject RIV: AN - Psychology Impact factor: 2.089, year: 2011

  17. Effect of crowd size on patient volume at a large, multipurpose, indoor stadium.

    Science.gov (United States)

    De Lorenzo, R A; Gray, B C; Bennett, P C; Lamparella, V J

    1989-01-01

    A prediction of patient volume expected at "mass gatherings" is desirable in order to provide optimal on-site emergency medical care. While several methods of predicting patient loads have been suggested, a reliable technique has not been established. This study examines the frequency of medical emergencies at the Syracuse University Carrier Dome, a 50,500-seat indoor stadium. Patient volume and level of care at collegiate basketball and football games as well as rock concerts, over a 7-year period were examined and tabulated. This information was analyzed using simple regression and nonparametric statistical methods to determine level of correlation between crowd size and patient volume. These analyses demonstrated no statistically significant increase in patient volume for increasing crowd size for basketball and football events. There was a small but statistically significant increase in patient volume for increasing crowd size for concerts. A comparison of similar crowd size for each of the three events showed that patient frequency is greatest for concerts and smallest for basketball. The study suggests that crowd size alone has only a minor influence on patient volume at any given event. Structuring medical services based solely on expected crowd size and not considering other influences such as event type and duration may give poor results.

  18. Land use change has stronger effects on functional diversity than taxonomic diversity in tropical Andean hummingbirds.

    Science.gov (United States)

    Tinoco, Boris A; Santillán, Vinicio E; Graham, Catherine H

    2018-03-01

    Land use change modifies the environment at multiple spatial scales, and is a main driver of species declines and deterioration of ecosystem services. However, most of the research on the effects of land use change has focused on taxonomic diversity, while functional diversity, an important predictor of ecosystem services, is often neglected. We explored how local and landscape scale characteristics influence functional and taxonomic diversity of hummingbirds in the Andes Mountains in southern Ecuador. Data was collected in six landscapes along a land use gradient, from an almost intact landscape to one dominated by cattle pastures. We used point counts to sample hummingbirds from 2011 to 2012 to assessed how local factors (i.e., vegetation structure, flowering plants richness, nectar availability) and landscape factors (i.e., landscape heterogeneity, native vegetation cover) influenced taxonomic and functional diversity. Then, we analyzed environment - trait relationships (RLQ test) to explore how different hummingbird functional traits influenced species responses to these factors. Taxonomic and functional diversity of hummingbirds were positively associated with landscape heterogeneity but only functional diversity was positively related to native vegetation coverage. We found a weak response of taxonomic and functional diversity to land use change at the local scale. Environment-trait associations showed that body mass of hummingbirds likely influenced species sensitivity to land use change. In conclusion, landscape heterogeneity created by land use change can positively influence hummingbird taxonomic and functional diversity; however, a reduction of native vegetation cover could decrease functional diversity. Given that functional diversity can mediate ecosystem services, the conservation of native vegetation cover could play a key role in the maintenance of hummingbird pollination services in the tropical Andes. Moreover, there are particular functional

  19. Naming and Categorization in Healthy Participants: Crowded Domains and Blurred Effects of Gender.

    Science.gov (United States)

    Moreno-Martínez, Francisco Javier; Moratilla-Pérez, Iván

    2016-09-20

    The study of category-specific effects has produced compelling insights into the structure, organization and functioning of cognitive processes. According to some accounts, the greater intra-category structural similarity for living things (LT) contributes to faster access to superordinate pictorial information, making LT easier to classify than structurally dissimilar items (i.e., nonliving things: NLT). Conversely, LT would be harder to name than NLT, as they must compete with within-domain structurally similar items in order to be properly discriminated. Additionally, it has been reported that men perform better with NLT than women, whereas women surpass men with LT but the reasons for this remain unclear. In the current study, we explored both the visual crowding hypothesis and the effects of gender by testing the performance of 40 healthy participants in classification and naming tasks. Analyses revealed that LT were classified significantly faster than NLT (η p 2 = .11), but named significantly slower (η p 2 = .25). Interestingly, the same results persisted after removing atypical categories that are known to distort the interpretation of data from the analyses. Moreover, we did not find the expected effects of gender. Men were more accurate than women naming NLT (η p 2 = .13), and women did not surpass men in any task.

  20. Crowd Theory and the Management of Crowds

    DEFF Research Database (Denmark)

    Borch, Christian

    2013-01-01

    a turn towards rational approaches difficult, and, on the other hand, that the rational approaches in their ignorance of collective emotional arousal present an inadequate picture of crowds and consequently have limited scope as guidelines for crowd management strategies....... suggest, rational conceptions of crowds should inform contemporary crowd management. This article questions this plea on two grounds. First, it demonstrates that there is no unidirectional connection between sociological crowd theory (whatever its content) and practical strategies for governing crowds...... that, in spite of its current scholarly popularity, there is no guarantee that the call for a practical employment of the rational notion of crowds will necessarily be successful. This is demonstrated by stressing, on the one hand, that irrational notions of crowds continue to thrive, thereby rendering...

  1. The sigh of the oppressed: The palliative effects of ideology are stronger for people living in highly unequal neighbourhoods.

    Science.gov (United States)

    Sengupta, Nikhil K; Greaves, Lara M; Osborne, Danny; Sibley, Chris G

    2017-09-01

    Ideologies that legitimize status hierarchies are associated with increased well-being. However, which ideologies have 'palliative effects', why they have these effects, and whether these effects extend to low-status groups remain unresolved issues. This study aimed to address these issues by testing the effects of the ideology of Symbolic Prejudice on well-being among low- and high-status ethnic groups (4,519 Europeans and 1,091 Māori) nested within 1,437 regions in New Zealand. Results showed that Symbolic Prejudice predicted increased well-being for both groups, but that this relationship was stronger for those living in highly unequal neighbourhoods. This suggests that it is precisely those who have the strongest need to justify inequality that accrue the most psychological benefit from subscribing to legitimizing ideologies. © 2017 The British Psychological Society.

  2. The Effect of Agile Workspace and Remote Working on Experiences of Privacy, Crowding and Satisfaction

    Directory of Open Access Journals (Sweden)

    Trevor Keeling

    2015-08-01

    Full Text Available Occupant density is an important and basic metric of space use efficiency. It affects user experience of privacy, crowding and satisfaction. The effect of agile working has been two fold. Firstly, offices have an increasing range of workspace settings such as break out space, collaborative space and contemplative space in contrast to the traditional workspace settings of assigned desks and formal meeting rooms. Secondly, office workers have become increasingly mobile as they are able to work from a greater variety of locations both in and out of their main place of work. This study asks whether workers who occupy agile workspaces and those with greater mobility experience privacy differently from workers with more conventional offices and work patterns. The experience of privacy can be considered in terms of retreat from people, control of information flow and control of interactions. Our results show that agile workspaces improve the ability to control information compared with open plan offices. It was also found that highly mobile workers are more sensitive to the negative effects of interacting with people. From this a taxonomy of offices is defined in terms of the features that contribute to the experience of privacy.

  3. Changing attitudes toward smoking and smoking susceptibility through peer crowd targeting: more evidence from a controlled study.

    Science.gov (United States)

    Moran, Meghan Bridgid; Sussman, Steve

    2015-01-01

    Peer crowd identification consistently predicts an adolescent's smoking behavior. As such, several interventions have targeted adolescents and young adults based on their identification with a specific crowd (e.g., Hipsters). This study uses a controlled experimental design to isolate and test the effect of peer crowd targeting in an antismoking ad on antismoking attitudes and smoking susceptibility. Two hundred and thirty-nine adolescents, age 13-15 years, completed a baseline survey and then viewed an antismoking ad targeting one of eight crowds; 1 week later they completed a posttest. Participants were assessed on antismoking attitudes and smoking susceptibility. Adolescents who strongly identified with the crowd targeted by the ad reported stronger antismoking attitudes and lower levels of smoking susceptibility. Those who disidentified with the crowd targeted in the ad exhibited not statistically significant increases in smoking susceptibility and weaker antismoking attitudes at posttest. These findings indicate that targeting youths based on their peer crowd is a useful strategy for antismoking interventions. Additional research should further examine whether youths who disidentify with the targeted crowd in an ad exhibit reactance against the message.

  4. Achieving external validity in home advantage research: generalizing crowd noise effects

    Directory of Open Access Journals (Sweden)

    Tony D Myers

    2014-06-01

    Full Text Available Different factors have been postulated to explain the home advantage phenomenon in sport. One plausible explanation investigated has been the influence of a partisan home crowd on sports officials’ decisions. Different types of studies have tested the crowd influence hypothesis including purposefully designed experiments. However, while experimental studies investigating crowd influences have high levels of internal validity, they suffer from a lack of external validity; decision-making in a laboratory setting bearing little resemblance to decision-making in live sports settings. This focused review initially considers threats to external validity in applied and theoretical experimental research. Discussing how such threats can be addressed using representative design by focusing on a recently published study that arguably provides the first experimental evidence of the impact of live crowd noise on officials in sport. The findings of this controlled experiment conducted in a real tournament setting offer some confirmation of the validity of laboratory experimental studies in the area. Finally directions for future research and the future conduct of crowd noise studies are discussed.

  5. Achieving external validity in home advantage research: generalizing crowd noise effects.

    Science.gov (United States)

    Myers, Tony D

    2014-01-01

    Different factors have been postulated to explain the home advantage phenomenon in sport. One plausible explanation investigated has been the influence of a partisan home crowd on sports officials' decisions. Different types of studies have tested the crowd influence hypothesis including purposefully designed experiments. However, while experimental studies investigating crowd influences have high levels of internal validity, they suffer from a lack of external validity; decision-making in a laboratory setting bearing little resemblance to decision-making in live sports settings. This focused review initially considers threats to external validity in applied and theoretical experimental research. Discussing how such threats can be addressed using representative design by focusing on a recently published study that arguably provides the first experimental evidence of the impact of live crowd noise on officials in sport. The findings of this controlled experiment conducted in a real tournament setting offer a level of confirmation of the findings of laboratory studies in the area. Finally directions for future research and the future conduct of crowd noise studies are discussed.

  6. Crowd wisdom drives intelligent manufacturing

    Directory of Open Access Journals (Sweden)

    Jiaqi Lu

    2017-03-01

    Full Text Available Purpose – A fundamental problem for intelligent manufacturing is to equip the agents with the ability to automatically make judgments and decisions. This paper aims to introduce the basic principle for intelligent crowds in an attempt to show that crowd wisdom could help in making accurate judgments and proper decisions. This further shows the positive effects that crowd wisdom could bring to the entire manufacturing process. Design/methodology/approach – Efforts to support the critical role of crowd wisdom in intelligent manufacturing involve theoretical explanation, including a discussion of several prevailing concepts, such as consumer-to-business (C2B, crowdfunding and an interpretation of the contemporary Big Data mania. In addition, an empirical study with three business cases was conducted to prove the conclusion that our ideas could well explain the current business phenomena and guide the future of manufacturing. Findings – This paper shows that crowd wisdom could help make accurate judgments and proper decisions. It further shows the positive effects that crowd wisdom could bring to the entire manufacturing process. Originality/value – The paper highlights the importance of crowd wisdom in manufacturing with sufficient theoretical and empirical analysis, potentially providing a guideline for future industry.

  7. Bilingual recognition memory: stronger performance but weaker levels-of-processing effects in the less fluent language.

    Science.gov (United States)

    Francis, Wendy S; Gutiérrez, Marisela

    2012-04-01

    The effects of bilingual proficiency on recognition memory were examined in an experiment with Spanish-English bilinguals. Participants learned lists of words in English and Spanish under shallow- and deep-encoding conditions. Overall, hit rates were higher, discrimination greater, and response times shorter in the nondominant language, consistent with effects previously observed for lower frequency words. Levels-of-processing effects in hit rates, discrimination, and response time were stronger in the dominant language. Specifically, with shallow encoding, the advantage for the nondominant language was larger than with deep encoding. The results support the idea that memory performance in the nondominant language is impacted by both the greater demand for cognitive resources and the lower familiarity of the words.

  8. Effect of crowding and confinement on first-passage times: A model study

    Science.gov (United States)

    Antoine, C.; Talbot, J.

    2016-06-01

    We study the "color dynamics" of a hard-disk fluid confined in an annulus, as well as the corresponding hard-sphere system in three dimensions, using event-driven simulation in order to explore the effect of confinement and self-crowding on the search for targets. We compute the mean first-passage times (MFPTs) of red particles transiting from the outer to the inner boundary as well as those of blue particles passing from the inner to the outer boundary for different packing fractions and geometries. In the steady state the reaction rate, defined as the rate of collision of red particles with the inner boundary, is inversely proportional to the sum of the MFPTs. The reaction rate is wall mediated (ballistic) at low densities and diffusion controlled at higher densities and displays a maximum at intermediate densities. At moderate to high densities, the presence of layering has a strong influence on the search process. The numerical results for the reaction rate and MFPTs are compared with a ballistic model at low densities and a Smoluchowski approach with uniform diffusivities at higher densities. We discuss the reasons for the limited validity of the theoretical approaches. The maximum in the reaction rate is qualitatively well rendered by a Bosanquet-like approach that interpolates between the two regimes. Finally, we compute the position-dependent diffusivity from the MFPTs and observe that it is out of phase with the radial density.

  9. [Estimates of the size of inhibitory areas in crowding effects in periphery].

    Science.gov (United States)

    Bondarko, V M; Danilova, M V; Solnushkin, S D; Chikhman, V N

    2014-01-01

    In psychophysical experiments we studied how surround influences recognition of test objects. The tests were low-contrast Landolt rings of the size 1.1, 1.5 and 2.3 deg. Their centers were located at 13.2 deg from the fixation point. The additional objects were similar Landolt rings or rings without gaps. The distance between the centers of the test and the additional objects varied from 2.2 to 13.2 deg. Inone experiment, the task of the observer was to identify both the test objects and the surrounding objects. In the second experiment the stimulus layout was the same, but'identification of only the test stimulus was required. In both experiments, deterioration of performance was found at all distances between the test objects and the surround, but the deterioration was more significant when the observer carried out the dual task. The data showed that the size of the inhibitory areas in our case does not comply with the Bouma low which states that the size of the interaction areas are equal to half of the eccentricity where the test is presented. Further deterioration of performance in the dual task reveals the contribution of attention into peripheral crowding effects.

  10. Effect on Perceived Stimulation dan Perceived Crowding on the Decision of the Unplanned Purchase (Impulse Buying

    Directory of Open Access Journals (Sweden)

    Enggal Sriwardiningsih

    2011-11-01

    Full Text Available Purchase decisions aren’t made necessarily planned, because impulsive buying is such a result of environmental stimuli shopping. Things affecting unplanned purchasing decisions are perceived by stimulation and crowding. The purpose of this study is to determine whether there are influences between perceived crowding and stimulation of impulse buying simultaneously or partial. The object used is one of the largest retailers in Cilegon. This research design is quantitative analysis of the consumer unit. The collecting data technique includes using questionnaires, interviews, and literature from previous research. Data processed using the SPSS 16.0 program through the validity and reliability, normality test, and regression analysis. The study states that there is significant influence between perceived crowding and perceived stimulation both simultaneous and partial response to impulse buying. 

  11. Ameliorating the emergency department workflow by involving the observation unit: effects on crowding

    Directory of Open Access Journals (Sweden)

    Primiano Iannone

    2015-06-01

    Full Text Available Crowding adversely affects the performance of emergency departments (EDs by worsening efficiency, timeliness of care, clinical outcomes and patients’ satisfaction. We describe in this study our attempt at improving crowding by modifying the roles and workflow of the ED physicians. The observation unit physician was given the additional duty of prioritizing admissions and managing unclear, complex cases, which were previously under the responsibility of front line emergency physicians. We analyzed two corresponding periods, both before the intervention (9897 ED attendances in 2012 and after the intervention (10,297 attendances in 2013. Most of the crowding indices improved significantly, including timeliness of triage, of first medical contact, access to resus area, and overall length of stay in ED. Also, emergency hospital admissions, average specialist consultations and imaging studies per patient decreased significantly. The observation unit workload increased. There was no significant excess of adverse events.

  12. Effect of temporary open-air markets on the sound environment and acoustic perception based on the crowd density characteristics.

    Science.gov (United States)

    Meng, Qi; Sun, Yang; Kang, Jian

    2017-12-01

    The sound environment and acoustic perception of open-air markets, which are very common in high-density urban open spaces, play important roles in terms of the urban soundscape. Based on objective and subjective measurements of a typical temporary open-air market in Harbin city, China, the effects of the temporary open-air market on the sound environment and acoustic perception were studied, considering different crowd densities. It was observed that a temporary open-air market without zoning increases the sound pressure level and subjective loudness by 2.4dBA and 0.21dBA, respectively, compared to the absence of a temporary market. Different from the sound pressure level and subjective loudness, the relationship between crowd density and the perceived acoustic comfort is parabolic. Regarding the effect of a temporary open-air market with different zones on the sound environment and acoustic perception, when the crowd densities were the same, subjective loudness in the fruit and vegetable sales area was always higher than in the food sales area and the clothing sales area. In terms of acoustic comfort, with an increase in crowd density, acoustic comfort in the fruit and vegetable sales area decreased, and acoustic comfort in the food sales area and the clothing sales area exhibited a parabolic change trend of increase followed by decrease. Overall, acoustic comfort can be effectively improved by better planning temporary open-air markets in high-density urban open spaces. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. Adults with dyslexia demonstrate large effects of crowding and detrimental effects of distractors in a visual tilt discrimination task.

    Directory of Open Access Journals (Sweden)

    Rizan Cassim

    Full Text Available Previous research has shown that adults with dyslexia (AwD are disproportionately impacted by close spacing of stimuli and increased numbers of distractors in a visual search task compared to controls [1]. Using an orientation discrimination task, the present study extended these findings to show that even in conditions where target search was not required: (i AwD had detrimental effects of both crowding and increased numbers of distractors; (ii AwD had more pronounced difficulty with distractor exclusion in the left visual field and (iii measures of crowding and distractor exclusion correlated significantly with literacy measures. Furthermore, such difficulties were not accounted for by the presence of covarying symptoms of ADHD in the participant groups. These findings provide further evidence to suggest that the ability to exclude distracting stimuli likely contributes to the reported visual attention difficulties in AwD and to the aetiology of literacy difficulties. The pattern of results is consistent with weaker and asymmetric attention in AwD.

  14. Effect of crowding, temperature and age on glia activation and dopaminergic neurotoxicity induced by MDMA in the mouse brain.

    Science.gov (United States)

    Frau, Lucia; Simola, Nicola; Porceddu, Pier Francesca; Morelli, Micaela

    2016-09-01

    3,4-methylenedyoxymethamphetamine (MDMA or "ecstasy"), a recreational drug of abuse, can induce glia activation and dopaminergic neurotoxicity. Since MDMA is often consumed in crowded environments featuring high temperatures, we studied how these factors influenced glia activation and dopaminergic neurotoxicity induced by MDMA. C57BL/6J adolescent (4 weeks old) and adult (12 weeks old) mice received MDMA (4×20mg/kg) in different conditions: 1) while kept 1, 5, or 10×cage at room temperature (21°C); 2) while kept 5×cage at either room (21°C) or high (27°C) temperature. After the last MDMA administration, immunohistochemistry was performed in the caudate-putamen for CD11b and GFAP, to mark microglia and astroglia, and in the substantia nigra pars compacta for tyrosine hydroxylase, to mark dopaminergic neurons. MDMA induced glia activation and dopaminergic neurotoxicity, compared with vehicle administration. Crowding (5 or 10 mice×cage) amplified MDMA-induced glia activation (in adult and adolescent mice) and dopaminergic neurotoxicity (in adolescent mice). Conversely, exposure to a high environmental temperature (27°C) potentiated MDMA-induced glia activation in adult and adolescent mice kept 5×cage, but not dopaminergic neurotoxicity. Crowding and exposure to a high environmental temperature amplified MDMA-induced hyperthermia, and a positive correlation between body temperature and activation of either microglia or astroglia was found in adult and adolescent mice. These results provide further evidence that the administration setting influences the noxious effects of MDMA in the mouse brain. However, while crowding amplifies both glia activation and dopaminergic neurotoxicity, a high environmental temperature exacerbates glia activation only. Copyright © 2016 Elsevier B.V. All rights reserved.

  15. Deep Learning from Crowds

    DEFF Research Database (Denmark)

    Rodrigues, Filipe; Pereira, Francisco Camara

    Over the last few years, deep learning has revolutionized the field of machine learning by dramatically improving the stateof-the-art in various domains. However, as the size of supervised artificial neural networks grows, typically so does the need for larger labeled datasets. Recently...... networks from crowds. We begin by describing an EM algorithm for jointly learning the parameters of the network and the reliabilities of the annotators. Then, a novel general-purpose crowd layer is proposed, which allows us to train deep neural networks end-to-end, directly from the noisy labels......, crowdsourcing has established itself as an efficient and cost-effective solution for labeling large sets of data in a scalable manner, but it often requires aggregating labels from multiple noisy contributors with different levels of expertise. In this paper, we address the problem of learning deep neural...

  16. Effect of anterior crowding or spacing on oral health-related quality of life: a cross-sectional study

    Directory of Open Access Journals (Sweden)

    Hassan AH

    2018-03-01

    patients with ASM reported being self-conscious. Results indicated a statistically significant association between educational level with anterior crowding malocclusion (ACM; p=0.02 and ASM (p=0.01 with Q3 “painful aching”. Moreover, findings indicated a statistically significant association (p=0.04 between income and ACM with Q5 “self-consciousness”. On the other hand, results showed no significant association between gender with either ACM or ASM.Conclusion: This study sheds light on how anterior malocclusion (crowding or spacing impacts OHRQoL negatively, especially heightening self-consciousness about their appearance. These effects should be addressed by the orthodontist during the course of treatment. Keywords: OHRQoL, malocclusion, OHIP-14, patient preference 

  17. Nitrogen fertilization has a stronger effect on soil nitrogen-fixing bacterial communities than elevated atmospheric CO2.

    Science.gov (United States)

    Berthrong, Sean T; Yeager, Chris M; Gallegos-Graves, Laverne; Steven, Blaire; Eichorst, Stephanie A; Jackson, Robert B; Kuske, Cheryl R

    2014-05-01

    Biological nitrogen fixation is the primary supply of N to most ecosystems, yet there is considerable uncertainty about how N-fixing bacteria will respond to global change factors such as increasing atmospheric CO2 and N deposition. Using the nifH gene as a molecular marker, we studied how the community structure of N-fixing soil bacteria from temperate pine, aspen, and sweet gum stands and a brackish tidal marsh responded to multiyear elevated CO2 conditions. We also examined how N availability, specifically, N fertilization, interacted with elevated CO2 to affect these communities in the temperate pine forest. Based on data from Sanger sequencing and quantitative PCR, the soil nifH composition in the three forest systems was dominated by species in the Geobacteraceae and, to a lesser extent, Alphaproteobacteria. The N-fixing-bacterial-community structure was subtly altered after 10 or more years of elevated atmospheric CO2, and the observed shifts differed in each biome. In the pine forest, N fertilization had a stronger effect on nifH community structure than elevated CO2 and suppressed the diversity and abundance of N-fixing bacteria under elevated atmospheric CO2 conditions. These results indicate that N-fixing bacteria have complex, interacting responses that will be important for understanding ecosystem productivity in a changing climate.

  18. Crowding-out effect of coal industry investment in coal mining area: taking Shanxi province in China as a case.

    Science.gov (United States)

    Li, Li; Lei, Yalin; Xu, Qun; Wu, Sanmang; Yan, Dan; Chen, Jiabin

    2017-10-01

    The rapid development of coal industry in Shanxi province in China has important effects on its economic development. A large amount of money has been invested into the coal industry and other related industries during the recent years. However, research on the investment effect of Shanxi's coal industry was rare. In order to analyze the investment effect of coal industry, based on the crowding-out effect model, cointegration test, and the data available in Shanxi Statistical Yearbooks, this paper calculates the effect between coal industry investment and other 17 industry investment. The results show that the investment of coal industry produces crowding-out effect on food industry, building materials industry, and machinery industry. Increasing 1% of the coal industry investment can reduce 0.25% of the food industry investment, or 0.6% of building materials industry investment, or 0.52% of the machinery industry investment, which implies that Shanxi province should adjust coal industrial structure, promote the balance development of coal industry and other industries, so as to promote its economic growth.

  19. The Crowding-Out Effects of Garbage Fees and Voluntary Source Separation Programs on Waste Reduction: Evidence from China

    Directory of Open Access Journals (Sweden)

    Hongyun Han

    2016-07-01

    Full Text Available This paper examines how and to what degree government policies of garbage fees and voluntary source separation programs, with free indoor containers and garbage bags, can affect the effectiveness of municipal solid waste (MSW management, in the sense of achieving a desirable reduction of per capita MSW generation. Based on city-level panel data for years 1998–2012 in China, our empirical analysis indicates that per capita MSW generated is increasing with per capita disposable income, average household size, education levels of households, and the lagged per capita MSW. While both garbage fees and source separation programs have separately led to reductions in per capita waste generation, the interaction of the two policies has resulted in an increase in per capita waste generation due to the following crowding-out effects: Firstly, the positive effect of income dominates the negative effect of the garbage fee. Secondly, there are crowding-out effects of mandatory charging system and the subsidized voluntary source separation on per capita MSW generation. Thirdly, small subsidies and tax punishments have reduced the intrinsic motivation for voluntary source separation of MSW. Thus, compatible fee charging system, higher levels of subsidies, and well-designed public information and education campaigns are required to promote household waste source separation and reduction.

  20. Microorganisms maintain crowding homeostasis

    NARCIS (Netherlands)

    van den Berg, Jonas; Boersma, Arnold J; Poolman, Bert

    2017-01-01

    Macromolecular crowding affects the mobility of biomolecules, protein folding and stability, and the association of macromolecules with each other. Local differences in crowding that arise as a result of subcellular components and supramolecular assemblies contribute to the structural organization

  1. A method of emotion contagion for crowd evacuation

    Science.gov (United States)

    Cao, Mengxiao; Zhang, Guijuan; Wang, Mengsi; Lu, Dianjie; Liu, Hong

    2017-10-01

    The current evacuation model does not consider the impact of emotion and personality on crowd evacuation. Thus, there is large difference between evacuation results and the real-life behavior of the crowd. In order to generate more realistic crowd evacuation results, we present a method of emotion contagion for crowd evacuation. First, we combine OCEAN (Openness, Extroversion, Agreeableness, Neuroticism, Conscientiousness) model and SIS (Susceptible Infected Susceptible) model to construct the P-SIS (Personalized SIS) emotional contagion model. The P-SIS model shows the diversity of individuals in crowd effectively. Second, we couple the P-SIS model with the social force model to simulate emotional contagion on crowd evacuation. Finally, the photo-realistic rendering method is employed to obtain the animation of crowd evacuation. Experimental results show that our method can simulate crowd evacuation realistically and has guiding significance for crowd evacuation in the emergency circumstances.

  2. Localization of protein aggregation in Escherichia coli is governed by diffusion and nucleoid macromolecular crowding effect.

    Directory of Open Access Journals (Sweden)

    Anne-Sophie Coquel

    2013-04-01

    Full Text Available Aggregates of misfolded proteins are a hallmark of many age-related diseases. Recently, they have been linked to aging of Escherichia coli (E. coli where protein aggregates accumulate at the old pole region of the aging bacterium. Because of the potential of E. coli as a model organism, elucidating aging and protein aggregation in this bacterium may pave the way to significant advances in our global understanding of aging. A first obstacle along this path is to decipher the mechanisms by which protein aggregates are targeted to specific intercellular locations. Here, using an integrated approach based on individual-based modeling, time-lapse fluorescence microscopy and automated image analysis, we show that the movement of aging-related protein aggregates in E. coli is purely diffusive (Brownian. Using single-particle tracking of protein aggregates in live E. coli cells, we estimated the average size and diffusion constant of the aggregates. Our results provide evidence that the aggregates passively diffuse within the cell, with diffusion constants that depend on their size in agreement with the Stokes-Einstein law. However, the aggregate displacements along the cell long axis are confined to a region that roughly corresponds to the nucleoid-free space in the cell pole, thus confirming the importance of increased macromolecular crowding in the nucleoids. We thus used 3D individual-based modeling to show that these three ingredients (diffusion, aggregation and diffusion hindrance in the nucleoids are sufficient and necessary to reproduce the available experimental data on aggregate localization in the cells. Taken together, our results strongly support the hypothesis that the localization of aging-related protein aggregates in the poles of E. coli results from the coupling of passive diffusion-aggregation with spatially non-homogeneous macromolecular crowding. They further support the importance of "soft" intracellular structuring (based on

  3. Effects of Ala-Gln feeding strategies on growth, metabolism, and crowding stress resistance of juvenile Cyprinus carpio var. Jian.

    Science.gov (United States)

    Chen, Xiu-Mei; Guo, Gui-Liang; Sun, Li; Yang, Qiu-Shi; Wang, Gui-Qin; Qin, Gui-Xin; Zhang, Dong-Ming

    2016-04-01

    The present study was conducted to evaluate the effects of different L-alanyl-l-glutamine (Ala-Gln) feeding strategies on the growth performance, metabolism and crowding stress resistance related parameters in juvenile Jian carp (Cyprinus carpio var. Jian) under crowded condition (80 g/L). Juvenile Jian carp (initial weight 26.1 ± 0.6 g) were distributed into five groups which fed with graded concentrations (0% or 1.0%) of Ala-Gln for eight weeks. Control group (I, 0/0) fed with control diet (0% Ala-Gln) throughout the feeding trial. The other four groups employed different control and experimental diet feeding strategies ranging from two weeks control diet fed and two weeks experimental diet (1% Ala-Gln) fed (II, 0/2) to eight weeks experimental diet fed (V, 4/4). Results revealed that Mean weight gain (MEG) under all different feeding strategies of Ala-Gln were significantly higher than that of the control group (p < 0.05), and MEG of group II (201.90%) was even higher than that of group IV (184.70%). Liver glycogen and blood total protein of groups II, III and V were significantly higher than that in groups I and IV (p < 0.05). The highest level of serum thyroxine (10.07 ng/ml), insulin-like growth factor-I (52.40 ng/ml) and insulin (9.73 μ IU/mL) were observed in group V. However, diet supplemented with Ala-Gln did not affect the levels of serum glucose, cortisol and catecholamine in fish. The mRNA expression of GR1a, GR1b and GR2 were also significantly changed in Ala-Gln supplementation groups compared with control group (p < 0.05). After fish intraperitoneally injected with virulent Aeromonas hydrophila, the fish survival rates were significantly increased in all Ala-Gln supplementation groups compared with control group (p < 0.05). Results from the present experiment showed the importance of dietary supplementation of Ala-Gln in benefaction of the growth performance, metabolism and crowding stress resistance in Jian carp breeding. The

  4. The effects of visual crowding, text size, and positional uncertainty on text legibility at a glance.

    Science.gov (United States)

    Dobres, Jonathan; Wolfe, Benjamin; Chahine, Nadine; Reimer, Bryan

    2018-07-01

    Reading at a glance, once a relatively infrequent mode of reading, is becoming common. Mobile interaction paradigms increasingly dominate the way in which users obtain information about the world, which often requires reading at a glance, whether from a smartphone, wearable device, or in-vehicle interface. Recent research in these areas has shown that a number of factors can affect text legibility when words are briefly presented in isolation. Here we expand upon this work by examining how legibility is affected by more crowded presentations. Word arrays were combined with a lexical decision task, in which the size of the text elements and the inter-line spacing (leading) between individual items were manipulated to gauge their relative impacts on text legibility. In addition, a single-word presentation condition that randomized the location of presentation was compared with previous work that held position constant. Results show that larger text was more legible than smaller text. Wider leading significantly enhanced legibility as well, but contrary to expectations, wider leading did not fully counteract decrements in legibility at smaller text sizes. Single-word stimuli presented with random positioning were more difficult to read than stationary counterparts from earlier studies. Finally, crowded displays required much greater processing time compared to single-word displays. These results have implications for modern interface design, which often present interactions in the form of scrollable and/or selectable lists. The present findings are of practical interest to the wide community of graphic designers and interface engineers responsible for developing our interfaces of daily use. Copyright © 2018 Elsevier Ltd. All rights reserved.

  5. Unpaid Crowd Complementors

    DEFF Research Database (Denmark)

    Boudreau, Kevin J.; Jeppesen, Lars Bo

    2014-01-01

    on network effects and strategies to attract large numbers of complementors remain advisable in such contexts? We test hypotheses related to these issues using data from 85 online multi-player game platforms with unpaid complementors. We find that complementor development responds to platform growth even......Platforms have evolved beyond just being organized as multi-sided markets with complementors selling to users. Complementors are often unpaid, working outside of a price system and driven by heterogeneous sources of motivation— which should affect how they respond to platform growth. Does reliance...... without sales incentives, but that attracting complementors has a net zero effect on on-going development and fails to stimulate network effects. We discuss conditions under which a strategy of using unpaid crowd complementors remains advantageous....

  6. Crowding and Density

    Science.gov (United States)

    Design and Environment, 1972

    1972-01-01

    Three-part report pinpointing problems and uncovering solutions for the dual concepts of density (ratio of people to space) and crowding (psychological response to density). Section one, A Primer on Crowding,'' reviews new psychological and social findings; section two, Density in the Suburbs,'' shows conflict between status quo and increased…

  7. Orientation-crowding within contours.

    Science.gov (United States)

    Glen, James C; Dakin, Steven C

    2013-07-15

    We examined how crowding (the breakdown of object recognition in the periphery caused by interference from "clutter") depends on the global arrangement of target and distracting flanker elements. Specifically we probed orientation discrimination using a near-vertical target Gabor flanked by two vertical distractor Gabors (one above and one below the target). By applying variable (opposite-sign) horizontal offsets to the positions of the two flankers we arranged the elements so that on some trials they formed contours with the target and on others they did not. While the presence of flankers generally elevated orientation discrimination thresholds for the target we observe maximal crowding not when flanker and targets were co-aligned but when a small spatial offset was applied to flanker location, so that contours formed between flanker and targets only when the target orientation was cued. We also report that observers' orientation judgments are biased, with target orientation appearing either attracted or repulsed by the global/contour orientation. A second experiment reveals that the sign of this effect is dependent both on observer and on eccentricity. In general, the magnitude of repulsion is reduced with eccentricity but whether this becomes attraction (of element orientation to contour orientation) is dependent on observer. We note however that across observers and eccentricities, the magnitude of repulsion correlates positively with the amount of release from crowding observed with co-aligned targets and flankers, supporting the notion of fluctuating bias as the basis for elevated crowding within contours.

  8. Avenues for crowd science in Hydrology.

    Science.gov (United States)

    Koch, Julian; Stisen, Simon

    2016-04-01

    Crowd science describes research that is conducted with the participation of the general public (the crowd) and gives the opportunity to involve the crowd in research design, data collection and analysis. In various fields, scientists have already drawn on underused human resources to advance research at low cost, with high transparency and large acceptance of the public due to the bottom up structure and the participatory process. Within the hydrological sciences, crowd research has quite recently become more established in the form of crowd observatories to generate hydrological data on water quality, precipitation or river flow. These innovative observatories complement more traditional ways of monitoring hydrological data and strengthen a community-based environmental decision making. However, the full potential of crowd science lies in internet based participation of the crowd and it is not yet fully exploited in the field of Hydrology. New avenues that are not primarily based on the outsourcing of labor, but instead capitalize the full potential of human capabilities have to emerge. In multiple realms of solving complex problems, like image detection, optimization tasks, narrowing of possible solutions, humans still remain more effective than computer algorithms. The most successful online crowd science projects Foldit and Galaxy Zoo have proven that the collective of tens of thousands users could clearly outperform traditional computer based science approaches. Our study takes advantage of the well trained human perception to conduct a spatial sensitivity analysis of land-surface variables of a distributed hydrological model to identify the most sensitive spatial inputs. True spatial performance metrics, that quantitatively compare patterns, are not trivial to choose and their applicability is often not universal. On the other hand humans can quickly integrate spatial information at various scales and are therefore a trusted competence. We selected

  9. Dense Crowds of Virtual Humans

    NARCIS (Netherlands)

    Stüvel, S.A.

    2016-01-01

    This thesis presents a novel crowd simulation method `Torso Crowds', aimed at the simulation of dense crowds. The method is based on the results of user studies and a motion capture experiment, which are also described in this thesis. Torso Crowds introduces a capsule shape to represent people in

  10. Effects of current crowding on light extraction efficiency of conventional GaN-based light-emitting diodes.

    Science.gov (United States)

    Cao, Bin; Li, Shuiming; Hu, Run; Zhou, Shengjun; Sun, Yi; Gan, Zhiying; Liu, Sheng

    2013-10-21

    Current crowding effects (CCEs) on light extraction efficiency (LEE) of conventional GaN-based light-emitting diodes (LEDs) are analyzed through Monte Carlo ray-tracing simulation. The non-uniform radiative power distribution of the active layer of the Monte Carlo model is obtained based on the current spreading theory and rate equation. The simulation results illustrate that CCE around n-pad (n-CCE) has little effect on LEE, while CCE around p-pad (p-CCE) results in a notable LEE droop due to the significant absorption of photons emitted under p-pad. LEE droop is alleviated by a SiO₂ current blocking layer (CBL) and reflective p-pad. Compared to the conventional LEDs without CBL, the simulated LEE of LEDs with CBL at 20 A/cm² and 70 A/cm² is enhanced by 7.7% and 19.0%, respectively. It is further enhanced by 7.6% and 11.4% after employing a reflective p-pad due to decreased absorption. These enhancements are in accordance with the experimental results. Output power of LEDs with CBL is enhanced by 8.7% and 18.2% at 20 A/cm² and 70 A/cm², respectively. And the reflective p-pad results in a further enhancement of 8.9% and 12.7%.

  11. Ecological effects of full and partial protection in the crowded Mediterranean Sea: a regional meta-analysis

    DEFF Research Database (Denmark)

    Giakoumi, Sylvaine; Scianna, Claudia; Plass-Johnson, Jeremiah Grahm

    2017-01-01

    the relationships between the level of protection and MPA size, age, and enforcement. Results revealed significant positive effects of protection for fisheries target species and negative effects for urchins as their predators benefited from protection. Full protection provided stronger effects than partial...... to inform decisions. In the human-dominated Mediterranean Sea, fully protected areas occupy only 0.04% of its surface. We evaluated the impacts of full and partial protection on biomass and density of fish assemblages, some commercially important fishes, and sea urchins in 24 Mediterranean MPAs. We explored...

  12. Simultaneous effect of initial weight, initial crowding, temperature and O2 concentration on the nutritional use of food by rainbow trout (Oncorhynchus mykiss).

    Science.gov (United States)

    Martinez, F J; Garcia, M P; Canteras, M; De Costa, J; Zamora, S

    1992-01-01

    The simultaneous effects of initial weight, initial crowding, temperature and O2 concentration on the following ratios: relative growth rate percent (RGRP), feed efficiency (FE), protein efficiency ratio (PER) and protein productive value (PPV) were studied in the rainbow trout. Multivariant equations were obtained for each of the mentioned indices. The joint effects of these factors were evidenced by means of a multiple correlation analysis. The influence of temperature and, to a lesser extent, of crowding, and O2 concentration on the nutritional use of food by the trout was demonstrated, their fundamental dependence on factors extrinsic to the animal being underlined. The non proportional changes in PER and PPV as temperature rises revealed that an increasing part of the ingested aminoacids were used for synthesis of fat, non for proteins edification.

  13. Molecular crowding defines a common origin for the Warburg effect in proliferating cells and the lactate threshold in muscle physiology.

    Directory of Open Access Journals (Sweden)

    Alexei Vazquez

    2011-04-01

    Full Text Available Aerobic glycolysis is a seemingly wasteful mode of ATP production that is seen both in rapidly proliferating mammalian cells and highly active contracting muscles, but whether there is a common origin for its presence in these widely different systems is unknown. To study this issue, here we develop a model of human central metabolism that incorporates a solvent capacity constraint of metabolic enzymes and mitochondria, accounting for their occupied volume densities, while assuming glucose and/or fatty acid utilization. The model demonstrates that activation of aerobic glycolysis is favored above a threshold metabolic rate in both rapidly proliferating cells and heavily contracting muscles, because it provides higher ATP yield per volume density than mitochondrial oxidative phosphorylation. In the case of muscle physiology, the model also predicts that before the lactate switch, fatty acid oxidation increases, reaches a maximum, and then decreases to zero with concomitant increase in glucose utilization, in agreement with the empirical evidence. These results are further corroborated by a larger scale model, including biosynthesis of major cell biomass components. The larger scale model also predicts that in proliferating cells the lactate switch is accompanied by activation of glutaminolysis, another distinctive feature of the Warburg effect. In conclusion, intracellular molecular crowding is a fundamental constraint for cell metabolism in both rapidly proliferating- and non-proliferating cells with high metabolic demand. Addition of this constraint to metabolic flux balance models can explain several observations of mammalian cell metabolism under steady state conditions.

  14. The Effects of Lipid Membranes, Crowding and Osmolytes on the Aggregation, and Fibrillation Propensity of Human IAPP

    Directory of Open Access Journals (Sweden)

    Mimi Gao

    2015-01-01

    Full Text Available Type 2 diabetes mellitus (T2DM is an age-related and metabolic disease. Its development is hallmarked, among others, by the dysfunction and degeneration of β-cells of the pancreatic islets of Langerhans. The major pathological characteristic thereby is the formation of extracellular amyloid deposits consisting of the islet amyloid polypeptide (IAPP. The process of human IAPP (hIAPP self-association, and the intermediate structures formed as well as the interaction of hIAPP with membrane systems seem to be, at least to a major extent, responsible for the cytotoxicity. Here we present a summary and comparison of the amyloidogenic propensities of hIAPP in bulk solution and in the presence of various neutral and charged lipid bilayer systems as well as biological membranes. We also discuss the cellular effects of macromolecular crowding and osmolytes on the aggregation pathway of hIAPP. Understanding the influence of different cellular factors on hIAPP aggregation will provide more insight into the onset of T2DM and help to develop novel therapeutic strategies.

  15. Water content differences have stronger effects than plant functional groups on soil bacteria in a steppe ecosystem.

    Directory of Open Access Journals (Sweden)

    Ximei Zhang

    Full Text Available Many investigations across natural and artificial plant diversity gradients have reported that both soil physicochemical factors and plant community composition affect soil microbial communities. To test the effect of plant diversity loss on soil bacterial communities, we conducted a five-year plant functional group removal experiment in a steppe ecosystem in Inner Mongolia (China. We found that the number and composition type of plant functional groups had no effect on bacterial diversity and community composition, or on the relative abundance of major taxa. In contrast, bacterial community patterns were significantly structured by soil water content differences among plots. Our results support researches that suggest that water availability is the key factor structuring soil bacterial communities in this semi-arid ecosystem.

  16. Do public works programs crowd-out pro-environmental behavior?

    DEFF Research Database (Denmark)

    Kahsay, Goytom Abraha; Kassie, Workineh Asmare; Beyene, Abebe Damte

    The Ethiopian food for work program typically induces forest conservation work. While economic outcomes have been studied before, little is known about the program’s environmental impact. We run a choice experiment among Ethiopian farmers eliciting preferences in a hypothetical afforestation...... program that mimics the Ethiopian food-for-work program. We find that introducing food incentives decreases willingness to participate in the program and participation rate increases with an increase in the proportion of individuals selected for food incentive. We also find that the crowding-out effect...... is stronger when food incentive recipients are selected based on income compared to lottery-based selection. Our data points to pro-social signaling as the most likely channel for the crowding-out effect. These results suggest that (1) food-for-work programs could have unintended negative environmental...

  17. High midday temperature stress has stronger effects on biomass than on photosynthesis: A mesocosm experiment on four tropical seagrass species.

    Science.gov (United States)

    George, Rushingisha; Gullström, Martin; Mangora, Mwita M; Mtolera, Matern S P; Björk, Mats

    2018-05-01

    The effect of repeated midday temperature stress on the photosynthetic performance and biomass production of seagrass was studied in a mesocosm setup with four common tropical species, including Thalassia hemprichii , Cymodocea serrulata , Enhalus acoroides , and Thalassodendron ciliatum . To mimic natural conditions during low tides, the plants were exposed to temperature spikes of different maximal temperatures, that is, ambient (29-33°C), 34, 36, 40, and 45°C, during three midday hours for seven consecutive days. At temperatures of up to 36°C, all species could maintain full photosynthetic rates (measured as the electron transport rate, ETR) throughout the experiment without displaying any obvious photosynthetic stress responses (measured as declining maximal quantum yield, Fv/Fm). All species except T. ciliatum could also withstand 40°C, and only at 45°C did all species display significantly lower photosynthetic rates and declining Fv/Fm. Biomass estimation, however, revealed a different pattern, where significant losses of both above- and belowground seagrass biomass occurred in all species at both 40 and 45°C (except for C. serrulata in the 40°C treatment). Biomass losses were clearly higher in the shoots than in the belowground root-rhizome complex. The findings indicate that, although tropical seagrasses presently can cope with high midday temperature stress, a few degrees increase in maximum daily temperature could cause significant losses in seagrass biomass and productivity.

  18. Crowds and Speculation

    DEFF Research Database (Denmark)

    Bondo Hansen, Kristian

    and crowd phenomena in order to fully understand how markets were perceived and conceptualised in the given historical period. Inspired by Michel Foucault’s reflections on the analysis of problematisations, the dissertation explores how practical, academic and popular accounts of financial markets...... problematised (i.e. reflected upon, contested and responded to) various crowd phenomena as they occurred in the markets. As part of the historical exposition, the dissertation examines how financial writers employed tropes and terminology from late nineteenth century crowd theories when describing and seeking....... Drawing on an archive of handbooks on how to become a successful investor or speculator, scholarly work on financial markets (from the academic fields of economics, sociology and psychology) as well as a range of popular (fictional and non-fictional) textual accounts of trading in financial markets...

  19. Engineering Requirements for crowds

    Directory of Open Access Journals (Sweden)

    Rogeiro Silva

    2015-12-01

    Full Text Available In the software project the interested parts are highly distributed and form numerous and heterogeneous groups, online or face, constituting what could be called crowds. The development of social applications and cloud computing and mobile has generated a marked increase in environments based requirements in crowds. Technical Requirements Engineering (RE traditional face these scalability issues, and require the co-presence of interested and engineers in joint meetings that can not be made in common physical environments. While different approaches have been introduced to partially automate RE in these contexts, still is required a multi-method approach to semi-automate all activities related to work with crowds. In this paper is propose an approach that integrates existing elicitation techniques and requirements analysis and is complemented by introducing new concepts. The information is collected through direct interaction and social collaboration, and through data mining techniques.

  20. Firms, crowds, and innovation.

    Science.gov (United States)

    Felin, Teppo; Lakhani, Karim R; Tushman, Michael L

    2017-05-01

    The purpose of this article is to suggest a (preliminary) taxonomy and research agenda for the topic of "firms, crowds, and innovation" and to provide an introduction to the associated special issue. We specifically discuss how various crowd-related phenomena and practices-for example, crowdsourcing, crowdfunding, user innovation, and peer production-relate to theories of the firm, with particular attention on "sociality" in firms and markets. We first briefly review extant theories of the firm and then discuss three theoretical aspects of sociality related to crowds in the context of strategy, organizations, and innovation: (1) the functions of sociality (sociality as extension of rationality, sociality as sensing and signaling, sociality as matching and identity), (2) the forms of sociality (independent/aggregate and interacting/emergent forms of sociality), and (3) the failures of sociality (misattribution and misapplication). We conclude with an outline of future research directions and introduce the special issue papers and essays.

  1. Grouping and crowding affect target appearance over different spatial scales.

    Directory of Open Access Journals (Sweden)

    Bilge Sayim

    Full Text Available Crowding is the impairment of peripheral target perception by nearby flankers. A number of recent studies have shown that crowding shares many features with grouping. Here, we investigate whether effects of crowding and grouping on target perception are related by asking whether they operate over the same spatial scale. A target letter T had two sets of flanking Ts of varying orientations. The first set was presented close to the target, yielding strong crowding. The second set was either close enough to cause crowding on their own or too far to cause crowding on their own. The Ts of the second set had the same orientation that either matched the target's orientation (Grouped condition or not (Ungrouped condition. In Experiment 1, the Grouped flankers reduced crowding independently of their distance from the target, suggesting that grouping operated over larger distances than crowding. In Experiments 2 and 3 we found that grouping did not affect sensitivity but produced a strong bias to report that the grouped orientation was present at the target location whether or not it was. Finally, we investigated whether this bias was a response or perceptual bias, rejecting the former in favor of a perceptual grouping explanation. We suggest that the effect of grouping is to assimilate the target to the identity of surrounding flankers when they are all the same, and that this shape assimilation effect differs in its spatial scale from the integration effect of crowding.

  2. An Analysis of the Effect of External Debt on Crowding-Out of Private ...

    African Journals Online (AJOL)

    Also, the huge debt and debt service raised future tax expectation and discouraged the private sector from undertaking investment projects. While the accelerator effect was present, the cost of investment goods negatively influenced private investment demand. Availability of credit seemed to have influenced the level of ...

  3. How to Mitigate Theme Park Crowding? A Prospective Coordination Approach

    Directory of Open Access Journals (Sweden)

    Yuguo Yuan

    2018-01-01

    Full Text Available Crowding is a key factor in tourists’ experience in theme parks, and mitigating crowding makes parks more competitive. This study examines how to effectively mitigate crowding in theme parks. First, a Markov-based method is developed to predict the spatial-temporal distribution of tourists in the park. Then, a prospective coordination approach based on the tourist distribution prediction is proposed. To evaluate the performance of this approach, an experiment is constructed using an agent-based simulation platform. The results indicate that the proposed method significantly outperforms existing methods. Furthermore, we conduct two experiments and, based on the results, offer several recommendations for crowd management.

  4. The Effect of Small Cosolutes that Mimic Molecular Crowding Conditions on the Stability of Triplexes Involving Duplex DNA

    Directory of Open Access Journals (Sweden)

    Anna Aviñó

    2016-02-01

    Full Text Available Triplex stability is studied in crowding conditions using small cosolutes (ethanol, acetonitrile and dimethylsulfoxide by ultraviolet (UV, circular dichroism (CD and nuclear magnetic resonance (NMR spectroscopies. The results indicate that the triplex is formed preferentially when the triplex forming oligonucleotide (TFO is RNA. In addition, DNA triplexes (D:D·D are clearly less stable in cosolute solutions while the stability of the RNA triplexes (R:D·D is only slightly decreased. The kinetic of triplex formation with RNA-TFO is slower than with DNA-TFO and the thermal stability of the triplex is increased with the salt concentration in EtOH-water solutions. Accordingly, RNA could be considered a potential molecule to form a stable triplex for regulatory purposes in molecular crowding conditions.

  5. Two-stage perceptual learning to break visual crowding.

    Science.gov (United States)

    Zhu, Ziyun; Fan, Zhenzhi; Fang, Fang

    2016-01-01

    When a target is presented with nearby flankers in the peripheral visual field, it becomes harder to identify, which is referred to as crowding. Crowding sets a fundamental limit of object recognition in peripheral vision, preventing us from fully appreciating cluttered visual scenes. We trained adult human subjects on a crowded orientation discrimination task and investigated whether crowding could be completely eliminated by training. We discovered a two-stage learning process with this training task. In the early stage, when the target and flankers were separated beyond a certain distance, subjects acquired a relatively general ability to break crowding, as evidenced by the fact that the breaking of crowding could transfer to another crowded orientation, even a crowded motion stimulus, although the transfer to the opposite visual hemi-field was weak. In the late stage, like many classical perceptual learning effects, subjects' performance gradually improved and showed specificity to the trained orientation. We also found that, when the target and flankers were spaced too finely, training could only reduce, rather than completely eliminate, the crowding effect. This two-stage learning process illustrates a learning strategy for our brain to deal with the notoriously difficult problem of identifying peripheral objects in clutter. The brain first learned to solve the "easy and general" part of the problem (i.e., improving the processing resolution and segmenting the target and flankers) and then tackle the "difficult and specific" part (i.e., refining the representation of the target).

  6. Stronger Fire-Resistant Epoxies

    Science.gov (United States)

    Fohlen, George M.; Parker, John A.; Kumar, Devendra

    1988-01-01

    New curing agent improves mechanical properties and works at lower temperature. Use of aminophenoxycyclotriphosphazene curing agents yields stronger, more heat- and fire-resistant epoxy resins. Used with solvent if necessary for coating fabrics or casting films.

  7. Optimal crowd evacuation

    NARCIS (Netherlands)

    Hoogendoorn, S.P.; Daamen, W.; Duives, D.C.; Van Wageningen-Kessels, F.L.M.

    2013-01-01

    This paper deals with the optimal allocation of routes, destination, and departure times to members of a crowd, for instance in case of an evacuation or another hazardous situation in which the people need to leave the area as quickly as possible. The generic approach minimizes the evacuation times,

  8. Simulation of Cognitive Pedestrian Agents Crowds in Crisis Situations

    Directory of Open Access Journals (Sweden)

    Margaret Lyell

    2006-06-01

    Full Text Available In crisis situations in an urban environment, first responder teams often must deal with crowds of people. Consider the case of a building fire in a dense city environment. People may be injured; walkways may be blocked, with fire equipment attempting to reach the scene. Crowd behavior can become an issue when trying to reach the injured, ensure safety and restore conditions to normal. The motivations of pedestrians that form the crowd can vary. Some are there because they are curious about the crisis situation. Others, attending to their individual concerns, may have found themselves in the 'wrong' location. They may be trying to leave the area, but the density of people as well as the spatial layout of the walkways may be impeding their progress. Other individuals, unaware of the fire, may be attempting to reach their intended destinations that happen to be near the crisis area, thus adding to crowd congestion. With a model of crowd behavior, effective strategies for resource usage in managing crowd behavior can be developed. Our approach to this problem is that of agent-based modeling and simulation. We develop a cognitive pedestrian agent model. Utilizing this model, we simulate crowd behavior in a 'city fire' scenario. Characteristics of crowd behavior with different pedestrian personality mixes and a strategy for crowd management are investigated

  9. Fluorescence Dynamics of a FRET Probe Designed for Crowding Studies

    NARCIS (Netherlands)

    Currie, Megan; Leopold, Hannah; Schwarz, Jacob; Boersma, Arnold J; Sheets, Erin D; Heikal, Ahmed A

    2017-01-01

    Living cells are crowded with macromolecules and organelles. As a result, there is an urgent need for molecular sensors for quantitative, site-specific assessment of the macromolecular crowding effects on a myriad of biochemical processes toward quantitative cell biology and biophysics. Here we

  10. Crowds and Crisis

    DEFF Research Database (Denmark)

    Borch, Christian

    The November Revolution in 1918 made manifest and further unleashed a political crisis in Germany, the consequences of which have been thoroughly examined. What has attracted less attention is how the Revolution also triggered a semantic crisis within sociology, namely with regard to conceptions...... selected aspects of classical crowd semantics – in particular notions of imitation and suggestibility – and for placing them centrally in the understanding of the social, in times of crisis and not....

  11. Prospects for stronger calandria tubes

    International Nuclear Information System (INIS)

    Ells, C.E.; Coleman, C.E.; Hosbons, R.R.; Ibrahim, E.F.; Doubt, G.L.

    1990-12-01

    The CANDU calandria tubes, made of seam welded and annealed Zircaloy-2, have given exemplary service in-reactor. Although not designed as a system pressure containment, calandria tubes may remain intact even in the face of pressure tube rupture. One such incident at Pickering Unit 2 demonstrated the economic advantage of such an outcome, and a case can be made for increasing the probability that other calandria tubes would perform in a similar fashion. Various methods of obtaining stronger calandria tubes are available, and reviewed here. When the tubes are internally pressurized, the weld is the weak section of the tube. Increasing the oxygen concentration in the starting sheet, and thickening the weld, are promising routes to a stronger tube

  12. Taming Crowded Visual Scenes

    Science.gov (United States)

    2014-08-12

    Nolan Warner, Mubarak Shah. Tracking in Dense Crowds Using Prominenceand Neighborhood Motion Concurrence, IEEE Transactions on Pattern Analysis...of  computer  vision,   computer   graphics  and  evacuation  dynamics  by  providing  a  common  platform,  and  provides...areas  that  includes  Computer  Vision,  Computer   Graphics ,  and  Pedestrian   Evacuation  Dynamics.  Despite  the

  13. Smoke in the Looking Glass: Effects of Discordance between Self- and Peer Rated Crowd Affiliation on Adolescent Anxiety, Depression and Self-Feelings

    Science.gov (United States)

    Brown, B. Bradford; Von Bank, Heather; Steinberg, Laurence

    2008-01-01

    Peer crowds serve as an identity marker for adolescents, indicating their image and status among peers; but adolescents do not always endorse peer appraisals of crowd affiliation. We report on two studies--one with 924 adolescents in grades 7-12 and a second with a more diverse population of 2,728 students in grades 9-11, followed for 2…

  14. Exits in order: How crowding affects particle lifetimes

    Energy Technology Data Exchange (ETDEWEB)

    Penington, Catherine J.; Simpson, Matthew J. [School of Mathematical Sciences, Queensland University of Technology, Brisbane (Australia); Baker, Ruth E. [Mathematical Institute, University of Oxford, Radcliffe Observatory Quarter, Woodstock Road, Oxford (United Kingdom)

    2016-06-28

    Diffusive processes are often represented using stochastic random walk frameworks. The amount of time taken for an individual in a random walk to intersect with an absorbing boundary is a fundamental property that is often referred to as the particle lifetime, or the first passage time. The mean lifetime of particles in a random walk model of diffusion is related to the amount of time required for the diffusive process to reach a steady state. Mathematical analysis describing the mean lifetime of particles in a standard model of diffusion without crowding is well known. However, the lifetime of agents in a random walk with crowding has received much less attention. Since many applications of diffusion in biology and biophysics include crowding effects, here we study a discrete model of diffusion that incorporates crowding. Using simulations, we show that crowding has a dramatic effect on agent lifetimes, and we derive an approximate expression for the mean agent lifetime that includes crowding effects. Our expression matches simulation results very well, and highlights the importance of crowding effects that are sometimes overlooked.

