2,374 research outputs found
Dynamical properties of a dissipative discontinuous map: A scaling investigation
The effects of dissipation on the scaling properties of nonlinear
discontinuous maps are investigated by analyzing the behavior of the average
squared action \left as a function of the -th iteration of
the map as well as the parameters and , controlling nonlinearity
and dissipation, respectively. We concentrate our efforts to study the case
where the nonlinearity is large; i.e., . In this regime and for large
initial action , we prove that dissipation produces an exponential
decay for the average action \left. Also, for , we
describe the behavior of \left using a scaling function and
analytically obtain critical exponents which are used to overlap different
curves of \left onto an universal plot. We complete our study
with the analysis of the scaling properties of the deviation around the average
action .Comment: 20 pages, 7 figure
Effect of biofertilizers and neem oil on the entomopathogenic fungi beauveria bassiana (Bals.) vuill. and metarhizium anisopliae (Metsch.) sorok.
The in vitro fungitoxic effect of three biofertilizers, E.M.-4, Multibion Ô and Supermagro used in organic agriculture and the neem oil (Azadirachta indica A. Juss) on the entomopathogenic fungi Metarhizium anisopliae and Beauveria bassiana was studied. These products were mixed in a medium where the two fungi were inoculated, and germination, vegetative growth and conidiogenesis were assessed. The biofertilizers Supermagro and E.M.- 4 showed to be less toxic for the two fungi whereas MultibionÔ caused major inhibition on M. anisopliae, with reductions in germination (-37.74%), colony diameter (-30.26%) and conidiogenesis (-42.62%). Neem oil promoted a larger negative effect on B. bassiana, inhibiting germination (-45.27%), colony diameter (-36.62%) and conidiogenesis (-84.93%)
The L\'evy Map: A two-dimensional nonlinear map characterized by tunable L\'evy flights
Once recognizing that point particles moving inside the extended version of
the rippled billiard perform L\'evy flights characterized by a L\'evy-type
distribution with , we derive a
generalized two-dimensional non-linear map able to produce L\'evy
flights described by with . Due to this property, we name
as the L\'evy Map. Then, by applying Chirikov's overlapping
resonance criteria we are able to identify the onset of global chaos as a
function of the parameters of the map. With this, we state the conditions under
which the L\'evy Map could be used as a L\'evy pseudo-random number generator
and, furthermore, confirm its applicability by computing scattering properties
of disordered wires.Comment: 6 pages, 5 figure
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What Happens in Vegas Stays on TripAdvisor? A Theory and Technique to Understand Narrativity in Consumer Reviews
Many consumers base their purchase decisions on online consumer reviews. An overlooked feature of these texts is their narrativity: the extent to which they tell a story. The authors construct a new theory of narrativity to link the narrative content and discourse of consumer reviews to consumer behavior. They also develop from scratch a computerized technique that reliably determines the degree of narrativity of 190,461 verbatim, online consumer reviews and validate the automated text analysis with two controlled experiments. More transporting (i.e., engaging) and persuasive reviews have better developed characters and events as well as more emotionally changing genres and dramatic event orders. This interdisciplinary, multimethod research should help future researchers (1) predict how narrativity affects consumers’ narrative transportation and persuasion, (2) measure the narrativity of large digital corpora of textual data, and (3) understand how this important linguistic feature varies along a continuum
Leaking from the phase space of the Riemann-Liouville fractional standard map
In this work we characterize the escape of orbits from the phase space of the
Riemann-Liouville (RL) fractional standard map (fSM). The RL-fSM, given in
action-angle variables, is derived from the equation of motion of the kicked
rotor when the second order derivative is substituted by a RL derivative of
fractional order . Thus, the RL-fSM is parameterized by and
which control the strength of nonlinearity and the fractional
order of the RL derivative, respectively. Indeed, for and given
initial conditions, the RL-fSM reproduces Chirikov's standard map. By computing
the survival probability and the frequency of escape
, for a hole of hight placed in the action axis, we
observe two scenarios: When the phase space is ergodic, both scattering
functions are scale invariant with the typical escape time
. In contrast, when
the phase space is not ergodic, the scattering functions show a clear
non-universal and parameter-dependent behavior
Matching fields of a long superconducting film
We obtain the vortex configurations, the matching fields and the
magnetization of a superconducting film with a finite cross section. The
applied magnetic field is normal to this cross section, and we use London
theory to calculate many of its properties, such as the local magnetic field,
the free energy and the induction for the mixed state. Thus previous similar
theoretical works, done for an infinitely long superconducting film, are
recovered here, in the special limit of a very long cross section.Comment: Contains a REVTeX file and 4 figure
Cohesion, team mental models, and collective efficacy: Towards an integrated framework of team dynamics in sport
A nomological network on team dynamics in sports consisting of a multi-framework perspective is introduced and tested. The aim was to explore the interrelationship among cohesion, team mental models (TMM), collective-efficacy (CE), and perceived performance potential (PPP). Three hundred and forty college-aged soccer players representing 17 different teams (8 female and 9 male) participated in the study. They responded to surveys on team cohesion, TMM, CE and PPP. Results are congruent with the theoretical conceptualization of a parsimonious view of team dynamics in sports. Specifically, cohesion was found to be an exogenous variable predicting both TMM and CE beliefs. TMM and CE were correlated and predicted PPP, which in turn accounted for 59% of the variance of objective performance scores as measured by teams’ season record. From a theoretical standpoint, findings resulted in a parsimonious view of team dynamics, which may represent an initial step towards clarifying the epistemological roots and nomological network of various team-level properties. From an applied standpoint, results suggest that team expertise starts with the establishment of team cohesion. Following the establishment of cohesiveness, teammates are able to advance team-related schemas and a collective sense of confidence. Limitations and key directions