  15. Setting up crowd science projects.

    Science.gov (United States)

    Scheliga, Kaja; Friesike, Sascha; Puschmann, Cornelius; Fecher, Benedikt

    2016-11-29

    Crowd science is scientific research that is conducted with the participation of volunteers who are not professional scientists. Thanks to the Internet and online platforms, project initiators can draw on a potentially large number of volunteers. This crowd can be involved to support data-rich or labour-intensive projects that would otherwise be unfeasible. So far, research on crowd science has mainly focused on analysing individual crowd science projects. In our research, we focus on the perspective of project initiators and explore how crowd science projects are set up. Based on multiple case study research, we discuss the objectives of crowd science projects and the strategies of their initiators for accessing volunteers. We also categorise the tasks allocated to volunteers and reflect on the issue of quality assurance as well as feedback mechanisms. With this article, we contribute to a better understanding of how crowd science projects are set up and how volunteers can contribute to science. We suggest that our findings are of practical relevance for initiators of crowd science projects, for science communication as well as for informed science policy making. © The Author(s) 2016.

  16. Setting up crowd science projects

    NARCIS (Netherlands)

    Scheliga, Kaja; Friesike, Sascha; Puschmann, Cornelius; Fecher, Benedikt

    2016-01-01

    Crowd science is scientific research that is conducted with the participation of volunteers who are not professional scientists. Thanks to the Internet and online platforms, project initiators can draw on a potentially large number of volunteers. This crowd can be involved to support data-rich or

  17. Molecular Crowding and Early Evolution

    Science.gov (United States)

    Saha, Ranajay; Pohorille, Andrew; Chen, Irene A.

    2014-12-01

    The environment of protocells might have been crowded with small molecules and functional and non-specific polymers. In addition to altering conformational equilibria, affecting reaction rates and changing the structure and activity of water, crowding might have enhanced the capabilities of protocells for evolutionary innovation through the creation of extended neutral networks in the fitness landscape.

  18. Molecular crowding and early evolution.

    Science.gov (United States)

    Saha, Ranajay; Pohorille, Andrew; Chen, Irene A

    2014-12-01

    The environment of protocells might have been crowded with small molecules and functional and non-specific polymers. In addition to altering conformational equilibria, affecting reaction rates and changing the structure and activity of water, crowding might have enhanced the capabilities of protocells for evolutionary innovation through the creation of extended neutral networks in the fitness landscape.

  19. Effects of soft interactions and bound mobility on diffusion in crowded environments: a model of sticky and slippery obstacles

    Science.gov (United States)

    Stefferson, Michael W.; Norris, Samantha L.; Vernerey, Franck J.; Betterton, Meredith D.; E Hough, Loren

    2017-08-01

    Crowded environments modify the diffusion of macromolecules, generally slowing their movement and inducing transient anomalous subdiffusion. The presence of obstacles also modifies the kinetics and equilibrium behavior of tracers. While previous theoretical studies of particle diffusion have typically assumed either impenetrable obstacles or binding interactions that immobilize the particle, in many cellular contexts bound particles remain mobile. Examples include membrane proteins or lipids with some entry and diffusion within lipid domains and proteins that can enter into membraneless organelles or compartments such as the nucleolus. Using a lattice model, we studied the diffusive movement of tracer particles which bind to soft obstacles, allowing tracers and obstacles to occupy the same lattice site. For sticky obstacles, bound tracer particles are immobile, while for slippery obstacles, bound tracers can hop without penalty to adjacent obstacles. In both models, binding significantly alters tracer motion. The type and degree of motion while bound is a key determinant of the tracer mobility: slippery obstacles can allow nearly unhindered diffusion, even at high obstacle filling fraction. To mimic compartmentalization in a cell, we examined how obstacle size and a range of bound diffusion coefficients affect tracer dynamics. The behavior of the model is similar in two and three spatial dimensions. Our work has implications for protein movement and interactions within cells.

  20. The sound of the crowd: auditory information modulates the perceived emotion of a crowd based on bodily expressions.

    Science.gov (United States)

    McHugh, Joanna E; Kearney, Gavin; Rice, Henry; Newell, Fiona N

    2012-02-01

    Although both auditory and visual information can influence the perceived emotion of an individual, how these modalities contribute to the perceived emotion of a crowd of characters was hitherto unknown. Here, we manipulated the ambiguity of the emotion of either a visual or auditory crowd of characters by varying the proportions of characters expressing one of two emotional states. Using an intersensory bias paradigm, unambiguous emotional information from an unattended modality was presented while participants determined the emotion of a crowd in an attended, but different, modality. We found that emotional information in an unattended modality can disambiguate the perceived emotion of a crowd. Moreover, the size of the crowd had little effect on these crossmodal influences. The role of audiovisual information appears to be similar in perceiving emotion from individuals or crowds. Our findings provide novel insights into the role of multisensory influences on the perception of social information from crowds of individuals. PsycINFO Database Record (c) 2012 APA, all rights reserved

  1. Motivating crowding theory - opening the black box of intrinsic motivation

    DEFF Research Database (Denmark)

    Jacobsen, Christian Bøtcher

    2010-01-01

    Public employees work for many other reasons than because they are paid for it. In other words, intrinsic motivation is an important determinant for their performance. Nonetheless, public sector organizations increasingly rely on extrinsic motivation factors such as monetary incentives to motivate...... employees. Motivation crowding theory claims that this may be at the expense of intrinsic motivation, if the extrinsic motivation factor is perceived to be controlling. On the other hand, intrinsic motivation will be enhanced (crowded in), if the extrinsic motivation factor is perceived to be supportive......, monetary incentives are found to cause different crowding effects for these different types of intrinsic motivation. The results call for more theoretical work on the drivers of motivation crowding effects and for practitioners to pay more attention to what type of intrinsic motivation is at stake, when...

  2. Strategy and your stronger hand.

    Science.gov (United States)

    Moore, Geoffrey A

    2005-12-01

    There are two kinds of businesses in the world, says the author. Knowing what they are--and which one your company is--will guide you to the right strategic moves. One kind includes businesses that compete on a complex-systems model. These companies have large enterprises as their primary customers. They seek to grow a customer base in the thousands, with no more than a handful of transactions per customer per year (indeed, in some years there may be none), and the average price per transaction ranges from six to seven figures. In this model, 1,000 enterprises each paying dollar 1 million per year would generate dollar 1 billion in annual revenue. The other kind of business competes on a volume-operations model. Here, vendors seek to acquire millions of customers, with tens or even hundreds of transactions per customer per year, at an average price of relatively few dollars per transaction. Under this model, it would take 10 million customers each spending dollar 8 per month to generate nearly dollar 1 billion in revenue. An examination of both models shows that they could not be further apart in their approach to every step along the classic value chain. The problem, though, is that companies in one camp often attempt to create new value by venturing into the other. In doing so, they fail to realize how their managerial habits have been shaped by the model they've grown up with. By analogy, they have a "handedness"--the equivalent of a person's right- or left-hand dominance--that makes them as adroit in one mode as they are awkward in the other. Unless you are in an industry whose structure forces you to attempt ambidexterity (in which case, special efforts are required to manage the inevitable dropped balls), you'll be far more successful making moves that favor your stronger hand.

  3. Social crowding in the night-time reduces an anxiety-like behavior and increases social interaction in adolescent mice.

    Science.gov (United States)

    Ago, Yukio; Tanaka, Tatsunori; Ota, Yuki; Kitamoto, Mari; Imoto, Emina; Takuma, Kazuhiro; Matsuda, Toshio

    2014-08-15

    Rearing in crowded conditions is a psychosocial stressor that affects biological functions. The effects of continuous crowding for many days have been studied, but those of crowding over a limited time have not. In this study, we examined the effects of night-time or daytime crowding over 2 weeks on behavior in adolescent and adult mice. Crowding (20 mice/cage) in either the night-time or daytime did not affect locomotor activity in the open field test or cognitive function in the fear conditioning test. In contrast, night-time crowding, but not daytime crowding, had an anxiolytic effect in the elevated plus-maze test and increased social interaction in adolescent mice, but not in adult mice. The first night-time, but not daytime, crowding increased plasma corticosterone levels in adolescent mice, although night-time crowding over 2 weeks did not affect the corticosterone levels. Furthermore, no significant effects of the first crowding were observed in adult mice. In a second crowding condition (six mice/small cage), the anxiolytic-like effects of night-time crowding and the change in plasma corticosterone levels were not observed, suggesting that the density of mice is not important for the behavioral consequences of crowding. Night-time crowding did not affect neurotrophic/growth factor levels and hippocampal neurogenesis in adolescent mice. These findings suggest that night-time crowding leads to anxiolytic-like behaviors in adolescent mice, and imply that night-time crowding stress in adolescence may be beneficial to brain functions. Copyright © 2014 Elsevier B.V. All rights reserved.

  4. What Macromolecular Crowding Can Do to a Protein

    Science.gov (United States)

    Kuznetsova, Irina M.; Turoverov, Konstantin K.; Uversky, Vladimir N.

    2014-01-01

    The intracellular environment represents an extremely crowded milieu, with a limited amount of free water and an almost complete lack of unoccupied space. Obviously, slightly salted aqueous solutions containing low concentrations of a biomolecule of interest are too simplistic to mimic the “real life” situation, where the biomolecule of interest scrambles and wades through the tightly packed crowd. In laboratory practice, such macromolecular crowding is typically mimicked by concentrated solutions of various polymers that serve as model “crowding agents”. Studies under these conditions revealed that macromolecular crowding might affect protein structure, folding, shape, conformational stability, binding of small molecules, enzymatic activity, protein-protein interactions, protein-nucleic acid interactions, and pathological aggregation. The goal of this review is to systematically analyze currently available experimental data on the variety of effects of macromolecular crowding on a protein molecule. The review covers more than 320 papers and therefore represents one of the most comprehensive compendia of the current knowledge in this exciting area. PMID:25514413

  5. To See (Like a Crowd

    Directory of Open Access Journals (Sweden)

    Hazem Ziada

    2015-07-01

    Full Text Available This paper explores the dynamics through which design drawings structure spatial strategies, particularly those with an agenda for socio-political change, while interrogating the drawings’ impacts on subjectivity. It dissects an early Soviet architectural drawing addressing the 1920s-30s' crowd-design-problem': using architectural space to generate a robust intersubjectivity in mass crowds. Revolutionary Soviet artists challenged inherited graphic regimes of viewing crowds from an alienating distance, proposing devices of 'immersion' to radically re-visualize mass crowds and re-conceptualize collectivity. Drawing on Suprematist compositions, the avant-garde Soviet Rationalist architects translated immersive principles from contemporary revolutionary art. The paper articulates the Rationalists’ alternative graphic framework which immerses the observer-cum-designer within crowd dynamics in a distinctively architectural way, while identifying its implications on spatial design: a space of undulating grounds, rhythmic choreographies and ‘textured’ visual fields. The paper also speculates on its implications redefining subjectivity; re-introducing emotion amongst the relations of production challenges canonical Historical Materialism.

  6. Working Longer Makes Students Stronger?

    DEFF Research Database (Denmark)

    Jensen, Vibeke Myrup

    Abstract: Despite much discussion on the role of education policy on school and student performance, we know little about the effects of school spending at the margin on student cognitive achievement beyond the effects of class size. Thus this paper examines the effects of annual ninth grade...... classroom hours in literacy and maths on ninth grade (aged 16) student performance in writing and maths, respectively. Using population data for Denmark in 2003-2006, I exploit unique policy-induced variation in classroom hours.On average, the reform changed classroom hours by 2.2-3.3% in literacy and maths...

  7. Effects of l-tryptophan on the growth, intestinal enzyme activities and non-specific immune response of sea cucumber (Apostichopus japonicus Selenka) exposed to crowding stress.

    Science.gov (United States)

    Zhang, Endong; Dong, Shuanglin; Wang, Fang; Tian, Xiangli; Gao, Qinfeng

    2018-04-01

    In order to reveal the effects of l-tryptophan (Trp) on the physiology and immune response of sea cucumber (Apostichopus japonicus Selenka) exposed to crowding stress, four density groups of sea cucumbers (i.e. 4, 8, 16 and 32 individuals per 40 L water, represented as L, ML, MH and H) were fed with diets containing 0, 1, 3 and 5% l-tryptophan respectively for 75 days. The results showed that the specific growth rates (SGR) of the sea cucumber fed with diet with 3% Trp (L, 2.1; ML, 1.76; MH, 1.2; H, 0.7) were significantly higher than those fed with basal diet without Trp supplementation (P sea cucumber fed diets with Trp (3%) had significantly higher phagocytic activities (0.28 OD540/10 6  cells, H) in coelomic fluid and respiratory burst activities (0.105 OD630/10 6  cells, MH) (P < .05). The results suggested that Trp cannot improve superoxide dismutase (SOD) activity at L, ML and MH densities. The alkaline phosphatase activity (AKP) significantly decreased at H stress density. Under the experimental conditions, the present results confirmed that a diet supplemented with 3% Trp was able to enhance intestinal enzyme activities, non-specific immune response and higher growth performance of A. japonicus. Copyright © 2018 Elsevier Ltd. All rights reserved.

  8. Theory of molecular crowding in Brownian hard-sphere liquids.

    Science.gov (United States)

    Zaccone, Alessio; Terentjev, Eugene M

    2012-06-01

    We derive an analytical pair potential of mean force for Brownian molecules in the liquid state. Our approach accounts for many-particle correlations of crowding particles of the liquid and for diffusive transport across the spatially modulated local density of crowders in the dense environment. Focusing on the limit of equal-size particles, we show that this diffusive transport leads to additional density- and structure-dependent terms in the interaction potential and to a much stronger attraction (by a factor of ≈4 at average volume fraction of crowders φ{0}=0.25) than in the standard depletion interaction where the diffusive effects are neglected. As an illustration of the theory, we use it to study the size of a polymer chain in a solution of inert crowders. Even in the case of an athermal background solvent, when a classical chain should be fully swollen, we find a sharp coil-globule transition of the ideal chain collapsing at a critical value of the crowder volume fraction φ{c}≈0.145.

  9. A stronger perfume for LPG

    Energy Technology Data Exchange (ETDEWEB)

    Willcox, C.K.

    1996-11-01

    The odorisation of Liquefied Petroleum Gas (LPG) is undertaken to improve the safe use and transport of this popular fuel. Effective LPG odorisation should enable leaks to be detected by any person with a normal sense of smell before gas concentrations reach a hazardous level. The objective is identical to that for odorising natural gas. However, the physical characteristics of propane and butane present particular difficulties. These do not occur with natural gas, which has a dynamic, flowing, simple-phase system. (author)

  10. A stronger perfume for LPG

    International Nuclear Information System (INIS)

    Willcox, C.K.

    1996-01-01

    The odorisation of Liquefied Petroleum Gas (LPG) is undertaken to improve the safe use and transport of this popular fuel. Effective LPG odorisation should enable leaks to be detected by any person with a normal sense of smell before gas concentrations reach a hazardous level. The objective is identical to that for odorising natural gas. However, the physical characteristics of propane and butane present particular difficulties. These do not occur with natural gas, which has a dynamic, flowing, simple-phase system. (author)

  11. Thermodynamics of Macromolecular Association in Heterogeneous Crowding Environments: Theoretical and Simulation Studies with a Simplified Model.

    Science.gov (United States)

    Ando, Tadashi; Yu, Isseki; Feig, Michael; Sugita, Yuji

    2016-11-23

    The cytoplasm of a cell is crowded with many different kinds of macromolecules. The macromolecular crowding affects the thermodynamics and kinetics of biological reactions in a living cell, such as protein folding, association, and diffusion. Theoretical and simulation studies using simplified models focus on the essential features of the crowding effects and provide a basis for analyzing experimental data. In most of the previous studies on the crowding effects, a uniform crowder size is assumed, which is in contrast to the inhomogeneous size distribution of macromolecules in a living cell. Here, we evaluate the free energy changes upon macromolecular association in a cell-like inhomogeneous crowding system via a theory of hard-sphere fluids and free energy calculations using Brownian dynamics trajectories. The inhomogeneous crowding model based on 41 different types of macromolecules represented by spheres with different radii mimics the physiological concentrations of macromolecules in the cytoplasm of Mycoplasma genitalium. The free energy changes of macromolecular association evaluated by the theory and simulations were in good agreement with each other. The crowder size distribution affects both specific and nonspecific molecular associations, suggesting that not only the volume fraction but also the size distribution of macromolecules are important factors for evaluating in vivo crowding effects. This study relates in vitro experiments on macromolecular crowding to in vivo crowding effects by using the theory of hard-sphere fluids with crowder-size heterogeneity.

  12. Spatial and Social Aspects of Crowding Perception

    Science.gov (United States)

    Baum, Andrew; Davis, Glenn E.

    1976-01-01

    This paper discusses mediation of the crowding experience in architectural interiors by three environmental variables: setting orientation, room color, and visual complexity of the interior. Data indicated interior design does influence space perception and crowding thresholds. (RH)

  13. Towards a South African crowd control model

    CSIR Research Space (South Africa)

    Modise, M

    2013-03-01

    Full Text Available . Phase 3, will be the development of decision support system for crowd control. This paper discusses Phase 1 of the project, which includes identification of various variables regarding crowd control and their relationships. During the Arab Spring...

  14. Female Psychology in August Strindberg's the Stronger

    OpenAIRE

    Sutandio, Anton; Apriliani, Erica

    2017-01-01

    This research aimed to offer interpretations of August Strindberg's The Stronger through the lens of female psychology. The Stronger is unique as it seemed very simple yet so intense and powerful with layers of interpretations. Written during 1888-1889, The Stronger, which only had two characters and only one speaking character, had become one of Strindberg's shortest yet important plays during his career. The female psychology approach used in the analysis would cover the discussion of gende...

  15. The allocation of attention and working memory in visual crowding.

    Science.gov (United States)

    Bacigalupo, Felix; Luck, Steven J

    2015-06-01

    When the distance between a visual target and nearby flankers falls below a critical distance, target discrimination declines precipitously. This is called "crowding." Many researchers have proposed that selective attention plays a role in crowding. However, although some research has examined the effects of directing attention toward versus away from the targets, no previous research has assessed how attentional allocation varies as a function of target-flanker distance in crowding. Here, we used ERPs to assess the operation of attention during crowding, focusing on the attention-related N2pc component. We used a typical crowding task in which participants were asked to report the category (vowel/consonant) of a lateralized target letter flanked by distractor letters at different distances. We tested the hypothesis that attention fails when the target-flanker distance becomes too small for attention to operate effectively. Consistent with this hypothesis, we found that N2pc amplitude was maximal at intermediate target-flanker distances and decreased substantially when crowding became severe. In addition, we examined the sustained posterior contralateral negativity (SPCN), which reflects the amount of information being maintained in working memory. Unlike the N2pc component, the SPCN increased in amplitude at small target-flanker distances, suggesting that observers stored information about the target and flankers in working memory when attention failed to select the target. Together, the N2pc and SPCN results suggest that attention and working memory play distinctive roles in crowding: Attention operates to minimize interference from the flankers at intermediate target-flanker distances, whereas working memory may be recruited when attention fails to select the target at small target-flanker distances.

  16. [The effect of prison crowding on prisoners' violence in Japan: testing with cointegration regressions and error correction models].

    Science.gov (United States)

    Yuma, Yoshikazu

    2010-08-01

    This research examined the effect of prison population densities (PPD) on inmate-inmate prison violence rates (PVR) in Japan using one-year-interval time-series data (1972-2006). Cointegration regressions revealed a long-run equilibrium relationship between PPD and PVR. PPD had a significant and increasing effect on PVR in the long-term. Error correction models showed that in the short-term, the effect of PPD was significant and positive on PVR, even after controlling for the effects of the proportions of males, age younger than 30 years, less than one-year incarceration, and prisoner/staff ratio. The results were discussed in regard to (a) differences between Japanese prisons and prisons in the United States, and (b) methodological problems found in previous research.

  17. Anchorage onto deciduous teeth: effectiveness of early rapid maxillary expansion in increasing dental arch dimension and improving anterior crowding

    OpenAIRE

    Mutinelli, Sabrina; Manfredi, Mario; Guiducci, Antonio; Denotti, Gloria; Cozzani, Mauro

    2015-01-01

    Background Anchorage onto permanent dentition is a common procedure in rapid maxillary expansion. However, replacing first permanent molars with the second deciduous molars seems to be an option to reduce some negative side effects during orthodontic treatment. The purpose of this study was to evaluate the dental effect of rapid maxillary expansion with anchorage exclusively onto deciduous teeth performed in the first period of transition. Methods Twenty patients with a lateral cross-bite tre...

  18. Females engage in stronger relationships: positive and negative effects of shrubs are more intense for Poa ligularis females than for males.

    Science.gov (United States)

    Graff, Pamela; Aguiar, Martin R; Almeida, Rocio J

    2018-05-22

    Dioecious plants are of particular concern in view of global environmental changes because reproductive females are more sensitive to abiotic stresses, thus compromising population viability. Positive interactions with other plants may counteract the direct effects of any abiotic environmental stress, allowing them to thrive and maintain a viable population in suboptimal habitats, although this process has not been tested for dioecious species. Furthermore, almost no data are available on the outcome of such species interactions and their link with local spatial patterns and sex ratios. We set up a field experiment with Poa ligularis, a dioecious native grass from the arid grasslands of South America. We studied the interaction of male and female plants with cushion shrubs of contrasting ecological strategies. We experimentally limited direct shrub-grass competition for soil moisture and transplanted plants to evaluate the amelioration of abiotic stress by shrub canopies (i.e. sun and wind) on grasses. We also studied the distribution of naturally established female and male plants to infer process-pattern relationships. Positive canopy effects as well as negative below-ground effects were more intense for females than for males. Deep-rooted Mulinum spinosum shrubs strongly facilitated survival, growth and reproduction of P. ligularis females. Naturally established female plants tended to distribute more closely to Mulinum than co-occurring males. Female growth suffered intensive negative root competition from the shallow-rooted Senecio filaginoides shrub. Interactions with other plants may reduce or enhance the effect of abiotic stresses on the seemingly maladapted sex to arid environments. We found that these biased interactions are evident in the current organization of sexes in the field, confirming our experimental findings. Therefore, indirect effects of climate change on population sex ratios may be expected if benefactor species abundances are

  19. Modelling asymmetric growth in crowded plant communities

    DEFF Research Database (Denmark)

    Damgaard, Christian

    2010-01-01

    A class of models that may be used to quantify the effect of size-asymmetric competition in crowded plant communities by estimating a community specific degree of size-asymmetric growth for each species in the community is suggested. The model consists of two parts: an individual size......-asymmetric growth part, where growth is assumed to be proportional to a power function of the size of the individual, and a term that reduces the relative growth rate as a decreasing function of the individual plant size and the competitive interactions from other plants in the neighbourhood....

  20. Faster, higher, stronger, older: Relative age effects are most influential during the youngest age grade of track and field athletics in the United Kingdom.

    Science.gov (United States)

    Kearney, Philip E; Hayes, Philip R; Nevill, Alan

    2018-03-07

    The relative age effect (RAE) is a common phenomenon in youth sport, whereby children born early in the selection year are more likely to experience success and to sustain participation. There is a lack of research investigating variables which influence RAEs within track and field athletics. Such information is vital to guide policies in relation to competition structure, youth development squads and coach education. A database of competition results was analysed to determine the extent to which RAEs were present in track and field athletics in the United Kingdom. Subsequent analyses examined whether age, sex, event and skill level influenced the RAE. Examination of 77,571 records revealed that RAEs were widespread, but most pronounced during Under 13 (U13) competitions; that is, during athletes' first exposure to formal track and field competition. Sex, event and skill level further influenced the existence and magnitude of RAEs at different age grades. Relative age is a key influencing factor within track and field athletics, especially at the youngest age category. Consequently, national governing bodies need to consider what administrative and stakeholder initiatives are necessary to minimise the effects of RAEs on young athletes' early experiences of competition.

  1. The wisdom of the crowd playing The Price Is Right.

    Science.gov (United States)

    Lee, Michael D; Zhang, Shunan; Shi, Jenny

    2011-07-01

    In The Price Is Right game show, players compete to win a prize, by placing bids on its price. We ask whether it is possible to achieve a "wisdom of the crowd" effect, by combining the bids to produce an aggregate price estimate that is superior to the estimates of individual players. Using data from the game show, we show that a wisdom of the crowd effect is possible, especially by using models of the decision-making processes involved in bidding. The key insight is that, because of the competitive nature of the game, what people bid is not necessarily the same as what they know. This means better estimates are formed by aggregating latent knowledge than by aggregating observed bids. We use our results to highlight the usefulness of models of cognition and decision-making in studying the wisdom of the crowd, which are often approached only from non-psychological statistical perspectives.

  2. Anchorage onto deciduous teeth: effectiveness of early rapid maxillary expansion in increasing dental arch dimension and improving anterior crowding.

    Science.gov (United States)

    Mutinelli, Sabrina; Manfredi, Mario; Guiducci, Antonio; Denotti, Gloria; Cozzani, Mauro

    2015-01-01

    Anchorage onto permanent dentition is a common procedure in rapid maxillary expansion. However, replacing first permanent molars with the second deciduous molars seems to be an option to reduce some negative side effects during orthodontic treatment. The purpose of this study was to evaluate the dental effect of rapid maxillary expansion with anchorage exclusively onto deciduous teeth performed in the first period of transition. Twenty patients with a lateral cross-bite treated exclusively by a Haas expander in early mixed dentition were retrospectively analyzed before treatment, at appliance removal, and at 21 months out of retention. The sagittal and transverse dimensions, together with the inter-canine arch and irregularity index, were digitally measured on scanned images of dental casts. The patients were compared with three balanced control groups (in total, 60 individuals) matched for gender. Two control groups had the same canine dental class as the treated group at T1, were in the inter-transitional period, and either had or lacked a lateral cross-bite. The last control group was comprised of adolescents in permanent dentition with a dental class I. The statistical analysis was performed by means of repeated-measures ANOVA for paired data and one-way ANOVA, the Kruskal-Wallis test, and the Mann-Whitney test for independent measures (α-level p dentition), the dental arch dimensions of treated patients were similar to those of adolescents with a dental class I and significantly wider than those of patients with a lateral cross-bite. Also, the anterior irregularity index was lower among patients who had undergone expansion treatments than in all untreated study participants. The Haas expander anchored to the deciduous teeth is effective in increasing the dental arch width in patients with a lateral cross-bite. The dimensions of the dental arch were modified earlier toward the values of the permanent dentition.

  3. Developing an emergency department crowding dashboard: A design science approach.

    Science.gov (United States)

    Martin, Niels; Bergs, Jochen; Eerdekens, Dorien; Depaire, Benoît; Verelst, Sandra

    2017-08-30

    As an emergency department (ED) is a complex adaptive system, the analysis of continuously gathered data is valuable to gain insight in the real-time patient flow. To support the analysis and management of ED operations, relevant data should be provided in an intuitive way. Within this context, this paper outlines the development of a dashboard which provides real-time information regarding ED crowding. The research project underlying this paper follows the principles of design science research, which involves the development and study of artifacts which aim to solve a generic problem. To determine the crowding indicators that are desired in the dashboard, a modified Delphi study is used. The dashboard is implemented using the open source Shinydashboard package in R. A dashboard is developed containing the desired crowding indicators, together with general patient flow characteristics. It is demonstrated using a dataset of a Flemish ED and fulfills the requirements which are defined a priori. The developed dashboard provides real-time information on ED crowding. This information enables ED staff to judge whether corrective actions are required in an effort to avoid the adverse effects of ED crowding. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. Does Temporal Integration Occur for Unrecognizable Words in Visual Crowding?

    Science.gov (United States)

    Zhou, Jifan; Lee, Chia-Lin; Li, Kuei-An; Tien, Yung-Hsuan; Yeh, Su-Ling

    2016-01-01

    Visual crowding—the inability to see an object when it is surrounded by flankers in the periphery—does not block semantic activation: unrecognizable words due to visual crowding still generated robust semantic priming in subsequent lexical decision tasks. Based on the previous finding, the current study further explored whether unrecognizable crowded words can be temporally integrated into a phrase. By showing one word at a time, we presented Chinese four-word idioms with either a congruent or incongruent ending word in order to examine whether the three preceding crowded words can be temporally integrated to form a semantic context so as to affect the processing of the ending word. Results from both behavioral (Experiment 1) and Event-Related Potential (Experiment 2 and 3) measures showed congruency effect in only the non-crowded condition, which does not support the existence of unconscious multi-word integration. Aside from four-word idioms, we also found that two-word (modifier + adjective combination) integration—the simplest kind of temporal semantic integration—did not occur in visual crowding (Experiment 4). Our findings suggest that integration of temporally separated words might require conscious awareness, at least under the timing conditions tested in the current study. PMID:26890366

  5. Polymer crowding and shape distributions in polymer-nanoparticle mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Lim, Wei Kang; Denton, Alan R., E-mail: alan.denton@ndsu.edu [Department of Physics, North Dakota State University, Fargo, North Dakota 58108-6050 (United States)

    2014-09-21

    Macromolecular crowding can influence polymer shapes, which is important for understanding the thermodynamic stability of polymer solutions and the structure and function of biopolymers (proteins, RNA, DNA) under confinement. We explore the influence of nanoparticle crowding on polymer shapes via Monte Carlo simulations and free-volume theory of a coarse-grained model of polymer-nanoparticle mixtures. Exploiting the geometry of random walks, we model polymer coils as effective penetrable ellipsoids, whose shapes fluctuate according to the probability distributions of the eigenvalues of the gyration tensor. Accounting for the entropic cost of a nanoparticle penetrating a larger polymer coil, we compute the crowding-induced shift in the shape distributions, radius of gyration, and asphericity of ideal polymers in a theta solvent. With increased nanoparticle crowding, we find that polymers become more compact (smaller, more spherical), in agreement with predictions of free-volume theory. Our approach can be easily extended to nonideal polymers in good solvents and used to model conformations of biopolymers in crowded environments.

  6. Is Malnutrition Associated with Crowding in Permanent Dentition?

    Directory of Open Access Journals (Sweden)

    Erika B. A. F. Thomaz

    2010-09-01

    Full Text Available Evidence suggests that energy-protein malnutrition is associated with impaired growth and development of facial bones. The objective of this study was to investigate the association between nutritional status and reduced space for dental eruption (crowding in permanent dentition. A cross-sectional study with probabilistic sampling design was used. We evaluated 2,060 students aged 12 to 15 years enrolled in schools in the northeast of Brazil. Crowding was defined according to World Health Organization (WHO as misalignment of teeth due to lack of space for them to erupt in the correct position. Nutritional status was evaluated by means of body mass index and height-for-age, using the WHO’s reference curves. Parents and adolescents responded to a questionnaire about demographic, socioeconomic, biological and behavioral characteristics. The associations were estimated by odds ratio (OR in multivariate logistic regression analysis (alpha = 0.05. Confounding and effect-modification were taken into account. An association between low height-for-age (z-score < –1SD and crowding was only observed in adolescents with a prolonged history of mouth breathing (OR = 3.1. No association was observed between underweight and crowding. Malnutrition is related to crowding in permanent dentition among mouth-breathing adolescents. Policy actions aimed at reducing low height-for-age and unhealthy oral habits are strongly recommended. However, further studies are needed to increase the consistency of these findings and improve understanding of the subject.

  7. Polymer crowding and shape distributions in polymer-nanoparticle mixtures

    International Nuclear Information System (INIS)

    Lim, Wei Kang; Denton, Alan R.

    2014-01-01

    Macromolecular crowding can influence polymer shapes, which is important for understanding the thermodynamic stability of polymer solutions and the structure and function of biopolymers (proteins, RNA, DNA) under confinement. We explore the influence of nanoparticle crowding on polymer shapes via Monte Carlo simulations and free-volume theory of a coarse-grained model of polymer-nanoparticle mixtures. Exploiting the geometry of random walks, we model polymer coils as effective penetrable ellipsoids, whose shapes fluctuate according to the probability distributions of the eigenvalues of the gyration tensor. Accounting for the entropic cost of a nanoparticle penetrating a larger polymer coil, we compute the crowding-induced shift in the shape distributions, radius of gyration, and asphericity of ideal polymers in a theta solvent. With increased nanoparticle crowding, we find that polymers become more compact (smaller, more spherical), in agreement with predictions of free-volume theory. Our approach can be easily extended to nonideal polymers in good solvents and used to model conformations of biopolymers in crowded environments

  8. Global crowd data to understand risk taking behavior: Understanding the costs of crowd sourcing

    Science.gov (United States)

    Hendrikx, J.; Johnson, J.

    2016-12-01

    Crowd sourcing is an increasingly common approach to collect data from a large number of places, people, or both, for a given phenomenon or observation. It is often thought of as a very cost effective approach to collect data from large spatial domains, or from difficult to reach areas, or for spatially discrete observations. While crowd sourcing data can provide a wealth of data beyond that which most research teams can collect themselves, there are many associated, and sometime unexpected costs with this approach. We present a case study of a crowd-sourced data collection campaign to collect GPS tracks of back country recreationalists in avalanche terrain. We ask the volunteers to track their outings using the GPS on their smart phone using a free application, and on the completion of their trip email us their track. On receipt of this track we automatically reply with a link to a decision making survey. In this way we collect data on both the physical attributes of their trip, as well as the social, psychological and demographic data about the person. While this approach has been very successful, it has come at a high cost time-wise. Much like the role of an online course instructor, instructor (or in this case researcher) presence is essential. Replying to emails, updating webpages, posting on social media, and connecting with your volunteer data collectors can become a full time job - and that's even before you start the data analysis. We encourage future researchers to plan ahead for this when starting a crowd sourcing project involving the general public, and seek advice and training in social media, web site development and communication techniques like semi-automated email.

  9. Household crowding and psychosocial health among Inuit in Greenland

    DEFF Research Database (Denmark)

    Riva, Mylène; Larsen, Christina Viskum Lytken; Bjerregaard, Peter

    2014-01-01

    men and women are differently influenced by their housing conditions. METHODS: Data on more than 3,000 Inuit aged 18 years and older are from the Inuit health in transition Greenland survey. Associations between household crowding and composition, and mental well-being and binge drinking were examined......OBJECTIVES: Poor housing conditions experienced by many Indigenous peoples threaten their health and well-being. This study examines whether household crowding is associated with poorer psychosocial health among Greenlanders, and the mediating role of social support. It also assesses whether Inuit...... using logistic regression models, adjusting for individuals' characteristics. RESULTS: Household crowding was associated with poorer mental well-being. Binge drinking was more common among people living in households without children. These effects were more important for women than for men...

  10. Direct crowding out, optimal taxation and pollution abatement

    Energy Technology Data Exchange (ETDEWEB)

    Van der Ploeg, Frederick [FEE, University of Amsterdam, Amsterdam (Netherlands); Bovenberg, A. Lans [CentER, Tilburg University, Tilburg (Netherlands)

    1993-05-01

    The interactions between direct crowding out, the provision of public goods, optimal taxation and environmental policy are explored. Greener preferences induce a larger tax rate by raising the non-distortionary level of the tax rate. If the marginal productivity of public abatement diminishes rapidly environmental quality improves mainly through a fall in economic activity and emissions. In this case, public consumption increases which crowds out labour supply and private consumption. However, if environmental policy is very effective public consumption falls in order to make room for public abatement. In this case, if labour supply is inelastic with respect to the after-tax wage and direct crowding in is strong, labour supply and economic activity may expand. 1 fig., 7 refs.

  11. Citizen Science and Crowdsourcing as effective STEM Education and Engagement activities for Diverse Audiences: case studies featured in THE CROWD & THE CLOUD public TV series.

    Science.gov (United States)

    Haines-Stiles, G.; Abdalati, W.; Akuginow, E.

    2017-12-01

    Citizen science and crowdsourcing are relatively unfamiliar terms to the general public, including parents, children and teachers, as seen in focus groups convened by the NSF-funded THE CROWD & THE CLOUD public television series. Once aware, however, of the potential of today's citizen science—often relying on smartphones, apps and innovative sensors—both citizens and professional scientists become excited and seek to learn more. CROWD & CLOUD, premiering on PBS stations in April 2017, hosted by former NASA Chief Scientist Waleed Abdalati, and streaming at CrowdAndCloud.org, features a wide range of projects supported by NASA, NOAA, USGS, EPA and other Federal agencies. Some, such as EyesOnALZ, a startup which aims to accelerate research on Alzheimer's disease, adapt a crowdsourcing model first developed to help analyze data returned by NASA's Stardust spacecraft. Early results from its "StallCatchers" puzzle-game show both high quality data and have been shown to cut one year's worth of academic labor down to one month of effort by "the crowd." While longstanding citizen science projects such as Audubon's Christmas Bird Count (starting in 1900) have proven their worth, Smartfin—embedding sensors in surfboard fins—is taking advantage of recent technical innovations to track sea surface temperatures and ocean acidification, with their accuracy validated by the Scripps Institution of Oceanography. The NASA-supported GLOBE Observer mosquito habitat mapper project uses a $6 microscope attached to a smartphone to aid in species identification. Some projects tap adult volunteers, but many, such as USGS's Nature's Notebook, also appeal to youngsters. In Albuquerque local teens track invasive species and help refuge managers, usefully supplementing the sole salaried ranger. In the Rockaways, New York, high school students plant pollinator gardens and promote ecosystem resilience following Superstorm Sandy. This presentation will feature short videos demonstrating

  12. Leveraging the wisdom of the crowd in software testing

    CERN Document Server

    Sharma, Mukesh

    2015-01-01

    Its scale, flexibility, cost effectiveness, and fast turnaround are just a few reasons why crowdsourced testing has received so much attention lately. While there are a few online resources that explain what crowdsourced testing is all about, there's been a need for a book that covers best practices, case studies, and the future of this technique.Filling this need, Leveraging the Wisdom of the Crowd in Software Testing shows you how to leverage the wisdom of the crowd in your software testing process. Its comprehensive coverage includes the history of crowdsourcing and crowdsourced testing, im

  13. Towards Detecting the Crowd Involved in Social Events

    Directory of Open Access Journals (Sweden)

    Wei Huang

    2017-10-01

    Full Text Available Knowing how people interact with urban environments is fundamental for a variety of fields, ranging from transportation to social science. Despite the fact that human mobility patterns have been a major topic of study in recent years, a challenge to understand large-scale human behavior when a certain event occurs remains due to a lack of either relevant data or suitable approaches. Psychological crowd refers to a group of people who are usually located at different places and show different behaviors, but who are very sensitively driven to take the same act (gather together by a certain event, which has been theoretically studied by social psychologists since the 19th century. This study aims to propose a computational approach using a machine learning method to model psychological crowds, contributing to the better understanding of human activity patterns under events. Psychological features and mental unity of the crowd are computed to detect the involved individuals. A national event happening across the USA in April, 2015 is analyzed using geotagged tweets as a case study to test our approach. The result shows that 81% of individuals in the crowd can be successfully detected. Through investigating the geospatial pattern of the involved users, not only can the event related users be identified but also those unobserved users before the event can be uncovered. The proposed approach can effectively represent the psychological feature and measure the mental unity of the psychological crowd, which sheds light on the study of large-scale psychological crowd and provides an innovative way to understanding human behavior under events.

  14. Crowd Sourcing to Improve Urban Stormwater Management

    Science.gov (United States)

    Minsker, B. S.; Band, L. E.; Heidari Haratmeh, B.; Law, N. L.; Leonard, L. N.; Rai, A.

    2017-12-01

    Over half of the world's population currently lives in urban areas, a number predicted to grow to 60 percent by 2030. Urban areas face unprecedented and growing challenges that threaten society's long-term wellbeing, including poverty; chronic health problems; widespread pollution and resource degradation; and increased natural disasters. These are "wicked" problems involving "systems of systems" that require unprecedented information sharing and collaboration across disciplines and organizational boundaries. Cities are recognizing that the increasing stream of data and information ("Big Data"), informatics, and modeling can support rapid advances on these challenges. Nonetheless, information technology solutions can only be effective in addressing these challenges through deeply human and systems perspectives. A stakeholder-driven approach ("crowd sourcing") is needed to develop urban systems that address multiple needs, such as parks that capture and treat stormwater while improving human and ecosystem health and wellbeing. We have developed informatics- and Cloud-based collaborative methods that enable crowd sourcing of green stormwater infrastructure (GSI: rain gardens, bioswales, trees, etc.) design and management. The methods use machine learning, social media data, and interactive design tools (called IDEAS-GI) to identify locations and features of GSI that perform best on a suite of objectives, including life cycle cost, stormwater volume reduction, and air pollution reduction. Insights will be presented on GI features that best meet stakeholder needs and are therefore most likely to improve human wellbeing and be well maintained.

  15. Crowd behaviour during high-stress evacuations in an immersive virtual environment

    Science.gov (United States)

    Kapadia, Mubbasir; Thrash, Tyler; Sumner, Robert W.; Gross, Markus; Helbing, Dirk; Hölscher, Christoph

    2016-01-01

    Understanding the collective dynamics of crowd movements during stressful emergency situations is central to reducing the risk of deadly crowd disasters. Yet, their systematic experimental study remains a challenging open problem due to ethical and methodological constraints. In this paper, we demonstrate the viability of shared three-dimensional virtual environments as an experimental platform for conducting crowd experiments with real people. In particular, we show that crowds of real human subjects moving and interacting in an immersive three-dimensional virtual environment exhibit typical patterns of real crowds as observed in real-life crowded situations. These include the manifestation of social conventions and the emergence of self-organized patterns during egress scenarios. High-stress evacuation experiments conducted in this virtual environment reveal movements characterized by mass herding and dangerous overcrowding as they occur in crowd disasters. We describe the behavioural mechanisms at play under such extreme conditions and identify critical zones where overcrowding may occur. Furthermore, we show that herding spontaneously emerges from a density effect without the need to assume an increase of the individual tendency to imitate peers. Our experiments reveal the promise of immersive virtual environments as an ethical, cost-efficient, yet accurate platform for exploring crowd behaviour in high-risk situations with real human subjects. PMID:27605166

  16. Crowd behaviour during high-stress evacuations in an immersive virtual environment.

    Science.gov (United States)

    Moussaïd, Mehdi; Kapadia, Mubbasir; Thrash, Tyler; Sumner, Robert W; Gross, Markus; Helbing, Dirk; Hölscher, Christoph

    2016-09-01

    Understanding the collective dynamics of crowd movements during stressful emergency situations is central to reducing the risk of deadly crowd disasters. Yet, their systematic experimental study remains a challenging open problem due to ethical and methodological constraints. In this paper, we demonstrate the viability of shared three-dimensional virtual environments as an experimental platform for conducting crowd experiments with real people. In particular, we show that crowds of real human subjects moving and interacting in an immersive three-dimensional virtual environment exhibit typical patterns of real crowds as observed in real-life crowded situations. These include the manifestation of social conventions and the emergence of self-organized patterns during egress scenarios. High-stress evacuation experiments conducted in this virtual environment reveal movements characterized by mass herding and dangerous overcrowding as they occur in crowd disasters. We describe the behavioural mechanisms at play under such extreme conditions and identify critical zones where overcrowding may occur. Furthermore, we show that herding spontaneously emerges from a density effect without the need to assume an increase of the individual tendency to imitate peers. Our experiments reveal the promise of immersive virtual environments as an ethical, cost-efficient, yet accurate platform for exploring crowd behaviour in high-risk situations with real human subjects. © 2016 The Authors.

  17. Macromolecular crowding directs extracellular matrix organization and mesenchymal stem cell behavior.

    Directory of Open Access Journals (Sweden)

    Adam S Zeiger

    Full Text Available Microenvironments of biological cells are dominated in vivo by macromolecular crowding and resultant excluded volume effects. This feature is absent in dilute in vitro cell culture. Here, we induced macromolecular crowding in vitro by using synthetic macromolecular globules of nm-scale radius at physiological levels of fractional volume occupancy. We quantified the impact of induced crowding on the extracellular and intracellular protein organization of human mesenchymal stem cells (MSCs via immunocytochemistry, atomic force microscopy (AFM, and AFM-enabled nanoindentation. Macromolecular crowding in extracellular culture media directly induced supramolecular assembly and alignment of extracellular matrix proteins deposited by cells, which in turn increased alignment of the intracellular actin cytoskeleton. The resulting cell-matrix reciprocity further affected adhesion, proliferation, and migration behavior of MSCs. Macromolecular crowding can thus aid the design of more physiologically relevant in vitro studies and devices for MSCs and other cells, by increasing the fidelity between materials synthesized by cells in vivo and in vitro.

  18. Macromolecular crowding directs extracellular matrix organization and mesenchymal stem cell behavior.

    Science.gov (United States)

    Zeiger, Adam S; Loe, Felicia C; Li, Ran; Raghunath, Michael; Van Vliet, Krystyn J

    2012-01-01

    Microenvironments of biological cells are dominated in vivo by macromolecular crowding and resultant excluded volume effects. This feature is absent in dilute in vitro cell culture. Here, we induced macromolecular crowding in vitro by using synthetic macromolecular globules of nm-scale radius at physiological levels of fractional volume occupancy. We quantified the impact of induced crowding on the extracellular and intracellular protein organization of human mesenchymal stem cells (MSCs) via immunocytochemistry, atomic force microscopy (AFM), and AFM-enabled nanoindentation. Macromolecular crowding in extracellular culture media directly induced supramolecular assembly and alignment of extracellular matrix proteins deposited by cells, which in turn increased alignment of the intracellular actin cytoskeleton. The resulting cell-matrix reciprocity further affected adhesion, proliferation, and migration behavior of MSCs. Macromolecular crowding can thus aid the design of more physiologically relevant in vitro studies and devices for MSCs and other cells, by increasing the fidelity between materials synthesized by cells in vivo and in vitro.

  19. Crowding depression of UV-mutagenesis in E. coli

    International Nuclear Information System (INIS)

    Bockrath, R.; Harper, D.; Kristoff, S.; Stanford Univ., CA

    1980-01-01

    Strains of E. coli Br were exposed to UV radiation and assayed for reversion mutation, using a standard selection medium. If more irradiated bacteria were assayed per petri dish, a proportional increase in the number of indicated reversion mutants was oud only up to a limiting plating density. Beyond a density of about 10 8 viable bacteria per petri dish, the number of indicated revertants per viable bacteriy assayed (the mutation frequency) decreased as the plating density was increased. The crowding depression of mutagenesis was more severe for de novo and converted suppressor mutations, the mutation frequency being reduced 100-fold at a plating density of about 6 x 10 9 viable bacteria per plate. The effect on backmutation was 10 times less. Crowding depression of mutagenesis occured in excision-proficient and -deficient strains, with identical effects in the 2 strains on de novo and converted suppressor mutation, but different effects on backmutations. There were no accompanying effects on viability. Irreversible loss of potential mutants during crowded growth was indicated in wash-off experiments. The kinetics suggested a half-life of approximately 1 h. Kinetics for accumulation by the bacteria of the limiting metabolite (tyrosine) on the assay plate indicated a short period of time for protein synthesis, but direct examination of the proteins synthesized during early growth on a crowded plate demonstrated successful induction of recA protein. (orig.)

  20. Which updates during an equity crowdfunding campaign increase crowd participation?

    NARCIS (Netherlands)

    Block, J. (Jörn); Hornuf, L. (Lars); Moritz, A. (Alexandra)

    2017-01-01

    textabstractStart-ups often post updates during equity crowdfunding campaigns. However, little is known about the effects of such updates on crowd participation. We investigate this question by using hand-collected data from 71 funding campaigns and 39,399 investment decisions on two German equity

  1. CrowdAidRepair: A Crowd-Aided Interactive Data Repairing Method

    KAUST Repository

    Zhou, Jian; Li, Zhixu; Gu, Binbin; Xie, Qing; Zhu, Jia; Zhang, Xiangliang; Li, Guoliang

    2016-01-01

    turn to use the power of crowd in data repairing, but the crowd power has its own drawbacks such as high human intervention cost and inevitable low efficiency. In this paper, we propose a crowd-aided interactive data repairing method which takes

  2. Chemical reaction due to stronger Ramachandran interaction

    Indian Academy of Sciences (India)

    The origin of a chemical reaction between two reactant atoms is associated with the activation energy, on the assumption that, high-energy collisions between these atoms, are the ones that overcome the activation energy. Here, we show that a stronger attractive van der Waals (vdW) and electron-ion Coulomb interactions ...

  3. Current density redistribution from no current crowding to current crowding in Pb-free solder joints with an extremely thick Cu layer

    International Nuclear Information System (INIS)

    Han, Jung Kyu; Choi, Daechul; Fujiyoshi, Masaru; Chiwata, Nobuhiko; Tu, King-Ning

    2012-01-01

    In order to remove the effect of current crowding on electromigration, thick Cu under-bump metallization has been widely adopted in the electronics industry. Three-dimensional (3-D) integrated circuits, using through Si via Cu column interconnects, is being developed, and it seems that current crowding may not be a reliability issue. However, statistical experiments and 3-D finite element simulation indicate that there is a transition from no current crowding to current crowding, caused by void growth at the cathode. An analysis of the electromigration-induced failure mechanism in solder joints having a very thick Cu layer is presented. It is a unique failure mechanism, different from that in flip chip technology. Moreover, the study of marker displacement shows two different stages of drift velocity, which clearly demonstrates the back-stress effect and the development of compressive stress.

  4. Socialization of Social Anxiety in Adolescent Crowds

    Science.gov (United States)

    Van Zalk, Nejra; Van Zalk, Maarten Herman Walter; Kerr, Margaret

    2011-01-01

    In this study, we looked at whether social anxiety is socialized, or influenced by peers' social anxiety, more in some peer crowds than others. Adolescents in crowds with eye-catching appearances such as Goths and Punks (here termed "Radical"), were compared with three comparison groups. Using data from 796 adolescents (353 girls and 443 boys; M…

  5. Is word recognition crowded in pure alexia?

    DEFF Research Database (Denmark)

    Sand, Katrine; Habekost, Thomas; Petersen, Anders

    2017-01-01

    Pure alexia is a selective deficit in reading, which arises following damage to the left ventral occipito-temporal cortex. Crowding, the inability to recognise objects in a clutter, has recently been hypothesised to be the underlying deficit of apperceptive visual agnosia1. Crowding normally occurs...

  6. How crowded is the prokaryotic cytoplasm?

    NARCIS (Netherlands)

    Spitzer, Jan; Poolman, Bert; Ferguson, Stuart

    2013-01-01

    We consider biomacromolecular crowding within the cytoplasm of prokaryotic cells as a two-phase system of 'supercrowded' cytogel and 'dilute' cytosol; we simplify and quantify this model for a coccoid cell over a wide range of biomacromolecular crowding. The key result shows that the supercrowded

  7. Crowd science user contribution patterns and their implications

    Science.gov (United States)

    Sauermann, Henry; Franzoni, Chiara

    2015-01-01

    Scientific research performed with the involvement of the broader public (the crowd) attracts increasing attention from scientists and policy makers. A key premise is that project organizers may be able to draw on underused human resources to advance research at relatively low cost. Despite a growing number of examples, systematic research on the effort contributions volunteers are willing to make to crowd science projects is lacking. Analyzing data on seven different projects, we quantify the financial value volunteers can bring by comparing their unpaid contributions with counterfactual costs in traditional or online labor markets. The volume of total contributions is substantial, although some projects are much more successful in attracting effort than others. Moreover, contributions received by projects are very uneven across time-a tendency toward declining activity is interrupted by spikes typically resulting from outreach efforts or media attention. Analyzing user-level data, we find that most contributors participate only once and with little effort, leaving a relatively small share of users who return responsible for most of the work. Although top contributor status is earned primarily through higher levels of effort, top contributors also tend to work faster. This speed advantage develops over multiple sessions, suggesting that it reflects learning rather than inherent differences in skills. Our findings inform recent discussions about potential benefits from crowd science, suggest that involving the crowd may be more effective for some kinds of projects than others, provide guidance for project managers, and raise important questions for future research.

  8. States agree on stronger physical protection regime

    International Nuclear Information System (INIS)

    2005-01-01

    Full text: Delegates from 89 countries agreed on 8 July to fundamental changes that will substantially strengthen the Convention on the Physical Protection of Nuclear Material (CPPNM). IAEA Director General Mohamed ElBaradei welcomed the agreement in saying 'This new and stronger treaty is an important step towards greater nuclear security by combating, preventing, and ultimately punishing those who would engage in nuclear theft, sabotage or even terrorism. It demonstrates that there is indeed a global commitment to remedy weaknesses in our nuclear security regime.' The amended CPPNM makes it legally binding for States Parties to protect nuclear facilities and material in peaceful domestic use, storage as well as transport. It will also provide for expanded cooperation between and among States regarding rapid measures to locate and recover stolen or smuggled nuclear material, mitigate any radiological consequences of sabotage, and prevent and combat related offences. The original CPPNM applied only to nuclear material in international transport. Conference President Dr. Alec Baer said 'All 89 delegations demonstrated real unity of purpose. They put aside some very genuine national concerns in favour of the global interest and the result is a much improved convention that is better suited to addressing the nuclear security challenges we currently face.' The new rules will come into effect once they have been ratified by two-thirds of the 112 States Parties of the Convention, expected to take several years. 'But concrete actions are already taking place around the world. For more than 3 years, the IAEA has been implementing a systematic Nuclear Security plan, including physical protection activities designed to prevent, detect and respond to malicious acts,' said Anita Nillson, Director of the IAEA's Office of Nuclear Security. The Agency's Nuclear Security Fund, set up after the events of 9/11, has delivered $19.5 million in practical assistance to 121 countries

  9. Rhythmic crowd bobbing on a grandstand simulator

    Science.gov (United States)

    Comer, A. J.; Blakeborough, A.; Williams, M. S.

    2013-01-01

    It is widely accepted that concerted human activity such as bouncing or bobbing can excite cantilever grandstands. Crowd coordination can be unwitting and may be exacerbated by structural motion caused by resonant structural response. This is an area of uncertainty in the design and analysis of modern grandstands. This paper presents experimental measurement and analysis of rhythmic crowd bobbing loads obtained from tests on a grandstand simulator with two distinct support conditions; (a) rigid, and; (b) flexible. It was found that significant structural vibration at the bobbing frequency did not increase the effective bobbing load. Structural motion at the bobbing frequency caused a reduction in the dynamic load factor (DLF) at the frequency of the second harmonic while those at the first and third harmonics were unaffected. Two plausible reasons for this are: (a) the bobbing group were unable to supply significant energy to the system at the frequency of the second harmonic; (b) the bobbing group altered their bobbing style to reduce the response of the grandstand simulator. It was deduced that the bobbing group did not absorb energy from the dynamic system. Furthermore, dynamic load factors for groups of test subjects bobbing on a rigid structure were typically greater than those of synthesised groups derived from individuals bobbing alone, possibly due to group effects such as audio and visual stimuli from neighbouring test subjects. Last, the vibration levels experienced by the test subjects appear to be below levels likely to cause discomfort. This is to be expected as the test subjects were themselves controlling the magnitude and duration of vibration for the bobbing tests considered.

  10. Multiple Level Crowding: Crowding at the Object Parts Level and at the Object Configural level.

    Science.gov (United States)

    Kimchi, Ruth; Pirkner, Yossef

    2015-01-01

    In crowding, identification of a peripheral target in the presence of nearby flankers is worse than when the target appears alone. Prevailing theories hold that crowding occurs because of integration or "pooling" of low-level features at a single, relatively early stage of visual processing. Recent studies suggest that crowding can occur also between high-level object representations. The most relevant findings come from studies with faces and may be specific to faces. We examined whether crowding can occur at the object configural level in addition to part-level crowding, using nonface objects. Target (a disconnected square or diamond made of four elements) identification was measured at varying eccentricities. The flankers were similar either to the target parts or to the target configuration. The results showed crowding in both cases: Flankers interfered with target identification such that identification accuracy decreased with an increase in eccentricity, and no interference was observed at the fovea. Crowding by object parts, however, was weaker and had smaller spatial extent than crowding by object configurations; we related this finding to the relationship between crowding and perceptual organization. These results provide strong evidence that crowding occurs not only between object parts but also between configural representations of objects. © The Author(s) 2015.

  11. New insights into turbulent pedestrian movement pattern in crowd-quakes

    International Nuclear Information System (INIS)

    Ma, J; Song, W G; Lo, S M; Fang, Z M

    2013-01-01

    Video recordings right before the Love Parade disaster have been quantitatively analyzed to explore the bursts of unusual crowd movement patterns, crowd-quakes. The pedestrian movement pattern in this incident was special for the reason that it happened in a congested counter flow scenario, where stopped pedestrians were involved. No one was believed to have pushed others intentionally at the beginning, however, under this situation, the body contacts among the pedestrians still induced a force spread, which then led to velocity fluctuation. As indicated by the individual velocity-related features, the densely crowded pedestrian movement displayed turbulent flow features. Further analyzing the overall flow field, we also found that the pedestrian flow field shared typical patterns with turbulent fluid flow. As a result of the turbulent state, different clusters of pedestrians displayed different velocity features. Thus crowd pressure which took into account the velocity and density information was proved to be a good indicator of crowd disasters. Based on these essential features of pedestrian crowd-quakes, a minimal model, i.e., a pedestrian crowd-quake model, was established. Effects including pedestrian gait, stress conservation level and personal intention to escape were explored. (paper)

  12. An Energy based Method to Measure the Crowd Safety

    NARCIS (Netherlands)

    Yin, H.; Li, D.; Zheng, X.

    2014-01-01

    How to evaluate crowd safety in crowded areas is a tough, but important, problem. According to accident-causing theory, uncontrolled release of hazardous energy among overcrowded pedestrians is the basic cause of crowd disaster. Therefore, crowd energy is modeled in this paper, which takes both

  13. Stochastic reaction-diffusion algorithms for macromolecular crowding

    Science.gov (United States)

    Sturrock, Marc

    2016-06-01

    Compartment-based (lattice-based) reaction-diffusion algorithms are often used for studying complex stochastic spatio-temporal processes inside cells. In this paper the influence of macromolecular crowding on stochastic reaction-diffusion simulations is investigated. Reaction-diffusion processes are considered on two different kinds of compartmental lattice, a cubic lattice and a hexagonal close packed lattice, and solved using two different algorithms, the stochastic simulation algorithm and the spatiocyte algorithm (Arjunan and Tomita 2010 Syst. Synth. Biol. 4, 35-53). Obstacles (modelling macromolecular crowding) are shown to have substantial effects on the mean squared displacement and average number of molecules in the domain but the nature of these effects is dependent on the choice of lattice, with the cubic lattice being more susceptible to the effects of the obstacles. Finally, improvements for both algorithms are presented.

  14. Macromolecular crowding compacts unfolded apoflavodoxin and causes severe aggregation of the off-pathway intermediate during apoflavodoxin folding

    NARCIS (Netherlands)

    Engel, R.; Westphal, A.H.; Huberts, D.; Nabuurs, S.M.; Lindhoud, S.; Visser, A.J.W.G.; Mierlo, van C.P.M.

    2008-01-01

    To understand how proteins fold in vivo, it is important to investigate the effects of macromolecular crowding on protein folding. Here, the influence of crowding on in vitro apoflavodoxin folding, which involves a relatively stable off-pathway intermediate with molten globule characteristics, is

  15. NIH Abroad: Pictures Are Crowd Pullers

    Science.gov (United States)

    ... turn Javascript on. "Pictures Are Crowd Pullers …" Art, culture, and the Internet combine to intervene against malaria ... Not ripe mangoes. Not witchcraft. The images and words, which speak directly to local beliefs in villages ...

  16. Crowdings betydning for antallet af tvangsfikseringer

    DEFF Research Database (Denmark)

    Bak, Jesper; Nielsen, Lea Marie; Hæssum, Birte

    2017-01-01

    I denne artikel vil vi beskrive et par af resultaterne fra forskningsprojektet ”Mechanical restraint. Preventive Factors in Theory and Practice” samt et eksempel fra praksis om crowdings betydning for hvor meget der bliver tvangsfikseret....

  17. Crowd Behavior Algorithm Development for COMBAT XXI

    Science.gov (United States)

    2017-05-30

    non-combatants to military operations in an urban area. We show how to link this model with COMBATXXI at the application programming interface (API...level so that the model can be run in tight conjunction with COMBATXXI. TRAC and other anaytic organizations can use this type of crowd model to... organizations , and materiel. crowd, agent-based modeling , combat models , COMBATXXI, NetLogo, mega-cities, civilians on the battlefield Unclassified U U U U 39

  18. Interaction with virtual crowd in Immersive and semi‐Immersive Virtual Reality systems

    OpenAIRE

    Kyriakou, Marios; Pan, Xueni; Chrysanthou, Yiorgos

    2016-01-01

    This study examines attributes of virtual human behavior that may increase the plausibility of a simulated crowd and affect the user's experience in Virtual Reality. Purpose-developed experiments in both Immersive and semi-Immersive Virtual Reality systems queried the impact of collision and basic interaction between real-users and the virtual crowd and their effect on the apparent realism and ease of navigation within Virtual Reality (VR). Participants' behavior and subjective measurements i...

  19. Linking crowding, visual span, and reading.

    Science.gov (United States)

    He, Yingchen; Legge, Gordon E

    2017-09-01

    The visual span is hypothesized to be a sensory bottleneck on reading speed with crowding thought to be the major sensory factor limiting the size of the visual span. This proposed linkage between crowding, visual span, and reading speed is challenged by the finding that training to read crowded letters reduced crowding but did not improve reading speed (Chung, 2007). Here, we examined two properties of letter-recognition training that may influence the transfer to improved reading: the spatial arrangement of training stimuli and the presence of flankers. Three groups of nine young adults were trained with different configurations of letter stimuli at 10° in the lower visual field: a flanked-local group (flanked letters localized at one position), a flanked-distributed group (flanked letters distributed across different horizontal locations), and an isolated-distributed group (isolated and distributed letters). We found that distributed training, but not the presence of flankers, appears to be necessary for the training benefit to transfer to increased reading speed. Localized training may have biased attention to one specific, small area in the visual field, thereby failing to improve reading. We conclude that the visual span represents a sensory bottleneck on reading, but there may also be an attentional bottleneck. Reducing the impact of crowding can enlarge the visual span and can potentially facilitate reading, but not when adverse attentional bias is present. Our results clarify the association between crowding, visual span, and reading.

  20. Effects of Macromolecular Crowding on Human Adipose Stem Cell Culture in Fetal Bovine Serum, Human Serum, and Defined Xeno-Free/Serum-Free Conditions.

    Science.gov (United States)

    Patrikoski, Mimmi; Lee, Michelle Hui Ching; Mäkinen, Laura; Ang, Xiu Min; Mannerström, Bettina; Raghunath, Michael; Miettinen, Susanna

    2017-01-01

    Microenvironment plays an important role for stem cell proliferation and differentiation. Macromolecular crowding (MMC) was recently shown to assist stem cells in forming their own matrix microenvironment in vitro. The ability of MMC to support adipose stem cell (ASC) proliferation, metabolism, and multilineage differentiation was studied under different conditions: fetal bovine serum- (FBS-) and human serum- (HS-) based media and xeno- and serum-free (XF/SF) media. Furthermore, the immunophenotype of ASCs under MMC was evaluated. The proliferative capacity of ASCs under MMC was attenuated in each condition. However, osteogenic differentiation was enhanced under MMC, shown by increased deposition of mineralized matrix in FBS and HS cultures. Likewise, significantly greater lipid droplet accumulation and increased collagen IV deposition indicated enhanced adipogenesis under MMC in FBS and HS cultures. In contrast, chondrogenic differentiation was attenuated in ASCs expanded under MMC. The ASC immunophenotype was maintained under MMC with significantly higher expression of CD54. However, MMC impaired metabolic activity and differentiation capacity of ASCs in XF/SF conditions. Both the supportive and inhibitory effects of MMC on ASC are culture condition dependent. In the presence of serum, MMC maintains ASC immunophenotype and enhances adipogenic and osteogenic differentiation at the cost of reduced proliferation.

  1. LHC Season 2: A stronger machine

    CERN Multimedia

    Dominguez, Daniel

    2015-01-01

    1) New magnets / De nouveaux aimants 2) Stronger connections / Des jonctions électriques renforcées 3) Safer magnets / Des aimants plus sûrs 4) Higher energy beams / Des faisceaux d’énergie plus élevée 5) Narrower beams / Des faisceaux plus serrés 6) Smaller but closer proton packets / Des groupes de protons plus petits mais plus rapprochés 7) Higher voltage / Une tension plus haute 8) Superior cryogenics / Un système cryogénique amélioré 9) Radiation-resistant electronics / Une électronique qui résiste aux radiations 10) More secure vacuum / Un vide plus sûr

  2. Explaining effervescence: Investigating the relationship between shared social identity and positive experience in crowds.

    Science.gov (United States)

    Hopkins, Nick; Reicher, Stephen D; Khan, Sammyh S; Tewari, Shruti; Srinivasan, Narayanan; Stevenson, Clifford

    2016-01-01

    We investigated the intensely positive emotional experiences arising from participation in a large-scale collective event. We predicted such experiences arise when those attending a collective event are (1) able to enact their valued collective identity and (2) experience close relations with other participants. In turn, we predicted both of these to be more likely when participants perceived crowd members to share a common collective identity. We investigated these predictions in a survey of pilgrims (N = 416) attending a month-long Hindu pilgrimage festival in north India. We found participants' perceptions of a shared identity amongst crowd members had an indirect effect on their positive experience at the event through (1) increasing participants' sense that they were able to enact their collective identity and (2) increasing the sense of intimacy with other crowd members. We discuss the implications of these data for how crowd emotion should be conceptualised.

  3. Study on Evaluation Indicators System of Crowd Management for Transfer Stations Based on Pedestrian Simulation

    Directory of Open Access Journals (Sweden)

    Guanghou Zhang

    2011-12-01

    Full Text Available Improving safety and convenience of transfer is one of the most vital tasks in subway system planning, design and operation management. Because of complicated space layout and crowded pedestrian, crowd control is a big challenge for management of transfer stations. Thus, a quantitative evaluation should be done before improvement measures are carried out. Literature review showed that present evaluation indicators about crowd management in subway system were all based on fixed value or experience. Dynamic effect caused by pedestrian congestion and various facility combination cannot be represented based on these indicators. Thus, in this paper, based on the pedestrian simulation tool, dynamic evaluation indicators system of crowd management was established from the point of safety, cost-effectiveness and comfort. In order to aid decision makers to identify the most appropriate scenario to improve the effectiveness of crowd management, Matter-Element Analysis (MEA was used to rate different scenarios. A pedestrian simulation model of a designing intermodal transfer station was built and four different scenarios were tested to demonstrate how to use this indicators system. Simulation results were evaluated based on the dynamic indicators system and MEA. The application results show that the dynamic evaluation indicators system is operational and can reflect level of the crowd management in transfer station comprehensively and precisely.

  4. CrowdAidRepair: A Crowd-Aided Interactive Data Repairing Method

    KAUST Repository

    Zhou, Jian

    2016-03-25

    Data repairing aims at discovering and correcting erroneous data in databases. Traditional methods relying on predefined quality rules to detect the conflict between data may fail to choose the right way to fix the detected conflict. Recent efforts turn to use the power of crowd in data repairing, but the crowd power has its own drawbacks such as high human intervention cost and inevitable low efficiency. In this paper, we propose a crowd-aided interactive data repairing method which takes the advantages of both rule-based method and crowd-based method. Particularly, we investigate the interaction between crowd-based repairing and rule-based repairing, and show that by doing crowd-based repairing to a small portion of values, we can greatly improve the repairing quality of the rule-based repairing method. Although we prove that the optimal interaction scheme using the least number of values for crowd-based repairing to maximize the imputation recall is not feasible to be achieved, still, our proposed solution identifies an efficient scheme through investigating the inconsistencies and the dependencies between values in the repairing process. Our empirical study on three data collections demonstrates the high repairing quality of CrowdAidRepair, as well as the efficiency of the generated interaction scheme over baselines.

  5. Crowd Behavior, Crowd Control, and the Use of Non-Lethal Weapons

    Science.gov (United States)

    2001-01-01

    that U.S. forces know these repertoires of actions when they operate in different cultures. Dr. Waddington provided the example of the Zulu tribe in...6 The History of Hostile Crowds and Riots...Mobs, and Non-lethal Weapons,” by Lieutenant Sid Heal. The History of Hostile Crowds and Riots Dr. Wendy Gilpin conducted background research on hostile

  6. Innovative funding solution for special projects: Crowd funding

    Directory of Open Access Journals (Sweden)

    Sentot Imam Wahjono

    2015-06-01

    Full Text Available The aim of this paper is to examine the influence of crowd funding knowledge, applica-tion, platform, and project initiator toward successful crowd funding. This study conducted by quantitative approach, data have been collected with web-based ques-tionnaires via Kickstarter.com direct message and e-mail to 200 successful crowd funding project initiators as a sample and as much 152 sets questionnaire returned by a complete answer and should be analyzed further. Deployment and data collection take 3 month from October to December 2013. This study found evidence that crowd funding knowledge, crowd funding application, crowd funding platform, and project initiator has positive and significant relationship toward the success of crowd funding. The implication from this research is crowd funding can be a source of capital to finance the projects, not just rely on traditional sources of financing just like banking and capital markets. Crowd funding can be innovative funding solution.

  7. Does Prison Crowding Predict Higher Rates of Substance Use Related Parole Violations? A Recurrent Events Multi-Level Survival Analysis.

    Directory of Open Access Journals (Sweden)

    Michael A Ruderman

    Full Text Available This administrative data-linkage cohort study examines the association between prison crowding and the rate of post-release parole violations in a random sample of prisoners released with parole conditions in California, for an observation period of two years (January 2003 through December 2004.Crowding overextends prison resources needed to adequately protect inmates and provide drug rehabilitation services. Violence and lack of access to treatment are known risk factors for drug use and substance use disorders. These and other psychosocial effects of crowding may lead to higher rates of recidivism in California parolees.Rates of parole violation for parolees exposed to high and medium levels of prison crowding were compared to parolees with low prison crowding exposure. Hazard ratios (HRs with 95% confidence intervals (CIs were estimated using a Cox model for recurrent events. Our dataset included 13070 parolees in California, combining individual level parolee data with aggregate level crowding data for multilevel analysis.Comparing parolees exposed to high crowding with those exposed to low crowding, the effect sizes from greatest to least were absconding violations (HR 3.56 95% CI: 3.05-4.17, drug violations (HR 2.44 95% CI: 2.00-2.98, non-violent violations (HR 2.14 95% CI: 1.73-2.64, violent and serious violations (HR 1.88 95% CI: 1.45-2.43, and technical violations (HR 1.86 95% CI: 1.37-2.53.Prison crowding predicted higher rates of parole violations after release from prison. The effect was magnitude-dependent and particularly strong for drug charges. Further research into whether adverse prison experiences, such as crowding, are associated with recidivism and drug use in particular may be warranted.

  8. Does Prison Crowding Predict Higher Rates of Substance Use Related Parole Violations? A Recurrent Events Multi-Level Survival Analysis.

    Science.gov (United States)

    Ruderman, Michael A; Wilson, Deirdra F; Reid, Savanna

    2015-01-01

    This administrative data-linkage cohort study examines the association between prison crowding and the rate of post-release parole violations in a random sample of prisoners released with parole conditions in California, for an observation period of two years (January 2003 through December 2004). Crowding overextends prison resources needed to adequately protect inmates and provide drug rehabilitation services. Violence and lack of access to treatment are known risk factors for drug use and substance use disorders. These and other psychosocial effects of crowding may lead to higher rates of recidivism in California parolees. Rates of parole violation for parolees exposed to high and medium levels of prison crowding were compared to parolees with low prison crowding exposure. Hazard ratios (HRs) with 95% confidence intervals (CIs) were estimated using a Cox model for recurrent events. Our dataset included 13070 parolees in California, combining individual level parolee data with aggregate level crowding data for multilevel analysis. Comparing parolees exposed to high crowding with those exposed to low crowding, the effect sizes from greatest to least were absconding violations (HR 3.56 95% CI: 3.05-4.17), drug violations (HR 2.44 95% CI: 2.00-2.98), non-violent violations (HR 2.14 95% CI: 1.73-2.64), violent and serious violations (HR 1.88 95% CI: 1.45-2.43), and technical violations (HR 1.86 95% CI: 1.37-2.53). Prison crowding predicted higher rates of parole violations after release from prison. The effect was magnitude-dependent and particularly strong for drug charges. Further research into whether adverse prison experiences, such as crowding, are associated with recidivism and drug use in particular may be warranted.

  9. Does Prison Crowding Predict Higher Rates of Substance Use Related Parole Violations? A Recurrent Events Multi-Level Survival Analysis

    Science.gov (United States)

    Ruderman, Michael A.; Wilson, Deirdra F.; Reid, Savanna

    2015-01-01

    Objective This administrative data-linkage cohort study examines the association between prison crowding and the rate of post-release parole violations in a random sample of prisoners released with parole conditions in California, for an observation period of two years (January 2003 through December 2004). Background Crowding overextends prison resources needed to adequately protect inmates and provide drug rehabilitation services. Violence and lack of access to treatment are known risk factors for drug use and substance use disorders. These and other psychosocial effects of crowding may lead to higher rates of recidivism in California parolees. Methods Rates of parole violation for parolees exposed to high and medium levels of prison crowding were compared to parolees with low prison crowding exposure. Hazard ratios (HRs) with 95% confidence intervals (CIs) were estimated using a Cox model for recurrent events. Our dataset included 13070 parolees in California, combining individual level parolee data with aggregate level crowding data for multilevel analysis. Results Comparing parolees exposed to high crowding with those exposed to low crowding, the effect sizes from greatest to least were absconding violations (HR 3.56 95% CI: 3.05–4.17), drug violations (HR 2.44 95% CI: 2.00–2.98), non-violent violations (HR 2.14 95% CI: 1.73–2.64), violent and serious violations (HR 1.88 95% CI: 1.45–2.43), and technical violations (HR 1.86 95% CI: 1.37–2.53). Conclusions Prison crowding predicted higher rates of parole violations after release from prison. The effect was magnitude-dependent and particularly strong for drug charges. Further research into whether adverse prison experiences, such as crowding, are associated with recidivism and drug use in particular may be warranted. PMID:26492490

  10. Multiscale diffusion of a molecular probe in a crowded environment: a concept

    Science.gov (United States)

    Currie, Megan; Thao, Chang; Timerman, Randi; Welty, Robb; Berry, Brenden; Sheets, Erin D.; Heikal, Ahmed A.

    2015-08-01

    Living cells are crowded with macromolecules and organelles. Yet, it is not fully understood how macromolecular crowding affects the myriad of biochemical reactions, transport and the structural stability of biomolecules that are essential to cellular function and survival. These molecular processes, with or without electrostatic interactions, in living cells are therefore expected to be distinct from those carried out in test tube in dilute solutions where excluded volumes are absent. Thus there is an urgent need to understand the macromolecular crowding effects on cellular and molecular biophysics towards quantitative cell biology. In this report, we investigated how biomimetic crowding affects both the rotational and translation diffusion of a small probe (rhodamine green, RhG). For biomimetic crowding agents, we used Ficoll-70 (synthetic polymer), bovine serum albumin and ovalbumin (proteins) at various concentrations in a buffer at room temperature. As a control, we carried out similar measurements on glycerolenriched buffer as an environment with homogeneous viscosity as a function of glycerol concentration. The corresponding bulk viscosity was measured independently to test the validity of the Stokes-Einstein model of a diffusing species undergoing a random walk. For rotational diffusion (ps-ns time scale), we used time-resolved anisotropy measurements to examine potential binding of RhG as a function of the crowding agents (surface structure and size). For translational diffusion (μs-s time scale), we used fluorescence correlation spectroscopy for single-molecule fluctuation analysis. Our results allow us to examine the diffusion model of a molecular probe in crowded environments as a function of concentration, length scale, homogeneous versus heterogeneous viscosity, size and surface structures. These biomimetic crowding studies, using non-invasive fluorescence spectroscopy methods, represent an important step towards understanding cellular biophysics and

  11. Gas Marbles: Much Stronger than Liquid Marbles

    Science.gov (United States)

    Timounay, Yousra; Pitois, Olivier; Rouyer, Florence

    2017-06-01

    Enwrapping liquid droplets with hydrophobic particles allows the manufacture of so-called "liquid marbles" [Aussillous and Quéré Nature (London) 411, 924 (2001); , 10.1038/35082026Mahadevan Nature (London)411, 895 (2001), 10.1038/35082164]. The recent intensive research devoted to liquid marbles is justified by their very unusual physical and chemical properties and by their potential for various applications, from microreactors to water storage, including water pollution sensors [Bormashenko Curr. Opin. Colloid Interface Sci. 16, 266 (2011), 10.1016/j.cocis.2010.12.002]. Here we demonstrate that this concept can be successfully applied for encapsulating and protecting small gas pockets within an air environment. Similarly to their liquid counterparts, those new soft-matter objects, that we call "gas marbles," can sustain external forces. We show that gas marbles are surprisingly tenfold stronger than liquid marbles and, more importantly, they can sustain both positive and negative pressure differences. This magnified strength is shown to originate from the strong cohesive nature of the shell. Those interesting properties could be exploited for imprisoning valuable or polluted gases or for designing new aerated materials.

  12. Solving the worldwide emergency department crowding problem - what can we learn from an Israeli ED?

    Science.gov (United States)

    Pines, Jesse M; Bernstein, Steven L

    2015-01-01

    ED crowding is a prevalent and important issue facing hospitals in Israel and around the world, including North and South America, Europe, Australia, Asia and Africa. ED crowding is associated with poorer quality of care and poorer health outcomes, along with extended waits for care. Crowding is caused by a periodic mismatch between the supply of ED and hospital resources and the demand for patient care. In a recent article in the Israel Journal of Health Policy Research, Bashkin et al. present an Ishikawa diagram describing several factors related to longer length of stay (LOS), and higher levels of ED crowding, including management, process, environmental, human factors, and resource issues. Several solutions exist to reduce ED crowding, which involve addressing several of the issues identified by Bashkin et al. This includes reducing the demand for and variation in care, and better matching the supply of resources to demands in care in real time. However, what is needed to reduce crowding is an institutional imperative from senior leadership, implemented by engaged ED and hospital leadership with multi-disciplinary cross-unit collaboration, sufficient resources to implement effective interventions, access to data, and a sustained commitment over time. This may move the culture of a hospital to facilitate improved flow within and across units and ultimately improve quality and safety over the long-term.

  13. Emergency department crowding in Singapore: Insights from a systems thinking approach.

    Science.gov (United States)

    Schoenenberger, Lukas K; Bayer, Steffen; Ansah, John P; Matchar, David B; Mohanavalli, Rajagopal L; Lam, Sean Sw; Ong, Marcus Eh

    2016-01-01

    Emergency Department crowding is a serious and international health care problem that seems to be resistant to most well intended but often reductionist policy approaches. In this study, we examine Emergency Department crowding in Singapore from a systems thinking perspective using causal loop diagramming to visualize the systemic structure underlying this complex phenomenon. Furthermore, we evaluate the relative impact of three different policies in reducing Emergency Department crowding in Singapore: introduction of geriatric emergency medicine, expansion of emergency medicine training, and implementation of enhanced primary care. The construction of the qualitative causal loop diagram is based on consultations with Emergency Department experts, direct observation, and a thorough literature review. For the purpose of policy analysis, a novel approach, the path analysis, is applied. The path analysis revealed that both the introduction of geriatric emergency medicine and the expansion of emergency medicine training may be associated with undesirable consequences contributing to Emergency Department crowding. In contrast, enhancing primary care was found to be germane in reducing Emergency Department crowding; in addition, it has apparently no negative side effects, considering the boundary of the model created. Causal loop diagramming was a powerful tool for eliciting the systemic structure of Emergency Department crowding in Singapore. Additionally, the developed model was valuable in testing different policy options.

  14. Household crowding associated with childhood otitis media hospitalisations in New Zealand.

    Science.gov (United States)

    Bowie, Christopher; Pearson, Amber L; Campbell, Malcolm; Barnett, Ross

    2014-06-01

    To examine the association between hospitalisations for otitis media and area-level measures of household crowding among children in New Zealand. Counts of hospital admissions for otitis media by census area unit were offset against population data from the 2006 national census. Area-level household crowding, exposure to tobacco smoke in the home, equivalised income and individual-level characteristics age and sex were adjusted for. To examine effect modification by ethnicity, three separate poisson models were examined for the total, Māori and non-Māori populations. Household crowding was significantly associated with hospital admissions for otitis media after adjustment in all three models. Neighbourhoods with the highest compared to the lowest proportion of crowded homes exhibited incidence rate ratios of 1.25 (95%CI 1.12-1.37) in the total population, 1.59 (95%CI 1.21-2.04) in the Māori restricted model and 1.17 (95%CI 1.06-1.32) in the non-Māori restricted model. Otitis media hospitalisations are associated with area-level measures of household crowding and other risk factors in this ecological study. The largest increase in otitis media incidence relative to neighbourhood rates of household crowding was exhibited among Māori cases of otitis media. This study adds weight to the growing body of literature linking infectious disease risk to overcrowding in the home. © 2014 The Authors. ANZJPH © 2014 Public Health Association of Australia.

  15. Perceptual learning eases crowding by reducing recognition errors but not position errors.

    Science.gov (United States)

    Xiong, Ying-Zi; Yu, Cong; Zhang, Jun-Yun

    2015-08-01

    When an observer reports a letter flanked by additional letters in the visual periphery, the response errors (the crowding effect) may result from failure to recognize the target letter (recognition errors), from mislocating a correctly recognized target letter at a flanker location (target misplacement errors), or from reporting a flanker as the target letter (flanker substitution errors). Crowding can be reduced through perceptual learning. However, it is not known how perceptual learning operates to reduce crowding. In this study we trained observers with a partial-report task (Experiment 1), in which they reported the central target letter of a three-letter string presented in the visual periphery, or a whole-report task (Experiment 2), in which they reported all three letters in order. We then assessed the impact of training on recognition of both unflanked and flanked targets, with particular attention to how perceptual learning affected the types of errors. Our results show that training improved target recognition but not single-letter recognition, indicating that training indeed affected crowding. However, training did not reduce target misplacement errors or flanker substitution errors. This dissociation between target recognition and flanker substitution errors supports the view that flanker substitution may be more likely a by-product (due to response bias), rather than a cause, of crowding. Moreover, the dissociation is not consistent with hypothesized mechanisms of crowding that would predict reduced positional errors.

  16. Structures and functions in the crowded nucleus: new biophysical insights

    Directory of Open Access Journals (Sweden)

    Ronald eHancock

    2014-09-01

    Full Text Available Concepts and methods from the physical sciences have catalysed remarkable progress in understanding the cell nucleus in recent years. To share this excitement with physicists and encourage their interest in this field, this review offers an overview of how the physics which underlies structures and functions in the nucleus is becoming more clear thanks to methods which have been developed to simulate and study macromolecules, polymers, and colloids. The environment in the nucleus is very crowded with macromolecules, making entropic (depletion forces major determinants of interactions. Simulation and experiments are consistent with their key role in forming membraneless compartments such as nucleoli, PML and Cajal bodies, and discrete territories for chromosomes. The chromosomes, giant linear polyelectrolyte polymers, exist in vivo in a state like a polymer melt. Looped conformations are predicted in crowded conditions, and have been confirmed experimentally and are central to the regulation of gene expression. Polymer theory has revealed how the chromosomes are so highly compacted in the nucleus, forming a crumpled globule with fractal properties which avoids knots and entanglements in DNA while allowing facile accessibility for its replication and transcription. Entropic repulsion between looped polymers can explain the confinement of each chromosome to a discrete region of the nucleus. Crowding and looping are predicted to facilitate finding the specific targets of factors which modulate activities of DNA. Simulation shows that entropic effects contribute to finding and repairing potentially lethal double-strand breaks in DNA by increasing the mobility of the broken ends, favouring their juxtaposition for repair. Signaling pathways are strongly influenced by crowding, which favours a processive mode of response (consecutive reactions without releasing substrates. This new information contributes to understanding the sometimes counter

  17. Bayesian network model of crowd emotion and negative behavior

    Science.gov (United States)

    Ramli, Nurulhuda; Ghani, Noraida Abdul; Hatta, Zulkarnain Ahmad; Hashim, Intan Hashimah Mohd; Sulong, Jasni; Mahudin, Nor Diana Mohd; Rahman, Shukran Abd; Saad, Zarina Mat

    2014-12-01

    The effects of overcrowding have become a major concern for event organizers. One aspect of this concern has been the idea that overcrowding can enhance the occurrence of serious incidents during events. As one of the largest Muslim religious gathering attended by pilgrims from all over the world, Hajj has become extremely overcrowded with many incidents being reported. The purpose of this study is to analyze the nature of human emotion and negative behavior resulting from overcrowding during Hajj events from data gathered in Malaysian Hajj Experience Survey in 2013. The sample comprised of 147 Malaysian pilgrims (70 males and 77 females). Utilizing a probabilistic model called Bayesian network, this paper models the dependence structure between different emotions and negative behaviors of pilgrims in the crowd. The model included the following variables of emotion: negative, negative comfortable, positive, positive comfortable and positive spiritual and variables of negative behaviors; aggressive and hazardous acts. The study demonstrated that emotions of negative, negative comfortable, positive spiritual and positive emotion have a direct influence on aggressive behavior whereas emotion of negative comfortable, positive spiritual and positive have a direct influence on hazardous acts behavior. The sensitivity analysis showed that a low level of negative and negative comfortable emotions leads to a lower level of aggressive and hazardous behavior. Findings of the study can be further improved to identify the exact cause and risk factors of crowd-related incidents in preventing crowd disasters during the mass gathering events.

  18. Why not “just for the money”? An experimental vignette study of the cognitive price effects and crowding effects of performance-related pay

    DEFF Research Database (Denmark)

    Jacobsen, Christian Bøtcher; Jensen, Lars Engelbrecht

    2017-01-01

    whether the mechanism is motivational as expected. This study finds support for these expectations using a vignette survey experimental setup of 1,152 responses (from 384 respondents). The results indicate that PRP positively affects organizational citizenship behavior (OCB), but that this effect......-controlling, the importance of intrinsic motivation can actually increase. The implications of this study are that PRP is not necessarily harmful, and that managers should pay close attention to how their employees perceive performance-based pay systems....

  19. Crowd-Sourced Intelligence Agency: Prototyping counterveillance

    Directory of Open Access Journals (Sweden)

    Jennifer Gradecki

    2017-02-01

    Full Text Available This paper discusses how an interactive artwork, the Crowd-Sourced Intelligence Agency (CSIA, can contribute to discussions of Big Data intelligence analytics. The CSIA is a publicly accessible Open Source Intelligence (OSINT system that was constructed using information gathered from technical manuals, research reports, academic papers, leaked documents, and Freedom of Information Act files. Using a visceral heuristic, the CSIA demonstrates how the statistical correlations made by automated classification systems are different from human judgment and can produce false-positives, as well as how the display of information through an interface can affect the judgment of an intelligence agent. The public has the right to ask questions about how a computer program determines if they are a threat to national security and to question the practicality of using statistical pattern recognition algorithms in place of human judgment. Currently, the public’s lack of access to both Big Data and the actual datasets intelligence agencies use to train their classification algorithms keeps the possibility of performing effective sous-dataveillance out of reach. Without this data, the results returned by the CSIA will not be identical to those of intelligence agencies. Because we have replicated how OSINT is processed, however, our results will resemble the type of results and mistakes made by OSINT systems. The CSIA takes some initial steps toward contributing to an informed public debate about large-scale monitoring of open source, social media data and provides a prototype for counterveillance and sousveillance tools for citizens.

  20. Crowding with conjunctions of simple features.

    Science.gov (United States)

    Põder, Endel; Wagemans, Johan

    2007-11-20

    Several recent studies have related crowding with the feature integration stage in visual processing. In order to understand the mechanisms involved in this stage, it is important to use stimuli that have several features to integrate, and these features should be clearly defined and measurable. In this study, Gabor patches were used as target and distractor stimuli. The stimuli differed in three dimensions: spatial frequency, orientation, and color. A group of 3, 5, or 7 objects was presented briefly at 4 deg eccentricity of the visual field. The observers' task was to identify the object located in the center of the group. A strong effect of the number of distractors was observed, consistent with various spatial pooling models. The analysis of incorrect responses revealed that these were a mix of feature errors and mislocalizations of the target object. Feature errors were not purely random, but biased by the features of distractors. We propose a simple feature integration model that predicts most of the observed regularities.

  1. National conference on crowd-funding - Presentations

    International Nuclear Information System (INIS)

    Bour, Daniel; Raguet, Alex; Arnaud, Christophe; Olive, Catherine; Herriou, Jean-Pierre; Lemaignan, Benoit; Camps, Mathieu; Gauduchon, Marie-Veronique; Hostache, Julien; Clerc, Jean-Marc; Feraudy, Nicolas de; Petit, Frederic; Blais, Armaury; Egnell, Luc; Desvigne, Alain; Floc'h, Romain; Forgues, Benoit; Kuzdzal, Matthieu

    2016-12-01

    This conference was organised in the framework of the CrowdFundRES European project (European Union's Horizon 2020 research and innovation programme under grant agreement No. 646435). Its objectives were: - to provide a comprehensive overview of solar energy crowd-funding in Europe and in France; - to inform about the French legal framework; - to answer the pending questions regarding the conditions of application of the call for bids; - to identify the most suitable modalities for project developers; - to shed light on the possibilities offered to local communities and to their citizens; - to present concrete examples of realisations with their experience feedback; - to exchange on crowd-funding structuring at the service of energy transition in France and in regions. This document brings together the different presentations (slides) given at this conference

  2. Virtual Crowds Methods, Simulation, and Control

    CERN Document Server

    Pelechano, Nuria; Allbeck, Jan

    2008-01-01

    There are many applications of computer animation and simulation where it is necessary to model virtual crowds of autonomous agents. Some of these applications include site planning, education, entertainment, training, and human factors analysis for building evacuation. Other applications include simulations of scenarios where masses of people gather, flow, and disperse, such as transportation centers, sporting events, and concerts. Most crowd simulations include only basic locomotive behaviors possibly coupled with a few stochastic actions. Our goal in this survey is to establish a baseline o

  3. Directing the wisdom of the crowd

    DEFF Research Database (Denmark)

    Clauss, Thomas; Breitenecker, Robert J.; Kraus, Sascha

    2018-01-01

    and the community as well as among community members into account. We empirically investigated potential success factors for crowdfunding projects of entrepreneurs on the base of 430 projects from the German crowdfunding platform Visionbakery. Our results show that social interaction during a crowdfunding campaign...... indeed increases the likelihood of its success. As comments from crowd members on particular projects might be positive or negative and can also provide additional argumentation or raise questions, comments can cause a dialog among crowd members. This shows that herding might not only be related...

  4. EMOTIONAL CONTAGION AND MOOD IN CROWD SERVING AS AUDIENCE

    Directory of Open Access Journals (Sweden)

    Beno Arnejcic

    2015-06-01

    Full Text Available The global world is gradually becoming a world of separated crowds despite the artificial wire and wireless connection through television and the Internet. Crowds remain a prevailing subject of research in different social studies, and the research of changes in the psychological structure of crowds and their characteristics is still of primary interest. The main focus of the research is on the interpretation of the results of the research paper about a special separated crowd called audience. It was observed how students, constituting the crowd, perceive a crowd on video. The observation was focused on the research of emotional contagion and mood in the crowd serving as audience. While watching a mass event on a big screen, the crowd serving as audience emotionally converges with someone else, in our case with public speakers.

  5. A systematic review on ‘Foveal Crowding’ in visually impaired children and perceptual learning as a method to reduce Crowding

    Directory of Open Access Journals (Sweden)

    Huurneman Bianca

    2012-07-01

    Full Text Available Abstract Background This systematic review gives an overview of foveal crowding (the inability to recognize objects due to surrounding nearby contours in foveal vision and possible interventions. Foveal crowding can have a major effect on reading rate and deciphering small pieces of information from busy visual scenes. Three specific groups experience more foveal crowding than adults with normal vision (NV: 1 children with NV, 2 visually impaired (VI children and adults and 3 children with cerebral visual impairment (CVI. The extent and magnitude of foveal crowding as well as interventions aimed at reducing crowding were investigated in this review. The twofold goal of this review is : [A] to compare foveal crowding in children with NV, VI children and adults and CVI children and [B] to compare interventions to reduce crowding. Methods Three electronic databases were used to conduct the literature search: PubMed, PsycINFO (Ovid, and Cochrane. Additional studies were identified by contacting experts. Search terms included visual perception, contour interaction, crowding, crowded, and contour interactions. Results Children with normal vision show an extent of contour interaction over an area 1.5–3× as large as that seen in adults NV. The magnitude of contour interaction normally ranges between 1–2 lines on an acuity chart and this magnitude is even larger when stimuli are arranged in a circular configuration. Adults with congenital nystagmus (CN show interaction areas that are 2× larger than those seen adults with NV. The magnitude of the crowding effect is also 2× as large in individuals with CN as in individuals with NV. Finally, children with CVI experience a magnitude of the crowding effect that is 3× the size of that experienced by adults with NV. Conclusions The methodological heterogeneity, the diversity in paradigms used to measure crowding, made it impossible to conduct a meta-analysis. This is the first systematic review to

  6. Crowd counting via scale-adaptive convolutional neural network

    OpenAIRE

    Zhang, Lu; Shi, Miaojing; Chen, Qiaobo

    2017-01-01

    The task of crowd counting is to automatically estimate the pedestrian number in crowd images. To cope with the scale and perspective changes that commonly exist in crowd images, state-of-the-art approaches employ multi-column CNN architectures to regress density maps of crowd images. Multiple columns have different receptive fields corresponding to pedestrians (heads) of different scales. We instead propose a scale-adaptive CNN (SaCNN) architecture with a backbone of fixed small receptive fi...

  7. The Crowd in Requirements Engineering: The Landscape and Challenges

    NARCIS (Netherlands)

    Groen, Eduard C.; Seyff, Norbert; Ali, Raian; Dalpiaz, Fabiano; Doerr, Joerg; Guzman, Emitza; Hosseini, Mahmood; Marco, Jordi; Oriol, Marc; Perini, Anna; Stade, Melanie

    2017-01-01

    Crowd-based requirements engineering (CrowdRE) could significantly change RE. Performing RE activities such as elicitation with the crowd of stakeholders turns RE into a participatory effort, leads to more accurate requirements, and ultimately boosts software quality. Although any stakeholder in the

  8. Noncanonical structures and their thermodynamics of DNA and RNA under molecular crowding: beyond the Watson-Crick double helix.

    Science.gov (United States)

    Sugimoto, Naoki

    2014-01-01

    How does molecular crowding affect the stability of nucleic acid structures inside cells? Water is the major solvent component in living cells, and the properties of water in the highly crowded media inside cells differ from that in buffered solution. As it is difficult to measure the thermodynamic behavior of nucleic acids in cells directly and quantitatively, we recently developed a cell-mimicking system using cosolutes as crowding reagents. The influences of molecular crowding on the structures and thermodynamics of various nucleic acid sequences have been reported. In this chapter, we discuss how the structures and thermodynamic properties of nucleic acids differ under various conditions such as highly crowded environments, compartment environments, and in the presence of ionic liquids, and the major determinants of the crowding effects on nucleic acids are discussed. The effects of molecular crowding on the activities of ribozymes and riboswitches on noncanonical structures of DNA- and RNA-like quadruplexes that play important roles in transcription and translation are also described. © 2014 Elsevier Inc. All rights reserved.

  9. Data For: Heading Through A Crowd

    OpenAIRE

    Riddell, Hugh; Lappe, Markus

    2018-01-01

    Data and analysis scripts to accompany the article "Heading Through A Crowd" by Dr. Hugh Riddell and Prof. Dr. Markus Lappe. All analysis scripts are in SPSS format. Data has been provided in SPSS and .txt formats. Any correspondence should be addressed to Prof. Dr. Markus Lappe.

  10. The crowd in the Occupy movement

    NARCIS (Netherlands)

    Ossewaarde, Marinus R.R.

    2013-01-01

    In this article, I recast Elias Canetti's notion of crowds by placing it in the framework provided by Friedrich Nietzsche's Heraclitean dialectic of Apollonian and Dionysian opposites. The argument is introduced that, in European societies, the forms of social existence are mainly Apollonian,

  11. Crowd-sourcing with Uncertain Quality

    DEFF Research Database (Denmark)

    Papakonstantinou, Athanasios; Bogetoft, Peter

    This article addresses two important issues in crowd-sourcing: ex ante uncertainty about the quality and cost of different workers and strategic behaviour. We present a novel multi-dimensional auction that incentivises the workers to make partial enquiry into the task and to honestly report quality...

  12. How to Move in a Jostling Crowd

    Indian Academy of Sciences (India)

    For people living in big cities it is an ordeal to walk in a bus stand or a railway station. They get stuck helplessly in a crowd. They are simply pushed around and all their efforts to move forward appear futile. Only the most energetic can wade through the constantly moving sea of people. How about the weaker ones?

  13. Wise Crowd Content Assessment and Educational Rubrics

    Science.gov (United States)

    Passonneau, Rebecca J.; Poddar, Ananya; Gite, Gaurav; Krivokapic, Alisa; Yang, Qian; Perin, Dolores

    2018-01-01

    Development of reliable rubrics for educational intervention studies that address reading and writing skills is labor-intensive, and could benefit from an automated approach. We compare a main ideas rubric used in a successful writing intervention study to a highly reliable wise-crowd content assessment method developed to evaluate…

  14. Using the crowd as an innovation partner.

    Science.gov (United States)

    Boudreau, Kevin J; Lakhani, Karim R

    2013-04-01

    From Apple to Merck to Wikipedia, more and more organizations are turning to crowds for help in solving their most vexing innovation and research questions, but managers remain understandably cautious. It seems risky and even unnatural to push problems out to vast groups of strangers distributed around the world, particularly for companies built on a history of internal innovation. How can intellectual property be protected? How can a crowd-sourced solution be integrated into corporate operations? What about the costs? These concerns are all reasonable, the authors write, but excluding crowdsourcing from the corporate innovation tool kit means losing an opportunity. After a decade of study, they have identified when crowds tend to outperform internal organizations (or not). They outline four ways to tap into crowd-powered problem solving--contests, collaborative communities, complementors, and labor markets--and offer a system for picking the best one in a given situation. Contests, for example, are suited to highly challenging technical, analytical, and scientific problems; design problems; and creative or aesthetic projects. They are akin to running a series of independent experiments that generate multiple solutions--and if those solutions cluster at some extreme, a company can gain insight into where a problem's "technical frontier" lies. (Internal R&D may generate far less information.)

  15. Household behaviour crowds out support for climate change policy when sufficient progress is perceived

    Science.gov (United States)

    Werfel, Seth H.

    2017-07-01

    Household actions and government policies are both necessary to mitigate the effects of climate change. However, household behaviour may crowd out public support for government action by creating the perception of sufficient progress. Here we demonstrate this crowding-out effect in public opinion using survey experiments with more than 14,000 participants in Japan. Subjects who were randomly assigned to report their energy-saving actions following the shutdown of the Fukushima power plant were less likely to support a tax increase on carbon emissions. Treatment effects were larger for subjects who had completed more actions. Further evidence suggests that the crowding-out effect may have been driven by an increase in the perceived importance of individual actions relative to government regulation and a decrease in the perceived issue importance of energy and environmental sustainability.

  16. An Improved Convolutional Neural Network on Crowd Density Estimation

    Directory of Open Access Journals (Sweden)

    Pan Shao-Yun

    2016-01-01

    Full Text Available In this paper, a new method is proposed for crowd density estimation. An improved convolutional neural network is combined with traditional texture feature. The data calculated by the convolutional layer can be treated as a new kind of features.So more useful information of images can be extracted by different features.In the meantime, the size of image has little effect on the result of convolutional neural network. Experimental results indicate that our scheme has adequate performance to allow for its use in real world applications.

  17. Combat Conditioning: The Need for Stronger Marines

    Science.gov (United States)

    2008-02-18

    pounds. This leads to overuse injuries that can reduce a unit’s combat effectiveness. Typically the injuries are isolated to the lower...extremities in the form of femoral and hip stress fractures. The way to avoid these types of injuries is to strengthen the muscles around these areas as...shows how the average weight carried by warriors has increased over time. 3 “ CrossFit is a core strength and conditioning program

  18. Synergistic rate boosting of collagen fibrillogenesis in heterogeneous mixtures of crowding agents.

    Science.gov (United States)

    Dewavrin, Jean-Yves; Abdurrahiem, Muhammed; Blocki, Anna; Musib, Mrinal; Piazza, Francesco; Raghunath, Michael

    2015-03-26

    The competition for access to space that arises between macromolecules is the basis of the macromolecular crowding phenomenon, known to modulate biochemical reactions in subtle ways. Crowding is a highly conserved physiological condition in and around cells in metazoans, and originates from a mixture of heterogeneous biomolecules. Here, using collagen fibrillogenesis as an experimental test platform and ideas from the theory of nonideal solutions, we show that an entropy-based synergy is created by a mixture of two different populations of artificial crowders, providing small crowders with extra volume occupancy when in the vicinity of bigger crowders. We present the physiological mechanism by which synergistic effects maximize volume exclusion with the minimum amount of heterogeneous crowders, demonstrating how the evolutionarily optimized crowded conditions found in vivo can be reproduced effectively in vitro.

  19. Applying Crowd Psychology to Develop Recommendations for the Management of Mass Decontamination

    Science.gov (United States)

    Drury, John; Rubin, G. James; Williams, Richard; Amlôt, Richard

    2015-01-01

    Mass decontamination is a public health intervention employed by emergency responders following a chemical, biological, or radiological release. It involves a crowd of people whose interactions with each other and with the emergency responders managing the incident are likely to affect the success of the decontamination process. The way in which members of the public collectively experience decontamination is likely to affect their behavior and hence is crucial to the success of the decontamination process. Consequently, responders and the responsible authorities need to understand crowd psychology during mass emergencies and disasters. Recently, the social identity approach to crowd psychology has been applied to explain public perceptions and behavior during mass emergencies. This approach emphasizes that crowd events are characteristically intergroup encounters, in which the behavior of one group can affect the perceptions and behavior of another. We summarize the results from a program of research in which the social identity approach was applied to develop and test recommendations for the management of mass decontamination. The findings from this program of research show that (1) responders' perceptions of crowd behavior matter; (2) participants value greater communication and this affects their compliance; and (3) social identity processes explain the relationship between effective responder communication and relevant outcome variables, such as public compliance, public cooperation, and public anxiety. Based on this program of research, we recommend 4 responder management strategies that focus on increasing public compliance, increasing orderly and cooperative behavior among members of the public, reducing public anxiety, and respecting public needs for privacy. PMID:25812428

  20. Crowding and delivery of healthcare in emergency departments: the European perspective.

    LENUS (Irish Health Repository)

    Jayaprakash, Namita

    2009-11-01

    Emergency department (ED) crowding is a multifactorial problem, resulting in increased ED waiting times, decreased patient satisfaction and deleterious domino effects on the entire hospital. Although difficult to define and once limited to anecdotal evidence, crowding is receiving more attention as attempts are made to quantify the problem objectively. It is a worldwide phenomenon with regional influences, as exemplified when analyzing the problem in Europe compared to that of the United States. In both regions, an aging population, limited hospital resources, staff shortages and delayed ancillary services are key contributors; however, because the structure of healthcare differs from country to country, varying influences affect the issue of crowding. The approach to healthcare delivery as a right of all people, as opposed to a free market commodity, depends on governmental organization and appropriation of funds. Thus, public funding directly influences potential crowding factors, such as number of hospital beds, community care facilities, and staffing. Ultimately ED crowding is a universal problem with distinctly regional root causes; thus, any approach to address the problem must be tailored to regional influences.

  1. Applying crowd psychology to develop recommendations for the management of mass decontamination.

    Science.gov (United States)

    Carter, Holly; Drury, John; Rubin, G James; Williams, Richard; Amlôt, Richard

    2015-01-01

    Mass decontamination is a public health intervention employed by emergency responders following a chemical, biological, or radiological release. It involves a crowd of people whose interactions with each other and with the emergency responders managing the incident are likely to affect the success of the decontamination process. The way in which members of the public collectively experience decontamination is likely to affect their behavior and hence is crucial to the success of the decontamination process. Consequently, responders and the responsible authorities need to understand crowd psychology during mass emergencies and disasters. Recently, the social identity approach to crowd psychology has been applied to explain public perceptions and behavior during mass emergencies. This approach emphasizes that crowd events are characteristically intergroup encounters, in which the behavior of one group can affect the perceptions and behavior of another. We summarize the results from a program of research in which the social identity approach was applied to develop and test recommendations for the management of mass decontamination. The findings from this program of research show that (1) responders' perceptions of crowd behavior matter; (2) participants value greater communication and this affects their compliance; and (3) social identity processes explain the relationship between effective responder communication and relevant outcome variables, such as public compliance, public cooperation, and public anxiety. Based on this program of research, we recommend 4 responder management strategies that focus on increasing public compliance, increasing orderly and cooperative behavior among members of the public, reducing public anxiety, and respecting public needs for privacy.

  2. Making muscles "stronger": exercise, nutrition, drugs.

    Science.gov (United States)

    Aagaard, P

    2004-06-01

    As described in this review, maximal muscle strength is strongly influenced by resistive-types of exercise, which induce adaptive changes in both neuromuscular function and muscle morphology. Further, timed intake of protein in conjunction with resistance training elicit greater strength and muscle size gains than resistance training alone. Creatine supplementation amplifies the hypertrophic response to resistance training, although some individuals may not respond positively. Locally produced muscle growth factors are upregulated during creatine supplementation, which contributes to increase the responsiveness of muscle cells to intensive training stimuli. Usage of anabolic steroids boosts muscle hypertrophy beyond inherent genetical limits, not only by increasing the DNA transcription rate for myofibrillar proteins but also by increasing the nucleus-to-cytoplasm ratio due to accelerated activation of myogenic satellite cells. However, severe tissue damaging effects exist with anabolic steroids, some of which are irreversible.

  3. Crowd-Sourced Intelligence Agency: Prototyping counterveillance

    OpenAIRE

    Jennifer Gradecki; Derek Curry

    2017-01-01

    This paper discusses how an interactive artwork, the Crowd-Sourced Intelligence Agency (CSIA), can contribute to discussions of Big Data intelligence analytics. The CSIA is a publicly accessible Open Source Intelligence (OSINT) system that was constructed using information gathered from technical manuals, research reports, academic papers, leaked documents, and Freedom of Information Act files. Using a visceral heuristic, the CSIA demonstrates how the statistical correlations made by automate...

  4. Microscopic and macroscopic models for pedestrian crowds

    OpenAIRE

    Makmul, Juntima

    2016-01-01

    This thesis is concerned with microscopic and macroscopic models for pedes- trian crowds. In the first chapter, we consider pedestrians exit choices and model human behaviour in an evacuation process. Two microscopic models, discrete and continuous, are studied in this chapter. The former is a cellular automaton model and the latter is a social force model. Different numerical test cases are investigated and their results are compared. In chapter 2, a hierarchy of models for...

  5. Waiting room crowding and agitation in a dedicated psychiatric emergency service.

    Science.gov (United States)

    El-Mallakh, Rif S; Whiteley, Amanda; Wozniak, Tanya; Ashby, McCray; Brown, Shawn; Colbert-Trowel, Danya; Pennington, Tammy; Thompson, Michael; Tasnin, Rokeya; Terrell, Christina L

    2012-05-01

    Emergency department crowding is a growing problem that impacts patient care and safety. The effect of crowding has not been examined in emergency psychiatric services. The association between patient census and use of restraints, seclusion, and anti-agitation medications as needed was examined for 1 month. A total of 689 patients were seen in 31 days. The average hourly census was 6.8 ± 2.8 (range 0 to 18). There were 33 incidences of seclusion or restraint and an additional 15 instances of medications administered for agitation. The use of seclusion, restraint, or medication for agitation was significantly associated with census (r2 = 0.3, F = 5.47, P = .036). Crowding in emergency psychiatric waiting rooms may increase the need for seclusion, restraint, or medications for agitation.

  6. The effects of protein crowding in bacterial photosynthetic membranes on the flow of quinone redox species between the photochemical reaction center and the ubiquinol-cytochrome c2 oxidoreductase.

    Science.gov (United States)

    Woronowicz, Kamil; Sha, Daniel; Frese, Raoul N; Sturgis, James N; Nanda, Vikas; Niederman, Robert A

    2011-08-01

    Atomic force microscopy (AFM) of the native architecture of the intracytoplasmic membrane (ICM) of a variety of species of purple photosynthetic bacteria, obtained at submolecular resolution, shows a tightly packed arrangement of light harvesting (LH) and reaction center (RC) complexes. Since there are no unattributed structures or gaps with space sufficient for the cytochrome bc(1) or ATPase complexes, they are localized in membrane domains distinct from the flat regions imaged by AFM. This has generated a renewed interest in possible long-range pathways for lateral diffusion of UQ redox species that functionally link the RC and the bc(1) complexes. Recent proposals to account for UQ flow in the membrane bilayer are reviewed, along with new experimental evidence provided from an analysis of intrinsic near-IR fluorescence emission that has served to test these hypotheses. The results suggest that different mechanism of UQ flow exist between species such as Rhodobacter sphaeroides, with a highly organized arrangement of LH and RC complexes and fast RC electron transfer turnover, and Phaeospirillum molischianum with a more random organization and slower RC turnover. It is concluded that packing density of the peripheral LH2 antenna in the Rba. sphaeroides ICM imposes constraints that significantly slow the diffusion of UQ redox species between the RC and cytochrome bc(1) complex, while in Phs. molischianum, the crowding of the ICM with LH3 has little effect upon UQ diffusion. This supports the proposal that in this type of ICM, a network of RC-LH1 core complexes observed in AFM provides a pathway for long-range quinone diffusion that is unaffected by differences in LH complex composition or organization.

  7. Effects of larval crowding on development time, survival and weight at metamorphosis in Aedes aegypti (Diptera: Culicidae Efectos del hacinamiento larval en el tiempo de desarrollo, la supervivencia y el peso en la metamorfosis de Aedes aegypti (Diptera: Culicidae

    Directory of Open Access Journals (Sweden)

    Arnaldo Maciá

    2009-06-01

    Full Text Available The effects of larval crowding on survival, weight at metamorphosis and development time were assessed in the dengue mosquito, Aedes aegypti L., under a controlled environment. Larval cohorts were bred at 7 different densities (4, 8, 16, 32, 64, 128 and 256 larvae / 175 ml pot, while keeping constant water volume and food amount and quality, under controlled temperature and photoperiod. Natural detritus, mainly leaves, obtained from containers naturally colonized by A. aegypti, were used as a source of nutrients for larvae. Development time, mortality, mass at metamorphosis, and total biomass were recorded for each density. Development time ranged from 4 to 23 days in males, and from 5 to 24 in females, whereby larvae took longer to develop at 64 (females and 128 (males larvae per recipient. At high densities there was a male-biased sex proportion. At densities equal to or higher than 0.4 larvae/ml (0.32 larvae/cm² there was an increase of mortality. An inverse relationship between larval density and pupal weight was detected. Biomass per individual reached asymptotic values of about 1 mg/individual at a density of 128 individuals/pot (0.64 larvae/cm². This experiment shows that this southern strain of A. aegypti is sensitive to crowding in small containers.Los efectos del hacinamiento larval sobre el tiempo de desarrollo, la supervivencia y el peso en la metamorfosis fueron estudiados en el mosquito del dengue, Aedes aegypti L., en el laboratorio. Se criaron cohortes de larvas en 7 densidades (4, 8, 16, 32, 64, 128 y 256 larvas/ recipiente de 175 ml mientras se mantuvo constante el volumen de agua y la calidad y cantidad de alimento, bajo fotoperíodo y temperatura controlados. Se usaron detritos naturales, principalmente hojas, obtenidos de contenedores colonizados naturalmente por A. aegypti como fuente de nutrientes para las larvas. En cada densidad se registraron el tiempo de desarrollo, la mortalidad, el peso en la metamorfosis y la

  8. The Educational Program "Zajedno Jaci" (Stronger Together) in Croatia

    Science.gov (United States)

    Spanja, Sanja

    2011-01-01

    In this paper, we explore intercultural learning undertaken through the educational program "Stronger Together." The program "Stronger Together" was created in 1998 in order to support and educate teachers working with children in post-war regions of Croatia using intercultural education and cooperative learning as tools for…

  9. Stronger Schrödinger-like uncertainty relations

    International Nuclear Information System (INIS)

    Song, Qiu-Cheng; Qiao, Cong-Feng

    2016-01-01

    Highlights: • A stronger Schrödinger-like uncertainty relation in the sum of variances of two observables is obtained. • An improved Schrödinger-like uncertainty relation in the product of variances of two observables is obtained. • A stronger uncertainty relation in the sum of variances of three observables is proposed. - Abstract: Uncertainty relation is one of the fundamental building blocks of quantum theory. Nevertheless, the traditional uncertainty relations do not fully capture the concept of incompatible observables. Here we present a stronger Schrödinger-like uncertainty relation, which is stronger than the relation recently derived by Maccone and Pati (2014) [11]. Furthermore, we give an additive uncertainty relation which holds for three incompatible observables, which is stronger than the relation newly obtained by Kechrimparis and Weigert (2014) [12] and the simple extension of the Schrödinger uncertainty relation.

  10. Secure Nearest Neighbor Query on Crowd-Sensing Data

    Directory of Open Access Journals (Sweden)

    Ke Cheng

    2016-09-01

    Full Text Available Nearest neighbor queries are fundamental in location-based services, and secure nearest neighbor queries mainly focus on how to securely and quickly retrieve the nearest neighbor in the outsourced cloud server. However, the previous big data system structure has changed because of the crowd-sensing data. On the one hand, sensing data terminals as the data owner are numerous and mistrustful, while, on the other hand, in most cases, the terminals find it difficult to finish many safety operation due to computation and storage capability constraints. In light of they Multi Owners and Multi Users (MOMU situation in the crowd-sensing data cloud environment, this paper presents a secure nearest neighbor query scheme based on the proxy server architecture, which is constructed by protocols of secure two-party computation and secure Voronoi diagram algorithm. It not only preserves the data confidentiality and query privacy but also effectively resists the collusion between the cloud server and the data owners or users. Finally, extensive theoretical and experimental evaluations are presented to show that our proposed scheme achieves a superior balance between the security and query performance compared to other schemes.

  11. Age-related changes in crowding and reading speed

    OpenAIRE

    Liu, Rong; Patel, Bhavika N.; Kwon, MiYoung

    2017-01-01

    Crowding, the inability to recognize objects in clutter, is known to play a role in developmental changes in reading speed. Here, we investigated whether crowding also plays a role in age-related changes in reading speed. We recruited 18 young (mean age: 22.6???3.5; range: 18~31) and 21 older adults (mean age: 58.2???7.0; range: 50~73) with normal vision. Reading speed was measured with short blocks of text. The degree of crowding was determined by measuring crowding zone (the distance betwee...

  12. Crowding and Cognitive Development: The Mediating Role of Maternal Responsiveness among 36-Month-Old Children

    Science.gov (United States)

    Evans, Gary W.; Ricciuti, Henry N.; Hope, Steven; Schoon, Ingrid; Bradley, Robert H.; Corwyn, Robert F.; Hazan, Cindy

    2010-01-01

    Residential crowding in both U.S. and U.K. samples of 36-month-old children is related concurrently to the Bracken scale, a standard index of early cognitive development skills including letter and color identification, shape recognition, and elementary numeric comprehension. In the U.S. sample, these effects also replicate prospectively.…

  13. Simulating crowd evacuation with socio-cultural, cognitive, and emotional elements

    NARCIS (Netherlands)

    van der Wal, C. Natalie; Formolo, Daniel; Robinson, Mark A.; Minkov, Michael; Bosse, Tibor

    2017-01-01

    In this research, the effects of culture, cognitions, and emotions on crisis management and prevention are analysed. An agent-based crowd evacuation simulation model was created, named IMPACT, to study the evacuation process from a transport hub. To extend previous research, various socio-cultural,

  14. Do monetary rewards crowd out intrinsic motivations of volunteers? Some empirical evidence for Italian volunteers

    OpenAIRE

    Damiano Fiorillo

    2009-01-01

    The paper studies the determinants of regular volunteering departing from previous literature on extrinsic and intrinsic motivations. It contributes to the literature investigating the role of monetary rewards to influence intrinsic motivation. Using a simple framework that allows me to study the effect of monetary rewards on intrinsic motivation, the paper shows, controlling for endogenous bias, that monetary rewards crowd-out intrinsic motivation.

  15. A face in the crowd: a non-invasive and cost effective photo-identification methodology to understand the fine scale movement of eastern water dragons.

    Directory of Open Access Journals (Sweden)

    Riana Zanarivero Gardiner

    Full Text Available Ectothermic vertebrates face many challenges of thermoregulation. Many species rely on behavioral thermoregulation and move within their landscape to maintain homeostasis. Understanding the fine-scale nature of this regulation through tracking techniques can provide a better understanding of the relationships between such species and their dynamic environments. The use of animal tracking and telemetry technology has allowed the extensive collection of such data which has enabled us to better understand the ways animals move within their landscape. However, such technologies do not come without certain costs: they are generally invasive, relatively expensive, can be too heavy for small sized animals and unreliable in certain habitats. This study provides a cost-effective and non-invasive method through photo-identification, to determine fine scale movements of individuals. With our methodology, we have been able to find that male eastern water dragons (Intellagama leuseurii have home ranges one and a half times larger than those of females. Furthermore, we found intraspecific differences in the size of home ranges depending on the time of the day. Lastly, we found that location mostly influenced females' home ranges, but not males and discuss why this may be so. Overall, we provide valuable information regarding the ecology of the eastern water dragon, but most importantly demonstrate that non-invasive photo-identification can be successfully applied to the study of reptiles.

  16. A face in the crowd: a non-invasive and cost effective photo-identification methodology to understand the fine scale movement of eastern water dragons.

    Science.gov (United States)

    Gardiner, Riana Zanarivero; Doran, Erik; Strickland, Kasha; Carpenter-Bundhoo, Luke; Frère, Celine

    2014-01-01

    Ectothermic vertebrates face many challenges of thermoregulation. Many species rely on behavioral thermoregulation and move within their landscape to maintain homeostasis. Understanding the fine-scale nature of this regulation through tracking techniques can provide a better understanding of the relationships between such species and their dynamic environments. The use of animal tracking and telemetry technology has allowed the extensive collection of such data which has enabled us to better understand the ways animals move within their landscape. However, such technologies do not come without certain costs: they are generally invasive, relatively expensive, can be too heavy for small sized animals and unreliable in certain habitats. This study provides a cost-effective and non-invasive method through photo-identification, to determine fine scale movements of individuals. With our methodology, we have been able to find that male eastern water dragons (Intellagama leuseurii) have home ranges one and a half times larger than those of females. Furthermore, we found intraspecific differences in the size of home ranges depending on the time of the day. Lastly, we found that location mostly influenced females' home ranges, but not males and discuss why this may be so. Overall, we provide valuable information regarding the ecology of the eastern water dragon, but most importantly demonstrate that non-invasive photo-identification can be successfully applied to the study of reptiles.

  17. Standing out in the crowd

    DEFF Research Database (Denmark)

    Bialkova, Svetlana; Grunert, Klaus G; Trijp, Hans van

    2013-01-01

    non-dense area. These effects were modulated by label type and chromaticity. The results show that information density is a key factor for consumer attention to (nutrition) information. Implications for policy makers and food producers who want to optimize package design layout and thus help consumers......Whether and how information density on front-of-pack design affects consumers’ attention for nutrition labels is explored. The main manipulation concerned the number and type of nutrition labels (directive-, semi-, and non-directive), chromaticity (monochrome vs. traffic light color-coded scheme......); number and type of additional design elements; and the distance between the label and additional design elements. Attention was measured by performance in visual search task. Performance was slower with increasing number of additional design elements, and when the label appeared in a dense rather than...

  18. The Financial Impact of Emergency Department Crowding

    Directory of Open Access Journals (Sweden)

    Foley, Mathew

    2011-05-01

    Full Text Available Objective: The economic benefits of reducing emergency department (ED crowding are potentially substantial as they may decrease hospital length of stay. Hospital administrators and public officials may therefore be motivated to implement crowding protocols. We sought to identify a potential cost of ED crowding by evaluating the contribution of excess ED length of stay (LOS to overall hospital length of stay. Methods: We performed a retrospective review of administrative data of adult patients from two urban hospitals (one county and one university in Brooklyn, New York from 2006-2007. Data was provided by each facility. Extrapolating from prior research (Krochmal and Riley, 2005, we determined the increase in total hospital LOS due to extended ED lengths of stay, and applied cost and charge analyses for the two separate facilities. Results: We determined that 6,205 (5.0% admitted adult patients from the county facility and 3,017 (3.4% patients from the university facility were held in the ED greater than one day over a one-year period. From prior research, it has been estimated that each of these patient’s total hospital length of stay was increased on average by 11.7% (0.61 days at the county facility, and 0.71 days at the university facility. The increased charges over one year at the county facility due to the extended ED LOS was therefore approximately $9.8 million, while the increased costs at the university facility were approximately $3.9 million. Conclusion: Based on extrapolations from Krochmal and Riley applied to two New York urban hospitals, the county hospital could potentially save $9.8 million in charges and the university hospital $3.9 million in costs per year if they eliminate ED boarding of adult admitted patients by improving movement to the inpatient setting. [West J Emerg Med. 2011;12(2:192-197.

  19. Women's political participation leads to stronger local economies ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    2016-06-08

    Jun 8, 2016 ... Under changes to India's constitution, Indian women are gaining a stronger ... Legal reforms are encouraging women to contribute to economic growth ... on a panel on empowering women entrepreneurs at IDRC in Ottawa.

  20. Game theoretic aspects of crowd renting | Nwobi-Okoye | Science ...

    African Journals Online (AJOL)

    Politicians and businessmen use various strategies to outwit their opponents. One such strategy is crowd renting, a powerful virtual strategy. A mathematical model developed by Nwobi-Okoye using game theory is used to show that crowd renting would always be the equilibrium strategy in strategic interactions involving ...

  1. Navigation for Characters and Crowds in Complex Virtual Environments

    NARCIS (Netherlands)

    van Toll, W.G.

    2017-01-01

    In a crowd simulation, virtual walking characters need to compute and traverse paths through a virtual environment while avoiding collisions. Simulations of large crowds occur increasingly often in computer games, in which real-time performance is required. Also, there is an increasing demand for

  2. Designing for crowd well-being : Needs and design suggestions

    NARCIS (Netherlands)

    Li, J.; De Ridder, H.; Vermeeren, A.P.O.S.; Conrado, C.; Martella, C.

    2013-01-01

    This paper investigates the needs or criteria for sustaining well-being in crowded situations through two focus group discussions with a total of ten participants. We conclude that pursuing crowd well-being could be divided into two different cases: one is obtaining the enhancement of the current

  3. Crowd-based innovaties: verschuivende verantwoordelijkheden in een institutional void

    NARCIS (Netherlands)

    Slot, M.J.; Cuppen, E.H.W.J.; Doorn, N.; Galeano Galvan, M.J.; Klievink, A.J.

    2017-01-01

    The crowd increasingly plays a key role in facilitating innovations in a variety of sectors, spurred on by IT developments and the concomitant increase in connectivity. Initiatives in this direction, captured under the umbrella term ‘crowd-based innovations’, offer novel opportunities in

  4. Quantitative Comparison Between Crowd Models for Evacuation Planning and Evaluation

    NARCIS (Netherlands)

    Viswanathan, V.; Lee, C.E.; Lees, M.H.; Cheong, S.A.; Sloot, P.M.A.

    2014-01-01

    Crowd simulation is rapidly becoming a standard tool for evacuation planning and evaluation. However, the many crowd models in the literature are structurally different, and few have been rigorously calibrated against real-world egress data, especially in emergency situations. In this paper we

  5. Influence of Music on the Behaviors of Crowd in Urban Open Public Spaces.

    Science.gov (United States)

    Meng, Qi; Zhao, Tingting; Kang, Jian

    2018-01-01

    Sound environment plays an important role in urban open spaces, yet studies on the effects of perception of the sound environment on crowd behaviors have been limited. The aim of this study, therefore, is to explore how music, which is considered an important soundscape element, affects crowd behaviors in urban open spaces. On-site observations were performed at a 100 m × 70 m urban leisure square in Harbin, China. Typical music was used to study the effects of perception of the sound environment on crowd behaviors; then, these behaviors were classified into movement (passing by and walking around) and non-movement behaviors (sitting). The results show that the path of passing by in an urban leisure square with music was more centralized than without music. Without music, 8.3% of people passing by walked near the edge of the square, whereas with music, this percentage was zero. In terms of the speed of passing by behavior, no significant difference was observed with the presence or absence of background music. Regarding the effect of music on walking around behavior in the square, the mean area and perimeter when background music was played were smaller than without background music. The mean speed of those exhibiting walking around behavior with background music in the square was 0.296 m/s slower than when no background music was played. For those exhibiting sitting behavior, when background music was not present, crowd density showed no variation based on the distance from the sound source. When music was present, it was observed that as the distance from the sound source increased, crowd density of those sitting behavior decreased accordingly.

  6. Designing interactive technology for crowd experiences - beyond sanitization

    DEFF Research Database (Denmark)

    Veerasawmy, Rune

    2014-01-01

    This dissertation concerns the topic on designing interactive technology for crowd expe- riences. It takes the outset in the experience-oriented design approach within interaction design, exploring the research question how can we conceptually understand and design interactive technology for crowd...... experiences? Through theoretical studies of sociological crowd theory and pragmatist perspectives on experience combined with design exper- iments at sporting events this dissertation establishes an conceptual understanding of crowd experience. The outcome of this work is furthermore synthesized...... in a conceptual model of social experiences that presents crowd experiences as a distinct type of social experience. This is different from what previously have been explored within experi- ence-oriented design. This dissertation is composed of four research papers framed by an overview that summarizes...

  7. German crowd-investing platforms: Literature review and survey

    Directory of Open Access Journals (Sweden)

    David Grundy

    2016-12-01

    Full Text Available This article presents a comprehensive overview of the current German crowd-investing market drawing on a data-set of 31 crowd-investing platforms including the analysis of 265 completed projects. While crowd-investing market still only represents a niche in the German venture capital market, there is potential for an increase in both market volume and in average project investment. The market share is distributed among a few crowd-investing platforms with high entry barriers for new platforms although platforms that specialise in certain sectors have managed to successfully enter the market. German crowd-investing platforms are found to promote mainly internet-based enterprises (36% followed by projects in real estate (24% and green projects (19%, with the median money raised 100,000 euro.

  8. Conservatives Anticipate and Experience Stronger Emotional Reactions to Negative Outcomes.

    Science.gov (United States)

    Joel, Samantha; Burton, Caitlin M; Plaks, Jason E

    2014-02-01

    The present work examined whether conservatives and liberals differ in their anticipation of their own emotional reactions to negative events. In two studies, participants imagined experiencing positive or negative outcomes in domains that do not directly concern politics. In Study 1, 190 American participants recruited online (64 male, Mage  = 32 years) anticipated their emotional responses to romantic relationship outcomes. In Study 2, 97 Canadian undergraduate students (26 male, Mage  = 21 years) reported on their anticipated and experienced emotional responses to academic outcomes. In both studies, more conservative participants predicted they would feel stronger negative emotions following negative outcomes than did more liberal participants. Furthermore, a longitudinal follow-up of Study 2 participants revealed that more conservative participants actually felt worse than more liberal participants after receiving a lower-than-desired exam grade. These effects remained even when controlling for the Big Five traits, prevention focus, and attachment style (Study 1), and optimism (Study 2). We discuss how the relationship between political orientation and anticipated affect likely contributes to differences between conservatives and liberals in styles of decision and policy choices. © 2013 Wiley Periodicals, Inc.

  9. Extracting foreground ensemble features to detect abnormal crowd behavior in intelligent video-surveillance systems

    Science.gov (United States)

    Chan, Yi-Tung; Wang, Shuenn-Jyi; Tsai, Chung-Hsien

    2017-09-01

    Public safety is a matter of national security and people's livelihoods. In recent years, intelligent video-surveillance systems have become important active-protection systems. A surveillance system that provides early detection and threat assessment could protect people from crowd-related disasters and ensure public safety. Image processing is commonly used to extract features, e.g., people, from a surveillance video. However, little research has been conducted on the relationship between foreground detection and feature extraction. Most current video-surveillance research has been developed for restricted environments, in which the extracted features are limited by having information from a single foreground; they do not effectively represent the diversity of crowd behavior. This paper presents a general framework based on extracting ensemble features from the foreground of a surveillance video to analyze a crowd. The proposed method can flexibly integrate different foreground-detection technologies to adapt to various monitored environments. Furthermore, the extractable representative features depend on the heterogeneous foreground data. Finally, a classification algorithm is applied to these features to automatically model crowd behavior and distinguish an abnormal event from normal patterns. The experimental results demonstrate that the proposed method's performance is both comparable to that of state-of-the-art methods and satisfies the requirements of real-time applications.

  10. High fat diet prevents over-crowding induced decrease of sex ratio in mice.

    Directory of Open Access Journals (Sweden)

    Madhukar Shivajirao Dama

    Full Text Available Adaptive theory predicts that mothers would be advantaged by adjusting the sex ratio of their offspring in relation to their offspring's future reproductive success. In the present study, we tested the effect of housing mice under crowded condition on the sex ratio and whether the fat content of the diet has any influence on the outcome of pregnancies. Three-week-old mice were placed on the control diet (NFD for 3 weeks. Thereafter the mice were allotted randomly to two groups of 7 cages each with 4, 6, 8, 10, 12, 14, and 16 mice in every cage to create increasing crowding gradient and fed either NFD or high fat diet (HFD. After 4 weeks, dams were bred and outcomes of pregnancy were analyzed. The average dam body weight (DBW at conception, litter size (LS and SR were significantly higher in HFD fed dams. Further, male biased litters declined with increasing crowding in NFD group but not in HFD. The LS and SR in NFD declined significantly with increasing crowding, whereas only LS was reduced in HFD group. We conclude that female mice housed under overcrowding conditions shift offspring SR in favor of daughters in consistent with the TW hypothesis and high fat diet reduces this influence of overcrowding.

  11. Crowding and hopping in a protein’s diffusive transport on DNA

    International Nuclear Information System (INIS)

    Koslover, Elena F; Spakowitz, Andrew J; Díaz de la Rosa, Mario

    2017-01-01

    Diffusion is a ubiquitous phenomenon that impacts virtually all processes that involve random fluctuations, and as such, the foundational work of Smoluchowski has proven to be instrumental in addressing innumerable problems. Here, we focus on a critical biological problem that relies on diffusive transport and is analyzed using a probabilistic treatment originally developed by Smoluchowski. The search of a DNA binding protein for its specific target site is believed to rely on non-specific binding to DNA with transient hops along the chain. In this work, we address the impact of protein crowding along the DNA on the transport of a DNA-binding protein. The crowders dramatically alter the dynamics of the protein while bound to the DNA, resulting in single-file transport that is subdiffusive in nature. However, transient unbinding and hopping results in a long-time behavior (shown to be superdiffusive) that is qualitatively unaffected by the crowding on the DNA. Thus, hopping along the chain mitigates the role that protein crowding has in restricting the translocation dynamics along the chain. The superdiffusion coefficient is influenced by the quantitative values of the effective binding rate, which is influenced by protein crowding. We show that vacancy fraction and superdiffusion coefficient exhibits a non-monotonic relationship under many circumstances. We leverage analytical theory and dynamic Monte Carlo simulations to address this problem. With several additional contributions, the core of our modeling work adopts a reaction-diffusion framework that is based on Smoluchowski’s original work. (paper)

  12. Eyes on crowding : Crowding is preserved when responding by eye and similarly affects identity and position accuracy

    NARCIS (Netherlands)

    Yildirim, Funda; Meyer, Vincent; Cornelissen, Frans W.

    Peripheral vision guides recognition and selection of targets for eye movements. Crowding-a decline in recognition performance that occurs when a potential target is surrounded by other, similar, objects-influences peripheral object recognition. A recent model study suggests that crowding may be due

  13. Hopping in the Crowd to Unveil Network Topology

    Science.gov (United States)

    Asllani, Malbor; Carletti, Timoteo; Di Patti, Francesca; Fanelli, Duccio; Piazza, Francesco

    2018-04-01

    We introduce a nonlinear operator to model diffusion on a complex undirected network under crowded conditions. We show that the asymptotic distribution of diffusing agents is a nonlinear function of the nodes' degree and saturates to a constant value for sufficiently large connectivities, at variance with standard diffusion in the absence of excluded-volume effects. Building on this observation, we define and solve an inverse problem, aimed at reconstructing the a priori unknown connectivity distribution. The method gathers all the necessary information by repeating a limited number of independent measurements of the asymptotic density at a single node, which can be chosen randomly. The technique is successfully tested against both synthetic and real data and is also shown to estimate with great accuracy the total number of nodes.

  14. Resolving stellar populations with crowded field 3D spectroscopy

    Science.gov (United States)

    Kamann, S.; Wisotzki, L.; Roth, M. M.

    2013-01-01

    We describe a new method of extracting the spectra of stars from observations of crowded stellar fields with integral field spectroscopy (IFS). Our approach extends the well-established concept of crowded field photometry in images into the domain of 3-dimensional spectroscopic datacubes. The main features of our algorithm follow. (1) We assume that a high-fidelity input source catalogue already exists, e.g. from HST data, and that it is not needed to perform sophisticated source detection in the IFS data. (2) Source positions and properties of the point spread function (PSF) vary smoothly between spectral layers of the datacube, and these variations can be described by simple fitting functions. (3) The shape of the PSF can be adequately described by an analytical function. Even without isolated PSF calibrator stars we can therefore estimate the PSF by a model fit to the full ensemble of stars visible within the field of view. (4) By using sparse matrices to describe the sources, the problem of extracting the spectra of many stars simultaneously becomes computationally tractable. We present extensive performance and validation tests of our algorithm using realistic simulated datacubes that closely reproduce actual IFS observations of the central regions of Galactic globular clusters. We investigate the quality of the extracted spectra under the effects of crowding with respect to the resulting signal-to-noise ratios (S/N) and any possible changes in the continuum level, as well as with respect to absorption line spectral parameters, radial velocities, and equivalent widths. The main effect of blending between two nearby stars is a decrease in the S/N in their spectra. The effect increases with the crowding in the field in a way that the maximum number of stars with useful spectra is always ~0.2 per spatial resolution element. This balance breaks down when exceeding a total source density of one significantly detected star per resolution element. We also explore the

  15. Public Service Motivation and Monetary Incentives: Substitutes or Motivation Crowding?

    DEFF Research Database (Denmark)

    Jacobsen, Christian Bøtcher

    2011-01-01

    Motivation is probably one of the most important determinants for organizational performance, because it stimulates effort and effective behaviors among people in the organization. But what type of motivation should public managers rely on? The PSM literature has argued that public service...... motivation is the most important type of motivation in the delivery of public service, because it substitutes for egoistic motivation. Organizations whose members have high levels of PSM are therefore expected to be less dependent on utilitarian motivators such as monetary incentives. Motivation crowding...... theory, on the other hand, argues that the relationship is opposite, so it is the degree of incentives that affects motivation. Both arguments lead to expectations of an association between public service motivation and monetary incentives, but so far this complex relationship has not been entangled...

  16. The Subject in the Crowd: A Critical Discussion of Jodi Dean’s “Crowds and Party”

    Directory of Open Access Journals (Sweden)

    Jacob Johanssen

    2016-10-01

    Full Text Available This article presents a critical discussion of Jodi Dean’s (2016 book “Crowds and Party”. I pay particular attention to her discussion of crowds that is influenced by psychoanalysis. Dean has put forward an important argument for the affectivity within crowds that may be transformed into a Communist Party that is characterised by a similar affective infrastructure. I suggest that Dean’s discussion of affect is slightly vague at times and may be supplemented with Sigmund Freud’s work on affect. In contrast to Dean, who stresses the collectivity and deindividuation of the crowd, I argue that the crowd needs to be thought of as a place where individuality and collectivity come together and remain in tension.

  17. Insulin-like growth factor-1 (IGF-1) enhances the osteogenic activity of bone morphogenetic protein-6 (BMP-6) in vitro and in vivo, and together have a stronger osteogenic effect than when IGF-1 is combined with BMP-2.

    Science.gov (United States)

    Rico-Llanos, Gustavo A; Becerra, Jose; Visser, Rick

    2017-07-01

    Bone morphogenetic protein-2 (BMP-2) is widely used in orthopedic surgery and bone tissue engineering because of its strong osteogenic activity. However, BMP-2 treatments have several drawbacks and many groups are actively exploring alternatives. Since BMP-6 has been demonstrated to be more osteoinductive, its use, either alone or together with other growth factors, might be an interesting option. In this work, we have compared the effect of BMP-2, BMP-6, or insulin-like growth factor-1 (IGF-1), either alone or in combination. Murine preosteoblasts were treated with 15 nM IGF-1 and/or 6 nM BMP-2 or -6 and the expression of osteogenic marker genes, proliferation, and alkaline phosphatase (ALP) activity in vitro were analyzed. The results showed that IGF-1 greatly enhanced the BMP-induced osteogenic differentiation of these cells in general and that the ALP activity in the cultures was higher when the combination was made with BMP-6 than with BMP-2. Furthermore, we tested the osteogenic potential of these treatments in vivo by loading 25 pmoles of IGF-1 and/or 10 pmoles of BMP-2 or -6 onto absorbable collagen sponges and implanting them into an ectopic bone formation model in rats. This study revealed that only BMP-6 was able to induce bone formation at the used dose and that the addition of IGF-1 contributed to an increase of the mineralization in the implants. Hence, the combination of BMP-6 with IGF-1 might be a better alternative than BMP-2 for orthopedic surgery or bone tissue engineering approaches. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 1867-1875, 2017. © 2017 Wiley Periodicals, Inc.

  18. Crowded: a crowd-sourced perspective of events as they happen

    Science.gov (United States)

    Brantingham, Richard; Hossain, Aleem

    2013-05-01

    `Crowded' is a web-based application developed by the Defence Science & Technology Laboratory (Dstl) that collates imagery of a particular location from a variety of media sources to provide an operator with real-time situational awareness. Emergency services and other relevant agencies have detected or become aware of an event - a riot or an explosion, for instance - and its location or text associated with it. The ubiquity of mobile devices allows people to collect and upload media of the incident to the Internet, in real time. Crowded manages the interactions with online sources of media: Flickr; Instagram; YouTube; Twitter; and Transport for London traffic cameras, to retrieve imagery that is being uploaded at that point in time. In doing so, it aims to provide human operators with near-instantaneous `eyes-on' from a variety of different perspectives. The first instantiation of Crowded was implemented as a series of integrated web-services with the aim of rapidly understanding whether the approach was viable. In doing so, it demonstrated how non-traditional, open sources can be used to provide a richer current intelligence picture than can be obtained alone from classified sources. The development of Crowded also explored how open source technology and cloud-based services can be used in the modern intelligence and security environment to provide a multi-agency Common Operating Picture to help achieve a co-ordinated response. The lessons learned in building the prototype are currently being used to design and develop a second version, and identify options and priorities for future development.

  19. A comparative evaluation of crowding stress on muscle HSP90 and myostatin expression in salmonids

    Science.gov (United States)

    Galt, Nicholas J.; Froehlich, Jacob Michael; McCormick, Stephen; Biga, Peggy R.

    2018-01-01

    Stress is a major factor that contributes to poor production and animal welfare concerns in aquaculture. As such, a thorough understanding of mechanisms involved in the stress response is imperative to developing strategies to mitigate the negative side effects of stressors, including the impact of high stocking densities on growth. The purpose of this study was to determine how the muscle growth inhibitor, myostatin, and the stress-responsive gene HSP90 are regulated in response to crowding stress in rainbow trout (Oncorhynchus mykiss), cutthroat trout (Oncorhynchus clarki), brook trout (Salvelinus fontinalis), and Atlantic salmon (Salmo salar). All species exhibited higher cortisol and glucose levels following the handling stress, indicating physiological response to the treatment. Additionally, all species, except rainbow trout, exhibited higher HSP90 levels in muscle after a 48 h crowding stress. Crowding stress resulted in a decrease of myostatin-1ain brook trout white muscle but not red muscle, while, myostatin-1a and -2a levels increased in white muscle and myostatin-1b levels increased in red muscle in Atlantic salmon. In rainbow trout, no significant changes were detected in either muscle type, but myostatin-1awas upregulated in both white and red skeletal muscle in the closely related cutthroat trout. The variation in response to crowding suggests a complex and species-specific interaction between stress and the muscle gene regulation in these salmonids. Only Atlantic salmon and cutthroat trout exhibited increased muscle myostatin transcription, and also exhibited the largest increase in circulating glucose in response to crowding. These results suggest that species-specific farming practices should be carefully examined in order to optimize low stress culture conditions.

  20. Crowded orbits conflict and cooperation in space

    CERN Document Server

    James

    2014-01-01

    Written for all readers, this expert analysis details the basics of space technology, diplomacy, commerce, exploration, and military applications from the mid-twentieth century to today. Space has become increasingly crowded since the end of the Cold War, and this book pays particular attention to the politics and economics of space and recent debates over national security, focusing on the competing themes of international competition and cooperation and the effort to avoid dangerous conflicts. Unfortunately, the growth of human space activity and challenges to existing international tools of management, such as rules, laws, and treaties, have increased the likelihood of conflict over a diminishing pool of space resources close to Earth. Drawing on more than twenty years of experience in international space debates and policy, James Clay Moltz points to the logic of cooperation and collaboration among the expanding number of space actors, considering their shared challenges regarding space traffic, orbital d...

  1. iCrowd: agent-based behavior modeling and crowd simulator

    Science.gov (United States)

    Kountouriotis, Vassilios I.; Paterakis, Manolis; Thomopoulos, Stelios C. A.

    2016-05-01

    Initially designed in the context of the TASS (Total Airport Security System) FP-7 project, the Crowd Simulation platform developed by the Integrated Systems Lab of the Institute of Informatics and Telecommunications at N.C.S.R. Demokritos, has evolved into a complete domain-independent agent-based behavior simulator with an emphasis on crowd behavior and building evacuation simulation. Under continuous development, it reflects an effort to implement a modern, multithreaded, data-oriented simulation engine employing latest state-of-the-art programming technologies and paradigms. It is based on an extensible architecture that separates core services from the individual layers of agent behavior, offering a concrete simulation kernel designed for high-performance and stability. Its primary goal is to deliver an abstract platform to facilitate implementation of several Agent-Based Simulation solutions with applicability in several domains of knowledge, such as: (i) Crowd behavior simulation during [in/out] door evacuation. (ii) Non-Player Character AI for Game-oriented applications and Gamification activities. (iii) Vessel traffic modeling and simulation for Maritime Security and Surveillance applications. (iv) Urban and Highway Traffic and Transportation Simulations. (v) Social Behavior Simulation and Modeling.

  2. Crowd-Sourced Global Earthquake Early Warning

    Science.gov (United States)

    Minson, S. E.; Brooks, B. A.; Glennie, C. L.; Murray, J. R.; Langbein, J. O.; Owen, S. E.; Iannucci, B. A.; Hauser, D. L.

    2014-12-01

    Although earthquake early warning (EEW) has shown great promise for reducing loss of life and property, it has only been implemented in a few regions due, in part, to the prohibitive cost of building the required dense seismic and geodetic networks. However, many cars and consumer smartphones, tablets, laptops, and similar devices contain low-cost versions of the same sensors used for earthquake monitoring. If a workable EEW system could be implemented based on either crowd-sourced observations from consumer devices or very inexpensive networks of instruments built from consumer-quality sensors, EEW coverage could potentially be expanded worldwide. Controlled tests of several accelerometers and global navigation satellite system (GNSS) receivers typically found in consumer devices show that, while they are significantly noisier than scientific-grade instruments, they are still accurate enough to capture displacements from moderate and large magnitude earthquakes. The accuracy of these sensors varies greatly depending on the type of data collected. Raw coarse acquisition (C/A) code GPS data are relatively noisy. These observations have a surface displacement detection threshold approaching ~1 m and would thus only be useful in large Mw 8+ earthquakes. However, incorporating either satellite-based differential corrections or using a Kalman filter to combine the raw GNSS data with low-cost acceleration data (such as from a smartphone) decreases the noise dramatically. These approaches allow detection thresholds as low as 5 cm, potentially enabling accurate warnings for earthquakes as small as Mw 6.5. Simulated performance tests show that, with data contributed from only a very small fraction of the population, a crowd-sourced EEW system would be capable of warning San Francisco and San Jose of a Mw 7 rupture on California's Hayward fault and could have accurately issued both earthquake and tsunami warnings for the 2011 Mw 9 Tohoku-oki, Japan earthquake.

  3. CrowdPhase: crowdsourcing the phase problem

    Energy Technology Data Exchange (ETDEWEB)

    Jorda, Julien; Sawaya, Michael R. [Institute for Genomics and Proteomics, 611 Charles Young Drive East, Los Angeles, CA 90095 (United States); Yeates, Todd O., E-mail: yeates@mbi.ucla.edu [Institute for Genomics and Proteomics, 611 Charles Young Drive East, Los Angeles, CA 90095 (United States); Molecular Biology Institute, 611 Charles Young Drive East, Los Angeles, CA 90095 (United States); University of California, 611 Charles Young Drive East, Los Angeles, CA 90095 (United States)

    2014-06-01

    The idea of attacking the phase problem by crowdsourcing is introduced. Using an interactive, multi-player, web-based system, participants work simultaneously to select phase sets that correspond to better electron-density maps in order to solve low-resolution phasing problems. The human mind innately excels at some complex tasks that are difficult to solve using computers alone. For complex problems amenable to parallelization, strategies can be developed to exploit human intelligence in a collective form: such approaches are sometimes referred to as ‘crowdsourcing’. Here, a first attempt at a crowdsourced approach for low-resolution ab initio phasing in macromolecular crystallography is proposed. A collaborative online game named CrowdPhase was designed, which relies on a human-powered genetic algorithm, where players control the selection mechanism during the evolutionary process. The algorithm starts from a population of ‘individuals’, each with a random genetic makeup, in this case a map prepared from a random set of phases, and tries to cause the population to evolve towards individuals with better phases based on Darwinian survival of the fittest. Players apply their pattern-recognition capabilities to evaluate the electron-density maps generated from these sets of phases and to select the fittest individuals. A user-friendly interface, a training stage and a competitive scoring system foster a network of well trained players who can guide the genetic algorithm towards better solutions from generation to generation via gameplay. CrowdPhase was applied to two synthetic low-resolution phasing puzzles and it was shown that players could successfully obtain phase sets in the 30° phase error range and corresponding molecular envelopes showing agreement with the low-resolution models. The successful preliminary studies suggest that with further development the crowdsourcing approach could fill a gap in current crystallographic methods by making it

  4. CrowdPhase: crowdsourcing the phase problem

    International Nuclear Information System (INIS)

    Jorda, Julien; Sawaya, Michael R.; Yeates, Todd O.

    2014-01-01

    The idea of attacking the phase problem by crowdsourcing is introduced. Using an interactive, multi-player, web-based system, participants work simultaneously to select phase sets that correspond to better electron-density maps in order to solve low-resolution phasing problems. The human mind innately excels at some complex tasks that are difficult to solve using computers alone. For complex problems amenable to parallelization, strategies can be developed to exploit human intelligence in a collective form: such approaches are sometimes referred to as ‘crowdsourcing’. Here, a first attempt at a crowdsourced approach for low-resolution ab initio phasing in macromolecular crystallography is proposed. A collaborative online game named CrowdPhase was designed, which relies on a human-powered genetic algorithm, where players control the selection mechanism during the evolutionary process. The algorithm starts from a population of ‘individuals’, each with a random genetic makeup, in this case a map prepared from a random set of phases, and tries to cause the population to evolve towards individuals with better phases based on Darwinian survival of the fittest. Players apply their pattern-recognition capabilities to evaluate the electron-density maps generated from these sets of phases and to select the fittest individuals. A user-friendly interface, a training stage and a competitive scoring system foster a network of well trained players who can guide the genetic algorithm towards better solutions from generation to generation via gameplay. CrowdPhase was applied to two synthetic low-resolution phasing puzzles and it was shown that players could successfully obtain phase sets in the 30° phase error range and corresponding molecular envelopes showing agreement with the low-resolution models. The successful preliminary studies suggest that with further development the crowdsourcing approach could fill a gap in current crystallographic methods by making it

  5. NECESSITY FACTORS AND PREDICTORS OF DENTAL CROWDING TREATMENT

    Directory of Open Access Journals (Sweden)

    Georgeta ZEGAN

    2015-09-01

    Full Text Available The aim of the study was to identify the significant necessity and predictive factors of dental crowding treatment, on 422 subjects (165 boys and 257 girls from the North-East part of Romania. Correlations have been established between dental crowding and age, dentition, Angle class of malocclusions, the etiological factors, types and modalities of treatments, and types of orthodontic appliances employed (p0.05. The necessity and predictive factors of the treatment were adequate with age, dentition, severity of crowding and Angle class of malocclusion.

  6. Estimating the number of people in crowded scenes

    Science.gov (United States)

    Kim, Minjin; Kim, Wonjun; Kim, Changick

    2011-01-01

    This paper presents a method to estimate the number of people in crowded scenes without using explicit object segmentation or tracking. The proposed method consists of three steps as follows: (1) extracting space-time interest points using eigenvalues of the local spatio-temporal gradient matrix, (2) generating crowd regions based on space-time interest points, and (3) estimating the crowd density based on the multiple regression. In experimental results, the efficiency and robustness of our proposed method are demonstrated by using PETS 2009 dataset.

  7. CROWDING AND SHOPPING VALUE IN LOW-INCOME RETAIL CENTERS

    Directory of Open Access Journals (Sweden)

    Izabelle Quezado

    2014-07-01

    Full Text Available Considering the great potential of low-income consumption, this research is based on the scales developed by Babin, Darden and Griffin (1994 and by Machleit, Kellaris and Eroglu (1994, aiming to investigate hedonic and utilitarian consumer behavior and its relation with low-income perception of crowding. A research was performed with 404 consumers in real store environment and the results showed that consumers revealed being prone to utilitarian behavior in both centers. About crowding phenomenon, the consumers felt more uncomfortable by crowding at the commercial center with less infrastructure. There were indices that this discomfort was less intense in hedonic consumers.

  8. A Stronger Reason for the Right to Sign Languages

    Science.gov (United States)

    Trovato, Sara

    2013-01-01

    Is the right to sign language only the right to a minority language? Holding a capability (not a disability) approach, and building on the psycholinguistic literature on sign language acquisition, I make the point that this right is of a stronger nature, since only sign languages can guarantee that each deaf child will properly develop the…

  9. Female Psychology in August Strindberg’s The Stronger

    Directory of Open Access Journals (Sweden)

    Anton Sutandio

    2017-11-01

    Full Text Available This research aimed to offer interpretations of August Strindberg’s The Stronger through the lens of female psychology. The Stronger is unique as it seemed very simple yet so intense and powerful with layers of interpretations. Written during 1888-1889, The Stronger, which only had two characters and only one speaking character, had become one of Strindberg’s shortest yet important plays during his career. The female psychology approach used in the analysis would cover the discussion of gender role, women’s self-esteem, competition for males, women’s friendships, ego style, and female psychology. It was an interdisciplinary research that combined structuralist, historical, biographical, and feminist approach to gain a better interpretation on the play. By referring to three different sources on the concept of female psychology, the analysis offered different and interesting interpretations on the nature and dynamics of the two female characters’ relationship. The Stronger has shown an enigmatic attraction in Strindberg’s authorship in which the readers could see the co-existence, collision, conflict, and merge of different paradigms concerning sex, gender, and sexuality.

  10. Women's political participation leads to stronger local economies ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Edgard Rodriguez - IDRC. Women attend a self-help group meeting near Hyderabad, India. Keenara Khanderia. Under changes to India's constitution, Indian women are gaining a stronger political voice. Legal reforms are encouraging women to contribute to economic growth and investments in community growth.

  11. Designing for crowd well-being : Current designs, strategies and future design suggestions

    NARCIS (Netherlands)

    Li, J.; de Ridder, H.; Vermeeren, A.P.O.S.; Conrado, C.; Martella, C.

    2013-01-01

    This paper introduces the concept of crowd well-being and the needs for sustaining it. Crowd well-being can be interpreted as crowd members’ evaluations on their emotional reactions, moods and judgments they form about their satisfactions, goals or needs fulfillment in a crowded situation according

  12. The wisdom of the crowd in funding: information heterogeneity and social networks of crowdfunders

    NARCIS (Netherlands)

    Polzin, Friedemann; Toxopeus, Helen; Stam, Erik

    2018-01-01

    Crowdfunding has enabled large crowds to fund innovative projects. This type of funding might tap into the wisdom of crowds who were previously disconnected from the funding process. We distinguish between in-crowd and out-crowd funders (with and without ties to project creators) in order to test

  13. The wisdom of the crowd in funding: : Information heterogeneity and social networks of crowdfunder

    NARCIS (Netherlands)

    Polzin, F.H.J.; Toxopeus, H.S.; Stam, F.C.

    2016-01-01

    Crowdfunding has enabled large crowds to fund innovative projects. This type of funding might tap into the wisdom of crowds who were previously disconnected from the funding process. We distinguish between in-crowd and out-crowd funders (with and without ties to project creators) in order to test

  14. Crowding-in: how Indian civil society organizations began mobilizing around climate change.

    Science.gov (United States)

    Ylä-Anttila, Tuomas; Swarnakar, Pradip

    2017-06-01

    This paper argues that periodic waves of crowding-in to 'hot' issue fields are a recurring feature of how globally networked civil society organizations operate, especially in countries of the Global South. We elaborate on this argument through a study of Indian civil society mobilization around climate change. Five key mechanisms contribute to crowding-in processes: (1) the expansion of discursive opportunities; (2) the event effects of global climate change conferences; (3) the network effects created by expanding global civil society networks; (4) the adoption and innovation of action repertoires; and (5) global pressure effects creating new opportunities for civil society. Our findings contribute to the world society literature, with an account of the social mechanisms through which global institutions and political events affect national civil societies, and to the social movements literature by showing that developments in world society are essential contributors to national mobilization processes. © London School of Economics and Political Science 2017.

  15. Anterior maxillary segmental distraction for correction of maxillary hypoplasia and dental crowding in cleft palate patients: a preliminary report.

    Science.gov (United States)

    Wang, X-X; Wang, X; Li, Z-L; Yi, B; Liang, C; Jia, Y-L; Zou, B-S

    2009-12-01

    To evaluate the feasibility of anterior maxillary segmental distraction (AMSD) to correct maxillary hypoplasia and severe dental crowding in cleft lip and palate (CLP) patients, 7 patients (average age 16.4 years) with maxillary hypoplasia, shortened maxillary dental arch length and severe anterior dental crowding secondary to CLP were selected for this study. After anterior maxillary segmental osteotomy, 3 patients were treated using bilateral internal distraction devices, and 4 patients were treated using rigid external distraction devices. Photographs and radiographs were taken to review the improvement in facial profile and occlusion after distraction. An average 10.25 mm anterior maxillary advancement was obtained in all patients after 10-23 days of distraction and 9-16 weeks of consolidation. The sella-nasion-point A (SNA) angle increased from 69.5 degrees to 79.6 degrees. Midface convexity was greatly improved and velopharyngeal competence was preserved. The maxillary dental arch length was greatly increased by 10.1 mm (P<0.01). Dental crowding and malocclusion were corrected by orthodontic treatment. These results show that AMSD can effectively correct the hypoplastic maxilla and severe dental crowding associated with CLP by increasing the midface convexity and dental arch length while preserving velopharyngeal function, and dental crowding can be corrected without requiring tooth extraction.

  16. Design optimization of deep groove ball bearings using crowding ...

    Indian Academy of Sciences (India)

    Aparna Duggirala

    2018-02-07

    Feb 7, 2018 ... The technique is applied to bearings used in transmission system of a tractor for the purpose of ... different types of AI techniques have been used [8–12]. ..... with a crowding distance based external archive maintenance.

  17. Household Crowding During Childhood and Long-Term Education Outcomes.

    Science.gov (United States)

    Lopoo, Leonard M; London, Andrew S

    2016-06-01

    Household crowding, or having more household members than rooms in one's residence, could potentially affect a child's educational attainment directly through a number of mechanisms. We use U.S. longitudinal data from the Panel Study of Income Dynamics to derive new measures of childhood crowding and estimate negative associations between crowding during one's high school years and, respectively, high school graduation by age 19 and maximum education at age 25. These negative relationships persist in multivariate models in which we control for the influence of a variety of factors, including socioeconomic status and housing-cost burden. Given the importance of educational attainment for a range of midlife and later-life outcomes, this study suggests that household crowding during one's high school years is an engine of cumulative inequality over the life course.

  18. Diffusion in crowded biological environments: applications of Brownian dynamics

    OpenAIRE

    Długosz, Maciej; Trylska, Joanna

    2011-01-01

    Biochemical reactions in living systems occur in complex, heterogeneous media with total concentrations of macromolecules in the range of 50 - 400 mg/ml. Molecular species occupy a significant fraction of the immersing medium, up to 40% of volume. Such complex and volume-occupied environments are generally termed 'crowded' and/or 'confined'. In crowded conditions non-specific interactions between macromolecules may hinder diffusion - a major process determining metabolism, transport, and sign...

  19. Emulating a crowded intracellular environment in vitro dramatically improves RT-PCR performance

    International Nuclear Information System (INIS)

    Lareu, Ricky R.; Harve, Karthik S.; Raghunath, Michael

    2007-01-01

    The polymerase chain reaction's (PCR) phenomenal success in advancing fields as diverse as Medicine, Agriculture, Conservation, or Paleontology is based on the ability of using isolated prokaryotic thermostable DNA polymerases in vitro to copy DNA irrespective of origin. This process occurs intracellularly and has evolved to function efficiently under crowded conditions, namely in an environment packed with macromolecules. However, current in vitro practice ignores this important biophysical parameter of life. In order to more closely emulate conditions of intracellular biochemistry in vitro we added inert macromolecules into reverse transcription (RT) and PCR. We show dramatic improvements in all parameters of RT-PCR including 8- to 10-fold greater sensitivity, enhanced polymerase processivity, higher specific amplicon yield, greater primer annealing and specificity, and enhanced DNA polymerase thermal stability. The faster and more efficient reaction kinetics was a consequence of the cumulative molecular and thermodynamic effects of the excluded volume effect created by macromolecular crowding

  20. Stronger vection in junior high school children than in adults.

    Science.gov (United States)

    Shirai, Nobu; Imura, Tomoko; Tamura, Rio; Seno, Takeharu

    2014-01-01

    Previous studies have shown that even elementary school-aged children (7 and 11 years old) experience visually induced perception of illusory self-motion (vection) (Lepecq et al., 1995, Perception, 24, 435-449) and that children of a similar age (mean age = 9.2 years) experience more rapid and stronger vection than do adults (Shirai et al., 2012, Perception, 41, 1399-1402). These findings imply that although elementary school-aged children experience vection, this ability is subject to further development. To examine the subsequent development of vection, we compared junior high school students' (N = 11, mean age = 14.4 years) and adults' (N = 10, mean age = 22.2 years) experiences of vection. Junior high school students reported significantly stronger vection than did adults, suggesting that the perceptual experience of junior high school students differs from that of adults with regard to vection and that this ability undergoes gradual changes over a relatively long period of development.

  1. Crowded letter and crowded picture logMAR acuity in children with amblyopia: a quantitative comparison.

    Science.gov (United States)

    O'Boyle, Cathy; Chen, Sean I; Little, Julie-Anne

    2017-04-01

    Clinically, picture acuity tests are thought to overestimate visual acuity (VA) compared with letter tests, but this has not been systematically investigated in children with amblyopia. This study compared VA measurements with the LogMAR Crowded Kay Picture test to the LogMAR Crowded Keeler Letter acuity test in a group of young children with amblyopia. 58 children (34 male) with amblyopia (22 anisometropic, 18 strabismic and 18 with both strabismic/anisometropic amblyopia) aged 4-6 years (mean=68.7, range=48-83 months) underwent VA measurements. VA chart testing order was randomised, but the amblyopic eye was tested before the fellow eye. All participants wore up-to-date refractive correction. The Kay Picture test significantly overestimated VA by 0.098 logMAR (95% limits of agreement (LOA), 0.13) in the amblyopic eye and 0.088 logMAR (95% LOA, 0.13) in the fellow eye, respectively (pocclusion therapy, refractive correction or type of amblyopia on VA results (p>0.23). For both the amblyopic and fellow eyes, Bland-Altman plots demonstrated a systematic and predictable difference between Kay Picture and Keeler Letter charts across the range of acuities tested (Keeler acuity: amblyopic eye 0.75 to -0.05 logMAR; fellow eye 0.45 to -0.15 logMAR). Linear regression analysis (pamblyopia. Due to the predictable difference found between both crowded logMAR acuity tests, it is reasonable to adjust Kay Picture acuity thresholds by +0.10 logMAR to compute expected Keeler Letter acuity scores. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  2. CrowdMag - Crowdsourcing magnetic data

    Science.gov (United States)

    Nair, M. C.; Boneh, N.; Chulliat, A.

    2014-12-01

    In the CrowdMag project, we explore whether digital magnetometers built in modern mobile phones can be used as scientific instruments to measure Earth's magnetic field. Most modern mobile phones have digital magnetometers to orient themselves. A phone's magnetometer measures three components of the local magnetic field with a typical sensitivity of about 150 to 600 nanotesla (nT). By combining data from vector magnetometers and accelerometers, phone's orientation is determined. Using phone's Internet connection, magnetic data and location are sent to a central server. At the server, we check quality of the magnetic data from all users and make the data available to the public as aggregate maps. We have two long-term goals. 1) Develop near-real-time models of Earth's time changing magnetic field by reducing man-made noise from crowdsourced data and combining it with geomagnetic data from other sources. 2) Improving accuracy of magnetic navigation by mapping magnetic noise sources (for e.g. power transformer and iron pipes). Key challenges to this endeavor are the low sensitivity of the phone's magnetometer and the noisy environment within and surrounding the phone. URL : http://www.ngdc.noaa.gov/geomag/crowdmag.shtml

  3. Nudging Cooperation in a Crowd Experiment.

    Science.gov (United States)

    Niella, Tamara; Stier-Moses, Nicolás; Sigman, Mariano

    2016-01-01

    We examine the hypothesis that driven by a competition heuristic, people don't even reflect or consider whether a cooperation strategy may be better. As a paradigmatic example of this behavior we propose the zero-sum game fallacy, according to which people believe that resources are fixed even when they are not. We demonstrate that people only cooperate if the competitive heuristic is explicitly overridden in an experiment in which participants play two rounds of a game in which competition is suboptimal. The observed spontaneous behavior for most players was to compete. Then participants were explicitly reminded that the competing strategy may not be optimal. This minor intervention boosted cooperation, implying that competition does not result from lack of trust or willingness to cooperate but instead from the inability to inhibit the competition bias. This activity was performed in a controlled laboratory setting and also as a crowd experiment. Understanding the psychological underpinnings of these behaviors may help us improve cooperation and thus may have vast practical consequences to our society.

  4. Dialogue Police, Decision Making, and the Management of Public Order During Protest Crowd Events

    DEFF Research Database (Denmark)

    Gorringe, Hugo; Stott, Clifford; Rosie, Michael

    2012-01-01

    making and enhanced police proportionality. The subsequent impact upon crowd dynamics allowed for an improved capacity for proactive public order management, encouraged ‘self-regulation’ in the crowd, and avoided the unnecessary police use of force at moments of tension. The implications of the analysis......Following the major riots within England in August 2011, the efficacy of public order police decision making was brought into a sharp focus. None the less, the reform of this mode of policing within the UK was already underway with a strong emphasis upon policing through consent and the need...... in the north of England. This paper draws out lessons to be learned from what proved to be a highly successful dialogue-based approach to policing protests. We contend that dialogue and liaison were effective because they allowed for an ongoing dynamic risk assessment that improved command-level decision...

  5. Crowd density estimation based on convolutional neural networks with mixed pooling

    Science.gov (United States)

    Zhang, Li; Zheng, Hong; Zhang, Ying; Zhang, Dongming

    2017-09-01

    Crowd density estimation is an important topic in the fields of machine learning and video surveillance. Existing methods do not provide satisfactory classification accuracy; moreover, they have difficulty in adapting to complex scenes. Therefore, we propose a method based on convolutional neural networks (CNNs). The proposed method improves performance of crowd density estimation in two key ways. First, we propose a feature pooling method named mixed pooling to regularize the CNNs. It replaces deterministic pooling operations with a parameter that, by studying the algorithm, could combine the conventional max pooling with average pooling methods. Second, we present a classification strategy, in which an image is divided into two cells and respectively categorized. The proposed approach was evaluated on three datasets: two ground truth image sequences and the University of California, San Diego, anomaly detection dataset. The results demonstrate that the proposed approach performs more effectively and easily than other methods.

  6. Crowdsourcing Stream Stage in Data Scarce Regions: Applications of CrowdHydrology

    Science.gov (United States)

    Lowry, C.; Fienen, M. N.

    2013-12-01

    Crowdsourced data collection using citizen scientists and mobile phones is a promising way to collect supplemental information in data scarce or remote regions. The research presented here explore the possibilities and pitfalls of crowdsourcing hydrologic data via mobile phone text messaging through the example of CrowdHydrology, a distributed network of over 40 stream gages in four states. Signage at the CrowdHydrology gages ask citizen scientists to answer to a simple question via text message: 'What is the water height?'. While these data in no way replace more traditional measurements of stream stage, they do provide low cost supplemental measurements in data scarce regions. Results demonstrate the accuracy of crowdsourced data and provide insight for successful future crowdsourced data collection efforts. A less recognized benefit is that even in data rich areas, crowdsourced data collection is a cost-effective way to perform quality assurance on more sophisticated, and costly, data collection efforts.

  7. Continuous limit of a crowd motion and herding model: Analysis and numerical simulations

    KAUST Repository

    Pietschmann, Jan-Frederik

    2011-11-01

    In this paper we study the continuum limit of a cellular automaton model used for simulating human crowds with herding behaviour. We derive a system of non-linear partial differential equations resembling the Keller-Segel model for chemotaxis, however with a non-monotone interaction. The latter has interesting consequences on the behaviour of the model\\'s solutions, which we highlight in its analysis. In particular we study the possibility of stationary states, the formation of clusters and explore their connection to congestion. We also introduce an efficient numerical simulation approach based on an appropriate hybrid discontinuous Galerkin method, which in particular allows flexible treatment of complicated geometries. Extensive numerical studies also provide a better understanding of the strengths and shortcomings of the herding model, in particular we examine trapping effects of crowds behind nonconvex obstacles. © American Institute of Mathematical Sciences.

  8. Continuous limit of a crowd motion and herding model: Analysis and numerical simulations

    KAUST Repository

    Pietschmann, Jan-Frederik; Markowich, Peter Alexander; Burger, Martin

    2011-01-01

    In this paper we study the continuum limit of a cellular automaton model used for simulating human crowds with herding behaviour. We derive a system of non-linear partial differential equations resembling the Keller-Segel model for chemotaxis, however with a non-monotone interaction. The latter has interesting consequences on the behaviour of the model's solutions, which we highlight in its analysis. In particular we study the possibility of stationary states, the formation of clusters and explore their connection to congestion. We also introduce an efficient numerical simulation approach based on an appropriate hybrid discontinuous Galerkin method, which in particular allows flexible treatment of complicated geometries. Extensive numerical studies also provide a better understanding of the strengths and shortcomings of the herding model, in particular we examine trapping effects of crowds behind nonconvex obstacles. © American Institute of Mathematical Sciences.

  9. Understanding consumer's responses to negative emotions related to crowding on satisfaction and impulse purchase in retail: the mediating role of coping

    Directory of Open Access Journals (Sweden)

    Marlette Cassia Oliveira Ferreira

    Full Text Available Abstract The perception of crowding, understood as an individual's response to crowds, can be observed in retail environments and influences positive and negative emotions. In this research we test the mediating effect of coping – rational strategies adopted to deal with negative emotions – in the relationship between negative emotions (resulting from crowding perception and consumer behavior (measured by impulse purchase and satisfaction. The findings related to coping explain to what extent there is a positive response to human density in the retail environment. For this, a theoretical model was developed which includes the relationships among perception of crowding, positive and negative emotions, and consumer behavior. The model enhances the understanding of the crowding phenomenon by including relationships mediated by an oppositional strategy (coping dimension between negative emotions and consumer behaviors. To test the theoretical model, a survey was conducted with 456 respondents and hypothesis tests using structural equation modeling. It was evidenced that crowding perception has more robust effects on negative emotions than positive emotions. It is emphasized that with the inclusion of opposition mediation, the weak direct relationship between negative emotions and behaviors, becomes a positive relationship between negative emotion and impulse purchase, and negative emotion and satisfaction. In addition to the theoretical contributions of the tested model, future research and managerial implications are proposed at the end of the article.

  10. Macromolecular crowding gives rise to microviscosity, anomalous diffusion and accelerated actin polymerization.

    Science.gov (United States)

    Rashid, Rafi; Chee, Stella Min Ling; Raghunath, Michael; Wohland, Thorsten

    2015-04-30

    Macromolecular crowding (MMC) has been used in various in vitro experimental systems to mimic in vivo physiology. This is because the crowded cytoplasm of cells contains many different types of solutes dissolved in an aqueous medium. MMC in the extracellular microenvironment is involved in maintaining stem cells in their undifferentiated state (niche) as well as in aiding their differentiation after they have travelled to new locations outside the niche. MMC at physiologically relevant fractional volume occupancies (FVOs) significantly enhances the adipogenic differentiation of human bone marrow-derived mesenchymal stem cells during chemically induced adipogenesis. The mechanism by which MMC produces this enhancement is not entirely known. In the context of extracellular collagen deposition, we have recently reported the importance of optimizing the FVO while minimizing the bulk viscosity. Two opposing properties will determine the net rate of a biochemical reaction: the negative effect of bulk viscosity and the positive effect of the excluded volume, the latter being expressed by the FVO. In this study we have looked more closely at the effect of viscosity on reaction rates. We have used fluorimetry to measure the rate of actin polymerization and fluorescence correlation spectroscopy (FCS) to measure diffusion of various probes in solutions containing the crowder Ficoll at physiological concentrations. Similar to its effect on collagen, Ficoll enhanced the actin polymerization rate despite increasing the bulk viscosity. Our FCS measurements reveal a relatively minor component of anomalous diffusion. In addition, our measurements do suggest that microviscosity becomes relevant in a crowded environment. We ruled out bulk viscosity as a cause of the rate enhancement by performing the actin polymerization assay in glycerol. These opposite effects of Ficoll and glycerol led us to conclude that microviscosity becomes relevant at the length scale of the reacting

  11. Macromolecular crowding gives rise to microviscosity, anomalous diffusion and accelerated actin polymerization

    Science.gov (United States)

    Rashid, Rafi; Chee, Stella Min Ling; Raghunath, Michael; Wohland, Thorsten

    2015-05-01

    Macromolecular crowding (MMC) has been used in various in vitro experimental systems to mimic in vivo physiology. This is because the crowded cytoplasm of cells contains many different types of solutes dissolved in an aqueous medium. MMC in the extracellular microenvironment is involved in maintaining stem cells in their undifferentiated state (niche) as well as in aiding their differentiation after they have travelled to new locations outside the niche. MMC at physiologically relevant fractional volume occupancies (FVOs) significantly enhances the adipogenic differentiation of human bone marrow-derived mesenchymal stem cells during chemically induced adipogenesis. The mechanism by which MMC produces this enhancement is not entirely known. In the context of extracellular collagen deposition, we have recently reported the importance of optimizing the FVO while minimizing the bulk viscosity. Two opposing properties will determine the net rate of a biochemical reaction: the negative effect of bulk viscosity and the positive effect of the excluded volume, the latter being expressed by the FVO. In this study we have looked more closely at the effect of viscosity on reaction rates. We have used fluorimetry to measure the rate of actin polymerization and fluorescence correlation spectroscopy (FCS) to measure diffusion of various probes in solutions containing the crowder Ficoll at physiological concentrations. Similar to its effect on collagen, Ficoll enhanced the actin polymerization rate despite increasing the bulk viscosity. Our FCS measurements reveal a relatively minor component of anomalous diffusion. In addition, our measurements do suggest that microviscosity becomes relevant in a crowded environment. We ruled out bulk viscosity as a cause of the rate enhancement by performing the actin polymerization assay in glycerol. These opposite effects of Ficoll and glycerol led us to conclude that microviscosity becomes relevant at the length scale of the reacting

  12. Stronger misdirection in curved than in straight motion

    Directory of Open Access Journals (Sweden)

    Jorge eOtero-Millan

    2011-11-01

    Full Text Available Illusions developed by magicians are a rich and largely untapped source of insight into perception and cognition. Here we show that curved motion, as employed by the magician in a classic sleight of hand trick, generates stronger misdirection than rectilinear motion, and that this difference can be explained by the differential engagement of the smooth pursuit and the saccadic oculomotor systems. This research moreover exemplifies how the magician’s intuitive understanding of the spectator’s mindset can surpass that of the cognitive scientist in specific instances, and that observation-based behavioral insights developed by magicians are worthy of quantitative investigation in the neuroscience laboratory.

  13. The right of the stronger: The play Sisyphus and critias

    Directory of Open Access Journals (Sweden)

    Jordović Ivan

    2004-01-01

    Full Text Available The Focus of this study is the standpoint of the play Sisyphus and critias the leader of the thirty towards the right of the stronger. this is a question of constant interest in scientific circles, since its answer can serve as the indicator of the influence this famous theory has had. this interest has been encouraged by the fact that critias’ authorship of the play is questionable. however, the question of the author is not of primary importance for this article, because there are some arguments, among some well known ones, which were not considered and which Show that in this satire, regardless of the author and the purpose of this fragment, the right of the stronger is actually non-existant. the first argument to support this theory is that nomosphysis antithesis is nowhere explicitly mentioned although it is the crucial element of the right of the stronger. in addition there is no claim in the play that the exploitation of the strong by the week or by law accrued. the second argument is that despite the incapability of laws to prevent the secret injustice, they and their importance for the human society are depicted in a positive light. it should also be noted that, unlike callicles and glaucon, laws are created to stop the bad and not the good. the third argument is that the invention of religion is accepted as a positive achievement, which finally enables the overcoming of primeval times and lawlessness. the reflection of this argument is a positive characterization of the individual who invented the fear of gods. the fourth argument, which has not been taken into consideration so far is the way the supporters and opponents of lawlessness are described and marked as κακοί and έσξλοί in the satire only physically strong are considered as strong as opposed to callicles, where they are also spiritually superior. intelectually superior in Sisyphus is the inventor of the fear of gods who is also in favor of law and order. the fact

  14. Taxis and crowd-taxis: sharing as a private activity and public concern

    Directory of Open Access Journals (Sweden)

    Merethe Dotterud Leiren

    2016-06-01

    Full Text Available The sharing economy has generated interest among economists for its customer focus and potential to enhance competition. However, it has also caused uproar in industries which have felt competitive pressure, for example among the established stakeholders in the taxi industry. While regulations currently impose considerable costs on the taxi industry, they do not cover virtual transport innovations such as Uber. The lack of a level playing field between taxis and such ‘crowd-taxis’ has generated media attention and conflict. Taxi owners worry about decreasing revenues and taxi drivers about poor working conditions. Other concerns are related to poor transport preparedness, accessibility issues, quality assurance and tax evasion. Despite considerable media attention, there has so far been a lack of scholarly literature addressing the consequences of the sharing economy in the transport sector. Focusing on the Norwegian taxi market, we argue that crowd-taxis will likely produce a range of unanticipated effects, necessitating regulation. For example, crowd-taxis may contribute to a loss of transport preparedness in rural areas. The findings are based on first and secondary data and 19 interviews.

  15. New insights into the crowd characteristics in Mina

    Science.gov (United States)

    Wang, J. Y.; Weng, W. G.; Zhang, X. L.

    2014-11-01

    The significance of the study of the characteristics of crowd behavior is indubitable for safely organizing mass activities. There is insufficient material to conduct such research. In this paper, the Mina crowd disaster is quantitatively re-investigated. Its instantaneous velocity field is extracted from video material based on the cross-correlation algorithm. The properties of the stop-and-go waves, including fluctuation frequencies, wave propagation speeds, characteristic speeds, and time and space averaged velocity variances, are analyzed in detail. Thus, the database of the stop-and-go wave features is enriched, which is very important to crowd studies. The ‘turbulent’ flows are investigated with the proper orthogonal decomposition (POD) method which is widely used in fluid mechanics. And time series and spatial analysis are conducted to investigate the characteristics of the ‘turbulent’ flows. In this paper, the coherent structures and movement process are described by the POD method. The relationship between the jamming point and crowd path is analyzed. And the pressure buffer recognized in this paper is consistent with Helbing's high-pressure region. The results revealed here may be helpful for facilities design, modeling crowded scenarios and the organization of large-scale mass activities.

  16. Hailstorms over Switzerland: Verification of Crowd-sourced Data

    Science.gov (United States)

    Noti, Pascal-Andreas; Martynov, Andrey; Hering, Alessandro; Martius, Olivia

    2016-04-01

    The reports of smartphone users, witnessing hailstorms, can be used as source of independent, ground-based observation data on ground-reaching hailstorms with high temporal and spatial resolution. The presented work focuses on the verification of crowd-sourced data collected over Switzerland with the help of a smartphone application recently developed by MeteoSwiss. The precise location, time of hail precipitation and the hailstone size are included in the crowd-sourced data, assessed on the basis of the weather radar data of MeteoSwiss. Two radar-based hail detection algorithms, POH (Probability of Hail) and MESHS (Maximum Expected Severe Hail Size), in use at MeteoSwiss are confronted with the crowd-sourced data. The available data and investigation time period last from June to August 2015. Filter criteria have been applied in order to remove false reports from the crowd-sourced data. Neighborhood methods have been introduced to reduce the uncertainties which result from spatial and temporal biases. The crowd-sourced and radar data are converted into binary sequences according to previously set thresholds, allowing for using a categorical verification. Verification scores (e.g. hit rate) are then calculated from a 2x2 contingency table. The hail reporting activity and patterns corresponding to "hail" and "no hail" reports, sent from smartphones, have been analyzed. The relationship between the reported hailstone sizes and both radar-based hail detection algorithms have been investigated.

  17. Crosstalk in concurrent repeated games impedes direct reciprocity and requires stronger levels of forgiveness.

    Science.gov (United States)

    Reiter, Johannes G; Hilbe, Christian; Rand, David G; Chatterjee, Krishnendu; Nowak, Martin A

    2018-02-07

    Direct reciprocity is a mechanism for cooperation among humans. Many of our daily interactions are repeated. We interact repeatedly with our family, friends, colleagues, members of the local and even global community. In the theory of repeated games, it is a tacit assumption that the various games that a person plays simultaneously have no effect on each other. Here we introduce a general framework that allows us to analyze "crosstalk" between a player's concurrent games. In the presence of crosstalk, the action a person experiences in one game can alter the person's decision in another. We find that crosstalk impedes the maintenance of cooperation and requires stronger levels of forgiveness. The magnitude of the effect depends on the population structure. In more densely connected social groups, crosstalk has a stronger effect. A harsh retaliator, such as Tit-for-Tat, is unable to counteract crosstalk. The crosstalk framework provides a unified interpretation of direct and upstream reciprocity in the context of repeated games.

  18. Crowd Computing as a Cooperation Problem: An Evolutionary Approach

    Science.gov (United States)

    Christoforou, Evgenia; Fernández Anta, Antonio; Georgiou, Chryssis; Mosteiro, Miguel A.; Sánchez, Angel

    2013-05-01

    Cooperation is one of the socio-economic issues that has received more attention from the physics community. The problem has been mostly considered by studying games such as the Prisoner's Dilemma or the Public Goods Game. Here, we take a step forward by studying cooperation in the context of crowd computing. We introduce a model loosely based on Principal-agent theory in which people (workers) contribute to the solution of a distributed problem by computing answers and reporting to the problem proposer (master). To go beyond classical approaches involving the concept of Nash equilibrium, we work on an evolutionary framework in which both the master and the workers update their behavior through reinforcement learning. Using a Markov chain approach, we show theoretically that under certain----not very restrictive—conditions, the master can ensure the reliability of the answer resulting of the process. Then, we study the model by numerical simulations, finding that convergence, meaning that the system reaches a point in which it always produces reliable answers, may in general be much faster than the upper bounds given by the theoretical calculation. We also discuss the effects of the master's level of tolerance to defectors, about which the theory does not provide information. The discussion shows that the system works even with very large tolerances. We conclude with a discussion of our results and possible directions to carry this research further.

  19. Automatic trajectory measurement of large numbers of crowded objects

    Science.gov (United States)

    Li, Hui; Liu, Ye; Chen, Yan Qiu

    2013-06-01

    Complex motion patterns of natural systems, such as fish schools, bird flocks, and cell groups, have attracted great attention from scientists for years. Trajectory measurement of individuals is vital for quantitative and high-throughput study of their collective behaviors. However, such data are rare mainly due to the challenges of detection and tracking of large numbers of objects with similar visual features and frequent occlusions. We present an automatic and effective framework to measure trajectories of large numbers of crowded oval-shaped objects, such as fish and cells. We first use a novel dual ellipse locator to detect the coarse position of each individual and then propose a variance minimization active contour method to obtain the optimal segmentation results. For tracking, cost matrix of assignment between consecutive frames is trainable via a random forest classifier with many spatial, texture, and shape features. The optimal trajectories are found for the whole image sequence by solving two linear assignment problems. We evaluate the proposed method on many challenging data sets.

  20. Cloud-based crowd sensing: a framework for location-based crowd analyzer and advisor

    Science.gov (United States)

    Aishwarya, K. C.; Nambi, A.; Hudson, S.; Nadesh, R. K.

    2017-11-01

    Cloud computing is an emerging field of computer science to integrate and explore large and powerful computing systems and storages for personal and also for enterprise requirements. Mobile Cloud Computing is the inheritance of this concept towards mobile hand-held devices. Crowdsensing, or to be precise, Mobile Crowdsensing is the process of sharing resources from an available group of mobile handheld devices that support sharing of different resources such as data, memory and bandwidth to perform a single task for collective reasons. In this paper, we propose a framework to use Crowdsensing and perform a crowd analyzer and advisor whether the user can go to the place or not. This is an ongoing research and is a new concept to which the direction of cloud computing has shifted and is viable for more expansion in the near future.

  1. Jammed Humans in High-Density Crowd Disasters

    Science.gov (United States)

    Bottinelli, Arianna; Sumpter, David; Silverberg, Jesse

    When people gather in large groups like those found at Black Friday sales events, pilgrimages, heavy metal concerts, and parades, crowd density often becomes exceptionally high. As a consequence, these events can produce tragic outcomes such as stampedes and ''crowd crushes''. While human collective motion has been studied with active particle simulations, the underlying mechanisms for emergent behavior are less well understood. Here, we use techniques developed to study jammed granular materials to analyze an active matter model inspired by large groups of people gathering at a point of common interest. In the model, a single behavioral rule combined with body-contact interactions are sufficient for the emergence of a self-confined steady state, where particles fluctuate around a stable position. Applying mode analysis to this system, we find evidence for Goldstone modes, soft spots, and stochastic resonance, which may be the preferential mechanisms for dangerous emergent collective motions in crowds.

  2. Learning Multimodal Deep Representations for Crowd Anomaly Event Detection

    Directory of Open Access Journals (Sweden)

    Shaonian Huang

    2018-01-01

    Full Text Available Anomaly event detection in crowd scenes is extremely important; however, the majority of existing studies merely use hand-crafted features to detect anomalies. In this study, a novel unsupervised deep learning framework is proposed to detect anomaly events in crowded scenes. Specifically, low-level visual features, energy features, and motion map features are simultaneously extracted based on spatiotemporal energy measurements. Three convolutional restricted Boltzmann machines are trained to model the mid-level feature representation of normal patterns. Then a multimodal fusion scheme is utilized to learn the deep representation of crowd patterns. Based on the learned deep representation, a one-class support vector machine model is used to detect anomaly events. The proposed method is evaluated using two available public datasets and compared with state-of-the-art methods. The experimental results show its competitive performance for anomaly event detection in video surveillance.

  3. Macromolecular crowding: chemistry and physics meet biology (Ascona, Switzerland, 10-14 June 2012)

    Science.gov (United States)

    Foffi, G.; Pastore, A.; Piazza, F.; Temussi, P. A.

    2013-08-01

    exhaustive chronological account of the major milestones. It is clear that the concept of excluded volume as a key factor remains central to the concept of molecular crowding. As a consequence, simple descriptive paradigms borrowed essentially from colloid physics may still provide useful tools to understand the subtle effects of crowding and confinement in living matter. The contiguity between crowding, colloids and soft matter further emerged as an important concept in the course of the conference in several theoretical lectures and a few experimental ones. Dave Thirumalai, from the University of Maryland (USA), one of the most active theoreticians in the field of theoretical biophysics, outlined scaling theories, concepts from colloid literature and different simulation techniques to describe scenarios for crowding-induced changes in the structure and dynamics of proteins and RNA. In particular, he showed the importance of the shape of crowding particles in affecting folding oligomerization of amyloidogenic peptides. Johannes Schöneberg, from IMPRS, Mathematics Institute (Germany), illustrated ReaDDy , a newly developed particle-based simulation software tool for reaction-diffusion dynamics, developed in the group of Frank Noe at EMPRS. He showed that ReaDDy makes it possible to bridge the gap between soft matter and molecular dynamics (MD) simulations on the one hand and particle-based stochastic reaction-diffusion simulations on the other. We asked Johannes to organize a tutorial session to lead interested participants into the package and 'get their hands wet' under the guidance of the developers. The tutorial session was indeed successful and the broad possibilities offered by the simulation toolkit appeared to be clear to the participants. Paolo De Los Rios, from the Ecole Polytechnique Fédérale de Lausanne (EPFL, Switzerland), examined the complexity of the effects caused by crowding conditions from the point of view of statistical physics. Starting from a

  4. Macromolecular crowding: chemistry and physics meet biology (Ascona, Switzerland, 10-14 June 2012).

    Science.gov (United States)

    Foffi, G; Pastore, A; Piazza, F; Temussi, P A

    2013-08-02

    through an exhaustive chronological account of the major milestones. It is clear that the concept of excluded volume as a key factor remains central to the concept of molecular crowding. As a consequence, simple descriptive paradigms borrowed essentially from colloid physics may still provide useful tools to understand the subtle effects of crowding and confinement in living matter. The contiguity between crowding, colloids and soft matter further emerged as an important concept in the course of the conference in several theoretical lectures and a few experimental ones. Dave Thirumalai, from the University of Maryland (USA), one of the most active theoreticians in the field of theoretical biophysics, outlined scaling theories, concepts from colloid literature and different simulation techniques to describe scenarios for crowding-induced changes in the structure and dynamics of proteins and RNA. In particular, he showed the importance of the shape of crowding particles in affecting folding oligomerization of amyloidogenic peptides. Johannes Schöneberg, from IMPRS, Mathematics Institute (Germany), illustrated ReaDDy , a newly developed particle-based simulation software tool for reaction-diffusion dynamics, developed in the group of Frank Noe at EMPRS. He showed that ReaDDy makes it possible to bridge the gap between soft matter and molecular dynamics (MD) simulations on the one hand and particle-based stochastic reaction-diffusion simulations on the other. We asked Johannes to organize a tutorial session to lead interested participants into the package and 'get their hands wet' under the guidance of the developers. The tutorial session was indeed successful and the broad possibilities offered by the simulation toolkit appeared to be clear to the participants. Paolo De Los Rios, from the Ecole Polytechnique Fédérale de Lausanne (EPFL, Switzerland), examined the complexity of the effects caused by crowding conditions from the point of view of statistical physics. Starting

  5. Stronger multilayer acrylic dielectric elastomer actuators with silicone gel coatings

    Science.gov (United States)

    Lau, Gih-Keong; La, Thanh-Giang; Sheng-Wei Foong, Ervin; Shrestha, Milan

    2016-12-01

    Multilayer dielectric elastomer actuators (DEA) perform worst off than single-layer DEAs due to higher susceptibility to electro-thermal breakdown. This paper presents a hot-spot model to predict the electro-thermal breakdown field of DEAs and its dependence on thermal insulation. To inhibit the electrothermal breakdown, silicone gel coating was applied as barrier coating to multilayer acrylic DEA. The gel coating helps suppress the electro-thermally induced puncturing of DEA membrane at the hot spot. As a result, the gel-coated DEAs, in either a single layer or a multilayer stack, can produce 30% more isometric stress change as compared to those none-coated. These gel-coated acrylic DEAs show great potential to make stronger artificial muscles.

  6. Modeling, simulation and visual analysis of crowds a multidisciplinary perspective

    CERN Document Server

    Ali, Saad; Manocha, Dinesh; Shah, Mubarak

    2013-01-01

    Over the last several years there has been a growing interest in developing computational methodologies for modeling and analyzing movements and behaviors of 'crowds' of people. This interest spans several scientific areas that includes Computer Vision, Computer Graphics, and Pedestrian Evacuation Dynamics. Despite the fact that these different scientific fields are trying to model the same physical entity (i.e. a crowd of people), research ideas have evolved independently. As a result each discipline has developed techniques and perspectives that are characteristically their own.

  7. Crowd-sourced Archaeological Research: The MicroPasts Project

    Directory of Open Access Journals (Sweden)

    Chiara Bonacchi

    2014-10-01

    Full Text Available This paper offers a brief introduction to MicroPasts, a web-enabled crowd-sourcing and crowd-funding project whose overall goal is to promote the collection and use of high quality research data via institutional and community collaborations, both on- and off-line. In addition to introducing this initiative, the discussion below is a reflection of its lead author’s core contribution to the project and will dwell in more detail on one particular aspect of MicroPasts: its relevance to research and practice in public archaeology, cultural policy and heritage studies.

  8. Contemporary understanding of riots: Classical crowd psychology, ideology and the social identity approach.

    Science.gov (United States)

    Stott, Clifford; Drury, John

    2016-04-01

    This article explores the origins and ideology of classical crowd psychology, a body of theory reflected in contemporary popularised understandings such as of the 2011 English 'riots'. This article argues that during the nineteenth century, the crowd came to symbolise a fear of 'mass society' and that 'classical' crowd psychology was a product of these fears. Classical crowd psychology pathologised, reified and decontextualised the crowd, offering the ruling elites a perceived opportunity to control it. We contend that classical theory misrepresents crowd psychology and survives in contemporary understanding because it is ideological. We conclude by discussing how classical theory has been supplanted in academic contexts by an identity-based crowd psychology that restores the meaning to crowd action, replaces it in its social context and in so doing transforms theoretical understanding of 'riots' and the nature of the self. © The Author(s) 2016.

  9. Concentrated Solutions of Single-Chain Nanoparticles: A Simple Model for Intrinsically Disordered Proteins under Crowding Conditions.

    Science.gov (United States)

    Moreno, Angel J; Lo Verso, Federica; Arbe, Arantxa; Pomposo, José A; Colmenero, Juan

    2016-03-03

    By means of large-scale computer simulations and small-angle neutron scattering (SANS), we investigate solutions of single-chain nanoparticles (SCNPs), covering the whole concentration range from infinite dilution to melt density. The analysis of the conformational properties of the SCNPs reveals that these synthetic nano-objects share basic ingredients with intrinsically disordered proteins (IDPs), as topological polydispersity, generally sparse conformations, and locally compact domains. We investigate the role of the architecture of the SCNPs in their collapse behavior under macromolecular crowding. Unlike in the case of linear macromolecules, which experience the usual transition from self-avoiding to Gaussian random-walk conformations, crowding leads to collapsed conformations of SCNPs resembling those of crumpled globules. This behavior is already found at volume fractions (about 30%) that are characteristic of crowding in cellular environments. The simulation results are confirmed by the SANS experiments. Our results for SCNPs--a model system free of specific interactions--propose a general scenario for the effect of steric crowding on IDPs: collapse from sparse conformations at high dilution to crumpled globular conformations in cell environments.

  10. College Crowd-In: How Private Donations Positively Affect Alumni Giving

    Science.gov (United States)

    Gottfried, Michael A.

    2008-01-01

    The issue of donor behavior and crowding out has been pertinent in the economics literature, both theoretically and empirically. Aggregate research has not been decisive, nor have many studies analyzed education institutions. I begin with a theoretical model of crowding-out versus crowding-in donor behavior. I then employ a fixed effects…

  11. Crowd science : it is not just a matter of time (or funding)

    NARCIS (Netherlands)

    Vasileiadou, E.

    2014-01-01

    The last years, citizen science, or crowd science, has increased tremendously, both in number of projects, and number of participants. Most literature on crowd science focuses on its advantages, for both scientists, and the participating citizens. The challenges of crowd science come mainly from

  12. On current crowd management practices and the need for increased situation awareness, prediction, and intervention

    NARCIS (Netherlands)

    Martella, C.; Li, J.; Conrado, C.; Vermeeren, A.

    2017-01-01

    Recent accidents (News, 2006, 2010, 2013, 2015) show that crowded events can quickly turn into tragedies. The goal of crowd management is to avoid such accidents through careful planning and implementation. Crowd management practices are collaborative efforts between the different actors of the

  13. Alleviation of mandibular anterior crowding with copper-nickel-titanium vs nickel-titanium wires: a double-blind randomized control trial.

    Science.gov (United States)

    Pandis, Nikolaos; Polychronopoulou, Argy; Eliades, Theodore

    2009-08-01

    The purpose of this study was to investigate the efficiency of copper-nickel-titanium (CuNiTi) vs nickel-titanium (NiTi) archwires in resolving crowding of the anterior mandibular dentition. Sixty patients were included in this single-center, single-operator, double-blind randomized trial. All patients were bonded with the In Ovation-R self-ligating bracket (GAC, Central Islip, NY) with a 0.022-in slot, and the amount of crowding of the mandibular anterior dentition was assessed by using the irregularity index. The patients were randomly allocated into 2 groups of 30 patients, each receiving a 0.016-in CuNiTi 35 degrees C (Ormco, Glendora, Calif) or a 0.016-in NiTi (ModernArch, Wyomissing, Pa) wire. The type of wire selected for each patient was not disclosed to the provider or the patient. The date that each patient received a wire was recorded, and all patients were followed monthly for a maximum of 6 months. Demographic and clinical characteristics between the 2 wire groups were compared with the t test or the chi-square test and the Fisher exact test. Time to resolve crowding was explored with statistical methods for survival analysis, and alignment rate ratios for wire type and crowding level were calculated with Cox proportional hazards multivariate modeling. The type of wire (CuNiTi vs NiTi) had no significant effect on crowding alleviation (129.4 vs 121.4 days; hazard ratio, 1.3; P >0.05). Severe crowding (>5 on the irregularity index) showed a significantly higher probability of crowding alleviation duration relative to dental arches with a score of wires in laboratory and clinical conditions might effectively eliminate the laboratory-derived advantage of CuNiTi wires.

  14. Editorial Bias in Crowd-Sourced Political Information.

    Directory of Open Access Journals (Sweden)

    Joshua L Kalla

    Full Text Available The Internet has dramatically expanded citizens' access to and ability to engage with political information. On many websites, any user can contribute and edit "crowd-sourced" information about important political figures. One of the most prominent examples of crowd-sourced information on the Internet is Wikipedia, a free and open encyclopedia created and edited entirely by users, and one of the world's most accessed websites. While previous studies of crowd-sourced information platforms have found them to be accurate, few have considered biases in what kinds of information are included. We report the results of four randomized field experiments that sought to explore what biases exist in the political articles of this collaborative website. By randomly assigning factually true but either positive or negative and cited or uncited information to the Wikipedia pages of U.S. senators, we uncover substantial evidence of an editorial bias toward positivity on Wikipedia: Negative facts are 36% more likely to be removed by Wikipedia editors than positive facts within 12 hours and 29% more likely within 3 days. Although citations substantially increase an edit's survival time, the editorial bias toward positivity is not eliminated by inclusion of a citation. We replicate this study on the Wikipedia pages of deceased as well as recently retired but living senators and find no evidence of an editorial bias in either. Our results demonstrate that crowd-sourced information is subject to an editorial bias that favors the politically active.

  15. Editorial Bias in Crowd-Sourced Political Information.

    Science.gov (United States)

    Kalla, Joshua L; Aronow, Peter M

    2015-01-01

    The Internet has dramatically expanded citizens' access to and ability to engage with political information. On many websites, any user can contribute and edit "crowd-sourced" information about important political figures. One of the most prominent examples of crowd-sourced information on the Internet is Wikipedia, a free and open encyclopedia created and edited entirely by users, and one of the world's most accessed websites. While previous studies of crowd-sourced information platforms have found them to be accurate, few have considered biases in what kinds of information are included. We report the results of four randomized field experiments that sought to explore what biases exist in the political articles of this collaborative website. By randomly assigning factually true but either positive or negative and cited or uncited information to the Wikipedia pages of U.S. senators, we uncover substantial evidence of an editorial bias toward positivity on Wikipedia: Negative facts are 36% more likely to be removed by Wikipedia editors than positive facts within 12 hours and 29% more likely within 3 days. Although citations substantially increase an edit's survival time, the editorial bias toward positivity is not eliminated by inclusion of a citation. We replicate this study on the Wikipedia pages of deceased as well as recently retired but living senators and find no evidence of an editorial bias in either. Our results demonstrate that crowd-sourced information is subject to an editorial bias that favors the politically active.

  16. Indoor guided evacuation: TIN for graph generation and crowd evacuation

    Directory of Open Access Journals (Sweden)

    Mengchao Xu

    2016-05-01

    Full Text Available This paper presents two complementary methods: an approach to compute a network data-set for indoor space of a building by using its two-dimensional (2D floor plans and limited semantic information, combined with an optimal crowd evacuation method. The approach includes three steps: (1 generate critical points in the space, (2 connect neighbour points to build up the network, and then (3 run the optimal algorithm for optimal crowd evacuation from a room to the exit gates of the building. Triangulated Irregular Network (TIN is used in the first two steps. The optimal evacuation crowd is not based on the nearest evacuation gate for a person but relies on optimal sorting of the waiting lists at each gate of the room to be evacuated. As an example case, a rectangular room with 52 persons with two gates is evacuated in 102 elementary interval times (one interval corresponds to the time for one step for normal velocity walking, whereas it would have been evacuated in not less than 167 elementary steps. The procedure for generating the customized network involves the use of 2D floor plans of a building and some common Geographic Information System (GIS functions. This method combined with the optimal sorting lists will be helpful for guiding crowd evacuation during any emergency.

  17. Sequential sampling, magnitude estimation, and the wisdom of crowds

    DEFF Research Database (Denmark)

    Nash, Ulrik W.

    2017-01-01

    in the wisdom of crowds indicated by judgment distribution skewness. The present study reports findings from an experiment on magnitude estimation and supports these predictions. The study moreover demonstrates that systematic errors by groups of people can be corrected using information about the judgment...

  18. Chenang Beach and its Crowding Capacity: A Malaysian Perspective

    Directory of Open Access Journals (Sweden)

    Mohamad Diana

    2014-01-01

    Full Text Available This working paper focuses in enjoyment factors, specifically: number of beach users, perceived maximum number of beach users accepted, perceived maximum number of beach users that affects the tourism experience and perceived maximum number of beach users that affects the beach quality. At a deeper extent, the evaluation is categorized by number of visitation, visitation motivations, and Chenang Island’s push and pull factors. Relationships between variables were assessed using a two-phase evaluation framework where interestingly, only one demographic factor works with all the studied independent variables. It is also learned that the density of an area number of people seen is considered as a n accepted crowding factor, as opposed to this working paper scope experienced crowding . A unique relationship was observed for crowding level, and visitation satisfaction level and overall evaluation of Chenang beach quality. This working paper further supports the previous literature on the significance of beach carrying capacity management and it is learned that the idea of crowding standard is interlinks with ‘gender, ‘time spend’ and ‘number of boaters’. From findings, this working paper envisages the preferences polar exchange where this should be of interest to tourism-related personnel. It is within this working paper interest to highlight the pressing need in brandishing the image of Chenang Beach. This is to ensure that Chenang Beach, as a field, is maintaining its importance and popularity.

  19. The Gender Pay Gap, Fringe Benefits, and Occupational Crowding.

    Science.gov (United States)

    Solberg, Eric; Laughlin, Teresa

    1995-01-01

    In estimating earnings equations for seven occupations, when fringe benefits are excluded, women receive significantly lower wages in all but the most female-dominated occupation. Including fringe benefits makes gender significant in only one occupational category. Crowding of one gender into an occupation appears the primary determinant of the…

  20. Passengers, Crowding and Complexity : Models for passenger oriented public transport

    NARCIS (Netherlands)

    P.C. Bouman (Paul)

    2017-01-01

    markdownabstractPassengers, Crowding and Complexity was written as part of the Complexity in Public Transport (ComPuTr) project funded by the Netherlands Organisation for Scientific Research (NWO). This thesis studies in three parts how microscopic data can be used in models that have the potential

  1. Track-based event recognition in a realistic crowded environment

    NARCIS (Netherlands)

    Huis, J.R. van; Bouma, H.; Baan, J.; Burghouts, G.J.; Eendebak, P.T.; Hollander, R.J.M.; Dijk, J.; Rest, J.H.C. van

    2014-01-01

    Automatic detection of abnormal behavior in CCTV cameras is important to improve the security in crowded environments, such as shopping malls, airports and railway stations. This behavior can be characterized at different time scales, e.g., by small-scale subtle and obvious actions or by large-scale

  2. Crowd Analysis by Using Optical Flow and Density Based Clustering

    DEFF Research Database (Denmark)

    Santoro, Francesco; Pedro, Sergio; Tan, Zheng-Hua

    2010-01-01

    In this paper, we present a system to detect and track crowds in a video sequence captured by a camera. In a first step, we compute optical flows by means of pyramidal Lucas-Kanade feature tracking. Afterwards, a density based clustering is used to group similar vectors. In the last step...

  3. Households' ethnic background and crowding in public housing ...

    African Journals Online (AJOL)

    Crowded housing is one of the housing stresses that bother policy makers and housing ... ethnic and cultural origins occupying Lagos State Development and Property ... groups should be deliberately mixed to achieve ethnic and social integration. ... FAQ's · More about AJOL · AJOL's Partners · Terms and Conditions of Use ...

  4. Some Numerical Aspects on Crowd Motion - The Hughes Model

    KAUST Repository

    Gomes, Diogo A.; Machado Velho, Roberto

    2016-01-01

    Here, we study a crowd model proposed by R. Hughes in [5] and we describe a numerical approach to solve it. This model comprises a Fokker-Planck equation coupled with an Eikonal equation with Dirichlet or Neumann data. First, we establish a priori

  5. DNA strand exchange catalyzed by molecular crowding in PEG solutions

    KAUST Repository

    Feng, Bobo; Frykholm, Karolin; Nordé n, Bengt; Westerlund, Fredrik

    2010-01-01

    DNA strand exchange is catalyzed by molecular crowding and hydrophobic interactions in concentrated aqueous solutions of polyethylene glycol, a discovery of relevance for understanding the function of recombination enzymes and with potential applications to DNA nanotechnology. © 2010 The Royal Society of Chemistry.

  6. Crowd science and engineering: concept and research framework

    Directory of Open Access Journals (Sweden)

    Yueting Chai

    2017-03-01

    Full Text Available Purpose – The synthetic application and interaction of/between the internet, Internet of Things, cloud computing, big data, Industry 4.0 and other new patterns and new technologies shall breed future Web-based industrial operation system and social operation management patterns, manifesting as a crowd cyber eco-system composed of multiple interconnected intelligent agents (enterprises, individuals and governmental agencies and its dynamic behaviors. This paper aims to explore the basic principles and laws of such a system and its behavior. Design/methodology/approach – The authors propose the concepts of crowd science and engineering (CSE and expound its main content, thus forming a research framework of theories and methodologies of crowd science. Findings – CSE is expected to substantially promote the formation and development of crowd science and thus lay a foundation for the advancement of Web-based industrial operation system and social operation management patterns. Originality/value – This paper is the first one to propose the concepts of CSE, which lights the beacon for the future research in this area.

  7. Crowds As Complex Adaptive Systems: Strategic Implications For Law Enforcement

    Science.gov (United States)

    2016-03-01

    spread by word -of- mouth , news outlets, and social media .186 According to David Karpf, an assistant professor at George Washington University, the...71 6. A Word about Social Media ...such as the police. 6. A Word about Social Media The burgeoning role of social media is a significant development in crowd system dynamics. Social

  8. Enforcement costs: some humanitarian alternatives to stronger patent rights.

    Science.gov (United States)

    Trotter, Andrew

    2012-01-01

    Diseases that cause comparatively few problems in developed countries kill millions of people in the Third World each year. In many cases, people die because they cannot afford the medication needed to save their lives. In others, there are simply no drugs available because there are no wealthy western patients to justify pharmaceutical companies investing in a cure. This reveals a deep-seated problem within the patent system and the pharmaceutical industry that emphasises markets and profits at the expense of health and global welfare. Global efforts have seen substantial improvements in access to medicines in isolated areas, but with international agreements driving towards stronger patent protection and the expiry date for the TRIPS grace period fast approaching, it is time to consider alternatives which will allow the patent system to work for the humanitarian cause rather than against it. This paper considers two such problems in the patent system and pharmaceutical industry - prohibitive pricing and misdirected incentives - to offer a mode of regulation and enforcement that will support both a viable pharmaceutical industry and the human right to health and medication.

  9. PREFACE: Complex dynamics of fluids in disordered and crowded environments Complex dynamics of fluids in disordered and crowded environments

    Science.gov (United States)

    Coslovich, Daniele; Kahl, Gerhard; Krakoviack, Vincent

    2011-06-01

    Over the past two decades, the dynamics of fluids under nanoscale confinement has attracted much attention. Motivation for this rapidly increasing interest is based on both practical and fundamental reasons. On the practical and rather applied side, problems in a wide range of scientific topics, such as polymer and colloidal sciences, rheology, geology, or biophysics, benefit from a profound understanding of the dynamical behaviour of confined fluids. Further, effects similar to those observed in confinement are expected in fluids whose constituents have strong size or mass asymmetry, and in biological systems where crowding and obstruction phenomena in the cytosol are responsible for clear separations of time scales for macromolecular transport in the cell. In fundamental research, on the other hand, the interest focuses on the complex interplay between confinement and structural relaxation, which is responsible for the emergence of new phenomena in the dynamics of the system: in confinement, geometric constraints associated with the pore shape are imposed to the adsorbed fluids and an additional characteristic length scale, i.e. the pore size, comes into play. For many years, the topic has been mostly experimentally driven. Indeed, a broad spectrum of systems has been investigated by sophisticated experimental techniques, while theoretical and simulation studies were rather scarce due to conceptual and computational issues. In the past few years, however, theory and simulations could largely catch up with experiments. On one side, new theories have been put forward that duly take into account the porosity, the connectivity, and the randomness of the confinement. On the other side, the ever increasing available computational power now allows investigations that were far out of reach a few years ago. Nowadays, instead of isolated state points, systematic investigations on the dynamics of confined fluids, covering a wide range of system parameters, can be realized

  10. Improvement of healthcare quality in pediatric neurology by crowd technologies

    Directory of Open Access Journals (Sweden)

    O. V. Guzeva

    2016-01-01

    Full Text Available Crowdsourcing and crowdfunding in public health should be considered as an untraditional process of gathering new ideas and assets. Theirefficiency is associated with that a large number of people may be involved in using their specific knowledge to solve complex problems and projects. According to statistics, the annual incidence rate for epilepsy averages 70 per 100,000 population and the disease starts in childhood innearly half of the cases. So the early differential diagnosis of paroxysmal states in children at the early stage of the disease is a necessary condition for adequate drug therapy.Patients and methods. Only in the period from 2007 to 2009, the Center for Diagnosis and Treatment of Epilepsy and Sleep Disorders in Children and Adolescents, Department of Nervous System Diseases, Saint Petersburg State Pediatric Medical University, examined 259 children aged several weeks to 18 years with paroxysmal disorders of consciousness. Among them, there were 156 (60.23% boys and 103 (39.77% girls.Results and discussion. Based on the results obtained during the children's  comprehensive examinations using video-EEG monitoring, the investigators specified diagnoses in all the examinees and changed treatment in the vast majority of cases. Many nonepileptic paroxysms with external manifestations resemble epileptic seizures; these are rather frequently qualified as erroneous and treated as such. Only the comprehensive examination involving video-EEG monitoring may avoid misdiagnosis in children with different epilepsy types and nonepileptic paroxysms. Video-EEG combines the video monitoring recording of EEG readings and makes it possible to reveal epileptic activity during a seizure, to compare the clinical presentation of the latter with EEG changes, to locate an epileptogenic focus, and to differentiate epileptic seizures fromnonepileptic ones. The effective diagnosis of paroxysmal states in childhood is a complex scientific and social problem

  11. Cholinergic enhancement reduces orientation-specific surround suppression but not visual crowding

    Directory of Open Access Journals (Sweden)

    Anna A. Kosovicheva

    2012-09-01

    Full Text Available Acetylcholine (ACh reduces the spatial spread of excitatory fMRI responses in early visual cortex and the receptive field sizes of V1 neurons. We investigated the perceptual consequences of these physiological effects of ACh with surround suppression and crowding, two tasks that involve spatial interactions between visual field locations. Surround suppression refers to the reduction in perceived stimulus contrast by a high-contrast surround stimulus. For grating stimuli, surround suppression is selective for the relative orientations of the center and surround, suggesting that it results from inhibitory interactions in early visual cortex. Crowding refers to impaired identification of a peripheral stimulus in the presence of flankers and is thought to result from excessive integration of visual features. We increased synaptic ACh levels by administering the cholinesterase inhibitor donepezil to healthy human subjects in a placebo-controlled, double-blind design. In Exp. 1, we measured surround suppression of a central grating using a contrast discrimination task with three conditions: 1 surround grating with the same orientation as the center (parallel, 2 surround orthogonal to the center, or 3 no surround. Contrast discrimination thresholds were higher in the parallel than in the orthogonal condition, demonstrating orientation-specific surround suppression (OSSS. Cholinergic enhancement reduced thresholds only in the parallel condition, thereby reducing OSSS. In Exp. 2, subjects performed a crowding task in which they reported the identity of a peripheral letter flanked by letters on either side. We measured the critical spacing between the target and flanking letters that allowed reliable identification. Cholinergic enhancement had no effect on critical spacing. Our findings suggest that ACh reduces spatial interactions in tasks involving segmentation of visual field locations but that these effects may be limited to early visual cortical

  12. Factors Influencing Perceived Crowding of Tourists and Sustainable Tourism Destination Management

    Directory of Open Access Journals (Sweden)

    Qian Jin

    2016-09-01

    Full Text Available Studies on tourists crowding are developed to explore the perception of crowding, and these studies indicate crowding influence on sustainable development of tourist destinations. This study aims to reveal the influential factors of tourists’ perceived crowding. We obtained data from interviewing over 400 tourists and five senior tourism officials in Xi’an, China. This study firstly applies factor analysis to identify the constructed variables of tourists’ motivations from the principle component analysis. It then examines the correlation between nationality and perceived crowding. Consequently, a multiple regression is used to identify the connection between motivations and perceived crowding. The results of the study indicate nationality and motivation as two significant influential factors to perceived crowding management. This study also shows that management in tourist destinations would benefit from provision of the authentic travel experience integrated with zoning the travel destination.

  13. Adolescent peer crowds and patterns of belief in the boundaries of personal authority.

    Science.gov (United States)

    Daddis, Christopher

    2010-10-01

    Patterns of authority beliefs were examined among peer crowds in 598 middle school (M=12.97 years), early high school (M=15.10 years), and late high school adolescents (M=18.25 years). Participants reported beliefs regarding the boundaries of personal authority across personal, prudential, conventional, moral, and multifaceted issues. As expected, analyses revealed persistent differences in belief patterns among crowds within each age group. Tough and Alternative crowds asserted personal authority across all issues, while Prep and Outcast crowds endorsed parental authority. Jock, Hip Hop, and Normal crowds presented with shared-control patterns, but each crowd ceded and asserted authority over different issues. Discussion focused on crowds' roles in the development of group differences in the boundaries of personal authority.

  14. Solutions to emergency department 'boarding' and crowding are underused and may need to be legislated.

    Science.gov (United States)

    Rabin, Elaine; Kocher, Keith; McClelland, Mark; Pines, Jesse; Hwang, Ula; Rathlev, Niels; Asplin, Brent; Trueger, N Seth; Weber, Ellen

    2012-08-01

    The practice of keeping admitted patients on stretchers in hospital emergency department hallways for hours or days, called "boarding," causes emergency department crowding and can be harmful to patients. Boarding increases patients' morbidity, lengths of hospital stay, and mortality. Strategies that optimize bed management reduce boarding by improving the efficiency of hospital patient flow, but these strategies are grossly underused. Convincing hospital leaders of the value of such solutions, and educating patients to advocate for such changes, may promote improvements. If these strategies do not work, legislation may be required to effect meaningful change.

  15. Perceptual learning improves contrast sensitivity, visual acuity, and foveal crowding in amblyopia.

    Science.gov (United States)

    Barollo, Michele; Contemori, Giulio; Battaglini, Luca; Pavan, Andrea; Casco, Clara

    2017-01-01

    Amblyopic observers present abnormal spatial interactions between a low-contrast sinusoidal target and high-contrast collinear flankers. It has been demonstrated that perceptual learning (PL) can modulate these low-level lateral interactions, resulting in improved visual acuity and contrast sensitivity. We measured the extent and duration of generalization effects to various spatial tasks (i.e., visual acuity, Vernier acuity, and foveal crowding) through PL on the target's contrast detection. Amblyopic observers were trained on a contrast-detection task for a central target (i.e., a Gabor patch) flanked above and below by two high-contrast Gabor patches. The pre- and post-learning tasks included lateral interactions at different target-to-flankers separations (i.e., 2, 3, 4, 8λ) and included a range of spatial frequencies and stimulus durations as well as visual acuity, Vernier acuity, contrast-sensitivity function, and foveal crowding. The results showed that perceptual training reduced the target's contrast-detection thresholds more for the longest target-to-flanker separation (i.e., 8λ). We also found generalization of PL to different stimuli and tasks: contrast sensitivity for both trained and untrained spatial frequencies, visual acuity for Sloan letters, and foveal crowding, and partially for Vernier acuity. Follow-ups after 5-7 months showed not only complete maintenance of PL effects on visual acuity and contrast sensitivity function but also further improvement in these tasks. These results suggest that PL improves facilitatory lateral interactions in amblyopic observers, which usually extend over larger separations than in typical foveal vision. The improvement in these basic visual spatial operations leads to a more efficient capability of performing spatial tasks involving high levels of visual processing, possibly due to the refinement of bottom-up and top-down networks of visual areas.

  16. Peer Crowd Identification and Adolescent Health Behaviors: Results From a Statewide Representative Study.

    Science.gov (United States)

    Jordan, Jeffrey W; Stalgaitis, Carolyn A; Charles, John; Madden, Patrick A; Radhakrishnan, Anjana G; Saggese, Daniel

    2018-02-01

    Peer crowds are macro-level subcultures that share similarities across geographic areas. Over the past decade, dozens of studies have explored the association between adolescent peer crowds and risk behaviors, and how they can inform public health efforts. However, despite the interest, researchers have not yet reported on crowd size and risk levels from a representative sample, making it difficult for practitioners to apply peer crowd science to interventions. The current study reports findings from the first statewide representative sample of adolescent peer crowd identification and health behaviors. Weighted data were analyzed from the 2015 Virginia Youth Survey of Health Behaviors ( n = 4,367). Peer crowds were measured via the I-Base Survey™, a photo-based peer crowd survey instrument. Frequencies and confidence intervals of select behaviors including tobacco use, substance use, nutrition, physical activity, and violence were examined to identify high- and low-risk crowds. Logistic regression was used to calculate adjusted odds ratios for each crowd and behavior. Risky behaviors clustered in two peer crowds. Hip Hop crowd identification was associated with substance use, violence, and some depression and suicidal behaviors. Alternative crowd identification was associated with increased risk for some substance use behaviors, depression and suicide, bullying, physical inactivity, and obesity. Mainstream and, to a lesser extent, Popular, identities were associated with decreased risk for most behaviors. Findings from the first representative study of peer crowds and adolescent behavior identify two high-risk groups, providing critical insights for practitioners seeking to maximize public health interventions by targeting high-risk crowds.

  17. Meaningful interpretation of subdiffusive measurements in living cells (crowded environment) by fluorescence fluctuation microscopy.

    Science.gov (United States)

    Baumann, Gerd; Place, Robert F; Földes-Papp, Zeno

    2010-08-01

    In living cell or its nucleus, the motions of molecules are complicated due to the large crowding and expected heterogeneity of the intracellular environment. Randomness in cellular systems can be either spatial (anomalous) or temporal (heterogeneous). In order to separate both processes, we introduce anomalous random walks on fractals that represented crowded environments. We report the use of numerical simulation and experimental data of single-molecule detection by fluorescence fluctuation microscopy for detecting resolution limits of different mobile fractions in crowded environment of living cells. We simulate the time scale behavior of diffusion times tau(D)(tau) for one component, e.g. the fast mobile fraction, and a second component, e.g. the slow mobile fraction. The less the anomalous exponent alpha the higher the geometric crowding of the underlying structure of motion that is quantified by the ratio of the Hausdorff dimension and the walk exponent d(f)/d(w) and specific for the type of crowding generator used. The simulated diffusion time decreases for smaller values of alpha # 1 but increases for a larger time scale tau at a given value of alpha # 1. The effect of translational anomalous motion is substantially greater if alpha differs much from 1. An alpha value close to 1 contributes little to the time dependence of subdiffusive motions. Thus, quantitative determination of molecular weights from measured diffusion times and apparent diffusion coefficients, respectively, in temporal auto- and crosscorrelation analyses and from time-dependent fluorescence imaging data are difficult to interpret and biased in crowded environments of living cells and their cellular compartments; anomalous dynamics on different time scales tau must be coupled with the quantitative analysis of how experimental parameters change with predictions from simulated subdiffusive dynamics of molecular motions and mechanistic models. We first demonstrate that the crowding exponent

  18. SOBER-MCS: Sociability-Oriented and Battery Efficient Recruitment for Mobile Crowd-Sensing

    Directory of Open Access Journals (Sweden)

    Fazel Anjomshoa

    2018-05-01

    Full Text Available The Internet of Things (IoT concept is aiming at being an integral part of the next generation networking services by introducing pervasiveness and ubiquitous interconnectivity of uniquely-identifiable objects. The massive availability of personalized smart devices such as smartphones and wearables enable their penetration into the IoT ecosystem with their built-in sensors, particularly in Mobile Crowd-Sensing (MCS campaigns. The MCS systems achieve the objectives of the large-scale non-dedicated sensing concept in the IoT if a sufficient number of participants are engaged to the collaborative data acquisition process. Therefore, user recruitment is a key challenge in MCS, which requires effective incentivization of cooperative, truthful and trustworthy users. A grand concern for the participants is the battery drain on the mobile devices. It is a known fact that battery drain in a smartphone is a function of the user activity, which can be modeled under various contexts. With this in mind, we propose a new social activity-aware recruitment policy, namely Sociability-Oriented and Battery-Efficient Recruitment for Mobile Crowd-Sensing (SOBER-MCS. SOBER-MCS uses sociability and the residual power of the participant smartphones as two primary criteria in the selection of participating devices. The former is an indicator of the participant willingness toward sensing campaigns, whereas the latter is used to prioritize personal use over crowd-sensing under critical battery levels. We use sociability profiles that were obtained in our previous work and use those values to simulate the sociability behavior of a large pool of participants in an MCS environment. Through simulations, we show that SOBER-MCS is able to introduce battery savings up to 18.5% while improving user and platform utilities by 12% and 20%, respectively.

  19. SOBER-MCS: Sociability-Oriented and Battery Efficient Recruitment for Mobile Crowd-Sensing.

    Science.gov (United States)

    Anjomshoa, Fazel; Kantarci, Burak

    2018-05-17

    The Internet of Things (IoT) concept is aiming at being an integral part of the next generation networking services by introducing pervasiveness and ubiquitous interconnectivity of uniquely-identifiable objects. The massive availability of personalized smart devices such as smartphones and wearables enable their penetration into the IoT ecosystem with their built-in sensors, particularly in Mobile Crowd-Sensing (MCS) campaigns. The MCS systems achieve the objectives of the large-scale non-dedicated sensing concept in the IoT if a sufficient number of participants are engaged to the collaborative data acquisition process. Therefore, user recruitment is a key challenge in MCS, which requires effective incentivization of cooperative, truthful and trustworthy users. A grand concern for the participants is the battery drain on the mobile devices. It is a known fact that battery drain in a smartphone is a function of the user activity, which can be modeled under various contexts. With this in mind, we propose a new social activity-aware recruitment policy, namely Sociability-Oriented and Battery-Efficient Recruitment for Mobile Crowd-Sensing (SOBER-MCS). SOBER-MCS uses sociability and the residual power of the participant smartphones as two primary criteria in the selection of participating devices. The former is an indicator of the participant willingness toward sensing campaigns, whereas the latter is used to prioritize personal use over crowd-sensing under critical battery levels. We use sociability profiles that were obtained in our previous work and use those values to simulate the sociability behavior of a large pool of participants in an MCS environment. Through simulations, we show that SOBER-MCS is able to introduce battery savings up to 18.5% while improving user and platform utilities by 12% and 20%, respectively.

  20. One Year After Fukushima, Nuclear Safety Is Stronger

    International Nuclear Information System (INIS)

    2012-01-01

    Full text: Nuclear power is safer than it was a year ago as the nuclear industry, regulators and governments act on the lessons of Fukushima, but that safety must never be taken for granted, said Yukiya Amano, Director General of the International Atomic Energy Agency (IAEA). Speaking ahead of the first anniversary of the Fukushima Daiichi nuclear accident on 11 March, Amano said a culture of constant vigilance and improvement was vital to ensure that the benefits of nuclear power could be harnessed as safely as humanly possible. 'Nuclear safety is stronger than it was a year ago', he said. 'Fukushima Daiichi was a very serious accident, but we know what went wrong and we have a clear course of action to tackle those causes - not only in Japan, but anywhere in the world. 'Now we have to keep up the momentum. Complacency can kill'. On 11 March 2011 a huge earthquake and tsunami left more than 20 000 people dead or missing in eastern Japan. Amidst widespread destruction, the tsunami slammed into the Fukushima Daiichi Nuclear Power Station, disabling cooling systems and leading to fuel meltdowns in three of the six Units. The accident was a jolt to the nuclear industry, regulators and governments. It was triggered by a massive force of nature, but it was existing weaknesses of design regarding defence against natural hazards, regulatory oversight, accident management and emergency response that allowed it to unfold as it did. For example: The nuclear regulator was not sufficiently independent, allowing weak oversight of the operator, TEPCO, and regulatory requirements fell short of international best practice; Not enough attention was paid to guarding against possible extreme events at the Fukushima Daiichi site, leaving critical safety functions such as cooling systems vulnerable to the tsunami; Training to respond to serious accidents was inadequate, as were mitigation measures to prevent hydrogen explosions and protect the venting system; and Accident command lines

  1. Quality-Aware Incentive Mechanism for Mobile Crowd Sensing

    Directory of Open Access Journals (Sweden)

    Ling-Yun Jiang

    2017-01-01

    Full Text Available Mobile crowd sensing (MCS is a novel sensing paradigm which can sense human-centered daily activities and the surrounding environment. The impact of mobility and selfishness of participants on the data reliability cannot be ignored in most mobile crowd sensing systems. To address this issue, we present a universal system model based on the reverse auction framework and formulate the problem as the Multiple Quality Multiple User Selection (MQMUS problem. The quality-aware incentive mechanism (QAIM is proposed to meet the quality requirement of data reliability. We demonstrate that the proposed incentive mechanism achieves the properties of computational efficiency, individual rationality, and truthfulness. And meanwhile, we evaluate the performance and validate the theoretical properties of our incentive mechanism through extensive simulation experiments.

  2. Crowding-facilitated macromolecular transport in attractive micropost arrays.

    Science.gov (United States)

    Chien, Fan-Tso; Lin, Po-Keng; Chien, Wei; Hung, Cheng-Hsiang; Yu, Ming-Hung; Chou, Chia-Fu; Chen, Yeng-Long

    2017-05-02

    Our study of DNA dynamics in weakly attractive nanofabricated post arrays revealed crowding enhances polymer transport, contrary to hindered transport in repulsive medium. The coupling of DNA diffusion and adsorption to the microposts results in more frequent cross-post hopping and increased long-term diffusivity with increased crowding density. We performed Langevin dynamics simulations and found maximum long-term diffusivity in post arrays with gap sizes comparable to the polymer radius of gyration. We found that macromolecular transport in weakly attractive post arrays is faster than in non-attractive dense medium. Furthermore, we employed hidden Markov analysis to determine the transition of macromolecular adsorption-desorption on posts and hopping between posts. The apparent free energy barriers are comparable to theoretical estimates determined from polymer conformational fluctuations.

  3. Disaster Risk Reduction through Innovative Uses of Crowd Sourcing (Invited)

    Science.gov (United States)

    Berger, J.; Greene, M.

    2010-12-01

    Crowd sourcing can be described as a method of distributed problem-solving. It takes advantage of the power of the crowd, which can in some cases be a community of experts and in other cases the collective insight of a broader range of contributors with varying degrees of domain knowledge. The term crowd sourcing was first used by Jeff Howe in a June 2006 Wired magazine article “The Rise of Crowdsourcing,” and is a combination of the terms “crowd” and “outsourcing.” Some commonly known examples of crowd sourcing, in its broadest sense, include Wikepedia, distributed participatory design projects, and consumer websites such as Yelp and Angie’s List. The popularity and success of early large-scale crowd sourcing activities is made possible through leveraging Web 2.0 technologies that allow for mass participation from distributed individuals. The Earthquake Engineering Research Institute (EERI) in Oakland, California recently participated in two crowd sourcing projects. One was initiated and coordinated by EERI, while in the second case EERI was invited to contribute once the crowd sourcing activity was underway. In both projects there was: 1) the determination of a problem or set of tasks that could benefit immediately from the engagement of an informed volunteer group of professionals; 2) a segmenting of the problem into discrete pieces that could be completed in a short period of time (from ten minutes to four hours); 3) a call to action, where an interested community was made aware of the project; and 4) the collection, aggregation, vetting and ultimately distribution of the results in a relatively short period of time. The first EERI crowd sourcing example was the use of practicing engineers and engineering students in California to help estimate the number of pre-1980 concrete buildings in the high seismic risk counties in the state. This building type is known to perform poorly in earthquakes, and state officials were interested in understanding

  4. Crowd-Sourcing the Aesthetics of Platform Games

    DEFF Research Database (Denmark)

    Shaker, Noor; Yannakakis, Georgios N.; Togelius, Julian

    2014-01-01

    What are the aesthetics of platform games and what makes a platform level engaging, challenging and/or frustrating? We attempt to answer such questions through mining a large-set of crowd-sourced gameplay data of a clone of the classic platform game Super Mario Bros. The data consists of 40 short...... game levels that differ along six key level design parameters. Collectively, these levels are played 1560 times over the Internet and the perceived experience is annotated by experiment participants via self-reported ranking (pairwise preferences). Given the wealth of this crowd-sourced data, as all...... details about players’ in-game behaviour are logged, the problem becomes one of extracting meaningful numerical features at the appropriate level of abstraction for the construction of generic computational models of player experience and, thereby, game aesthetics. We explore dissimilar types of features...

  5. Facilitated aggregation of FG nucleoporins under molecular crowding conditions.

    Science.gov (United States)

    Milles, Sigrid; Huy Bui, Khanh; Koehler, Christine; Eltsov, Mikhail; Beck, Martin; Lemke, Edward A

    2013-02-01

    Intrinsically disordered and phenylalanine-glycine-rich nucleoporins (FG Nups) form a crowded and selective transport conduit inside the NPC that can only be transited with the help of nuclear transport receptors (NTRs). It has been shown in vitro that FG Nups can assemble into two distinct appearances, amyloids and hydrogels. If and how these phenomena are linked and if they have a physiological role still remains unclear. Using a variety of high-resolution fluorescence and electron microscopic (EM) tools, we reveal that crowding conditions mimicking the NPC environment can accelerate the aggregation and amyloid formation speed of yeast and human FG Nups by orders of magnitude. Aggregation can be inhibited by NTRs, providing a rationale on how the cell might control amyloid formation of FG Nups. The superb spatial resolving power of EM also reveals that hydrogels are enlaced amyloid fibres, and these findings have implications for existing transport models and for NPC assembly.

  6. Facilitated diffusion in a crowded environment: from kinetics to stochastics

    International Nuclear Information System (INIS)

    Meroz, Yasmine; Klafter, Joseph; Eliazar, Iddo

    2009-01-01

    Facilitated diffusion is a fundamental search process used to describe the problem of a searcher protein finding a specific target site over a very large DNA strand. In recent years macromolecular crowding has been recognized to affect this search process. In this paper, we bridge between two different modelling methodologies of facilitated diffusion: the physics-oriented kinetic approach, which yields the reaction rate of the search process, and the probability-oriented stochastic approach, which yields the probability distribution of the search duration. We translate the former approach to the latter, ascertaining that the two approaches yield coinciding results, both with and without macromolecular crowding. We further show that the stochastic approach markedly generalizes the kinetic approach by accommodating a vast array of search mechanisms, including mechanisms having no reaction rates, and thus being beyond the realm of the kinetic approach.

  7. SPITZER IRAC PHOTOMETRY FOR TIME SERIES IN CROWDED FIELDS

    Energy Technology Data Exchange (ETDEWEB)

    Novati, S. Calchi; Beichman, C. [NASA Exoplanet Science Institute, MS 100-22, California Institute of Technology, Pasadena, CA 91125 (United States); Gould, A.; Fausnaugh, M.; Gaudi, B. S.; Pogge, R. W.; Wibking, B.; Zhu, W.; Poleski, R. [Department of Astronomy, Ohio State University, 140 W. 18th Ave., Columbus, OH 43210 (United States); Yee, J. C. [Harvard-Smithsonian Center for Astrophysics, 60 Garden St., Cambridge, MA 02138 (United States); Bryden, G.; Henderson, C. B.; Shvartzvald, Y. [Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA 91109 (United States); Carey, S. [Spitzer, Science Center, MS 220-6, California Institute of Technology, Pasadena, CA (United States); Udalski, A.; Pawlak, M.; Szymański, M. K.; Skowron, J.; Mróz, P.; Kozłowski, S. [Warsaw University Observatory, Al. Ujazdowskie 4, 00-478 Warszawa (Poland); Collaboration: Spitzer team; OGLE group; and others

    2015-12-01

    We develop a new photometry algorithm that is optimized for the Infrared Array Camera (IRAC) Spitzer time series in crowded fields and that is particularly adapted to faint or heavily blended targets. We apply this to the 170 targets from the 2015 Spitzer microlensing campaign and present the results of three variants of this algorithm in an online catalog. We present detailed accounts of the application of this algorithm to two difficult cases, one very faint and the other very crowded. Several of Spitzer's instrumental characteristics that drive the specific features of this algorithm are shared by Kepler and WFIRST, implying that these features may prove to be a useful starting point for algorithms designed for microlensing campaigns by these other missions.

  8. Origins of microstructural transformations in charged vesicle suspensions: the crowding hypothesis.

    Science.gov (United States)

    Seth, Mansi; Ramachandran, Arun; Murch, Bruce P; Leal, L Gary

    2014-09-02

    It is observed that charged unilamellar vesicles in a suspension can spontaneously deflate and subsequently transition to form bilamellar vesicles, even in the absence of externally applied triggers such as salt or temperature gradients. We provide strong evidence that the driving force for this deflation-induced transition is the repulsive electrostatic pressure between charged vesicles in concentrated suspensions, above a critical effective volume fraction. We use volume fraction measurements and cryogenic transmission electron microscopy imaging to quantitatively follow both the macroscopic and microstructural time-evolution of cationic diC18:1 DEEDMAC vesicle suspensions at different surfactant and salt concentrations. A simple model is developed to estimate the extent of deflation of unilamellar vesicles caused by electrostatic interactions with neighboring vesicles. It is determined that when the effective volume fraction of the suspension exceeds a critical value, charged vesicles in a suspension can experience "crowding" due to overlap of their electrical double layers, which can result in deflation and subsequent microstructural transformations to reduce the effective volume fraction of the suspension. Ordinarily in polydisperse colloidal suspensions, particles interacting via a repulsive potential transform into a glassy state above a critical volume fraction. The behavior of charged vesicle suspensions reported in this paper thus represents a new mechanism for the relaxation of repulsive interactions in crowded situations.

  9. Crowd Sourced Formal Verification-Augmentation (CSFV-A)

    Science.gov (United States)

    2016-06-01

    Projects Agency (DARPA), Air Force Research Laboratory (AFRL), Charles River Analytics Inc., and TopCoder, Inc. will be holding a contest to reward...CROWD SOURCED FORMAL VERIFICATION – AUGMENTATION (CSFV-A) CHARLES RIVER ANALYTICS, INC. JUNE 2016 FINAL TECHNICAL REPORT APPROVED FOR PUBLIC...CSFV 5e. TASK NUMBER TC 5f. WORK UNIT NUMBER RA 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) Charles River Analytics, Inc. 625 Mount Auburn

  10. Crowding out intrinsic motivation in the public sector

    OpenAIRE

    Georgellis, Y; Iossa, E; Tabvuma, V

    2011-01-01

    Employing intrinsically motivated individuals has been proposed as a means of improving public sector performance. In this article, we investigate whether intrinsic motivation affects the sorting of employees between the private and the public sectors, paying particular attention to whether extrinsic rewards crowd out intrinsic motivation. Using British longitudinal data, we find that individuals are attracted to the public sector by the intrinsic rather than the extrinsic rewards that the se...

  11. Crowded, Confined, and Frustrated: Dynamics of Molecules Tethered to Nanoparticles

    KAUST Repository

    Agarwal, Praveen

    2012-12-01

    Above a critical chemistry-dependent molecular weight, all polymer molecules entangle and, as a result, exhibit slow dynamics, enhanced viscosity, and elasticity. Herein we report on the dynamics of low molecular weight polymers tethered to nanoparticles and find that even conventionally unentangled chains manifest dynamical features similar to entangled, long-chain molecules. Our findings are shown to imply that crowding and confinement of polymers on particles produce topological constraints analogous to those in entangled systems. © 2012 American Physical Society.

  12. Characterizing Crowd Participation and Productivity of Foldit Through Web Scraping

    Science.gov (United States)

    2016-03-01

    of home computer users as a method to tackle other problems. Howe first coined “Crowdsourcing” in an article for Wired magazine titled “The Rise of...terms of biotechnology , DNA technology has applications ranging from self-assembling nanotechnology to logical circuits and programming. Taking some...crowdsourcing,” Wired Magazine , vol. 14, pp. 1–4, 2006. [22] D. C. Brabham, “The myth of amateur crowds: A critical discourse analysis of crowdsourcing

  13. The multi-niche crowding genetic algorithm: Analysis and applications

    Energy Technology Data Exchange (ETDEWEB)

    Cedeno, Walter [Univ. of California, Davis, CA (United States)

    1995-09-01

    The ability of organisms to evolve and adapt to the environment has provided mother nature with a rich and diverse set of species. Only organisms well adapted to their environment can survive from one generation to the next, transferring on the traits, that made them successful, to their offspring. Competition for resources and the ever changing environment drives some species to extinction and at the same time others evolve to maintain the delicate balance in nature. In this disertation we present the multi-niche crowding genetic algorithm, a computational metaphor to the survival of species in ecological niches in the face of competition. The multi-niche crowding genetic algorithm maintains stable subpopulations of solutions in multiple niches in multimodal landscapes. The algorithm introduces the concept of crowding selection to promote mating among members with qirnilar traits while allowing many members of the population to participate in mating. The algorithm uses worst among most similar replacement policy to promote competition among members with similar traits while allowing competition among members of different niches as well. We present empirical and theoretical results for the success of the multiniche crowding genetic algorithm for multimodal function optimization. The properties of the algorithm using different parameters are examined. We test the performance of the algorithm on problems of DNA Mapping, Aquifer Management, and the File Design Problem. Applications that combine the use of heuristics and special operators to solve problems in the areas of combinatorial optimization, grouping, and multi-objective optimization. We conclude by presenting the advantages and disadvantages of the algorithm and describing avenues for future investigation to answer other questions raised by this study.

  14. Combining Crowd and Expert Labels using Decision Theoretic Active Learning

    Science.gov (United States)

    2015-10-11

    including those la- beled by a classifier trained on using the labels acquired so far). For example, a simple loss function would just be the number...model is used to predict the probability that each crowd la- beled item is correct. This estimate is in turn used to weight the corresponding...costs) for each state using Algorithm 1 as a subroutine. We consider taking the possible action for each item not yet la- beled by the expert. Thus each

  15. Traffic instabilities in self-organized pedestrian crowds.

    Directory of Open Access Journals (Sweden)

    Mehdi Moussaïd

    Full Text Available In human crowds as well as in many animal societies, local interactions among individuals often give rise to self-organized collective organizations that offer functional benefits to the group. For instance, flows of pedestrians moving in opposite directions spontaneously segregate into lanes of uniform walking directions. This phenomenon is often referred to as a smart collective pattern, as it increases the traffic efficiency with no need of external control. However, the functional benefits of this emergent organization have never been experimentally measured, and the underlying behavioral mechanisms are poorly understood. In this work, we have studied this phenomenon under controlled laboratory conditions. We found that the traffic segregation exhibits structural instabilities characterized by the alternation of organized and disorganized states, where the lifetime of well-organized clusters of pedestrians follow a stretched exponential relaxation process. Further analysis show that the inter-pedestrian variability of comfortable walking speeds is a key variable at the origin of the observed traffic perturbations. We show that the collective benefit of the emerging pattern is maximized when all pedestrians walk at the average speed of the group. In practice, however, local interactions between slow- and fast-walking pedestrians trigger global breakdowns of organization, which reduce the collective and the individual payoff provided by the traffic segregation. This work is a step ahead toward the understanding of traffic self-organization in crowds, which turns out to be modulated by complex behavioral mechanisms that do not always maximize the group's benefits. The quantitative understanding of crowd behaviors opens the way for designing bottom-up management strategies bound to promote the emergence of efficient collective behaviors in crowds.

  16. Patterns of residential crowding among Hispanics in later life: immigration, assimilation, and housing market factors.

    Science.gov (United States)

    Burr, Jeffrey A; Mutchler, Jan E; Gerst, Kerstin

    2010-11-01

    We describe patterns of residential crowding among older Hispanics and non-Hispanic Whites. We also examine hypotheses about the relationship of residential crowding with assimilation (language and duration of residence) and housing market characteristics. We employ a multilevel research design, using data from the 2000 U.S. Census of Population. Hierarchical linear models are utilized to estimate the association between residential crowding and both individual and housing market factors. Approximately one third of older Hispanics in metropolitan areas live in crowded housing compared with only one tenth of older non-Hispanic Whites. Foreign-born older persons report higher levels of crowding than U.S.-born older persons. Residential crowding differences between older Hispanics and non-Hispanics are not eliminated after controls are included. Older Hispanics who report better English language skills and a longer duration of residence in the United States live in less crowded housing. We do not find evidence for a relationship between crowding and residential segregation, but we find consistent evidence for an association between residential crowding and relative size of the Hispanic population. The forces that shape household composition and access to housing among older Hispanics appear to result in higher levels of residential crowding for this population.

  17. Statistical analysis of passenger-crowding in bus transport network of Harbin

    Science.gov (United States)

    Hu, Baoyu; Feng, Shumin; Li, Jinyang; Zhao, Hu

    2018-01-01

    Passenger flow data is indispensable but rare in the study of public transport networks. In this study, we focus on the passenger-crowding characteristics of the bus transport network of Harbin (BTN-H) based on passenger flow investigation. The three frequency histograms for all the uplinks and downlinks in Harbin are presented, including passengers on the bus at each section, crowding coefficients, and position parameters of crowded sections. The differences in crowding position are analyzed on each route. The distributions of degree and crowding degree (in directed space L) follow an exponential law. The new finding indicates that there are many stations with few crowded sections and a few stations with many crowded sections. The distributions of path length and crowded length (in directed space P) are presented based on the minimum transfer times, and it is found that they can be fitted by a composite Gaussian function and a Gaussian function, respectively. The stations and paths can be divided into three crowd levels. We conclude that BTN-H is crowded from a network-based perspective.

  18. Impacts of temperature and crowding on sex ratio, fecundity and Wolbachia infection intensity in the copepod, Mesocyclops thermocyclopoides.

    Science.gov (United States)

    Wiwatanaratanabutr, Itsanun; Grandjean, Frederic

    2016-11-01

    Wolbachia are a group of intracellular bacteria that cause reproductive alterations in arthropods. Here, we describe the effects of two environmental factors (crowding and temperature) on phenotypic expression of feminization, the host's fecundity and Wolbachia infection intensity among life cycle stages in the naturally Wolbachia-infected copepod, Mesocyclops thermocyclopoides. The copepod was first found to be co-infected with Wolbachia A- and B-supergroups Wolbachia strains based on wsp primers. The relative Wolbachia infection intensity within individuals was determined using quantitative real-time PCR and was significantly higher in the B-supergroup than in the A-supergroup. Experimental results of temperature effect on bacterial density in each developmental stage revealed a significant decrease in Wolbachia infection intensity following exposure to high temperature (37°C) in both sexes and implied that Wolbachia might survive in room temperature (25°C) better than in high temperature. Experimental results of crowding effects on Wolbachia infection intensity suggested a negative correlation between copepod nauplii and Wolbachia infection intensity. No effect of rearing temperature on the sex ratio was reported although the fecundity was significantly decreased by high temperature. The results showed that Wolbachia infection intensity to be correlated with crowding conditions and was decreased following exposure of elevated temperature. Copyright © 2016 Elsevier Inc. All rights reserved.

  19. Foot force models of crowd dynamics on a wobbly bridge.

    Science.gov (United States)

    Belykh, Igor; Jeter, Russell; Belykh, Vladimir

    2017-11-01

    Modern pedestrian and suspension bridges are designed using industry standard packages, yet disastrous resonant vibrations are observed, necessitating multimillion dollar repairs. Recent examples include pedestrian-induced vibrations during the opening of the Solférino Bridge in Paris in 1999 and the increased bouncing of the Squibb Park Bridge in Brooklyn in 2014. The most prominent example of an unstable lively bridge is the London Millennium Bridge, which started wobbling as a result of pedestrian-bridge interactions. Pedestrian phase locking due to footstep phase adjustment is suspected to be the main cause of its large lateral vibrations; however, its role in the initiation of wobbling was debated. We develop foot force models of pedestrians' response to bridge motion and detailed, yet analytically tractable, models of crowd phase locking. We use biomechanically inspired models of crowd lateral movement to investigate to what degree pedestrian synchrony must be present for a bridge to wobble significantly and what is a critical crowd size. Our results can be used as a safety guideline for designing pedestrian bridges or limiting the maximum occupancy of an existing bridge. The pedestrian models can be used as "crash test dummies" when numerically probing a specific bridge design. This is particularly important because the U.S. code for designing pedestrian bridges does not contain explicit guidelines that account for the collective pedestrian behavior.

  20. Anatomy of the Crowd4Discovery crowdfunding campaign.

    Science.gov (United States)

    Perlstein, Ethan O

    2013-01-01

    Crowdfunding allows the public to fund creative projects, including curiosity-driven scientific research. Last Fall, I was part of a team that raised $25,460 from an international coalition of "micropatrons" for an open, pharmacological research project called Crowd4Discovery. The goal of Crowd4Discovery is to determine the precise location of amphetamines inside mouse brain cells, and we are sharing the results of this project on the Internet as they trickle in. In this commentary, I will describe the genesis of Crowd4Discovery, our motivations for crowdfunding, an analysis of our fundraising data, and the nuts and bolts of running a crowdfunding campaign. Science crowdfunding is in its infancy but has already been successfully used by an array of scientists in academia and in the private sector as both a supplement and a substitute to grants. With traditional government sources of funding for basic scientific research contracting, an alternative model that couples fundraising and outreach - and in the process encourages more openness and accountability - may be increasingly attractive to researchers seeking to diversify their funding streams.

  1. Demotivating incentives and motivation crowding out in charitable giving.

    Science.gov (United States)

    Chao, Matthew

    2017-07-11

    Research has shown that extrinsic incentives can crowd out intrinsic motivation in many contexts. Despite this, many nonprofits offer conditional thank-you gifts, such as mugs or tote bags, in exchange for donations. In collaboration with a nonprofit, this study implements a direct mail field experiment and demonstrates that thank-you gifts reduced donation rates in a fundraising campaign. Attention-based multiattribute choice models suggest that this is because prospective donors shift attention to the salient gift offer, causing them to underweight less salient intrinsic motives. Attention to the gift may also cause individuals to adopt a more cost-benefit mindset, further de-emphasizing intrinsic motives. Consistent with these hypotheses, crowding out was driven by those who donated higher amounts in the previous year (i.e., those who likely had higher intrinsic motivation). In a complementary online experiment, thank-you gifts also reduced donation rates but only when the gift was visually salient. This corroborates the mediating role of attention in crowding out. Taken together, the laboratory and field results demonstrate that this fundraising technique can be demotivating in some contexts and that this may occur through an attention-based mechanism.

  2. Conceptualizing intragroup and intergroup dynamics within a controlled crowd evacuation.

    Science.gov (United States)

    Elzie, Terra; Frydenlund, Erika; Collins, Andrew J; Robinson, R Michael

    2015-01-01

    Social dynamics play a critical role in successful pedestrian evacuations. Crowd modeling research has made progress in capturing the way individual and group dynamics affect evacuations; however, few studies have simultaneously examined how individuals and groups interact with one another during egress. To address this gap, the researchers present a conceptual agent-based model (ABM) designed to study the ways in which autonomous, heterogeneous, decision-making individuals negotiate intragroup and intergroup behavior while exiting a large venue. A key feature of this proposed model is the examination of the dynamics among and between various groupings, where heterogeneity at the individual level dynamically affects group behavior and subsequently group/group interactions. ABM provides a means of representing the important social factors that affect decision making among diverse social groups. Expanding on the 2013 work of Vizzari et al., the researchers focus specifically on social factors and decision making at the individual/group and group/group levels to more realistically portray dynamic crowd systems during a pedestrian evacuation. By developing a model with individual, intragroup, and intergroup interactions, the ABM provides a more representative approximation of real-world crowd egress. The simulation will enable more informed planning by disaster managers, emergency planners, and other decision makers. This pedestrian behavioral concept is one piece of a larger simulation model. Future research will build toward an integrated model capturing decision-making interactions between pedestrians and vehicles that affect evacuation outcomes.

  3. POI Summarization by Aesthetics Evaluation From Crowd Source Social Media.

    Science.gov (United States)

    Qian, Xueming; Li, Cheng; Lan, Ke; Hou, Xingsong; Li, Zhetao; Han, Junwei

    2018-03-01

    Place-of-Interest (POI) summarization by aesthetics evaluation can recommend a set of POI images to the user and it is significant in image retrieval. In this paper, we propose a system that summarizes a collection of POI images regarding both aesthetics and diversity of the distribution of cameras. First, we generate visual albums by a coarse-to-fine POI clustering approach and then generate 3D models for each album by the collected images from social media. Second, based on the 3D to 2D projection relationship, we select candidate photos in terms of the proposed crowd source saliency model. Third, in order to improve the performance of aesthetic measurement model, we propose a crowd-sourced saliency detection approach by exploring the distribution of salient regions in the 3D model. Then, we measure the composition aesthetics of each image and we explore crowd source salient feature to yield saliency map, based on which, we propose an adaptive image adoption approach. Finally, we combine the diversity and the aesthetics to recommend aesthetic pictures. Experimental results show that the proposed POI summarization approach can return images with diverse camera distributions and aesthetics.

  4. The Wisdom of e-crowds: Can Masses Create Value?

    Directory of Open Access Journals (Sweden)

    Wieczerzycki Marcin

    2016-09-01

    Full Text Available With the rising popularity of the Internet, interactions between companies and their consumers have become more common and meaningful. Researchers often tend to apply the metaphor of community to these on-line networks of B2C relationships. However, this term implies durability and a long-term orientation. It does not cover more incidental, short-lived groups of consumers, who therefore should not be treated as communities. The purpose of this paper is to explore the ability of these short-term, collective consumer phenomena (addressed as e-crowds within the scope of this paper to create value. Based on a critical literature analysis that considers works from several different fields of knowledge (including management, economics, psychology and media studies and empirical examples, we argue that while lacking a complex internal organization, e-crowds are capable of creating use, exchange and sign value when certain conditions are met. However, they are equally likely to perform value-destroying activities, which present real risks for companies that interact with e-crowds.

  5. Polymer Crowding in Confined Polymer-Nanoparticle Mixtures

    Science.gov (United States)

    Davis, Wyatt J.; Denton, Alan R.

    Crowding can influence the conformations and thus functionality of macromolecules in quasi-two-dimensional environments, such as DNA or proteins confined to a cell membrane. We explore such crowding within a model of polymers as penetrable ellipses, whose shapes are governed by the statistics of a 2D random walk. The principal radii of the polymers fluctuate according to probability distributions of the eigenvalues of the gyration tensor. Within this coarse-grained model, we perform Monte Carlo simulations of mixtures of polymers and hard nanodisks, including trial changes in polymer conformation (shape and orientation). Penetration of polymers by nanodisks is incorporated with a free energy cost predicted by polymer field theory. Over ranges of size ratio and nanodisk density, we analyze the influence of crowding on polymer shape by computing eigenvalue distributions, mean radius of gyration, and mean asphericity of the polymer. We compare results with predictions of free-volume theory and with corresponding results in three dimensions. Our approach may help to interpret recent (and motivate future) experimental studies of biopolymers interacting with cell membranes, with relevance for drug delivery and gene therapy. This work was supported by the National Science Foundation under Grant No. DMR-1106331.

  6. Altruism, Rivalry and Crowding-Out in the Nonprofit Firm's Supply of Charity Services: The Case of Hospitals

    OpenAIRE

    Richard G. Frank; David S. Salkever

    1988-01-01

    This paper extends previous research on Individuals' supply of charitable donations to the behavior of nonprofit firms. Specifically, we study provision of charity care by private, nonprofit hospitals. We demonstrate that In the absence of large positive income effects on charity care supply, convex preferences for the nonprofit hospital imply crowding out by other private or government hospitals. Extending our model to include patient heterogeneity and impure altruism (rivalry) provides a po...

  7. CA-LOD: Collision Avoidance Level of Detail for Scalable, Controllable Crowds

    Science.gov (United States)

    Paris, Sébastien; Gerdelan, Anton; O'Sullivan, Carol

    The new wave of computer-driven entertainment technology throws audiences and game players into massive virtual worlds where entire cities are rendered in real time. Computer animated characters run through inner-city streets teeming with pedestrians, all fully rendered with 3D graphics, animations, particle effects and linked to 3D sound effects to produce more realistic and immersive computer-hosted entertainment experiences than ever before. Computing all of this detail at once is enormously computationally expensive, and game designers as a rule, have sacrificed the behavioural realism in favour of better graphics. In this paper we propose a new Collision Avoidance Level of Detail (CA-LOD) algorithm that allows games to support huge crowds in real time with the appearance of more intelligent behaviour. We propose two collision avoidance models used for two different CA-LODs: a fuzzy steering focusing on the performances, and a geometric steering to obtain the best realism. Mixing these approaches allows to obtain thousands of autonomous characters in real time, resulting in a scalable but still controllable crowd.

  8. Crowd Sourcing for Challenging Technical Problems and Business Model

    Science.gov (United States)

    Davis, Jeffrey R.; Richard, Elizabeth

    2011-01-01

    Crowd sourcing may be defined as the act of outsourcing tasks that are traditionally performed by an employee or contractor to an undefined, generally large group of people or community (a crowd) in the form of an open call. The open call may be issued by an organization wishing to find a solution to a particular problem or complete a task, or by an open innovation service provider on behalf of that organization. In 2008, the Space Life Sciences Directorate (SLSD), with the support of Wyle Integrated Science and Engineering, established and implemented pilot projects in open innovation (crowd sourcing) to determine if these new internet-based platforms could indeed find solutions to difficult technical challenges. These unsolved technical problems were converted to problem statements, also called "Challenges" or "Technical Needs" by the various open innovation service providers, and were then posted externally to seek solutions. In addition, an open call was issued internally to NASA employees Agency wide (10 Field Centers and NASA HQ) using an open innovation service provider crowd sourcing platform to post NASA challenges from each Center for the others to propose solutions). From 2008 to 2010, the SLSD issued 34 challenges, 14 externally and 20 internally. The 14 external problems or challenges were posted through three different vendors: InnoCentive, Yet2.com and TopCoder. The 20 internal challenges were conducted using the InnoCentive crowd sourcing platform designed for internal use by an organization. This platform was customized for NASA use and promoted as NASA@Work. The results were significant. Of the seven InnoCentive external challenges, two full and five partial awards were made in complex technical areas such as predicting solar flares and long-duration food packaging. Similarly, the TopCoder challenge yielded an optimization algorithm for designing a lunar medical kit. The Yet2.com challenges yielded many new industry and academic contacts in bone

  9. Hydration of Watson-Crick base pairs and dehydration of Hoogsteen base pairs inducing structural polymorphism under molecular crowding conditions.

    Science.gov (United States)

    Miyoshi, Daisuke; Nakamura, Kaori; Tateishi-Karimata, Hisae; Ohmichi, Tatsuo; Sugimoto, Naoki

    2009-03-18

    It has been revealed recently that molecular crowding, which is one of the largest differences between in vivo and in vitro conditions, is a critical factor determining the structure, stability, and function of nucleic acids. However, the effects of molecular crowding on Watson-Crick and Hoogsteen base pairs remain unclear. In order to investigate directly and quantitatively the molecular crowding effects on base pair types in nucleic acids, we designed intramolecular parallel- and antiparallel-stranded DNA duplexes consisting of Hoogsteen and Watson-Crick base pairs, respectively, as well as an intramolecular parallel-stranded triplex containing both types of base pairs. Thermodynamic analyses demonstrated that the values of free energy change at 25 degrees C for Hoogsteen base-pair formations decreased from +1.45 +/- 0.15 to +1.09 +/- 0.13 kcal mol(-1), and from -1.89 +/- 0.13 to -2.71 +/- 0.11 kcal mol(-1) in the intramolecular duplex and triplex, respectively, when the concentration of PEG 200 (polyethylene glycol with average molecular weight 200) increased from 0 to 20 wt %. However, corresponding values for Watson-Crick formation in the duplex and triplex increased from -10.2 +/- 0.2 to -8.7 +/- 0.1 kcal mol(-1), and from -10.8 +/- 0.2 to -9.2 +/- 0.2 kcal mol(-1), respectively. Furthermore, it was revealed that the opposing effects of molecular crowding on the Hoogsteen and Watson-Crick base pairs were due to different behaviors of water molecules binding to the DNA strands.

  10. The Visible Hand and the Crowd

    DEFF Research Database (Denmark)

    Kornberger, Martin

    2017-01-01

    The effectiveness and creativity of Linux, Wikipedia, and a plethora of other distributed innovation systems have attracted the attention of scholars, practitioners, and policy makers. The hallmark of these distributed innovation systems is that value creation transcends the boundaries of hierarc......The effectiveness and creativity of Linux, Wikipedia, and a plethora of other distributed innovation systems have attracted the attention of scholars, practitioners, and policy makers. The hallmark of these distributed innovation systems is that value creation transcends the boundaries...

  11. The 2D Structure of the T. brucei Preedited RPS12 mRNA Is Not Affected by Macromolecular Crowding

    Directory of Open Access Journals (Sweden)

    W.-Matthias Leeder

    2017-01-01

    Full Text Available Mitochondrial transcript maturation in African trypanosomes requires RNA editing to convert sequence-deficient pre-mRNAs into translatable mRNAs. The different pre-mRNAs have been shown to adopt highly stable 2D folds; however, it is not known whether these structures resemble the in vivo folds given the extreme “crowding” conditions within the mitochondrion. Here, we analyze the effects of macromolecular crowding on the structure of the mitochondrial RPS12 pre-mRNA. We use high molecular mass polyethylene glycol as a macromolecular cosolute and monitor the structure of the RNA globally and with nucleotide resolution. We demonstrate that crowding has no impact on the 2D fold and we conclude that the MFE structure in dilute solvent conditions represents a good proxy for the folding of the pre-mRNA in its mitochondrial solvent context.

  12. A configural dominant account of contextual cueing: Configural cues are stronger than colour cues.

    Science.gov (United States)

    Kunar, Melina A; John, Rebecca; Sweetman, Hollie

    2014-01-01

    Previous work has shown that reaction times to find a target in displays that have been repeated are faster than those for displays that have never been seen before. This learning effect, termed "contextual cueing" (CC), has been shown using contexts such as the configuration of the distractors in the display and the background colour. However, it is not clear how these two contexts interact to facilitate search. We investigated this here by comparing the strengths of these two cues when they appeared together. In Experiment 1, participants searched for a target that was cued by both colour and distractor configural cues, compared with when the target was only predicted by configural information. The results showed that the addition of a colour cue did not increase contextual cueing. In Experiment 2, participants searched for a target that was cued by both colour and distractor configuration compared with when the target was only cued by colour. The results showed that adding a predictive configural cue led to a stronger CC benefit. Experiments 3 and 4 tested the disruptive effects of removing either a learned colour cue or a learned configural cue and whether there was cue competition when colour and configural cues were presented together. Removing the configural cue was more disruptive to CC than removing colour, and configural learning was shown to overshadow the learning of colour cues. The data support a configural dominant account of CC, where configural cues act as the stronger cue in comparison to colour when they are presented together.

  13. Nest-crowdcontrol: Advanced video-based crowd monitoring for large public events

    OpenAIRE

    Monari, Eduardo; Fischer, Yvonne; Anneken, Mathias

    2015-01-01

    Current video surveillance systems still lack of intelligent video and data analysis modules for supporting situation awareness of decision makers. Especially in mass gatherings like large public events, the decision maker would benefit from different views of the area, especially from crowd density estimations. This article describes a multi-camera system called NEST and its application for crowd density analysis. First, the overall system design is presented. Based on this, the crowd densit...

  14. Crowd innovation : The role of uncertainty for opening up the innovation process in the public sector

    OpenAIRE

    Collm, Alexandra; Schedler, Kuno

    2011-01-01

    Innovations are complex processes that can be created internally, caused externally or generated collectively with stakeholders. Integrating crowdsourcing and open innovation and supported by Web 2.0 technologies, a new innovation practice, crowd innovation, has emerged. In this paper, we illustrate empirically the practice of crowd innovation and discuss institutional obstacles, which exist for implementing crowd innovation in the public sector. Referring to the normative mode of publicness ...

  15. Can visco-elastic phase separation, macromolecular crowding and colloidal physics explain nuclear organisation?

    Directory of Open Access Journals (Sweden)

    Iborra Francisco J

    2007-04-01

    Full Text Available Abstract Background The cell nucleus is highly compartmentalized with well-defined domains, it is not well understood how this nuclear order is maintained. Many scientists are fascinated by the different set of structures observed in the nucleus to attribute functions to them. In order to distinguish functional compartments from non-functional aggregates, I believe is important to investigate the biophysical nature of nuclear organisation. Results The various nuclear compartments can be divided broadly as chromatin or protein and/or RNA based, and they have very different dynamic properties. The chromatin compartment displays a slow, constrained diffusional motion. On the other hand, the protein/RNA compartment is very dynamic. Physical systems with dynamical asymmetry go to viscoelastic phase separation. This phase separation phenomenon leads to the formation of a long-lived interaction network of slow components (chromatin scattered within domains rich in fast components (protein/RNA. Moreover, the nucleus is packed with macromolecules in the order of 300 mg/ml. This high concentration of macromolecules produces volume exclusion effects that enhance attractive interactions between macromolecules, known as macromolecular crowding, which favours the formation of compartments. In this paper I hypothesise that nuclear compartmentalization can be explained by viscoelastic phase separation of the dynamically different nuclear components, in combination with macromolecular crowding and the properties of colloidal particles. Conclusion I demonstrate that nuclear structure can satisfy the predictions of this hypothesis. I discuss the functional implications of this phenomenon.

  16. Devaluation, crowding or skill specificity? Exploring the mechanisms behind the lower wages in female professions.

    Science.gov (United States)

    Grönlund, Anne; Magnusson, Charlotta

    2013-07-01

    A conspicuous finding in research on the gender wage gap is that wages are related to the percentage females in an occupation (percent F). Three mechanisms have been suggested to explain this relationship: a devaluation of women's work, a crowding of women into a limited number of occupations, and a female disadvantage in the accumulation of specific human capital. In this analysis, based on data from the Swedish Level of Living Survey of 2000 (n=2915), we distinguish between these mechanisms using measures of devaluation (Treiman's prestige scale), crowding (employee dependence on current employer) and specific human capital (on-the-job training). The results show that all the indicators are related to percent F, but not in a linear fashion, and that the percent F-effect on wages is overstated and misspecified. Female-dominated occupations stand out with lower wages than both male-dominated and gender-integrated occupations and this is not explained by any of our measures. Thus, if the hypotheses on segregation and wages should be sustained, they must be further specified and new measures must be found to prove their worth. Copyright © 2013 Elsevier Inc. All rights reserved.

  17. Modeling crowd behavior based on the discrete-event multiagent approach

    OpenAIRE

    Лановой, Алексей Феликсович; Лановой, Артем Алексеевич

    2014-01-01

    The crowd is a temporary, relatively unorganized group of people, who are in close physical contact with each other. Individual behavior of human outside the crowd is determined by many factors, associated with his intellectual activities, but inside the crowd the man loses his identity and begins to obey more simple laws of behavior.One of approaches to the construction of multi-level model of the crowd using discrete-event multiagent approach was described in the paper.Based on this analysi...

  18. Do External or Internal Technology Spillovers Have a Stronger Influence on Innovation Efficiency in China?

    Directory of Open Access Journals (Sweden)

    Xionghe Qin

    2017-09-01

    Full Text Available In this study, we bridge an important gap in the literature by comparing the extent to which external technology spillovers, as indicated by foreign direct investment (FDI, and internal technology spillovers, as indicated by university-institute-industry cooperation (UIC, influence innovation efficiency in China. We divide the innovation process into two sequential stages, namely the knowledge creation and technology commercialization stages, and employ a network data envelopment analysis approach to measure innovation efficiency at each stage. The spatial analysis of the distribution of knowledge creation efficiency and technology commercialization efficiency reveals the heterogeneity of innovation efficiency at the provincial level. Then, a panel data regression is used to analyze the effect of FDI and UIC on innovation efficiency at each stage, using data from 2009 to 2015 for 30 provinces in China. By comparing FDI with UIC, we find that FDI has a higher coefficient and stronger significance level at the knowledge creation stage, while only industry-institute linkages exhibit a stronger association with innovation efficiency at the technology commercialization stage.

  19. A game-based platform for crowd-sourcing biomedical image diagnosis and standardized remote training and education of diagnosticians

    Science.gov (United States)

    Feng, Steve; Woo, Minjae; Chandramouli, Krithika; Ozcan, Aydogan

    2015-03-01

    Over the past decade, crowd-sourcing complex image analysis tasks to a human crowd has emerged as an alternative to energy-inefficient and difficult-to-implement computational approaches. Following this trend, we have developed a mathematical framework for statistically combining human crowd-sourcing of biomedical image analysis and diagnosis through games. Using a web-based smart game (BioGames), we demonstrated this platform's effectiveness for telediagnosis of malaria from microscopic images of individual red blood cells (RBCs). After public release in early 2012 (http://biogames.ee.ucla.edu), more than 3000 gamers (experts and non-experts) used this BioGames platform to diagnose over 2800 distinct RBC images, marking them as positive (infected) or negative (non-infected). Furthermore, we asked expert diagnosticians to tag the same set of cells with labels of positive, negative, or questionable (insufficient information for a reliable diagnosis) and statistically combined their decisions to generate a gold standard malaria image library. Our framework utilized minimally trained gamers' diagnoses to generate a set of statistical labels with an accuracy that is within 98% of our gold standard image library, demonstrating the "wisdom of the crowd". Using the same image library, we have recently launched a web-based malaria training and educational game allowing diagnosticians to compare their performance with their peers. After diagnosing a set of ~500 cells per game, diagnosticians can compare their quantified scores against a leaderboard and view their misdiagnosed cells. Using this platform, we aim to expand our gold standard library with new RBC images and provide a quantified digital tool for measuring and improving diagnostician training globally.

  20. How update schemes influence crowd simulations

    International Nuclear Information System (INIS)

    Seitz, Michael J; Köster, Gerta

    2014-01-01

    Time discretization is a key modeling aspect of dynamic computer simulations. In current pedestrian motion models based on discrete events, e.g. cellular automata and the Optimal Steps Model, fixed-order sequential updates and shuffle updates are prevalent. We propose to use event-driven updates that process events in the order they occur, and thus better match natural movement. In addition, we present a parallel update with collision detection and resolution for situations where computational speed is crucial. Two simulation studies serve to demonstrate the practical impact of the choice of update scheme. Not only do density-speed relations differ, but there is a statistically significant effect on evacuation times. Fixed-order sequential and random shuffle updates with a short update period come close to event-driven updates. The parallel update scheme overestimates evacuation times. All schemes can be employed for arbitrary simulation models with discrete events, such as car traffic or animal behavior. (paper)

  1. Ministers at IAEA Conference Call for Stronger Nuclear Security

    International Nuclear Information System (INIS)

    2013-01-01

    Full text: Despite substantial progress in strengthening nuclear security in recent years, more needs to be done worldwide to defend against the threat of nuclear terrorism and other malicious acts involving nuclear or radiological material, a Ministerial Declaration at the IAEA's International Conference on Nuclear Security: Enhancing Global Efforts stated today. More than 1 300 participants at the Conference, which is open to all 159 IAEA Member States, will analyse past and current efforts and consider how future challenges can best be met to ensure effective and sustainable nuclear security worldwide. The Conference, which started in Vienna today and ends on Friday, includes representatives from 123 countries and 21 governmental and non-governmental organizations. The Ministerial Declaration, adopted at a plenary session attended by 34 government ministers and other Heads of Delegation including the Conference President, Hungarian Foreign Affairs Minister Janos Martonyi, says they ''remain concerned about the threat of nuclear and radiological terrorism and of other malicious acts or sabotage related to facilities and activities involving nuclear and other radioactive material.'' The Declaration - the first of its kind for nuclear security - notes that all States are responsible for their own nuclear security, but that international cooperation is important in supporting States' efforts to fulfil their responsibilities. It affirms the central role of the IAEA in strengthening nuclear security globally, and leading coordination of international activities in this field. ''We encourage all States to maintain highly effective nuclear security, including physical protection, for all nuclear and other radioactive material, their transport, use and storage and their associated facilities, as well as protecting sensitive information and maintaining the necessary nuclear security systems and measures to assess and manage their nuclear security effectively,'' the

  2. Altered immunity in crowded locust reduced fungal (Metarhizium anisopliae pathogenesis.

    Directory of Open Access Journals (Sweden)

    Yundan Wang

    2013-01-01

    Full Text Available The stress of living conditions, similar to infections, alters animal immunity. High population density is empirically considered to induce prophylactic immunity to reduce the infection risk, which was challenged by a model of low connectivity between infectious and susceptible individuals in crowded animals. The migratory locust, which exhibits polyphenism through gregarious and solitary phases in response to population density and displays different resistance to fungal biopesticide (Metarhizium anisopliae, was used to observe the prophylactic immunity of crowded animals. We applied an RNA-sequencing assay to investigate differential expression in fat body samples of gregarious and solitary locusts before and after infection. Solitary locusts devoted at least twice the number of genes for combating M. anisopliae infection than gregarious locusts. The transcription of immune molecules such as pattern recognition proteins, protease inhibitors, and anti-oxidation proteins, was increased in prophylactic immunity of gregarious locusts. The differentially expressed transcripts reducing gregarious locust susceptibility to M. anisopliae were confirmed at the transcriptional and translational level. Further investigation revealed that locust GNBP3 was susceptible to proteolysis while GNBP1, induced by M. anisopliae infection, resisted proteolysis. Silencing of gnbp3 by RNAi significantly shortened the life span of gregarious locusts but not solitary locusts. By contrast, gnbp1 silencing did not affect the life span of both gregarious and solitary locusts after M. anisopliae infection. Thus, the GNBP3-dependent immune responses were involved in the phenotypic resistance of gregarious locusts to fungal infection, but were redundant in solitary locusts. Our results indicated that gregarious locusts prophylactically activated upstream modulators of immune cascades rather than downstream effectors, preferring to quarantine rather than eliminate pathogens to

  3. Pedestrian Dynamics Feedback Control of Crowd Evacuation

    CERN Document Server

    Kachroo, Pushkin P.E; Al-nasur, Sadeq J; Shende, Apoorva

    2008-01-01

    Effective evacuation of people from closed spaces is an extremely important topic, since it can save real lives in emergency situations that can be brought about by natural and human made disasters. Usually there are static maps posted at various places at buildings that illustrate routes that should be taken during emergencies. However, when disasters happen, some of these routes might not be valid because of structural problems due to the disaster itself and more importantly because of the distribution of congestion of people spread over the area. The average flow of traffic depends on the traffic density. Therefore, if all the people follow the same route, or follow a route without knowing the congestion situation, they can end up being part of the congestion which results in very low flow rate or worse a traffic jam. Hence it becomes extremely important to design evacuations that inform people how fast and in which direction to move based on real-time information obtained about the people distribution usi...

  4. The imperative for stronger vaccine supply and logistics systems.

    Science.gov (United States)

    Zaffran, Michel; Vandelaer, Jos; Kristensen, Debra; Melgaard, Bjørn; Yadav, Prashant; Antwi-Agyei, K O; Lasher, Heidi

    2013-04-18

    With the introduction of new vaccines, developing countries are facing serious challenges in their vaccine supply and logistics systems. Storage capacity bottlenecks occur at national, regional, and district levels and system inefficiencies threaten vaccine access, availability, and quality. As countries adopt newer and more expensive vaccines and attempt to reach people at different ages and in new settings, their logistics systems must be strengthened and optimized. As a first step, national governments, donors, and international agencies have crafted a global vision for 2020 vaccine supply and logistics systems with detailed plans of action to achieve five priority objectives. Vaccine products and packaging are designed to meet the needs of developing countries. Immunization supply systems support efficient and effective vaccine delivery. The environmental impact of energy, materials, and processes used in immunization systems is minimized. Immunization information systems enable better and more timely decision-making. Competent and motivated personnel are empowered to handle immunization supply chain issues. Over the next decade, vaccine supply and logistics systems in nearly all developing countries will require significant investments of time and resources from global and national partners, donors, and governments. These investments are critical if we are to reach more people with current and newer vaccines. Copyright © 2012 Elsevier Ltd. All rights reserved.

  5. Agent-based simulation of reactions in the crowded and structured intracellular environment: Influence of mobility and location of the reactants

    Directory of Open Access Journals (Sweden)

    Lapin Alexei

    2011-05-01

    Full Text Available Abstract Background In this paper we apply a novel agent-based simulation method in order to model intracellular reactions in detail. The simulations are performed within a virtual cytoskeleton enriched with further crowding elements, which allows the analysis of molecular crowding effects on intracellular diffusion and reaction rates. The cytoskeleton network leads to a reduction in the mobility of molecules. Molecules can also unspecifically bind to membranes or the cytoskeleton affecting (i the fraction of unbound molecules in the cytosol and (ii furthermore reducing the mobility. Binding of molecules to intracellular structures or scaffolds can in turn lead to a microcompartmentalization of the cell. Especially the formation of enzyme complexes promoting metabolic channeling, e.g. in glycolysis, depends on the co-localization of the proteins. Results While the co-localization of enzymes leads to faster reaction rates, the reduced mobility decreases the collision rate of reactants, hence reducing the reaction rate, as expected. This effect is most prominent in diffusion limited reactions. Furthermore, anomalous diffusion can occur due to molecular crowding in the cell. In the context of diffusion controlled reactions, anomalous diffusion leads to fractal reaction kinetics. The simulation framework is used to quantify and separate the effects originating from molecular crowding or the reduced mobility of the reactants. We were able to define three factors which describe the effective reaction rate, namely f diff for the diffusion effect, f volume for the crowding, and f access for the reduced accessibility of the molecules. Conclusions Molecule distributions, reaction rate constants and structural parameters can be adjusted separately in the simulation allowing a comprehensive study of individual effects in the context of a realistic cell environment. As such, the present simulation can help to bridge the gap between in vivo and in vitro

  6. Can the online crowd match real expert judgments?

    DEFF Research Database (Denmark)

    Horn, Alexander

    2018-01-01

    , it is important that we better understand its possibilities and limitations. While previous results for low complexity coding tasks are encouraging, we assess whether and under what conditions simple and complex coding tasks can be outsourced to the crowd without sacrificing content validity in return...... for scalability. The simple task is to decide whether a party statement counts as positive reference to a concept – in our case equality. The complex task is to distinguish between five concepts of equality. To account for the crowdcoder’s contextual knowledge, we vary the IP restrictions. The basis for our...

  7. Learning Supervised Topic Models for Classification and Regression from Crowds

    DEFF Research Database (Denmark)

    Rodrigues, Filipe; Lourenco, Mariana; Ribeiro, Bernardete

    2017-01-01

    problems, which account for the heterogeneity and biases among different annotators that are encountered in practice when learning from crowds. We develop an efficient stochastic variational inference algorithm that is able to scale to very large datasets, and we empirically demonstrate the advantages...... annotation tasks, prone to ambiguity and noise, often with high volumes of documents, deem learning under a single-annotator assumption unrealistic or unpractical for most real-world applications. In this article, we propose two supervised topic models, one for classification and another for regression...

  8. Some Numerical Aspects on Crowd Motion - The Hughes Model

    KAUST Repository

    Gomes, Diogo A.

    2016-01-06

    Here, we study a crowd model proposed by R. Hughes in [5] and we describe a numerical approach to solve it. This model comprises a Fokker-Planck equation coupled with an Eikonal equation with Dirichlet or Neumann data. First, we establish a priori estimates for the solution. Second, we study radial solutions and identify a shock formation mechanism. Third, we illustrate the existence of congestion, the breakdown of the model, and the trend to the equilibrium. Finally, we propose a new numerical method and consider two numerical examples.

  9. CrowdWater - Can people observe what models need?

    Science.gov (United States)

    van Meerveld, I. H. J.; Seibert, J.; Vis, M.; Etter, S.; Strobl, B.

    2017-12-01

    CrowdWater (www.crowdwater.ch) is a citizen science project that explores the usefulness of crowd-sourced data for hydrological model calibration and prediction. Hydrological models are usually calibrated based on observed streamflow data but it is likely easier for people to estimate relative stream water levels, such as the water level above or below a rock, than streamflow. Relative stream water levels may, therefore, be a more suitable variable for citizen science projects than streamflow. In order to test this assumption, we held surveys near seven different sized rivers in Switzerland and asked more than 450 volunteers to estimate the water level class based on a picture with a virtual staff gauge. The results show that people can generally estimate the relative water level well, although there were also a few outliers. We also asked the volunteers to estimate streamflow based on the stick method. The median estimated streamflow was close to the observed streamflow but the spread in the streamflow estimates was large and there were very large outliers, suggesting that crowd-based streamflow data is highly uncertain. In order to determine the potential value of water level class data for model calibration, we converted streamflow time series for 100 catchments in the US to stream level class time series and used these to calibrate the HBV model. The model was then validated using the streamflow data. The results of this modeling exercise show that stream level class data are useful for constraining a simple runoff model. Time series of only two stream level classes, e.g. above or below a rock in the stream, were already informative, especially when the class boundary was chosen towards the highest stream levels. There was hardly any improvement in model performance when more than five water level classes were used. This suggests that if crowd-sourced stream level observations are available for otherwise ungauged catchments, these data can be used to constrain

  10. The new economy is stronger than you think.

    Science.gov (United States)

    Sahlman, W A

    1999-01-01

    Many policy makers at the Fed contend that the new economy is a fragile bubble--and that with the "irrational exuberance" of the capital markets, the sky is going to fall on the U.S. economy. That couldn't be further from the truth, according to William Sahlman. As long as the government doesn't interfere, he argues, the economy is sturdy, resilient, and raring to grow. The new economy is strong for several reasons. First, it is based on a business model that works. Any business system that relentlessly drives out inefficiency, forces intelligent business-process reengineering, and gives customers more of what they want will be sustainable. Second, it is built on America's admiration for entrepreneurs and its tolerance for failure, not to mention its easy access to capital. Third, the new economy is attracting the best and brightest minds in the country. And finally, says Sahlman, the new economy is strong because it is spreading. It may be primarily an American phenomenon now, but in a few short years it will start to show its effects everywhere, making the whole world a more productive place. Still, Sahlman believes, the road ahead is not without potholes and sharp curves. But that is what the new economy is all about, he maintains--companies attacking the status quo and entrenched players, companies experimenting to find new technologies that improve or replace earlier ones. Such activity presents no cause for alarm. The economic, social, and cultural factors undergirding the new economy are rock solid. It's simply a matter of letting them stand.

  11. Conflict management by hamadryas baboons (Papio hamadryas hamadryas) during crowding: a tension-reduction strategy.

    Science.gov (United States)

    Judge, P G; Griffaton, N S; Fincke, A M

    2006-10-01

    Primates change a variety of behavioral responses during short-term exposure to crowding. Under crowded conditions, rates of aggression, submissive behavior, and affiliative behavior may increase or decrease. Different patterns of change among these three categories of response have been interpreted as various coping "strategies" for managing the increased risk of conflict under crowded conditions. Grooming is of particular interest because this behavior is known to have a calming influence on the recipient and could be used to manage conflict under tense situations. A captive group of nine hamadryas baboons (Papio hamadryas hamadryas) composed of two harems was observed under short-term crowding to determine whether this species adopts conflict-management strategies similar to those described in other primates. The aggression, submission, affiliation, and displacement activities of the six adults in the group (two males and four females) were recorded, and behaviors in their small indoor quarters was compared with baseline behaviors in the outdoor section of their enclosure, which had over 10 times more space. Repeated-measures analysis of variance (ANOVA) was used to compare behavioral rates during crowding with baseline rates recorded immediately after crowding and during matched controls collected at the same time of day as the crowding sessions. Aggression and submission rates did not change significantly across conditions. Huddling together and proximity increased during crowding, and females increased grooming of their harem male during crowding. Displacement activities (e.g., pacing and self-grooming) increased during crowding, but scratching, an indicator of anxiety in primates, did not. The pattern of behavior exhibited by this group conforms to an active "tension-reduction" strategy in which animals successfully reduce the higher risk of aggression during crowding.

  12. Electromyographic characteristic of orbicularis oris in patients with dental crowding in permanent occlusion.

    Science.gov (United States)

    Dmytrenko, Maryna I; Kuroiedowa, Vira D

    2016-01-01

    electromyographic indices were developed for complex analysis of functional condition of orbicularis oris. to study electromyographic indices of orbicularis oris in patients with dental crowding in permanent occlusion. thirty four patients with malocclusion and a severe degree of severity of dental crowding (15 males, 19 females, aged 16-29 years) who underwent orthodontic examination. The treatment group was divided into three: Group Ia comprised 11 subjects with mandibular crowding (mean age 19,27 ± 1,08 years); group Ib, 10 patients with maxillary dental crowding (mean age 20,10 ± 1,60 years) and group Ic, 13 subjects with both maxillary and mandibular crowding (mean age 20,15 ± 1,45 years). The control group consisted of 10 patients with malocclusions but without dental crowding (mean age 20,70 ± 1,32 years). The findings were compared with similar indices in subjects with normal occlusion (mean age 21,3 ± 1,25 years). The index of orbicularis oris activity (ACTIV,%) was determined for each patient. A Student's t-test was used to analyze statistical difference between different groups. patients having crowding of maxillary teeth showed greater activity of muscles of the upper lip during maximum voluntary clenching (АCTІV= -0,99±7,44%). Activity of the muscles of the lower lip in patients with crowding of mandibular teeth (АСTІV=20,52±4,22%) and crowding of maxillary and mandibular teeth (АСTІV=17,93±4,33%) is prevailing. аctivity of the orbicularis oris in patients with malocclusion, complicated by dental crowding depend on clinical localization of crowding.

  13. Vehicular Visible Light Networks for Urban Mobile Crowd Sensing

    Directory of Open Access Journals (Sweden)

    Barbara M. Masini

    2018-04-01

    Full Text Available Crowd sensing is a powerful tool to map and predict interests and events. In the future, it could be boosted by an increasing number of connected vehicles sharing information and intentions. This will be made available by on board wireless connected devices able to continuously communicate with other vehicles and with the environment. Among the enabling technologies, visible light communication (VLC represents a low cost solution in the short term. In spite of the fact that vehicular communications cannot rely on the sole VLC due to the limitation provided by the light which allows communications in visibility only, VLC can however be considered to complement other wireless communication technologies which could be overloaded in dense scenarios. In this paper we evaluate the performance of VLC connected vehicles when urban crowd sensing is addressed and we compare the performance of sole vehicular visible light networks with that of VLC as a complementary technology of IEEE 802.11p. Results, obtained through a realistic simulation tool taking into account both the roadmap constraints and the technologies protocols, help to understand when VLC provides the major improvement in terms of delivered data varying the number and position of RSUs and the FOV of the receiver.

  14. LESSONS LEARNED ABOUT PUBLIC HEALTH FROM ONLINE CROWD SURVEILLANCE.

    Science.gov (United States)

    Hill, Shawndra; Merchant, Raina; Ungar, Lyle

    2013-09-10

    The Internet has forever changed the way people access information and make decisions about their healthcare needs. Patients now share information about their health at unprecedented rates on social networking sites such as Twitter and Facebook and on medical discussion boards. In addition to explicitly shared information about health conditions through posts, patients reveal data on their inner fears and desires about health when searching for health-related keywords on search engines. Data are also generated by the use of mobile phone applications that track users' health behaviors (e.g., eating and exercise habits) as well as give medical advice. The data generated through these applications are mined and repackaged by surveillance systems developed by academics, companies, and governments alike to provide insight to patients and healthcare providers for medical decisions. Until recently, most Internet research in public health has been surveillance focused or monitoring health behaviors. Only recently have researchers used and interacted with the crowd to ask questions and collect health-related data. In the future, we expect to move from this surveillance focus to the "ideal" of Internet-based patient-level interventions where healthcare providers help patients change their health behaviors. In this article, we highlight the results of our prior research on crowd surveillance and make suggestions for the future.

  15. Track-based event recognition in a realistic crowded environment

    Science.gov (United States)

    van Huis, Jasper R.; Bouma, Henri; Baan, Jan; Burghouts, Gertjan J.; Eendebak, Pieter T.; den Hollander, Richard J. M.; Dijk, Judith; van Rest, Jeroen H.

    2014-10-01

    Automatic detection of abnormal behavior in CCTV cameras is important to improve the security in crowded environments, such as shopping malls, airports and railway stations. This behavior can be characterized at different time scales, e.g., by small-scale subtle and obvious actions or by large-scale walking patterns and interactions between people. For example, pickpocketing can be recognized by the actual snatch (small scale), when he follows the victim, or when he interacts with an accomplice before and after the incident (longer time scale). This paper focusses on event recognition by detecting large-scale track-based patterns. Our event recognition method consists of several steps: pedestrian detection, object tracking, track-based feature computation and rule-based event classification. In the experiment, we focused on single track actions (walk, run, loiter, stop, turn) and track interactions (pass, meet, merge, split). The experiment includes a controlled setup, where 10 actors perform these actions. The method is also applied to all tracks that are generated in a crowded shopping mall in a selected time frame. The results show that most of the actions can be detected reliably (on average 90%) at a low false positive rate (1.1%), and that the interactions obtain lower detection rates (70% at 0.3% FP). This method may become one of the components that assists operators to find threatening behavior and enrich the selection of videos that are to be observed.

  16. Network dynamics of social influence in the wisdom of crowds.

    Science.gov (United States)

    Becker, Joshua; Brackbill, Devon; Centola, Damon

    2017-06-27

    A longstanding problem in the social, biological, and computational sciences is to determine how groups of distributed individuals can form intelligent collective judgments. Since Galton's discovery of the "wisdom of crowds" [Galton F (1907) Nature 75:450-451], theories of collective intelligence have suggested that the accuracy of group judgments requires individuals to be either independent, with uncorrelated beliefs, or diverse, with negatively correlated beliefs [Page S (2008) The Difference: How the Power of Diversity Creates Better Groups, Firms, Schools, and Societies ]. Previous experimental studies have supported this view by arguing that social influence undermines the wisdom of crowds. These results showed that individuals' estimates became more similar when subjects observed each other's beliefs, thereby reducing diversity without a corresponding increase in group accuracy [Lorenz J, Rauhut H, Schweitzer F, Helbing D (2011) Proc Natl Acad Sci USA 108:9020-9025]. By contrast, we show general network conditions under which social influence improves the accuracy of group estimates, even as individual beliefs become more similar. We present theoretical predictions and experimental results showing that, in decentralized communication networks, group estimates become reliably more accurate as a result of information exchange. We further show that the dynamics of group accuracy change with network structure. In centralized networks, where the influence of central individuals dominates the collective estimation process, group estimates become more likely to increase in error.

  17. People detection in crowded scenes using active contour models

    Science.gov (United States)

    Sidla, Oliver

    2009-01-01

    The detection of pedestrians in real-world scenes is a daunting task, especially in crowded situations. Our experience over the last years has shown that active shape models (ASM) can contribute significantly to a robust pedestrian detection system. The paper starts with an overview of shape model approaches, it then explains our approach which builds on top of Eigenshape models which have been trained using real-world data. These models are placed over candidate regions and matched to image gradients using a scoring function which integrates i) point distribution, ii) local gradient orientations iii) local image gradient strengths. A matching and shape model update process is iteratively applied in order to fit the flexible models to the local image content. The weights of the scoring function have a significant impact on the ASM performance. We analyze different settings of scoring weights for gradient magnitude, relative orientation differences, distance between model and gradient in an experiment which uses real-world data. Although for only one pedestrian model in an image computation time is low, the number of necessary processing cycles which is needed to track many people in crowded scenes can become the bottleneck in a real-time application. We describe the measures which have been taken in order to improve the speed of the ASM implementation and make it real-time capable.

  18. Crowd-sourced assessment of surgical skills in cricothyrotomy procedure.

    Science.gov (United States)

    Aghdasi, Nava; Bly, Randall; White, Lee W; Hannaford, Blake; Moe, Kris; Lendvay, Thomas S

    2015-06-15

    Objective assessment of surgical skills is resource intensive and requires valuable time of expert surgeons. The goal of this study was to assess the ability of a large group of laypersons using a crowd-sourcing tool to grade a surgical procedure (cricothyrotomy) performed on a simulator. The grading included an assessment of the entire procedure by completing an objective assessment of technical skills survey. Two groups of graders were recruited as follows: (1) Amazon Mechanical Turk users and (2) three expert surgeons from University of Washington Department of Otolaryngology. Graders were presented with a video of participants performing the procedure on the simulator and were asked to grade the video using the objective assessment of technical skills questions. Mechanical Turk users were paid $0.50 for each completed survey. It took 10 h to obtain all responses from 30 Mechanical Turk users for 26 training participants (26 videos/tasks), whereas it took 60 d for three expert surgeons to complete the same 26 tasks. The assessment of surgical performance by a group (n = 30) of laypersons matched the assessment by a group (n = 3) of expert surgeons with a good level of agreement determined by Cronbach alpha coefficient = 0.83. We found crowd sourcing was an efficient, accurate, and inexpensive method for skills assessment with a good level of agreement to experts' grading. Copyright © 2015 Elsevier Inc. All rights reserved.

  19. Deciphering the crowd: modeling and identification of pedestrian group motion.

    Science.gov (United States)

    Yücel, Zeynep; Zanlungo, Francesco; Ikeda, Tetsushi; Miyashita, Takahiro; Hagita, Norihiro

    2013-01-14

    Associating attributes to pedestrians in a crowd is relevant for various areas like surveillance, customer profiling and service providing. The attributes of interest greatly depend on the application domain and might involve such social relations as friends or family as well as the hierarchy of the group including the leader or subordinates. Nevertheless, the complex social setting inherently complicates this task. We attack this problem by exploiting the small group structures in the crowd. The relations among individuals and their peers within a social group are reliable indicators of social attributes. To that end, this paper identifies social groups based on explicit motion models integrated through a hypothesis testing scheme. We develop two models relating positional and directional relations. A pair of pedestrians is identified as belonging to the same group or not by utilizing the two models in parallel, which defines a compound hypothesis testing scheme. By testing the proposed approach on three datasets with different environmental properties and group characteristics, it is demonstrated that we achieve an identification accuracy of 87% to 99%. The contribution of this study lies in its definition of positional and directional relation models, its description of compound evaluations, and the resolution of ambiguities with our proposed uncertainty measure based on the local and global indicators of group relation.

  20. Deciphering the Crowd: Modeling and Identification of Pedestrian Group Motion

    Directory of Open Access Journals (Sweden)

    Norihiro Hagita

    2013-01-01

    Full Text Available Associating attributes to pedestrians in a crowd is relevant for various areas like surveillance, customer profiling and service providing. The attributes of interest greatly depend on the application domain and might involve such social relations as friends or family as well as the hierarchy of the group including the leader or subordinates. Nevertheless, the complex social setting inherently complicates this task. We attack this problem by exploiting the small group structures in the crowd. The relations among individuals and their peers within a social group are reliable indicators of social attributes. To that end, this paper identifies social groups based on explicit motion models integrated through a hypothesis testing scheme. We develop two models relating positional and directional relations. A pair of pedestrians is identified as belonging to the same group or not by utilizing the two models in parallel, which defines a compound hypothesis testing scheme. By testing the proposed approach on three datasets with different environmental properties and group characteristics, it is demonstrated that we achieve an identification accuracy of 87% to 99%. The contribution of this study lies in its definition of positional and directional relation models, its description of compound evaluations, and the resolution of ambiguities with our proposed uncertainty measure based on the local and global indicators of group relation.

  1. Vehicular Visible Light Networks for Urban Mobile Crowd Sensing.

    Science.gov (United States)

    Masini, Barbara M; Bazzi, Alessandro; Zanella, Alberto

    2018-04-12

    Crowd sensing is a powerful tool to map and predict interests and events. In the future, it could be boosted by an increasing number of connected vehicles sharing information and intentions. This will be made available by on board wireless connected devices able to continuously communicate with other vehicles and with the environment. Among the enabling technologies, visible light communication (VLC) represents a low cost solution in the short term. In spite of the fact that vehicular communications cannot rely on the sole VLC due to the limitation provided by the light which allows communications in visibility only, VLC can however be considered to complement other wireless communication technologies which could be overloaded in dense scenarios. In this paper we evaluate the performance of VLC connected vehicles when urban crowd sensing is addressed and we compare the performance of sole vehicular visible light networks with that of VLC as a complementary technology of IEEE 802.11p. Results, obtained through a realistic simulation tool taking into account both the roadmap constraints and the technologies protocols, help to understand when VLC provides the major improvement in terms of delivered data varying the number and position of RSUs and the FOV of the receiver.

  2. Planet Candidate Validation in K2 Crowded Fields

    Science.gov (United States)

    Rampalli, Rayna; Vanderburg, Andrew; Latham, David; Quinn, Samuel

    2018-01-01

    In just three years, the K2 mission has yielded some remarkable outcomes with the discovery of over 100 confirmed planets and 500 reported planet candidates to be validated. One challenge with this mission is the search for planets located in star-crowded regions. Campaign 13 is one such example, located towards the galactic plane in the constellation of Taurus. We subject the potential planetary candidates to a validation process involving spectroscopy to derive certain stellar parameters. Seeing-limited on/off imaging follow-up is also utilized in order to rule out false positives due to nearby eclipsing binaries. Using Markov chain Monte Carlo analysis, the best-fit parameters for each candidate are generated. These will be suitable for finding a candidate’s false positive probability through methods including feeding such parameters into the Validation of Exoplanet Signals using a Probabilistic Algorithm (VESPA). These techniques and results serve as important tools for conducting candidate validation and follow-up observations for space-based missions such as the upcoming TESS mission since TESS’s large camera pixels resemble K2’s star-crowded fields.

  3. Crowd-Sourcing (Semantically) Structured Multilingual Educational Content (CoSMEC)

    Science.gov (United States)

    Tarasowa, Darya; Auer, Sören; Khalili, Ali; Unbehauen, Jörg

    2014-01-01

    The support of multilingual content becomes crucial for educational platforms due to the benefits it offers. In this paper we propose a concept that allows content authors to use the power of the crowd to create (semantically) structured multilingual educational content out of their material. To enable the collaboration of the crowd, we expand our…

  4. Crowding Valuation in Urban Tram and Bus Transportation based on Smart Card Data

    NARCIS (Netherlands)

    Yap, M.D.; Cats, O.; Yu, S; van Arem, B.

    2017-01-01

    Crowding in public transport can be of major influence on passengers’ travel experience and therefore affect route and mode choice. Therefore, it is important to understand how crowding in urban public transport is perceived by passengers. The availability of individual smart card transactions

  5. On Streams and Incentives : A Synthesis of Individual and Collective Crowd Motion

    NARCIS (Netherlands)

    van Goethem, Arthur; Jaklin, Norman; Cook IV, Atlas; Geraerts, Roland|info:eu-repo/dai/nl/304830291

    2015-01-01

    We present a novel crowd simulation model that combines the advantages of agent-based and ow-based paradigms while only relying on local information. Our model can handle arbitrary and dynamically changing crowd densities, and it enables agents to gradually interpolate between individual and

  6. Detection of High-Density Crowds in Aerial Images Using Texture Classification

    Directory of Open Access Journals (Sweden)

    Oliver Meynberg

    2016-06-01

    Full Text Available Automatic crowd detection in aerial images is certainly a useful source of information to prevent crowd disasters in large complex scenarios of mass events. A number of publications employ regression-based methods for crowd counting and crowd density estimation. However, these methods work only when a correct manual count is available to serve as a reference. Therefore, it is the objective of this paper to detect high-density crowds in aerial images, where counting– or regression–based approaches would fail. We compare two texture–classification methodologies on a dataset of aerial image patches which are grouped into ranges of different crowd density. These methodologies are: (1 a Bag–of–words (BoW model with two alternative local features encoded as Improved Fisher Vectors and (2 features based on a Gabor filter bank. Our results show that a classifier using either BoW or Gabor features can detect crowded image regions with 97% classification accuracy. In our tests of four classes of different crowd-density ranges, BoW–based features have a 5%–12% better accuracy than Gabor.

  7. Revisiting Gustave Le Bon’s crowd theory in light of present-day critique

    DEFF Research Database (Denmark)

    Laursen, Rasmus Beedholm; Møller, Verner

    2017-01-01

    understanding of crowd or mass behaviour that proves Le Bon’s crowd theory wrong. However, in this paper, we challenge this perception not only by questioning Drury, Reicher and Stott’s interpretation of Le Bon, but also suggesting that the dialogue strategy that is based upon the ESIM, in fact, validates Le...

  8. Towards Believable Crowds : A Generic Multi-Level Framework for Agent Navigation

    NARCIS (Netherlands)

    van Toll, Wouter; Jaklin, Norman; Geraerts, Roland

    2015-01-01

    Path planning and crowd simulation are important computational tasks in computer games and applications of high social relevance, such as crowd management and safety training. Virtual characters (agents) need to autonomously find a path from their current position to a designated goal position. This

  9. Kinetic models for crowd dynamics. Comment on "Human behaviours in evacuation crowd dynamics: From modelling to "big data" toward crisis management" by N. Bellomo et al.

    Science.gov (United States)

    Banasiak, J.

    2016-09-01

    There has been a hierarchy of models of crowd behaviour. One can consider the crowd at the so called microscopic level, as a collection of individuals, and derive its description in the form of a (large) system of ordinary differential equations describing the position and velocity of each individual, in parallel to the Newton's description of matter, see e.g. [10]. Another possibility is to describe crowd, in analogy to fluid dynamics, by providing its density and velocity at a given point, see e.g. [11,12]. At the same time, it is recognized that crowd is 'living, social' system that is prone to exhibit rare, not easily predictable, behaviour in response to stress induced by the perception of danger, or of the action of specific agents, see e.g. [1,2]. This high probability of the occurrence of events that are far from average, makes the crowd behaviour similar to the processes with fat-tailed distribution of events. Such unlikely events have been metaphorically termed black swans in [14], or Lévy flights in [13]. While microscopic and macroscopic models can capture many features of crowd dynamics, including obstacles, see [3,8], such models are described by differential equations that inherently are local in space. At the same time, black swan events are often caused by non-local interactions such as self-organization, learning or adherence to some averaged group behaviour. It is known that such interactions are well described by mean field models best represented by integro-differential equations, such as the Boltzmann equation of the rarefied gas theory. This has made plausible to introduce crowd models at the intermediate, (meso) scale by describing the crowd by the one particle distribution function that gives the density of individuals at any particular state; that is, at a given point in the domain and moving with a specific velocity.

  10. The effect of mobile cellular network performance and contextual factors on smartphone users’ satisfaction : A study on QoE evaluation for YouTube video streaming via CrowdSourcing

    OpenAIRE

    Zhen, Zuguang

    2015-01-01

    Mobile data traffic will continue to show rapid growth in the coming years; however the data revenue is not rising fast enough to ensure the operators’ profitability. Therefore, mobile operators must seek new approaches to find out what service does the customers need and what quality makes the customers satisfied in order to keep their increasingly sophisticated customers satisfied at the same time minimizing their revenue gap. This paper investigate the effect of mobile cellular network per...

  11. Cross-cultural differences in tolerance for crowding: fact or fiction?

    Science.gov (United States)

    Evans, G W; Lepore, S J; Allen, K M

    2000-08-01

    It is widely believed that cultures vary in their tolerance for crowding. There is, however, little evidence to substantiate this belief, coupled with serious shortcomings in the extant literature. Tolerance for crowding has been confused with cultural differences in personal space preferences along with perceived crowding. Furthermore, the few studies that have examined cultural variability in reactions to crowding have compared subgroup correlations, which is not equivalent to a statistical interaction. Although the authors found a statistical interaction indicating that Asian Americans and Latin Americans differ in the way they perceive crowding in comparison to their fellow Anglo-American and African American citizens, all four ethnic groups suffer similar, negative psychological distress sequelae of high-density housing. These results hold independently of household income.

  12. Crowding in Visual Working Memory Reveals Its Spatial Resolution and the Nature of Its Representations.

    Science.gov (United States)

    Tamber-Rosenau, Benjamin J; Fintzi, Anat R; Marois, René

    2015-09-01

    Spatial resolution fundamentally limits any image representation. Although this limit has been extensively investigated for perceptual representations by assessing how neighboring flankers degrade the perception of a peripheral target with visual crowding, the corresponding limit for representations held in visual working memory (VWM) is unknown. In the present study, we evoked crowding in VWM and directly compared resolution in VWM and perception. Remarkably, the spatial resolution of VWM proved to be no worse than that of perception. However, mixture modeling of errors caused by crowding revealed the qualitatively distinct nature of these representations. Perceptual crowding errors arose from both increased imprecision in target representations and substitution of flankers for targets. By contrast, VWM crowding errors arose exclusively from substitutions, which suggests that VWM transforms analog perceptual representations into discrete items. Thus, although perception and VWM share a common resolution limit, exceeding this limit reveals distinct mechanisms for perceiving images and holding them in mind. © The Author(s) 2015.

  13. The challenges of launching a crowd based platform : A single case study of a Swedish service provider

    OpenAIRE

    Eliasson, Robert; Viklund, Tobias

    2013-01-01

    Using the concept of open innovation companies have started to look beyond their own borders using the crowd as a source for labour, knowledge and innovation. During the last few years the phenomena of crowdsourcing and crowdfunding have become increasingly popular as sources of competitive advantage through the crowd. While several studies have examined crowd based platforms focusing on the users, little attention has been brought to the companies starting these crowd based services. This st...

  14. Stronger activation of SREBP-1a by nucleus-localized HBx

    International Nuclear Information System (INIS)

    Wu, Qi; Qiao, Ling; Yang, Jian; Zhou, Yan; Liu, Qiang

    2015-01-01

    We previously showed that hepatitis B virus (HBV) X protein activates the sterol regulatory element-binding protein-1a (SREBP-1a). Here we examined the role of nuclear localization of HBx in this process. In comparison to the wild-type and cytoplasmic HBx, nuclear HBx had stronger effects on SREBP-1a and fatty acid synthase transcription activation, intracellular lipid accumulation and cell proliferation. Furthermore, nuclear HBx could activate HBV enhancer I/X promoter and was more effective on up-regulating HBV mRNA level in the context of HBV replication than the wild-type HBx, while the cytoplasmic HBx had no effect. Our results demonstrate the functional significance of the nucleus-localized HBx in regulating host lipogenic pathway and HBV replication. - Highlights: • Nuclear HBx is more effective on activating SREBP-1a and FASN transcription. • Nuclear HBx is more effective on enhancing intracellular lipid accumulation. • Nuclear HBx is more effective on enhancing cell proliferation. • Nuclear HBx up-regulates HBV enhancer I/X promoter activity. • Nuclear HBx increases HBV mRNA level in the context of HBV replication

  15. Stronger activation of SREBP-1a by nucleus-localized HBx

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Qi [VIDO-InterVac, Veterinary Microbiology, University of Saskatchewan, Saskatoon (Canada); Qiao, Ling [VIDO-InterVac, University of Saskatchewan, Saskatoon, Saskatchewan (Canada); Yang, Jian [Drug Discovery Group, University of Saskatchewan, Saskatoon, Saskatchewan (Canada); Zhou, Yan [VIDO-InterVac, Veterinary Microbiology, Vaccinology and Immunotherapeutics, University of Saskatchewan, Saskatoon, Saskatchewan (Canada); Liu, Qiang, E-mail: qiang.liu@usask.ca [VIDO-InterVac, Veterinary Microbiology, Vaccinology and Immunotherapeutics, University of Saskatchewan, Saskatoon, Saskatchewan (Canada)

    2015-05-08

    We previously showed that hepatitis B virus (HBV) X protein activates the sterol regulatory element-binding protein-1a (SREBP-1a). Here we examined the role of nuclear localization of HBx in this process. In comparison to the wild-type and cytoplasmic HBx, nuclear HBx had stronger effects on SREBP-1a and fatty acid synthase transcription activation, intracellular lipid accumulation and cell proliferation. Furthermore, nuclear HBx could activate HBV enhancer I/X promoter and was more effective on up-regulating HBV mRNA level in the context of HBV replication than the wild-type HBx, while the cytoplasmic HBx had no effect. Our results demonstrate the functional significance of the nucleus-localized HBx in regulating host lipogenic pathway and HBV replication. - Highlights: • Nuclear HBx is more effective on activating SREBP-1a and FASN transcription. • Nuclear HBx is more effective on enhancing intracellular lipid accumulation. • Nuclear HBx is more effective on enhancing cell proliferation. • Nuclear HBx up-regulates HBV enhancer I/X promoter activity. • Nuclear HBx increases HBV mRNA level in the context of HBV replication.

  16. Rigidity of a spherical capsule switches the localization of encapsulated particles between inner and peripheral regions under crowding condition: Simple model on cellular architecture

    Energy Technology Data Exchange (ETDEWEB)

    Shew, Chwen-Yang, E-mail: chwenyang.shew@csi.cuny.edu; Kondo, Kenta [Department of Chemistry, College of Staten Island, City University of New York, 2800 Victory Boulevard, Staten Island, New York 10314 (United States); Yoshikawa, Kenichi [Faculty of Life and Medical Sciences, Doshisha University, Kyoto 610-0394 (Japan)

    2014-01-14

    We have investigated the inhomogeneous interior of confined spherical cavities as capsules containing encapsulated binary hard sphere mixtures for different compositions and cavity wall rigidity. Such a greatly simplified model manifests the effects of macromolecular crowding arising from excluded volume interactions in a tiny cell or a cellular nucleus. By fixing the number of large particles, the level of crowding is adjusted by changing the amount of small hard spheres in the cavity. For a rigid cavity, large spheres tend to pack in liquid-like order apart from the surface to the center of the cavity as the crowding level is increased. Whereas, for a soft cavity, larger spheres tend to blend with small spheres in the peripheral region at near the boundary of the cavity, and are susceptible to be depleted from the interior of the cavity as the cavity becomes more crowded. These results may help future elucidation of the thermodynamic pathways to stabilize the inhomogeneous structure of mixtures confined in cavities, such as the derepression of genome materials around the interior rim of the nucleus in a cancerous cell.

  17. Rigidity of a spherical capsule switches the localization of encapsulated particles between inner and peripheral regions under crowding condition: Simple model on cellular architecture

    International Nuclear Information System (INIS)

    Shew, Chwen-Yang; Kondo, Kenta; Yoshikawa, Kenichi

    2014-01-01

    We have investigated the inhomogeneous interior of confined spherical cavities as capsules containing encapsulated binary hard sphere mixtures for different compositions and cavity wall rigidity. Such a greatly simplified model manifests the effects of macromolecular crowding arising from excluded volume interactions in a tiny cell or a cellular nucleus. By fixing the number of large particles, the level of crowding is adjusted by changing the amount of small hard spheres in the cavity. For a rigid cavity, large spheres tend to pack in liquid-like order apart from the surface to the center of the cavity as the crowding level is increased. Whereas, for a soft cavity, larger spheres tend to blend with small spheres in the peripheral region at near the boundary of the cavity, and are susceptible to be depleted from the interior of the cavity as the cavity becomes more crowded. These results may help future elucidation of the thermodynamic pathways to stabilize the inhomogeneous structure of mixtures confined in cavities, such as the derepression of genome materials around the interior rim of the nucleus in a cancerous cell

  18. Ultrafast spectroscopy on DNA-cleavage by endonuclease in molecular crowding.

    Science.gov (United States)

    Singh, Priya; Choudhury, Susobhan; Dutta, Shreyasi; Adhikari, Aniruddha; Bhattacharya, Siddhartha; Pal, Debasish; Pal, Samir Kumar

    2017-10-01

    The jam-packed intracellular environments differ the activity of a biological macromolecule from that in laboratory environments (in vitro) through a number of mechanisms called molecular crowding related to structure, function and dynamics of the macromolecule. Here, we have explored the structure, function and dynamics of a model enzyme protein DNase I in molecular crowing of polyethylene glycol (PEG; MW 3350). We have used steady state and picosecond resolved dynamics of a well-known intercalator ethidium bromide (EB) in a 20-mer double-stranded DNA (dsDNA) to monitor the DNA-cleavage by the enzyme in absence and presence PEG. We have also labelled the enzyme by a well-known fluorescent probe 8-anilino-1-naphthalenesulfonic acid ammonium salt (ANS) to study the molecular mechanism of the protein-DNA association through exited state relaxation of the probe in absence (dictated by polarity) and presence of EB in the DNA (dictated by Förster resonance energy transfer (FRET)). The overall and local structures of the protein in presence of PEG have been followed by circular dichroism and time resolved polarization gated spectroscopy respectively. The enhanced dynamical flexibility of protein in presence of PEG as revealed from excited state lifetime and polarization gated anisotropy of ANS has been correlated with the stronger DNA-binding for the higher nuclease activity. We have also used conventional experimental strategy of agarose gel electrophoresis to monitor DNA-cleavage and found consistent results of enhanced nuclease activities both on synthetic 20-mer oligonucleotide and long genomic DNA from calf thymus. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. Idea Screening in Engineering Design Using Employee-Driven Wisdom of the Crowds

    DEFF Research Database (Denmark)

    Onarheim, Balder; Christensen, Bo Thomas

    /ownership of ideas. The study shows that the crowd wisdom of employees significantly correlates with the preferences of the marketing team: overall, in top 12 selected ideas and in choice of idea categories. This match increases when including only the ratings of the most experienced employees. The experienced......The paper investigates the question of screening ideas in the ‘fuzzy front end’ of engineering design, examining the validity of employee voting schemes and related biases. After an employee-driven innovation project at {Company Name removed for review}, 99 ideas were to be screened for further...... development. Based on the concept of ‘wisdom of the crowds’, all ideas were individually rated by a broad selection of employees, and their choices of ideas and idea categories compared to those of a small team of senior marketers. The study also tested for two biases: visual complexity and endowment effect...

  20. Electrostatics promotes molecular crowding and selects the aggregation pathway in fibril-forming protein solutions

    International Nuclear Information System (INIS)

    Raccosta, S.; Martorana, V.; Manno, M.; Blanco, M.; Roberts, C.J.

    2016-01-01

    The role of intermolecular interaction in fibril-forming protein solutions and its relation with molecular conformation are crucial aspects for the control and inhibition of amyloid structures. Here, we study the fibril formation and the protein-protein interactions for two proteins at acidic ph, lysozyme and α-chymotrypsinogen. By using light scattering experiments and the Kirkwood-Buff integral approach, we show how concentration fluctuations are damped even at moderate protein concentrations by the dominant long-ranged electrostatic repulsion, which determines an effective crowded environment. In denaturing conditions, electrostatic repulsion keeps the monomeric solution in a thermodynamically metastable state, which is escaped through kinetically populated conformational sub-states. This explains how electrostatics acts as a gatekeeper in selecting a specific aggregation pathway.

  1. Crowding, Entropic Forces, and Confinement: Crucial Factors for Structures and Functions in the Cell Nucleus.

    Science.gov (United States)

    Hancock, R

    2018-04-01

    The view of the cell nucleus as a crowded system of colloid particles and that chromosomes are giant self-avoiding polymers is stimulating rapid advances in our understanding of its structure and activities, thanks to concepts and experimental methods from colloid, polymer, soft matter, and nano sciences and to increased computational power for simulating macromolecules and polymers. This review summarizes current understanding of some characteristics of the molecular environment in the nucleus, of how intranuclear compartments are formed, and of how the genome is highly but precisely compacted, and underlines the crucial, subtle, and sometimes unintuitive effects on structures and reactions of entropic forces caused by the high concentration of macromolecules in the nucleus.

  2. Content Analysis by the Crowd: Assessing the Usability of Crowdsourcing for Coding Latent Constructs

    Science.gov (United States)

    Lind, Fabienne; Gruber, Maria; Boomgaarden, Hajo G.

    2017-01-01

    ABSTRACT Crowdsourcing platforms are commonly used for research in the humanities, social sciences and informatics, including the use of crowdworkers to annotate textual material or visuals. Utilizing two empirical studies, this article systematically assesses the potential of crowdcoding for less manifest contents of news texts, here focusing on political actor evaluations. Specifically, Study 1 compares the reliability and validity of crowdcoded data to that of manual content analyses; Study 2 proceeds to investigate the effects of material presentation, different types of coding instructions and answer option formats on data quality. We find that the performance of the crowd recommends crowdcoded data as a reliable and valid alternative to manually coded data, also for less manifest contents. While scale manipulations affected the results, minor modifications of the coding instructions or material presentation did not significantly influence data quality. In sum, crowdcoding appears a robust instrument to collect quantitative content data. PMID:29118893

  3. Un commento in tema di "spiazzamento" (A comment on “crowding out”

    Directory of Open Access Journals (Sweden)

    G. VACIAGO

    2014-03-01

    Full Text Available In this brief note the author comments on Carlo D’Adda’s Greater precision regarding “crowding out”, offering three additional observations on the topic. While it is true that the concept was used largely in ideological terms in Italy, it resulted in the widespread belief that an increase in spending and the public debt was simultaneously the cause and effect of the weakening of the productive structure - in the way in which it alternately depended on a reduction in the propensity to spend in the private sector or on a restrictive monetary policy. Even if imprecise, this diagnosis does not seem to be far from reality. JEL: E51, H63, E52

  4. A method to harness global crowd-sourced data to understand travel behavior in avalanche terrain.

    Science.gov (United States)

    Hendrikx, J.; Johnson, J.

    2015-12-01

    To date, most studies of the human dimensions of decision making in avalanche terrain has focused on two areas - post-accident analysis using accident reports/interviews and, the development of tools as decision forcing aids. We present an alternate method using crowd-sourced citizen science, for understanding decision-making in avalanche terrain. Our project combines real-time GPS tracking via a smartphone application, with internet based surveys of winter backcountry users as a method to describe and quantify travel practices in concert with group decision-making dynamics, and demographic data of participants during excursions. Effectively, we use the recorded GPS track taken within the landscape as an expression of the decision making processes and terrain usage by the group. Preliminary data analysis shows that individual experience levels, gender, avalanche hazard, and group composition all influence the ways in which people travel in avalanche terrain. Our results provide the first analysis of coupled real-time GPS tracking of the crowd while moving in avalanche terrain combined with psychographic and demographic correlates. This research will lead to an improved understanding of real-time decision making in avalanche terrain. In this paper we will specifically focus on the presentation of the methods used to solicit, and then harness the crowd to obtain data in a unique and innovative application of citizen science where the movements within the terrain are the desired output data (Figure 1). Figure 1: Example GPS tracks sourced from backcountry winter users in the Teton Pass area (Wyoming), from the 2014-15 winter season, where tracks in red represent those recorded as self-assessed experts (as per our survey), and where tracks in blue represent those recorded as self-assessed intermediates. All tracks shown were obtained under similar avalanche conditions. Statistical analysis of terrain metrics showed that the experts used steeper terrain than the

  5. Isolation of cell nuclei using inert macromolecules to mimic the crowded cytoplasm.

    Directory of Open Access Journals (Sweden)

    Ronald Hancock

    Full Text Available Cell nuclei are commonly isolated and studied in media which include millimolar concentrations of cations, which conserve the nuclear volume by screening the negative charges on chromatin and maintaining its compaction. However, two factors question if these ionic conditions correctly reproduce the environment of nuclei in vivo: the small-scale motion and conformation of chromatin in vivo are not reproduced in isolated nuclei, and experiments and theory suggest that small ions in the cytoplasm are not free in the soluble phase but are predominantly bound to macromolecules. We studied the possible role in maintaining the structure and functions of nuclei in vivo of a further but frequently overlooked property of the cytoplasm, the crowding or osmotic effects caused by diffusible macromolecules whose concentration, measured in several studies, is in the range of 130 mg/ml. Nuclei which conserved their volume in the cell and their ultrastructure seen by electron microscopy were released from K562 cells in media containing the inert polymer 70 kDa Ficoll (50% w/v or 70 kDa dextran (35% w/v to replace the diffusible cytoplasmic molecules which were dispersed on cell lysis with digitonin, with 100 microM K-Hepes buffer as the only source of ions. Immunofluorescence labelling and experiments using cells expressing GFP-fusion proteins showed that internal compartments (nucleoli, PML and coiled bodies, foci of RNA polymerase II were conserved in these nuclei, and nascent RNA transcripts could be elongated. Our observations are consistent with the hypothesis that crowding by diffusible cytoplasmic macromolecules is a crucial but overlooked factor which supports the nucleus in vivo by equilibrating the opposing osmotic pressure cause by the high concentration of macromolecules in the nucleus, and suggest that crowded media provide more physiological conditions to study nuclear structure and functions. They may also help to resolve the long-standing paradox

  6. Analytic formalism for current crowding in light emitting diodes

    International Nuclear Information System (INIS)

    Lee, Kyu-Seok

    2012-01-01

    This paper presents an analytic approach to simulating current crowding (CC) in light-emitting diodes with parallel p- and n-contacts. The electrical potential difference across the p-i-n layers is derived from the Laplace equation, whereas the current density through the p-i-n layers is obtained from the current density - voltage relation of a single-diode model. Since these two properties influence each other, they are calculated iteratively. It is found that CC depends on the applied voltage (or the average current density), the sheet resistances of the p- and the n-contact layers, the width of the active region, and the specific series resistance and ideality factor of the p-i-n layers. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  7. Mobile Crowd Sensing for Traffic Prediction in Internet of Vehicles.

    Science.gov (United States)

    Wan, Jiafu; Liu, Jianqi; Shao, Zehui; Vasilakos, Athanasios V; Imran, Muhammad; Zhou, Keliang

    2016-01-11

    The advances in wireless communication techniques, mobile cloud computing, automotive and intelligent terminal technology are driving the evolution of vehicle ad hoc networks into the Internet of Vehicles (IoV) paradigm. This leads to a change in the vehicle routing problem from a calculation based on static data towards real-time traffic prediction. In this paper, we first address the taxonomy of cloud-assisted IoV from the viewpoint of the service relationship between cloud computing and IoV. Then, we review the traditional traffic prediction approached used by both Vehicle to Infrastructure (V2I) and Vehicle to Vehicle (V2V) communications. On this basis, we propose a mobile crowd sensing technology to support the creation of dynamic route choices for drivers wishing to avoid congestion. Experiments were carried out to verify the proposed approaches. Finally, we discuss the outlook of reliable traffic prediction.

  8. Mobile Crowd Sensing for Traffic Prediction in Internet of Vehicles

    Directory of Open Access Journals (Sweden)

    Jiafu Wan

    2016-01-01

    Full Text Available The advances in wireless communication techniques, mobile cloud computing, automotive and intelligent terminal technology are driving the evolution of vehicle ad hoc networks into the Internet of Vehicles (IoV paradigm. This leads to a change in the vehicle routing problem from a calculation based on static data towards real-time traffic prediction. In this paper, we first address the taxonomy of cloud-assisted IoV from the viewpoint of the service relationship between cloud computing and IoV. Then, we review the traditional traffic prediction approached used by both Vehicle to Infrastructure (V2I and Vehicle to Vehicle (V2V communications. On this basis, we propose a mobile crowd sensing technology to support the creation of dynamic route choices for drivers wishing to avoid congestion. Experiments were carried out to verify the proposed approaches. Finally, we discuss the outlook of reliable traffic prediction.

  9. Can the online-crowd match real expert judgments?

    DEFF Research Database (Denmark)

    Horn, Alexander

    2018-01-01

    ; using the coding of political texts as an example in which both strategies produce similar results. Since crowdcoding yields the potential to extend the replication standard to data production and to “scale” coding schemes based on a modest number of carefully devised test questions and answers......, it is important that we better understand its possibilities and limitations. While previous results for low complexity coding tasks are encouraging, we assess whether and under what conditions simple and complex coding tasks can be outsourced to the crowd without sacrificing content validity in return...... for scalability. The simple task is to decide whether a party statement counts as positive reference to a concept – in our case equality. The complex task is to distinguish between five concepts of equality. To account for the crowdcoder’s contextual knowledge, we vary the IP restrictions. The basis for our...

  10. Learning Supervised Topic Models for Classification and Regression from Crowds.

    Science.gov (United States)

    Rodrigues, Filipe; Lourenco, Mariana; Ribeiro, Bernardete; Pereira, Francisco C

    2017-12-01

    The growing need to analyze large collections of documents has led to great developments in topic modeling. Since documents are frequently associated with other related variables, such as labels or ratings, much interest has been placed on supervised topic models. However, the nature of most annotation tasks, prone to ambiguity and noise, often with high volumes of documents, deem learning under a single-annotator assumption unrealistic or unpractical for most real-world applications. In this article, we propose two supervised topic models, one for classification and another for regression problems, which account for the heterogeneity and biases among different annotators that are encountered in practice when learning from crowds. We develop an efficient stochastic variational inference algorithm that is able to scale to very large datasets, and we empirically demonstrate the advantages of the proposed model over state-of-the-art approaches.

  11. Cloud-Enhanced Robotic System for Smart City Crowd Control

    Directory of Open Access Journals (Sweden)

    Akhlaqur Rahman

    2016-12-01

    Full Text Available Cloud robotics in smart cities is an emerging paradigm that enables autonomous robotic agents to communicate and collaborate with a cloud computing infrastructure. It complements the Internet of Things (IoT by creating an expanded network where robots offload data-intensive computation to the ubiquitous cloud to ensure quality of service (QoS. However, offloading for robots is significantly complex due to their unique characteristics of mobility, skill-learning, data collection, and decision-making capabilities. In this paper, a generic cloud robotics framework is proposed to realize smart city vision while taking into consideration its various complexities. Specifically, we present an integrated framework for a crowd control system where cloud-enhanced robots are deployed to perform necessary tasks. The task offloading is formulated as a constrained optimization problem capable of handling any task flow that can be characterized by a Direct Acyclic Graph (DAG. We consider two scenarios of minimizing energy and time, respectively, and develop a genetic algorithm (GA-based approach to identify the optimal task offloading decisions. The performance comparison with two benchmarks shows that our GA scheme achieves desired energy and time performance. We also show the adaptability of our algorithm by varying the values for bandwidth and movement. The results suggest their impact on offloading. Finally, we present a multi-task flow optimal path sequence problem that highlights how the robot can plan its task completion via movements that expend the minimum energy. This integrates path planning with offloading for robotics. To the best of our knowledge, this is the first attempt to evaluate cloud-based task offloading for a smart city crowd control system.

  12. Cellular automaton model of crowd evacuation inspired by slime mould

    Science.gov (United States)

    Kalogeiton, V. S.; Papadopoulos, D. P.; Georgilas, I. P.; Sirakoulis, G. Ch.; Adamatzky, A. I.

    2015-04-01

    In all the living organisms, the self-preservation behaviour is almost universal. Even the most simple of living organisms, like slime mould, is typically under intense selective pressure to evolve a response to ensure their evolution and safety in the best possible way. On the other hand, evacuation of a place can be easily characterized as one of the most stressful situations for the individuals taking part on it. Taking inspiration from the slime mould behaviour, we are introducing a computational bio-inspired model crowd evacuation model. Cellular Automata (CA) were selected as a fully parallel advanced computation tool able to mimic the Physarum's behaviour. In particular, the proposed CA model takes into account while mimicking the Physarum foraging process, the food diffusion, the organism's growth, the creation of tubes for each organism, the selection of optimum tube for each human in correspondence to the crowd evacuation under study and finally, the movement of all humans at each time step towards near exit. To test the model's efficiency and robustness, several simulation scenarios were proposed both in virtual and real-life indoor environments (namely, the first floor of office building B of the Department of Electrical and Computer Engineering of Democritus University of Thrace). The proposed model is further evaluated in a purely quantitative way by comparing the simulation results with the corresponding ones from the bibliography taken by real data. The examined fundamental diagrams of velocity-density and flow-density are found in full agreement with many of the already published corresponding results proving the adequacy, the fitness and the resulting dynamics of the model. Finally, several real Physarum experiments were conducted in an archetype of the aforementioned real-life environment proving at last that the proposed model succeeded in reproducing sufficiently the Physarum's recorded behaviour derived from observation of the aforementioned

  13. Are current atomistic force fields accurate enough to study proteins in crowded environments?

    Directory of Open Access Journals (Sweden)

    Drazen Petrov

    2014-05-01

    Full Text Available The high concentration of macromolecules in the crowded cellular interior influences different thermodynamic and kinetic properties of proteins, including their structural stabilities, intermolecular binding affinities and enzymatic rates. Moreover, various structural biology methods, such as NMR or different spectroscopies, typically involve samples with relatively high protein concentration. Due to large sampling requirements, however, the accuracy of classical molecular dynamics (MD simulations in capturing protein behavior at high concentration still remains largely untested. Here, we use explicit-solvent MD simulations and a total of 6.4 µs of simulated time to study wild-type (folded and oxidatively damaged (unfolded forms of villin headpiece at 6 mM and 9.2 mM protein concentration. We first perform an exhaustive set of simulations with multiple protein molecules in the simulation box using GROMOS 45a3 and 54a7 force fields together with different types of electrostatics treatment and solution ionic strengths. Surprisingly, the two villin headpiece variants exhibit similar aggregation behavior, despite the fact that their estimated aggregation propensities markedly differ. Importantly, regardless of the simulation protocol applied, wild-type villin headpiece consistently aggregates even under conditions at which it is experimentally known to be soluble. We demonstrate that aggregation is accompanied by a large decrease in the total potential energy, with not only hydrophobic, but also polar residues and backbone contributing substantially. The same effect is directly observed for two other major atomistic force fields (AMBER99SB-ILDN and CHARMM22-CMAP as well as indirectly shown for additional two (AMBER94, OPLS-AAL, and is possibly due to a general overestimation of the potential energy of protein-protein interactions at the expense of water-water and water-protein interactions. Overall, our results suggest that current MD force fields

  14. The walking behaviour of pedestrian social groups and its impact on crowd dynamics.

    Directory of Open Access Journals (Sweden)

    Mehdi Moussaïd

    Full Text Available Human crowd motion is mainly driven by self-organized processes based on local interactions among pedestrians. While most studies of crowd behaviour consider only interactions among isolated individuals, it turns out that up to 70% of people in a crowd are actually moving in groups, such as friends, couples, or families walking together. These groups constitute medium-scale aggregated structures and their impact on crowd dynamics is still largely unknown. In this work, we analyze the motion of approximately 1500 pedestrian groups under natural condition, and show that social interactions among group members generate typical group walking patterns that influence crowd dynamics. At low density, group members tend to walk side by side, forming a line perpendicular to the walking direction. As the density increases, however, the linear walking formation is bent forward, turning it into a V-like pattern. These spatial patterns can be well described by a model based on social communication between group members. We show that the V-like walking pattern facilitates social interactions within the group, but reduces the flow because of its "non-aerodynamic" shape. Therefore, when crowd density increases, the group organization results from a trade-off between walking faster and facilitating social exchange. These insights demonstrate that crowd dynamics is not only determined by physical constraints induced by other pedestrians and the environment, but also significantly by communicative, social interactions among individuals.

  15. Routing in Dense Human Crowds Using Smartphone Movement Data and Optical Aerial Imagery

    Directory of Open Access Journals (Sweden)

    Florian Hillen

    2015-06-01

    Full Text Available In this paper, we propose a navigation approach for smartphones that enables visitors of major events to avoid crowded areas or narrow streets and to navigate out of dense crowds quickly. Two types of sensor data are integrated. Real-time optical images acquired and transmitted by an airborne camera system are used to compute an estimation of a crowd density map. For this purpose, a patch-based approach with a Gabor filter bank for texture classification in combination with an interest point detector and a smoothing function is applied. Furthermore, the crowd density is estimated based on location and movement speed of in situ smartphone measurements. This information allows for the enhancement of the overall crowd density layer. The composed density information is input to a least-cost routing workflow. Two possible use cases are presented, namely (i an emergency application and (ii a basic routing application. A prototypical implementation of the system is conducted as proof of concept. Our approach is capable of increasing the security level for major events. Visitors are able to avoid dense crowds by routing around them, while security and rescue forces are able to find the fastest way into the crowd.

  16. Agent Based Modeling and Simulation of Pedestrian Crowds In Panic Situations

    KAUST Repository

    Alrashed, Mohammed

    2016-11-01

    The increasing occurrence of panic stampedes during mass events has motivated studying the impact of panic on crowd dynamics and the simulation of pedestrian flows in panic situations. The lack of understanding of panic stampedes still causes hundreds of fatalities each year, not to mention the scarce methodical studies of panic behavior capable of envisaging such crowd dynamics. Under those circumstances, there are thousands of fatalities and twice that many of injuries every year caused be crowd stampede worldwide, despite the tremendous efforts of crowd control and massive numbers of safekeeping forces. Pedestrian crowd dynamics are generally predictable in high-density crowds where pedestrians cannot move freely and thus gives rise to self-propelling interactions between pedestrians. Although every pedestrian has personal preferences, the motion dynamics can be modeled as a social force in such crowds. These forces are representations of internal preferences and objectives to perform certain actions or movements. The corresponding forces can be controlled for each individual to represent a different variety of behaviors that can be associated with panic situations such as escaping danger, clustering, and pushing. In this thesis, we use an agent-based model of pedestrian behavior in panic situations to predict the collective human behavior in such crowd dynamics. The proposed simulations suggests a practical way to alleviate fatalities and minimize the evacuation time in panic situations. Moreover, we introduce contagious panic and pushing behavior, resulting in a more realistic crowd dynamics model. The proposed methodology describes the intensity and spread of panic for each individual as a function of distances between pedestrians.

  17. Quantifying the Effectiveness of Crowd-Sourced Serious Games

    Science.gov (United States)

    2014-09-01

    of All Metrics Used in the Thesis . . . . . . . . . . . . . . 37 Table 5.1 Average DAU and MAU for Selected Mobile , Social, and Online Games...of Sample VeriGames . . . . . . . . . . . . . . . . . . . . 41 Table 5.4 ER of Some Mobile , Social and Online Games and Developers . . 41 Table 5.5 ER...a code segment. A backend verification engine then combines the assertions produced from all related game instances and tries to obtain conditions

  18. PetroSim - a system to simulate crowd behaviors in emergency situations

    Energy Technology Data Exchange (ETDEWEB)

    Musse, Soraia R.; Silva, Andre T. da; Hardt, Katia; Barros, Leandro M.; Tonietto, Leandro [Universidade do Vale do Rio dos Sinos (UNISINOS), Sao Leopoldo, RS (Brazil). Dept. de Ciencia da Computacao; Roth, Bruno [Instituto Nacional de Pesquisas Espaciais (INPE), Sao Jose dos Campos, SP (Brazil); Rolim, Tuerte Amaral; Melo, Ricardo U.M.; Felipe, Luiz A.B. [PETROBRAS, Natal/Fortaleza, RN/CE (Brazil). Unidade de Negocios RN/CE

    2004-07-01

    This paper presents a framework to simulate the behaviors of crowds in panic situations. The main motivation for this work is to provide to safety engineers the possibility of simulating several aspects of panic situations involving crowds in real time. To accomplish this, we propose a complete framework to model the semantically informed environment as well as the intelligent virtual agents (IVA), which form the crowd who lives in the simulated virtual city. This work includes the integration of many knowledge areas such as VR, behavioral and visualization aspects required to the development of PetroSim. (author)

  19. From Man of the Crowd to Cybernaut: Edgar Allan Poe’s Transatlantic Journey—and Back.

    Directory of Open Access Journals (Sweden)

    Paul Jahshan

    2008-07-01

    Full Text Available The wild effects of the light enchained me to an examination of individual faces; and… it seemed that, in my then peculiar mental state, I could frequently read, even in that brief interval of a glance, the history of long years. (Poe 183‘This old man,’ I said at length, ‘is the type and the genius of deep crime. He refuses to be alone. He is the man of the crowd. It will be in vain to follow; for I shall learn no more of him, nor of his deeds…and perhaps it is but one of the great mercies o...

  20. On the Coded Packet Relay Network in the Presence of Neighbors:Benefits of Speaking in a Crowded Room

    OpenAIRE

    Khamfroush, Hana; Pahlevani, Peyman; Roetter, Daniel Enrique Lucani; Hundebøll, Martin; Fitzek, Frank

    2014-01-01

    This paper studies the problem of optimal use of a relay for reducing the transmission time of data packets from a source to a destination using network coding. More importantly, we address an effect that is typically overlooked in previous studies: the presence of active transmitting nodes in the neighborhood of such devices, which is typical in wireless mesh networks. We show that in systems with a fair medium access control mechanism (MAC), the use of a relay in a crowded medium brings for...

  1. Income is a stronger predictor of mortality than education in a national sample of US adults.

    Science.gov (United States)

    Sabanayagam, Charumathi; Shankar, Anoop

    2012-03-01

    Low socioeconomic status (SES) is associated with mortality in several populations. SES measures, such as education and income, may operate through different pathways. However, the independent effect of each measure mutually adjusting for the effect of other SES measures is not clear. The association between poverty-income ratio (PIR) and education and all-cause mortality among 15,646 adults, aged >20 years, who participated in the Third National Health and Nutrition Examination Survey in the USA, was examined. The lower PIR quartiles and less than high school education were positively associated with all-cause mortality in initial models adjusting for the demographic, lifestyle and clinical risk factors. After additional adjustment for education, the lower PIR quartiles were still significantly associated with all-cause mortality. The multivariable odds ratio (OR) [95% confidence interval (CI)] of all-cause mortality comparing the lowest to the highest quartile of PIR was 2.11 (1.52-2.95, p trend education was no longer associated with all-cause mortality [multivariable OR (95% CI) of all-cause mortality comparing less than high school to more than high school education was 1.05 (0.85-1.31, p trend=0.57)]. The results suggest that income may be a stronger predictor of mortality than education, and narrowing the income differentials may reduce the health disparities.

  2. Brain Potentials Highlight Stronger Implicit Food Memory for Taste than Health and Context Associations.

    Science.gov (United States)

    Hoogeveen, Heleen R; Jolij, Jacob; Ter Horst, Gert J; Lorist, Monicque M

    2016-01-01

    Increasingly consumption of healthy foods is advised to improve population health. Reasons people give for choosing one food over another suggest that non-sensory features like health aspects are appreciated as of lower importance than taste. However, many food choices are made in the absence of the actual perception of a food's sensory properties, and therefore highly rely on previous experiences of similar consumptions stored in memory. In this study we assessed the differential strength of food associations implicitly stored in memory, using an associative priming paradigm. Participants (N = 30) were exposed to a forced-choice picture-categorization task, in which the food or non-food target images were primed with either non-sensory or sensory related words. We observed a smaller N400 amplitude at the parietal electrodes when categorizing food as compared to non-food images. While this effect was enhanced by the presentation of a food-related word prime during food trials, the primes had no effect in the non-food trials. More specifically, we found that sensory associations are stronger implicitly represented in memory as compared to non-sensory associations. Thus, this study highlights the neuronal mechanisms underlying previous observations that sensory associations are important features of food memory, and therefore a primary motive in food choice.

  3. CROWDING-OUT OF GIANTS BY DWARFS: AN ORIGIN FOR THE LACK OF COMPANION PLANETS IN HOT JUPITER SYSTEMS

    International Nuclear Information System (INIS)

    Ogihara, Masahiro; Inutsuka, Shu-ichiro; Kobayashi, Hiroshi

    2013-01-01

    We investigate the formation of close-in terrestrial planets from planetary embryos under the influence of a hot Jupiter (HJ) using gravitational N-body simulations that include gravitational interactions between the gas disk and the terrestrial planet (e.g., type I migration). Our simulations show that several terrestrial planets efficiently form outside the orbit of the HJ, making a chain of planets, and all of them gravitationally interact directly or indirectly with the HJ through resonance, which leads to inward migration of the HJ. We call this mechanism of induced migration of the HJ ''crowding-out''. The HJ is eventually lost through collision with the central star, and only several terrestrial planets remain. We also find that the efficiency of the crowding-out effect depends on the model parameters; for example, the heavier the disk is, the more efficient the crowding-out is. When planet formation occurs in a massive disk, the HJ can be lost to the central star and is never observed. On the other hand, for a less massive disk, the HJ and terrestrial planets can coexist; however, the companion planets may be below the detection limit of current observations. In both cases, systems with a HJ and terrestrial planets have little chance of detection. Therefore, our model naturally explains the lack of companion planets in HJ systems regardless of the disk mass. In effect, our model provides a theoretical prediction for future observations; additional planets can be discovered just outside the HJ, and their masses should generally be small

  4. Age differences in autobiographical memory across the adult lifespan: older adults report stronger phenomenology.

    Science.gov (United States)

    Luchetti, Martina; Sutin, Angelina R

    2018-01-01

    As an individual's life story evolves across adulthood, the subjective experience (phenomenology) of autobiographical memory likely changes. In addition to age at retrieval, both the recency of the memory and the age when a memory is formed may be particularly important to its phenomenology. The present work examines the effect of three temporal factors on phenomenology ratings: (a) age of the participant, (b) age at the event reported in the memory, and (c) memory age (recency). A large sample of Americans (N = 1120), stratified by chronological age, recalled and rated two meaningful memories, a Turning Point and an Early Childhood Memory. Ratings of phenomenology (e.g., vividness of turning points) were higher among older adults compared to younger adults. Memories of events from the reminiscence bump were more positive in valence than events from other time periods but did not differ on other phenomenological dimensions; recent memories had stronger phenomenology than remote memories. In contrast to phenomenology, narrative content was generally unrelated to participant age, age at the event, or memory age. Overall, the findings indicate age-related differences in how meaningful memories are re-experienced.

  5. CrowdMapping: A Crowdsourcing-Based Terminology Mapping Method for Medical Data Standardization.

    Science.gov (United States)

    Mao, Huajian; Chi, Chenyang; Huang, Boyu; Meng, Haibin; Yu, Jinghui; Zhao, Dongsheng

    2017-01-01

    Standardized terminology is the prerequisite of data exchange in analysis of clinical processes. However, data from different electronic health record systems are based on idiosyncratic terminology systems, especially when the data is from different hospitals and healthcare organizations. Terminology standardization is necessary for the medical data analysis. We propose a crowdsourcing-based terminology mapping method, CrowdMapping, to standardize the terminology in medical data. CrowdMapping uses a confidential model to determine how terminologies are mapped to a standard system, like ICD-10. The model uses mappings from different health care organizations and evaluates the diversity of the mapping to determine a more sophisticated mapping rule. Further, the CrowdMapping model enables users to rate the mapping result and interact with the model evaluation. CrowdMapping is a work-in-progress system, we present initial results mapping terminologies.

  6. Agent Based Modeling and Simulation of Pedestrian Crowds In Panic Situations

    KAUST Repository

    Alrashed, Mohammed

    2016-01-01

    to self-propelling interactions between pedestrians. Although every pedestrian has personal preferences, the motion dynamics can be modeled as a social force in such crowds. These forces are representations of internal preferences and objectives to perform

  7. Parallel Motion Simulation of Large-Scale Real-Time Crowd in a Hierarchical Environmental Model

    Directory of Open Access Journals (Sweden)

    Xin Wang

    2012-01-01

    Full Text Available This paper presents a parallel real-time crowd simulation method based on a hierarchical environmental model. A dynamical model of the complex environment should be constructed to simulate the state transition and propagation of individual motions. By modeling of a virtual environment where virtual crowds reside, we employ different parallel methods on a topological layer, a path layer and a perceptual layer. We propose a parallel motion path matching method based on the path layer and a parallel crowd simulation method based on the perceptual layer. The large-scale real-time crowd simulation becomes possible with these methods. Numerical experiments are carried out to demonstrate the methods and results.

  8. Translational and rotational motions of proteins in a protein crowded environment

    NARCIS (Netherlands)

    Zorilla, S.; Hink, M.A.; Visser, A.J.W.G.; Lillo, M.P.

    2007-01-01

    Fluorescence correlation spectroscopy (FCS) was used to measure the translational diffusion of labeled apomyoglobin (tracer) in concentrated solutions of ribonuclease A and human serum albumin (crowders), as a quantitative model system of protein diffusive motions in crowded physiological

  9. Structure, function and folding of phosphoglycerate kinase are strongly perturbed by macromolecular crowding.

    Science.gov (United States)

    Samiotakis, Antonios; Dhar, Apratim; Ebbinghaus, Simon; Nienhaus, Lea; Homouz, Dirar; Gruebele, Martin; Cheung, Margaret

    2010-10-01

    We combine experiment and computer simulation to show how macromolecular crowding dramatically affects the structure, function and folding landscape of phosphoglycerate kinase (PGK). Fluorescence labeling shows that compact states of yeast PGK are populated as the amount of crowding agents (Ficoll 70) increases. Coarse-grained molecular simulations reveal three compact ensembles: C (crystal structure), CC (collapsed crystal) and Sph (spherical compact). With an adjustment for viscosity, crowded wild type PGK and fluorescent PGK are about 15 times or more active in 200 mg/ml Ficoll than in aqueous solution. Our results suggest a new solution to the classic problem of how the ADP and diphosphoglycerate binding sites of PGK come together to make ATP: rather than undergoing a hinge motion, the ADP and substrate sites are already located in proximity under crowded conditions that mimic the in vivo conditions under which the enzyme actually operates.

  10. Mathematical Capture of Human Crowd Behavioral Data for Computational Model Building, Verification, and Validation

    Science.gov (United States)

    2011-03-21

    throughout the experimental runs. Reliable and validated measures of anxiety ( Spielberger , 1983), as well as custom-constructed questionnaires about...Crowd modeling and simulation technologies. Transactions on modeling and computer simulation, 20(4). Spielberger , C. D. (1983

  11. Crowd-sourced assessment of technical skills: an adjunct to urology resident surgical simulation training.

    Science.gov (United States)

    Holst, Daniel; Kowalewski, Timothy M; White, Lee W; Brand, Timothy C; Harper, Jonathan D; Sorenson, Mathew D; Kirsch, Sarah; Lendvay, Thomas S

    2015-05-01

    Crowdsourcing is the practice of obtaining services from a large group of people, typically an online community. Validated methods of evaluating surgical video are time-intensive, expensive, and involve participation of multiple expert surgeons. We sought to obtain valid performance scores of urologic trainees and faculty on a dry-laboratory robotic surgery task module by using crowdsourcing through a web-based grading tool called Crowd Sourced Assessment of Technical Skill (CSATS). IRB approval was granted to test the technical skills grading accuracy of Amazon.com Mechanical Turk™ crowd-workers compared to three expert faculty surgeon graders. The two groups assessed dry-laboratory robotic surgical suturing performances of three urology residents (PGY-2, -4, -5) and two faculty using three performance domains from the validated Global Evaluative Assessment of Robotic Skills assessment tool. After an average of 2 hours 50 minutes, each of the five videos received 50 crowd-worker assessments. The inter-rater reliability (IRR) between the surgeons and crowd was 0.91 using Cronbach's alpha statistic (confidence intervals=0.20-0.92), indicating an agreement level between the two groups of "excellent." The crowds were able to discriminate the surgical level, and both the crowds and the expert faculty surgeon graders scored one senior trainee's performance above a faculty's performance. Surgery-naive crowd-workers can rapidly assess varying levels of surgical skill accurately relative to a panel of faculty raters. The crowds provided rapid feedback and were inexpensive. CSATS may be a valuable adjunct to surgical simulation training as requirements for more granular and iterative performance tracking of trainees become mandated and commonplace.

  12. Investigating the In-Vehicle Crowding Cost Functions for Public Transit Modes

    OpenAIRE

    Qin, Feifei

    2014-01-01

    In the densely populated metropolitan area, empirical studies have found that overcrowding inside transit vehicles has become substantially worse and worse over recent years. Chronic in-vehicle crowding is not only caused by a lack of physical infrastructure, but also triggered by inadequate service provisions. Given the prevalence of overcrowded transit vehicles, this paper conducts both quantitative and qualitative studies, especially focusing on remodeling the in-vehicle crowding cost func...

  13. Mixed emotions: Sensitivity to facial variance in a crowd of faces.

    Science.gov (United States)

    Haberman, Jason; Lee, Pegan; Whitney, David

    2015-01-01

    The visual system automatically represents summary information from crowds of faces, such as the average expression. This is a useful heuristic insofar as it provides critical information about the state of the world, not simply information about the state of one individual. However, the average alone is not sufficient for making decisions about how to respond to a crowd. The variance or heterogeneity of the crowd--the mixture of emotions--conveys information about the reliability of the average, essential for determining whether the average can be trusted. Despite its importance, the representation of variance within a crowd of faces has yet to be examined. This is addressed here in three experiments. In the first experiment, observers viewed a sample set of faces that varied in emotion, and then adjusted a subsequent set to match the variance of the sample set. To isolate variance as the summary statistic of interest, the average emotion of both sets was random. Results suggested that observers had information regarding crowd variance. The second experiment verified that this was indeed a uniquely high-level phenomenon, as observers were unable to derive the variance of an inverted set of faces as precisely as an upright set of faces. The third experiment replicated and extended the first two experiments using method-of-constant-stimuli. Together, these results show that the visual system is sensitive to emergent information about the emotional heterogeneity, or ambivalence, in crowds of faces.

  14. Cluster Risk of Walking Scenarios Based on Macroscopic Flow Model and Crowding Force Analysis

    Directory of Open Access Journals (Sweden)

    Xiaohong Li

    2018-02-01

    Full Text Available In recent years, accidents always happen in confined space such as metro stations because of congestion. Various researchers investigated the patterns of dense crowd behaviors in different scenarios via simulations or experiments and proposed methods for avoiding accidents. In this study, a classic continuum macroscopic model was applied to simulate the crowded pedestrian flow in typical scenarios such as at bottlenecks or with an obstacle. The Lax–Wendroff finite difference scheme and artificial viscosity filtering method were used to discretize the model to identify high-density risk areas. Furthermore, we introduced a contact crowding force test of the interactions among pedestrians at bottlenecks. Results revealed that in the most dangerous area, the individual on the corner position bears the maximum pressure in such scenarios is 90.2 N, and there is an approximate exponential relationship between crowding force and density indicated by our data. The results and findings presented in this paper can facilitate more reasonable and precise simulation models by utilizing crowding force and crowd density and ensure the safety of pedestrians in high-density scenarios.

  15. Lower-Body Muscle Structure and Jump Performance of Stronger and Weaker Surfing Athletes.

    Science.gov (United States)

    Secomb, Josh L; Nimphius, Sophia; Farley, Oliver R; Lundgren, Lina; Tran, Tai T; Sheppard, Jeremy M

    2016-07-01

    To identify whether there are any significant differences in the lower-body muscle structure and countermovement-jump (CMJ) and squat-jump (SJ) performance between stronger and weaker surfing athletes. Twenty elite male surfers had their lower-body muscle structure assessed with ultrasonography and completed a series of lower-body strength and jump tests including isometric midthigh pull (IMTP), CMJ, and SJ. Athletes were separated into stronger (n = 10) and weaker (n = 10) groups based on IMTP performance. Large significant differences were identified between the groups for vastus lateralis (VL) thickness (P = .02, ES = 1.22) and lateral gastrocnemius (LG) pennation angle (P = .01, ES = 1.20), and a large nonsignificant difference was identified in LG thickness (P = .08, ES = 0.89). Furthermore, significant differences were present between the groups for peak force, relative peak force, and jump height in the CMJ and SJ (P Stronger surfing athletes in this study had greater VL and LG thickness and LG pennation angle. These muscle structures may explain their better performance in the CMJ and SJ. A unique finding in this study was that the stronger group appeared to better use their strength and muscle structure for braking as they had significantly higher eccentric peak velocity and vertical displacement during the CMJ. This enhanced eccentric phase may have resulted in a greater production and subsequent utilization of stored elastic strain energy that led to the significantly better CMJ performance in the stronger group.

  16. Which global stock indices trigger stronger contagion risk in the Vietnamese stock market? Evidence using a bivariate analysis

    Directory of Open Access Journals (Sweden)

    Wang Kuan-Min

    2013-01-01

    Full Text Available This paper extends recent investigations into risk contagion effects on stock markets to the Vietnamese stock market. Daily data spanning October 9, 2006 to May 3, 2012 are sourced to empirically validate the contagion effects between stock markets in Vietnam, and China, Japan, Singapore, and the US. To facilitate the validation of contagion effects with market-related coefficients, this paper constructs a bivariate EGARCH model of dynamic conditional correlation coefficients. Using the correlation contagion test and Dungey et al.’s (2005 contagion test, we find contagion effects between the Vietnamese and four other stock markets, namely Japan, Singapore, China, and the US. Second, we show that the Japanese stock market causes stronger contagion risk in the Vietnamese stock market compared to the stock markets of China, Singapore, and the US. Finally, we show that the Chinese and US stock markets cause weaker contagion effects in the Vietnamese stock market because of stronger interdependence effects between the former two markets.

  17. Library on Crowd Behavior for Agents Treatment on Videogames

    Directory of Open Access Journals (Sweden)

    M. Proenza

    2013-01-01

    Full Text Available Abstract This paper covers the investigation process and further design and implementation of a library on crowd behaviors for videogames. Three methods were studied in order to pick up one of them, resulting to be Steering Behaviors method the one selected to be adopted. The library supports simulations with a large number of moving agents. It also copes with polygonal obstacles avoidance. Additionally, simulations can be adapted to many contexts by tuning some parameters. The library consists of an original design mostly based on Command Pattern that allows it to be easily usable and extendable.   Resumen Este documento cubre el proceso de investigación y el diseño e implementación de una biblioteca en los comportamientos de multitud de videojuegos. Tres métodos fueron estudiados con el fin de recoger a uno de ellos, el resultado es el método de dirección Comportamientos que se ha seleccionado para su adopción. La biblioteca admite simulaciones con un gran número de agentes móviles. También hace frente a la evitación obstáculos poligonales. Además, las simulaciones se pueden adaptar a diferentes contextos mediante la regulación de algunos parámetros. La biblioteca consta de un diseño original basado principalmente en modelo de comandos que permite que sea fácilmente utilizable y extensible.

  18. Using Telemedicine to Address Crowding in the ED.

    Science.gov (United States)

    Guss, Benjamin; Mishkin, David; Sharma, Rahul

    2016-11-01

    Some health systems are piloting telemedicine solutions in the ED to address crowding and decrease patient wait times. One new program, implemented at the Lisa Perry Emergency Center at New York Presbyterian (NYP) Weill Cornell Medical Center in New York, involves offering low-acuity patients the option of visiting an off-site physician via telemedicine hookup. Administrators note that the approach can get patients in and out of the ED within 30 minutes, and patients have thus far been highly satisfied with the approach. However, an earlier telemedicine program piloted at the University of San Diego Health System’s (UCSD) Hillcrest Hospital in 2013 got bogged down due to administrative and insurance reimbursement hurdles, although the approach showed enough promise that there is interest in restarting the program. In the NYP program, patients are identified as appropriate candidates for the program at triage. They can opt to be seen remotely or through traditional means in the ED’s fast-track section. Administrators note that patients with complex problems requiring extensive workups are not suitable for the telemedicine approach. The most challenging aspect of implementing a successful telemedicine program in the ED is getting the workflows right, according to administrators. An earlier ED-based telemedicine program piloted at UCSD ran into difficulties because the model required the involvement of two physicians, and some insurers did not want to pay for the telemedicine visits. However, patients were receptive.

  19. The politics of the face-in-the-crowd.

    Science.gov (United States)

    Mills, Mark; Smith, Kevin B; Hibbing, John R; Dodd, Michael D

    2014-06-01

    Recent work indicates that the more conservative one is, the faster one is to fixate on negative stimuli, whereas the less conservative one is, the faster one is to fixate on positive stimuli. The present series of experiments used the face-in-the-crowd paradigm to examine whether variability in the efficiency with which positive and negative stimuli are detected underlies such speed differences. Participants searched for a discrepant facial expression (happy or angry) amid a varying number of neutral distractors (Experiments 1 and 4). A combination of response time and eye movement analyses indicated that variability in search efficiency explained speed differences for happy expressions, whereas variability in post-selectional processes explained speed differences for angry expressions. These results appear to be emotionally mediated as search performance did not vary with political temperament when displays were inverted (Experiment 2) or when controlled processing was required for successful task performance (Experiment 3). Taken together, the present results suggest political temperament is at least partially instantiated by attentional biases for emotional material. PsycINFO Database Record (c) 2014 APA, all rights reserved.

  20. Making microenvironments: A look into incorporating macromolecular crowding into in vitro experiments, to generate biomimetic microenvironments which are capable of directing cell function for tissue engineering applications.

    Science.gov (United States)

    Benny, Paula; Raghunath, Michael

    2017-01-01

    Biomimetic microenvironments are key components to successful cell culture and tissue engineering in vitro. One of the most accurate biomimetic microenvironments is that made by the cells themselves. Cell-made microenvironments are most similar to the in vivo state as they are cell-specific and produced by the actual cells which reside in that specific microenvironment. However, cell-made microenvironments have been challenging to re-create in vitro due to the lack of extracellular matrix composition, volume and complexity which are required. By applying macromolecular crowding to current cell culture protocols, cell-made microenvironments, or cell-derived matrices, can be generated at significant rates in vitro. In this review, we will examine the causes and effects of macromolecular crowding and how it has been applied in several in vitro systems including tissue engineering.

  1. Association Between Self-Esteem and Depressive Symptoms Is Stronger Among Black than White Older Adults.

    Science.gov (United States)

    Assari, Shervin

    2017-08-01

    Although poor self-esteem is a core component of depression, we still do not know if racial and ethnic groups differ in the magnitude of this link. This study compared Black and White older adults on the association between self-esteem and depressive symptoms. With a cross-sectional design, this study enrolled 1493 older individuals (age 66 or more) from the 2001 Religion, Aging, and Health Survey, a nationally representative study in the United States. Participants were either Blacks (n = 734) or Whites (n = 759). Depressive symptoms and self-esteem were measured using brief measures of the Center for Epidemiological Studies-Depression scale (CES-D) and the Rosenberg Self-Esteem Scale, respectively. Demographics, socioeconomics, and self-rated health (SRH) were covariates and self-identified race was the moderator. Linear regression models were used for data analysis. Low self-esteem was associated with more depressive symptoms (B = 0.17, 95 % CI 0.15-0.28), above and beyond all covariates. We found a significant and positive interaction between race (Black) and poor self-esteem on depressive symptoms (B = 0.34, 95 % CI 0.17-0.36), suggesting a stronger association between self-esteem and depressive symptoms among Blacks compared to Whites. Although low self-esteem is associated with higher depressive symptoms in both Whites and Blacks (p self-esteem and high depressive symptoms are more closely associated among Blacks than Whites. It is not clear whether depression leaves a larger scar on self-esteem for Blacks, or Blacks are more vulnerable to the effect of low self-esteem on depression.

  2. The bigger, the stronger? Insights from muscle architecture and nervous characteristics in obese adolescent girls.

    Science.gov (United States)

    Garcia-Vicencio, S; Coudeyre, E; Kluka, V; Cardenoux, C; Jegu, A-G; Fourot, A-V; Ratel, S; Martin, V

    2016-02-01

    Young obese youth are generally stronger than lean youth. This has been linked to the loading effect of excess body mass, acting as a training stimulus comparable to strength training. Whether this triggers specific adaptations of the muscle architecture (MA) and voluntary activation (VA) that could account for the higher strength of obese subjects remains unknown. MA characteristics (that is, pennation angle (PA), fascicle length (FL) and muscle thickness (MT)) and muscle size (that is, anatomical cross-sectional area (ACSA)) of the knee extensor (KE) and plantar flexor (PF) muscles were evaluated in 12 obese and 12 non-obese adolescent girls (12-15 years). Maximal isometric torque and VA of the KE and PF muscles were also assessed. Results revealed higher PA (Pmuscles in obese girls. Moreover, obese individuals produced a higher absolute torque than their lean counterparts on the KE (224.6±39.5 vs 135.7±32.7 N m, respectively; Pmuscles (73.3±16.5 vs 44.5±6.2 N m; Pmuscles (r=0.45-0.55, P<0.05-0.01). MVC was also correlated with VA (KE: r=0.44, P<0.05; PF: r=0.65, P<0.001) and segmental lean mass (KE: r=0.48, P<0.05; PF: r=0.57, P<0.01). This study highlighted favorable muscular and nervous adaptations to obesity that account for the higher strength of obese youth. The excess of body mass supported during daily activities could act as a chronic training stimulus responsible for these adaptations.

  3. A stronger patch test elicitation reaction to the allergen hydroxycitronellal plus the irritant sodium lauryl sulfate

    DEFF Research Database (Denmark)

    Heydorn, S; Andersen, K E; Johansen, J D

    2003-01-01

    Household and cleaning products often contain both allergens and irritants. The aim of this double-blinded, randomized, paired study was to determine whether patch testing with an allergen (hydroxycitronellal) combined with an irritant [sodium lauryl sulfate (SLS)] cause a stronger patch test...

  4. Peptide-MHC class I stability is a stronger predictor of CTL immunogenicity than peptide affinity

    DEFF Research Database (Denmark)

    Harndahl, Mikkel Nors; Rasmussen, Michael; Nielsen, Morten

    2012-01-01

    Peptide-MHC class I stability is a stronger predictor of CTL immunogenicity than peptide affinity Mikkel Harndahla, Michael Rasmussena, Morten Nielsenb, Soren Buusa,∗ a Laboratory of Experimental Immunology, Faculty of Health Sciences, University of Copenhagen, Denmark b Center for Biological Seq...... al., 2007. J. Immunol. 178, 7890–7901. doi:10.1016/j.molimm.2012.02.025...

  5. BUILDING STRONGER STATE ENERGY PARTNERSHIPS WITH THE U.S. DEPARTMENT OF ENERGY

    Energy Technology Data Exchange (ETDEWEB)

    Kate Burke

    2002-11-01

    This technical progress report includes an update of the progress during the second year of cooperative agreement DE-FC26-00NT40802, Building Stronger State Energy Partnerships with the U.S. Department of Energy. The report also describes the barriers in conduct of the effort, and our assessment of future progress and activities.

  6. Becoming Stronger at Broken Places: A Model for Group Work with Young Adult from Divorced Families.

    Science.gov (United States)

    Hage, Sally M.; Nosanow, Mia

    2000-01-01

    Describes a model for group work with young adults from divorced families using an 8-session psychoeducational group intervention. Goals include reducing isolation, establishing connectedness, and building a stronger sense of identify. By educating young adults on topics such as assertiveness, communication skills, and self-esteem, it will give…

  7. A Human Capital Framework for a Stronger Teacher Workforce. Advancing Teaching--Improving Learning. White Paper

    Science.gov (United States)

    Myung, Jeannie; Martinez, Krissia; Nordstrum, Lee

    2013-01-01

    Building a stronger teacher workforce requires the thoughtful orchestration of multiple processes working together in a human capital system. This white paper presents a framework that can be used to take stock of current efforts to enhance the teacher workforce in school districts or educational organizations, as well as their underlying theories…

  8. Research on operation mode and risk of crowd-funding in China%中国股权众筹运作模式及风险研究

    Institute of Scientific and Technical Information of China (English)

    李倩; 王璐瑶

    2015-01-01

    近年来,互联网金融凭借着运营风险低、交易成本低、运作效率高的特点成为各地经济发展的重要手段,为世界金融发展注入了新的活力. 从分析股权众筹概念入手,研究国内股权众筹运作模式的发展和创新,采用二元Logit模型分析"领投+跟投"模式对股权众筹运营的促进作用,同时从法律风险和项目运营风险两方面对股权众筹运作模式进行风险分析并提出相应的防范措施,以便于更好地保护投资者的利益,促进股权众筹模式的发展.%In recent years, internet finance has become an important means of local economic development owing to its lower operational risk, lower transaction costs and higher efficiency, which has injected new vitality into the world financial development. Starting from the analysis of the definition of stock crowd-funding, the development and innovation of the operation mode of stock crowd-funding are researched. The binary Logit model is used to analyze the promoting effect of the mode of "leader+follower" on the operation of stock crowd-funding. At the same time, the risk analysis is carried out from the perspectives of legal risk and project operational risk, and the corresponding preventive measures are proposed, so as to better protect the interests of investors, and promote the development of stock crowd-funding.

  9. A Crowd Avoidance Method Using Circular Avoidance Path for Robust Person Following

    Directory of Open Access Journals (Sweden)

    Kohei Morishita

    2017-01-01

    Full Text Available A life-support service robot must avoid both static and dynamic obstacles for working in a real environment. Here, a static obstacle means an obstacle that does not move, and a dynamic obstacle is the one that moves. Assuming the robot is following a target person, we discuss how the robot avoids a crowd through which the target person passes and arrives at the target position. The purpose of this paper is to propose a crowd avoidance method that makes a robot to be able to avoid both static and dynamic obstacles. The method uses the surface points of the obstacles to form an avoidance region, and the robot moves along the edge of the region. We conducted experiments assuming various situations such that the robot was blocked, there was a wide gap in the crowd, or a person in the crowd yielded for the robot to pass through. As an experimental result, it was confirmed the robot could avoid the crowd even when the obstacles were aligned in an “inverted wedge” shape.

  10. Optimal Acceleration-Velocity-Bounded Trajectory Planning in Dynamic Crowd Simulation

    Directory of Open Access Journals (Sweden)

    Fu Yue-wen

    2014-01-01

    Full Text Available Creating complex and realistic crowd behaviors, such as pedestrian navigation behavior with dynamic obstacles, is a difficult and time consuming task. In this paper, we study one special type of crowd which is composed of urgent individuals, normal individuals, and normal groups. We use three steps to construct the crowd simulation in dynamic environment. The first one is that the urgent individuals move forward along a given path around dynamic obstacles and other crowd members. An optimal acceleration-velocity-bounded trajectory planning method is utilized to model their behaviors, which ensures that the durations of the generated trajectories are minimal and the urgent individuals are collision-free with dynamic obstacles (e.g., dynamic vehicles. In the second step, a pushing model is adopted to simulate the interactions between urgent members and normal ones, which ensures that the computational cost of the optimal trajectory planning is acceptable. The third step is obligated to imitate the interactions among normal members using collision avoidance behavior and flocking behavior. Various simulation results demonstrate that these three steps give realistic crowd phenomenon just like the real world.

  11. Macromolecular crowding-assisted fabrication of liquid-crystalline imprinted polymers.

    Science.gov (United States)

    Zhang, Chen; Zhang, Jing; Huang, Yan-Ping; Liu, Zhao-Sheng

    2015-04-01

    A macromolecular crowding-assisted liquid-crystalline molecularly imprinted monolith (LC-MIM) was prepared successfully for the first time. The imprinted stationary phase was synthesized with polymethyl methacrylate (PMMA) or polystyrene (PS) as the crowding agent, 4-cyanophenyl dicyclohexyl propylene (CPCE) as the liquid-crystal monomer, and hydroquinidine as the pseudo-template for the chiral separation of cinchona alkaloids in HPLC. A low level of cross-linker (26%) has been found to be sufficient to achieve molecular recognition on the crowding-assisted LC-MIM due to the physical cross-linking of mesogenic groups in place of chemical cross-linking, and baseline separation of quinidine and quinine could be achieved with good resolution (R(s) = 2.96), selectivity factor (α = 2.16), and column efficiency (N = 2650 plates/m). In contrast, the LC-MIM prepared without crowding agents displayed the smallest diastereoselectivity (α = 1.90), while the crowding-assisted MIM with high level of cross-linker (80%) obtained the greatest selectivity factor (α = 7.65), but the lowest column efficiency (N = 177 plates/m).

  12. A natural and readily available crowding agent: NMR studies of proteins in hen egg white.

    Science.gov (United States)

    Martorell, Gabriel; Adrover, Miquel; Kelly, Geoff; Temussi, Piero Andrea; Pastore, Annalisa

    2011-05-01

    In vitro studies of biological macromolecules are usually performed in dilute, buffered solutions containing one or just a few different biological macromolecules. Under these conditions, the interactions among molecules are diffusion limited. On the contrary, in living systems, macromolecules of a given type are surrounded by many others, at very high total concentrations. In the last few years, there has been an increasing effort to study biological macromolecules directly in natural crowded environments, as in intact bacterial cells or by mimicking natural crowding by adding proteins, polysaccharides, or even synthetic polymers. Here, we propose the use of hen egg white (HEW) as a simple natural medium, with all features of the media of crowded cells, that could be used by any researcher without difficulty and inexpensively. We present a study of the stability and dynamics behavior of model proteins in HEW, chosen as a prototypical, readily accessible natural medium that can mimic cytosol. We show that two typical globular proteins, dissolved in HEW, give NMR spectra very similar to those obtained in dilute buffers, although dynamic parameters are clearly affected by the crowded medium. The thermal stability of one of these proteins, measured in a range comprising both heat and cold denaturation, is also similar to that in buffer. Our data open new possibilities to the study of proteins in natural crowded media. Copyright © 2010 Wiley-Liss, Inc.

  13. The development of a quick-running prediction tool for the assessment of human injury owing to terrorist attack within crowded metropolitan environments.

    Science.gov (United States)

    Pope, Daniel J

    2011-01-27

    In the aftermath of the London '7/7' attacks in 2005, UK government agencies required the development of a quick-running tool to predict the weapon and injury effects caused by the initiation of a person borne improvised explosive device (PBIED) within crowded metropolitan environments. This prediction tool, termed the HIP (human injury predictor) code, was intended to:--assist the security services to encourage favourable crowd distributions and densities within scenarios of 'sensitivity'; --provide guidance to security engineers concerning the most effective location for protection systems; --inform rescue services as to where, in the case of such an event, individuals with particular injuries will be located; --assist in training medical personnel concerning the scope and types of injuries that would be sustained as a consequence of a particular attack; --assist response planners in determining the types of medical specialists (burns, traumatic amputations, lungs, etc.) required and thus identify the appropriate hospitals to receive the various casualty types. This document describes the algorithms used in the development of this tool, together with the pertinent underpinning physical processes. From its rudimentary beginnings as a simple spreadsheet, the HIP code now has a graphical user interface (GUI) that allows three-dimensional visualization of results and intuitive scenario set-up. The code is underpinned by algorithms that predict the pressure and momentum outputs produced by PBIEDs within open and confined environments, as well as the trajectories of shrapnel deliberately placed within the device to increase injurious effects. Further logic has been implemented to transpose these weapon effects into forms of human injury depending on where individuals are located relative to the PBIED. Each crowd member is subdivided into representative body parts, each of which is assigned an abbreviated injury score after a particular calculation cycle. The injury

  14. Crowd Sourcing a New Paradigm for Interactome Driven Drug Target Identification in Mycobacterium tuberculosis

    Science.gov (United States)

    Rohira, Harsha; Bhat, Ashwini G.; Passi, Anurag; Mukherjee, Keya; Choudhary, Kumari Sonal; Kumar, Vikas; Arora, Anshula; Munusamy, Prabhakaran; Subramanian, Ahalyaa; Venkatachalam, Aparna; S, Gayathri; Raj, Sweety; Chitra, Vijaya; Verma, Kaveri; Zaheer, Salman; J, Balaganesh; Gurusamy, Malarvizhi; Razeeth, Mohammed; Raja, Ilamathi; Thandapani, Madhumohan; Mevada, Vishal; Soni, Raviraj; Rana, Shruti; Ramanna, Girish Muthagadhalli; Raghavan, Swetha; Subramanya, Sunil N.; Kholia, Trupti; Patel, Rajesh; Bhavnani, Varsha; Chiranjeevi, Lakavath; Sengupta, Soumi; Singh, Pankaj Kumar; Atray, Naresh; Gandhi, Swati; Avasthi, Tiruvayipati Suma; Nisthar, Shefin; Anurag, Meenakshi; Sharma, Pratibha; Hasija, Yasha; Dash, Debasis; Sharma, Arun; Scaria, Vinod; Thomas, Zakir; Chandra, Nagasuma; Brahmachari, Samir K.; Bhardwaj, Anshu

    2012-01-01

    A decade since the availability of Mycobacterium tuberculosis (Mtb) genome sequence, no promising drug has seen the light of the day. This not only indicates the challenges in discovering new drugs but also suggests a gap in our current understanding of Mtb biology. We attempt to bridge this gap by carrying out extensive re-annotation and constructing a systems level protein interaction map of Mtb with an objective of finding novel drug target candidates. Towards this, we synergized crowd sourcing and social networking methods through an initiative ‘Connect to Decode’ (C2D) to generate the first and largest manually curated interactome of Mtb termed ‘interactome pathway’ (IPW), encompassing a total of 1434 proteins connected through 2575 functional relationships. Interactions leading to gene regulation, signal transduction, metabolism, structural complex formation have been catalogued. In the process, we have functionally annotated 87% of the Mtb genome in context of gene products. We further combine IPW with STRING based network to report central proteins, which may be assessed as potential drug targets for development of drugs with least possible side effects. The fact that five of the 17 predicted drug targets are already experimentally validated either genetically or biochemically lends credence to our unique approach. PMID:22808064

  15. Macromolecular diffusion in crowded media beyond the hard-sphere model.

    Science.gov (United States)

    Blanco, Pablo M; Garcés, Josep Lluís; Madurga, Sergio; Mas, Francesc

    2018-04-25

    The effect of macromolecular crowding on diffusion beyond the hard-core sphere model is studied. A new coarse-grained model is presented, the Chain Entanglement Softened Potential (CESP) model, which takes into account the macromolecular flexibility and chain entanglement. The CESP model uses a shoulder-shaped interaction potential that is implemented in the Brownian Dynamics (BD) computations. The interaction potential contains only one parameter associated with the chain entanglement energetic cost (Ur). The hydrodynamic interactions are included in the BD computations via Tokuyama mean-field equations. The model is used to analyze the diffusion of a streptavidin protein among different sized dextran obstacles. For this system, Ur is obtained by fitting the streptavidin experimental long-time diffusion coefficient Dlongversus the macromolecular concentration for D50 (indicating their molecular weight in kg mol-1) dextran obstacles. The obtained Dlong values show better quantitative agreement with experiments than those obtained with hard-core spheres. Moreover, once parametrized, the CESP model is also able to quantitatively predict Dlong and the anomalous exponent (α) for streptavidin diffusion among D10, D400 and D700 dextran obstacles. Dlong, the short-time diffusion coefficient (Dshort) and α are obtained from the BD simulations by using a new empirical expression, able to describe the full temporal evolution of the diffusion coefficient.

  16. Peripheral vision of youths with low vision: motion perception, crowding, and visual search.

    Science.gov (United States)

    Tadin, Duje; Nyquist, Jeffrey B; Lusk, Kelly E; Corn, Anne L; Lappin, Joseph S

    2012-08-24

    Effects of low vision on peripheral visual function are poorly understood, especially in children whose visual skills are still developing. The aim of this study was to measure both central and peripheral visual functions in youths with typical and low vision. Of specific interest was the extent to which measures of foveal function predict performance of peripheral tasks. We assessed central and peripheral visual functions in youths with typical vision (n = 7, ages 10-17) and low vision (n = 24, ages 9-18). Experimental measures used both static and moving stimuli and included visual crowding, visual search, motion acuity, motion direction discrimination, and multitarget motion comparison. In most tasks, visual function was impaired in youths with low vision. Substantial differences, however, were found both between participant groups and, importantly, across different tasks within participant groups. Foveal visual acuity was a modest predictor of peripheral form vision and motion sensitivity in either the central or peripheral field. Despite exhibiting normal motion discriminations in fovea, motion sensitivity of youths with low vision deteriorated in the periphery. This contrasted with typically sighted participants, who showed improved motion sensitivity with increasing eccentricity. Visual search was greatly impaired in youths with low vision. Our results reveal a complex pattern of visual deficits in peripheral vision and indicate a significant role of attentional mechanisms in observed impairments. These deficits were not adequately captured by measures of foveal function, arguing for the importance of independently assessing peripheral visual function.

  17. Crowd sourcing a new paradigm for interactome driven drug target identification in Mycobacterium tuberculosis.

    Directory of Open Access Journals (Sweden)

    Rohit Vashisht

    Full Text Available A decade since the availability of Mycobacterium tuberculosis (Mtb genome sequence, no promising drug has seen the light of the day. This not only indicates the challenges in discovering new drugs but also suggests a gap in our current understanding of Mtb biology. We attempt to bridge this gap by carrying out extensive re-annotation and constructing a systems level protein interaction map of Mtb with an objective of finding novel drug target candidates. Towards this, we synergized crowd sourcing and social networking methods through an initiative 'Connect to Decode' (C2D to generate the first and largest manually curated interactome of Mtb termed 'interactome pathway' (IPW, encompassing a total of 1434 proteins connected through 2575 functional relationships. Interactions leading to gene regulation, signal transduction, metabolism, structural complex formation have been catalogued. In the process, we have functionally annotated 87% of the Mtb genome in context of gene products. We further combine IPW with STRING based network to report central proteins, which may be assessed as potential drug targets for development of drugs with least possible side effects. The fact that five of the 17 predicted drug targets are already experimentally validated either genetically or biochemically lends credence to our unique approach.

  18. Counteracting estimation bias and social influence to improve the wisdom of crowds.

    Science.gov (United States)

    Kao, Albert B; Berdahl, Andrew M; Hartnett, Andrew T; Lutz, Matthew J; Bak-Coleman, Joseph B; Ioannou, Christos C; Giam, Xingli; Couzin, Iain D

    2018-04-01

    Aggregating multiple non-expert opinions into a collective estimate can improve accuracy across many contexts. However, two sources of error can diminish collective wisdom: individual estimation biases and information sharing between individuals. Here, we measure individual biases and social influence rules in multiple experiments involving hundreds of individuals performing a classic numerosity estimation task. We first investigate how existing aggregation methods, such as calculating the arithmetic mean or the median, are influenced by these sources of error. We show that the mean tends to overestimate, and the median underestimate, the true value for a wide range of numerosities. Quantifying estimation bias, and mapping individual bias to collective bias, allows us to develop and validate three new aggregation measures that effectively counter sources of collective estimation error. In addition, we present results from a further experiment that quantifies the social influence rules that individuals employ when incorporating personal estimates with social information. We show that the corrected mean is remarkably robust to social influence, retaining high accuracy in the presence or absence of social influence, across numerosities and across different methods for averaging social information. Using knowledge of estimation biases and social influence rules may therefore be an inexpensive and general strategy to improve the wisdom of crowds. © 2018 The Author(s).

  19. Protecting Mobile Crowd Sensing against Sybil Attacks Using Cloud Based Trust Management System

    Directory of Open Access Journals (Sweden)

    Shih-Hao Chang

    2016-01-01

    Full Text Available Mobile crowd sensing (MCS arises as a new sensing paradigm, which leverages citizens for large-scale sensing by various mobile devices to efficiently collect and share local information. Unlike other MCS application challenges that consider user privacy and data trustworthiness, this study focuses on the network trustworthiness problem, namely, Sybil attacks in MCS network. The Sybil attack in computer security is a type of security attack, which illegally forges multiple identities in peer-to-peer networks, namely, Sybil identities. These Sybil identities will falsify multiple identities that negatively influence the effectiveness of sensing data in this MCS network or degrading entire network performance. To cope with this problem, a cloud based trust management scheme (CbTMS was proposed to detect Sybil attacks in the MCS network. The CbTMS was proffered for performing active and passive checking scheme, in addition to the mobile PCS trustworthiness management, and includes a decision tree algorithm, to verify the covered nodes in the MCS network. Simulation studies show that our CbTMS can efficiently detect the malicious Sybil nodes in the network and cause 6.87 Wh power reduction compared with other malicious Sybil node attack mode.

  20. Peripheral Vision of Youths with Low Vision: Motion Perception, Crowding, and Visual Search

    Science.gov (United States)

    Tadin, Duje; Nyquist, Jeffrey B.; Lusk, Kelly E.; Corn, Anne L.; Lappin, Joseph S.

    2012-01-01

    Purpose. Effects of low vision on peripheral visual function are poorly understood, especially in children whose visual skills are still developing. The aim of this study was to measure both central and peripheral visual functions in youths with typical and low vision. Of specific interest was the extent to which measures of foveal function predict performance of peripheral tasks. Methods. We assessed central and peripheral visual functions in youths with typical vision (n = 7, ages 10–17) and low vision (n = 24, ages 9–18). Experimental measures used both static and moving stimuli and included visual crowding, visual search, motion acuity, motion direction discrimination, and multitarget motion comparison. Results. In most tasks, visual function was impaired in youths with low vision. Substantial differences, however, were found both between participant groups and, importantly, across different tasks within participant groups. Foveal visual acuity was a modest predictor of peripheral form vision and motion sensitivity in either the central or peripheral field. Despite exhibiting normal motion discriminations in fovea, motion sensitivity of youths with low vision deteriorated in the periphery. This contrasted with typically sighted participants, who showed improved motion sensitivity with increasing eccentricity. Visual search was greatly impaired in youths with low vision. Conclusions. Our results reveal a complex pattern of visual deficits in peripheral vision and indicate a significant role of attentional mechanisms in observed impairments. These deficits were not adequately captured by measures of foveal function, arguing for the importance of independently assessing peripheral visual function. PMID:22836766

  1. Spacing, crowding, and child mortality in Guinea-Bissau.

    Science.gov (United States)

    Aaby, P; Bukh, J; Lisse, I M; Smits, A J

    1983-07-16

    Evidence from a comparative survey of the Balantas in the Tombali region and the Mandingas and Fulas in the Oio region of Guinea-Bissau suggests that overcrowding is a risk factor for child health because the severity of infections increases when 2 or more children are sick simultaneously. Rural Mandingas and Fulas breastfeed for 30 months on average, while rural Balantas do so for 38 months. All groups abstain from sexual intercourse during lactation, resulting in fewer children among Balantas. Polygamy increases crowding in all groups, but adult Balanta men have separate households while Mandinga brothers often live together in the same household. On average, there were .93 children under 5 in Balanta households but 1.91 in Mandinga households. Each wife ideally has her own room among Balanta households, but Mandinga wives live together, with up to 10 women in the same circular hut. Balanta children leave their mothers' bed when the mother gives birth to another child, while Mandinga and Fula mothers may have several children in bed at the same time. Among Balantas an average of .17 persons slept in bed with a mother and child, while among the Mandingas .66 and among the Fulas .69 did so. The weight-for-age as a percentage of the World Health Organization standard for Balantas and Mandingas-Fulas respectively was 106% and 105% at 0-2 months; 104% and 92% at 3-5 months; 90% and 82% at 6-17 months; 86% and 77% at 18-35 months breastfed; and 89% and 81% at 18-35 months weaned. During 1980-81, when no major epidemics occurred, Balanta children under 6 months had a higher survival rate for the following year than did Mandinga and Fula children, with the mortality difference occuring while all children were still breastfed. 8% of Balanta children, 16% of Mandinga children, and 24% of Fula children died within 1 year of examination. Nutritional status did not determine risk of death, but variation in the severity of infection caused by overcrowding may have done so

  2. Spectral intensity dependence an isotropy of sources stronger than 0.1 Jy at 2700 MHz

    International Nuclear Information System (INIS)

    Balonek, T.J.; Broderick, J.J.; Condon, J.J.; Crawford, D.F.; Jauncey, D.L.

    1975-01-01

    The 1000-foot (305 m) telescope of the National Astronomy and Ionosphere Center was used to measure 430 MHz flux densities of sources stronger than 0.1 Jy at 2700 MHz. Distributions of the resulting two-point spectral indices α (430, 2700) of sources in the intensity range 0.1less than or equal toS<0.35 Jy were compared with α (318, 2700) distributions of sources stronger than 0.35 Jy at 2700 MHz. The median normal-component spectral index and fraction of flat-spectrum sources in the faintest sample do not continue the previously discovered trend toward increased spectral steepening of faint sources. This result differs from the prediction of simple evolutionary cosmological models and therefore favors the alternative explanation that local source-density inhomogeneities are responsible for the observed intensity dependence of spectral indices

  3. Dynamics-Based Stranded-Crowd Model for Evacuation in Building Bottlenecks

    Directory of Open Access Journals (Sweden)

    Lidi Huang

    2013-01-01

    Full Text Available In high-density public buildings, it is difficult to evacuate. So in this paper, we propose a novel quantitative evacuation model to insure people’s safety and reduce the risk of crowding. We analyze the mechanism of arch-like clogging phenomena during evacuation and the influencing factors in emergency situations at bottleneck passages; then we design a model based on crowd dynamics and apply the model to a stadium example. The example is used to compare evacuation results of crowd density with different egress widths in stranded zones. The results show this model proposed can guide the safe and dangerous egress widths in performance design and can help evacuation routes to be selected and optimized.

  4. The age of the crowd: A vision of modern civilization

    Directory of Open Access Journals (Sweden)

    Milivojević Snežana

    2007-01-01

    Full Text Available Gustave le Bon had been writing 'the science vulgarizer' during the time when film and television were still unknown. During the half century of the film television, comics, political posters and advertising boards, it was materialized, therefore confirmed, what his 'mass psychology' contained at the very beginning. During the period of one generation, the word culture was promoted into the culture of 'ideas with form' and 'audio-visual pictures.' Which influenced stronger on the collective consciousness. Mass communication aids are powerful means which affect the mass in order to expose them to suggestion and, even more, to create their own assembly-line production, in other words, the ways of their evaluation and opinion.

  5. The CrowdMag App - turning your smartphone into a travelling magnetic observatory

    Science.gov (United States)

    Saltus, Richard; Nair, Manoj

    2017-04-01

    In 2014, we started the "CrowdMag" Project to collect vector magnetic data from digital magnetometers in smartphones. In October 2014, we released our first-generation Android and iOS apps. Currently, the CrowdMag Project has more than 15,000 enthusiastic users contributing more than 12 million magnetic data points from around the world. NOAA's National Centers for Environmental Information (NCEI), in partnership with the University of Colorado's Cooperative Institute for Research in the Environmental Sciences (CIRES) develops magnetic field models to aid navigation, resource exploration and scientific research. We use observatories, satellites and ship/airborne surveys to measure the magnetic data. However, the measurements leave gaps in coverage, particularly for short-wavelength urban noise. Our ultimate goal is to use data from the CrowdMag Project to improve global magnetic data coverage. Here we present some early results from the analysis of the crowdsourced magnetic data. A global magnetic model derived solely based on CrowdMag data is generally consistent with satellite-derived models such as World Magnetic Model. A unique contribution of the CrowdMag Project is the collection of ground level magnetic data in densely populated regions with an unprecedented spatial resolution. For example, we show a magnetic map (by binning the data collected into 100x100m cells) of central Boulder using 170,000 data points collected by about 60 devices over the duration October 2014- January 2016. The median magnetic field value is consistent with the expected magnitude of the Earth's background magnetic field. The standard deviation of the CrowdMag total field (F) values is much higher than the expected natural (i.e., diurnal and geologic) magnetic field variation. However, the phone's magnetometer is sensitive enough to capture the larger magnitude magnetic signature from the urban magnetic sources. We discuss the reliability of crowdsourced magnetic maps and their

  6. Removal of proprioception by BCI raises a stronger body ownership illusion in control of a humanlike robot.

    Science.gov (United States)

    Alimardani, Maryam; Nishio, Shuichi; Ishiguro, Hiroshi

    2016-09-22

    Body ownership illusions provide evidence that our sense of self is not coherent and can be extended to non-body objects. Studying about these illusions gives us practical tools to understand the brain mechanisms that underlie body recognition and the experience of self. We previously introduced an illusion of body ownership transfer (BOT) for operators of a very humanlike robot. This sensation of owning the robot's body was confirmed when operators controlled the robot either by performing the desired motion with their body (motion-control) or by employing a brain-computer interface (BCI) that translated motor imagery commands to robot movement (BCI-control). The interesting observation during BCI-control was that the illusion could be induced even with a noticeable delay in the BCI system. Temporal discrepancy has always shown critical weakening effects on body ownership illusions. However the delay-robustness of BOT during BCI-control raised a question about the interaction between the proprioceptive inputs and delayed visual feedback in agency-driven illusions. In this work, we compared the intensity of BOT illusion for operators in two conditions; motion-control and BCI-control. Our results revealed a significantly stronger BOT illusion for the case of BCI-control. This finding highlights BCI's potential in inducing stronger agency-driven illusions by building a direct communication between the brain and controlled body, and therefore removing awareness from the subject's own body.

  7. VGI, crowd-sourcing, citizen science and neogeography are not the same!

    CSIR Research Space (South Africa)

    Cooper, Antony K

    2015-11-01

    Full Text Available StreetMap Real-time traffic monitoring Brown Moses Arab Spring Cyber-bullying Foldit Online Protein Puzzle SETI@Home Amateur astronomer Zooniverse: Planet Hunters Mappiness WideNoise 2nd South African Bird Atlas Project (SABAP2) Household consumption diary...SMS PPGIS ABCD Transparency and accountability Empower communities Brown Moses Virtual land art Cyber-bullying Crisis mapping Arab Spring Neogeography © CSIR 2015 Crowd sourcing ≠ CiCrowd sourcing Amazon Mechanical Turk Wikipedia Brown Moses...

  8. An Application of Graphics Processing Units to Geosimulation of Collective Crowd Behaviour

    Directory of Open Access Journals (Sweden)

    Cjoskāns Jānis

    2017-12-01

    Full Text Available The goal of the paper is to assess the ways for computational performance and efficiency improvement of collective crowd behaviour simulation by using parallel computing methods implemented on graphics processing unit (GPU. To perform an experimental evaluation of benefits of parallel computing, a new GPU-based simulator prototype is proposed and the runtime performance is analysed. Based on practical examples of pedestrian dynamics geosimulation, the obtained performance measurements are compared to several other available multiagent simulation tools to determine the efficiency of the proposed simulator, as well as to provide generic guidelines for the efficiency improvements of the parallel simulation of collective crowd behaviour.

  9. Treating dental crowding with mandibular incisor extraction in an Angle Class I patient

    Directory of Open Access Journals (Sweden)

    Gislana Braga Machado

    2015-06-01

    Full Text Available Mandibular dental crowding often encourages patients to seek orthodontic treatment. The orthodontist should decide between protrusion of incisors or decrease in dental volume so as to achieve proper alignment and leveling. The present study reports the treatment of an Angle Class I malocclusion adolescent female brachyfacial patient with severe mandibular dental crowding, increased curve of Spee and deep overbite. The patient was treated with extraction of a mandibular incisor. This case was presented to the Brazilian Board of Orthodontics and Dentofacial Orthopedics (BBO as a requirement for the title of certified by the BBO.

  10. Stronger constraints on non-Newtonian gravity from the Casimir effect

    Energy Technology Data Exchange (ETDEWEB)

    Mostepanenko, V M; Klimchitskaya, G L [Center of Theoretical Studies and Institute for Theoretical Physics, Leipzig University, D-04009, Leipzig (Germany); Decca, R S [Department of Physics, Indiana University-Purdue University Indianapolis, Indianapolis, IN 46202 (United States); Fischbach, E; Krause, D E [Department of Physics, Purdue University, West Lafayette, IN 47907 (United States); Lopez, D [Bell Laboratories, Lucent Technologies, Murray Hill, NJ 07974 (United States)

    2008-04-25

    We review new constraints on the Yukawa-type corrections to Newtonian gravity obtained recently from gravitational experiments and from the measurements of the Casimir force. Special attention is paid to the constraints following from the most precise dynamic determination of the Casimir pressure between the two parallel plates by means of a micromechanical torsional oscillator. The possibility of setting limits on the predictions of chameleon field theories using the results of gravitational experiments and Casimir force measurements is discussed.

  11. The impact of crowd noise on officiating in Muay Thai: achieving external validity in an experimental setting

    Directory of Open Access Journals (Sweden)

    Tony D Myers

    2012-09-01

    Full Text Available Numerous factors have been proposed to explain the home advantage in sport. Several authors have suggested that a partisan home crowd enhances home advantage and that this is at least in part a consequence of their influence on officiating. However, while experimental studies examining this phenomenon have high levels of internal validity (since only the ‘crowd noise’ intervention is allowed to vary, they suffer from a lack of external validity, with decision-making in a laboratory setting typically bearing little resemblance to decision-making in live sports settings. Conversely, observational and quasi-experimental studies with high levels of external validity suffer from low levels of internal validity as countless factors besides crowd noise vary. The present study provides a unique opportunity to address these criticisms, by conducting a controlled experiment on the impact of crowd noise on officiating in a live tournament setting. Seventeen qualified judges officiated on thirty Thai boxing bouts in a live international tournament setting featuring ‘home’ and ‘away’ boxers. In each bout, judges were randomised into a ‘noise’ (live sound or ‘no crowd noise’ (noise cancelling headphones and white noise condition, resulting in 59 judgements in the ‘no crowd noise’ and 61 in the ‘crowd noise’ condition. The results provide the first experimental evidence of the impact of live crowd noise on officials in sport. A cross-classified statistical model indicated that crowd noise had a statistically significant impact, equating to just over half a point per bout (in the context of five round bouts with the ‘ten point must’ scoring system shared with professional boxing. The practical significance of the findings, their implications for officiating and for the future conduct of crowd noise studies are discussed.

  12. The impact of crowd noise on officiating in muay thai: achieving external validity in an experimental setting.

    Science.gov (United States)

    Myers, Tony; Balmer, Nigel

    2012-01-01

    Numerous factors have been proposed to explain the home advantage in sport. Several authors have suggested that a partisan home crowd enhances home advantage and that this is at least in part a consequence of their influence on officiating. However, while experimental studies examining this phenomenon have high levels of internal validity (since only the "crowd noise" intervention is allowed to vary), they suffer from a lack of external validity, with decision-making in a laboratory setting typically bearing little resemblance to decision-making in live sports settings. Conversely, observational and quasi-experimental studies with high levels of external validity suffer from low levels of internal validity as countless factors besides crowd noise vary. The present study provides a unique opportunity to address these criticisms, by conducting a controlled experiment on the impact of crowd noise on officiating in a live tournament setting. Seventeen qualified judges officiated on thirty Thai boxing bouts in a live international tournament setting featuring "home" and "away" boxers. In each bout, judges were randomized into a "noise" (live sound) or "no crowd noise" (noise-canceling headphones and white noise) condition, resulting in 59 judgments in the "no crowd noise" and 61 in the "crowd noise" condition. The results provide the first experimental evidence of the impact of live crowd noise on officials in sport. A cross-classified statistical model indicated that crowd noise had a statistically significant impact, equating to just over half a point per bout (in the context of five round bouts with the "10-point must" scoring system shared with professional boxing). The practical significance of the findings, their implications for officiating and for the future conduct of crowd noise studies are discussed.

  13. Does foreign aid crowd out government investments? Evidence from rural health centres in Rwanda

    Science.gov (United States)

    Lu, Chunling; Cook, Benjamin; Desmond, Chris

    2017-01-01

    Background Rural healthcare facilities in low-income countries play a major role in providing primary care to rural populations. We examined the link of foreign aid with government investments and medical service provision in rural health centres in Rwanda. Methods Using the District Health System Strengthening Tool, a web-based database built by the Ministry of Health in Rwanda, we constructed two composite indices representing provision of (1) child and maternal care and (2) HIV, tuberculosis (TB) and malaria services in 330 rural health centres between 2009 and 2011. Financing variables in a healthcare centre included received funds from various sources, including foreign donors and government. We used multilevel random-effects model in regression analyses and examined the robustness of results to a range of alternative specification, including scale of dependent variables, estimation methods and timing of aid effects. Findings Both government and foreign donors increased their direct investments in the 330 rural healthcare centres during the period. Foreign aid was positively associated with government investments (0.13, 95% CI 0.06 to 0.19) in rural health centres. Aid in the previous year was positively associated with service provision for child and maternal health (0.008, 95% CI 0.002 to 0.014) and service provision for HIV, TB and malaria (0.014, 95% CI 0.004 to 0.022) in the current year. The results are robust when using fixed-effects models. Conclusions These findings suggest that foreign aid did not crowd out government investments in the rural healthcare centres. Foreign aid programmes, conducted in addition to government investments, could benefit rural residents in low-income countries through increased service provision in rural healthcare facilities. PMID:29082015

  14. ReaDDy--a software for particle-based reaction-diffusion dynamics in crowded cellular environments.

    Directory of Open Access Journals (Sweden)

    Johannes Schöneberg

    Full Text Available We introduce the software package ReaDDy for simulation of detailed spatiotemporal mechanisms of dynamical processes in the cell, based on reaction-diffusion dynamics with particle resolution. In contrast to other particle-based reaction kinetics programs, ReaDDy supports particle interaction potentials. This permits effects such as space exclusion, molecular crowding and aggregation to be modeled. The biomolecules simulated can be represented as a sphere, or as a more complex geometry such as a domain structure or polymer chain. ReaDDy bridges the gap between small-scale but highly detailed molecular dynamics or Brownian dynamics simulations and large-scale but little-detailed reaction kinetics simulations. ReaDDy has a modular design that enables the exchange of the computing core by efficient platform-specific implementations or dynamical models that are different from Brownian dynamics.

  15. Sexual harassment and emotional and behavioural symptoms in adolescence: stronger associations among boys than girls.

    Science.gov (United States)

    Kaltiala-Heino, Riittakerttu; Fröjd, Sari; Marttunen, Mauri

    2016-08-01

    To study the associations between subjection to sexual harassment and emotional (depression) and behavioural (delinquency) symptoms among 14-to-18-year-old adolescents, and gender differences within these associations. 90,953 boys and 91,746 girls aged 14-18 participated in the School Health Promotion Study (SHPS), a school-based survey designed to examine the health, health behaviours, and school experiences of teenagers. Experiences of sexual harassment were elicited with five questions addressing five separate forms of harassment. Depression was measured by the 13-item Beck Depression Inventory and delinquency with a modified version of the International Self-Report Delinquency Study (ISRD) instrument. Data were analysed using cross-tabulations with Chi-square statistics and logistic regression. All sexual harassment experiences studied were associated with both depression (adjusted odds ratios varied from 2.2 to 2.7 in girls and from 2.0 to 5.1 in boys) and delinquency (adjusted odds ratios 3.1-5.0 in girls and 1.7-6.9 in boys). Sexual name-calling had a stronger association with depression and with delinquency in girls (adjusted odds ratios, respectively, 2.4 and 4.2), than in boys (adjusted odds ratios, respectively, 2.0 and 1.7), but otherwise stronger associations with emotional and behavioural symptoms were seen in boys. Subjection to sexual harassment is associated with both emotional and behavioural symptoms in both girls and boys. The associations are mostly stronger for boys. Boys subjected to sexual harassment may feel particularly threatened regarding their masculinity, and there may be less support available for boys traumatised due to sexual harassment.

  16. The wisdom of crowds in action: Forecasting epidemic diseases with a web-based prediction market system.

    Science.gov (United States)

    Li, Eldon Y; Tung, Chen-Yuan; Chang, Shu-Hsun

    2016-08-01

    The quest for an effective system capable of monitoring and predicting the trends of epidemic diseases is a critical issue for communities worldwide. With the prevalence of Internet access, more and more researchers today are using data from both search engines and social media to improve the prediction accuracy. In particular, a prediction market system (PMS) exploits the wisdom of crowds on the Internet to effectively accomplish relatively high accuracy. This study presents the architecture of a PMS and demonstrates the matching mechanism of logarithmic market scoring rules. The system was implemented to predict infectious diseases in Taiwan with the wisdom of crowds in order to improve the accuracy of epidemic forecasting. The PMS architecture contains three design components: database clusters, market engine, and Web applications. The system accumulated knowledge from 126 health professionals for 31 weeks to predict five disease indicators: the confirmed cases of dengue fever, the confirmed cases of severe and complicated influenza, the rate of enterovirus infections, the rate of influenza-like illnesses, and the confirmed cases of severe and complicated enterovirus infection. Based on the winning ratio, the PMS predicts the trends of three out of five disease indicators more accurately than does the existing system that uses the five-year average values of historical data for the same weeks. In addition, the PMS with the matching mechanism of logarithmic market scoring rules is easy to understand for health professionals and applicable to predict all the five disease indicators. The PMS architecture of this study affords organizations and individuals to implement it for various purposes in our society. The system can continuously update the data and improve prediction accuracy in monitoring and forecasting the trends of epidemic diseases. Future researchers could replicate and apply the PMS demonstrated in this study to more infectious diseases and wider

  17. Production of plastified wood with stronger static bending strength means of polymerization induced by gamma radiation

    International Nuclear Information System (INIS)

    Silva Filho, Elias

    1999-01-01

    The use of gamma radiation to obtain wood-polymer composites is one of the applications of radiation that presents the most commercial interest. The process, denominated radiopolymerization, comprises the impregnation of monomers into the completely dried wood followed by exposure to gamma radiation to induce polymerization of the impregnated monomers. I this context, the present work aimed the application of this process to seven kinds of wood existing in the brazilian forests. The considered monomer is styrene and the gamma source is Cobalt-60. The obtained wood-polystyrene composites were found to have stronger static bending strength. (author)

  18. Why is the radial flow in central pA collisions stronger than in AA?

    International Nuclear Information System (INIS)

    Kalaydzhyan, Tigran; Shuryak, Edward

    2014-01-01

    Both the transverse size and entropy density per area in central pA collisions is smaller than in central AA, and yet the radial flow is stronger. We propose an explanation to this puzzle. Using a weak attraction between strings through the σ-meson exchange, fitted to the lattice data, we find collective implosion of the “spaghetti” multi-string state. Collectivization of the sigma field of the strings is the QCD analog of the black hole formation occurring in holographic models

  19. Selection is stronger in early-versus-late stages of divergence in a Neotropical livebearing fish.

    Science.gov (United States)

    Ingley, Spencer J; Johnson, Jerald B

    2016-03-01

    How selection acts to drive trait evolution at different stages of divergence is of fundamental importance in our understanding of the origins of biodiversity. Yet, most studies have focused on a single point along an evolutionary trajectory. Here, we provide a case study evaluating the strength of divergent selection acting on life-history traits at early-versus-late stages of divergence in Brachyrhaphis fishes. We find that the difference in selection is stronger in the early-diverged population than the late-diverged population, and that trait differences acquired early are maintained over time. © 2016 The Author(s).

  20. Building Stronger State Energy Partnerships with the U.S. Department of Energy

    Energy Technology Data Exchange (ETDEWEB)

    Marks, Kate

    2011-09-30

    This final technical report details the results of total work efforts and progress made from October 2007 – September 2011 under the National Association of State Energy Officials (NASEO) cooperative agreement DE-FC26-07NT43264, Building Stronger State Energy Partnerships with the U.S. Department of Energy. Major topical project areas in this final report include work efforts in the following areas: Energy Assurance and Critical Infrastructure, State and Regional Technical Assistance, Regional Initiative, Regional Coordination and Technical Assistance, and International Activities in China. All required deliverables have been provided to the National Energy Technology Laboratory and DOE program officials.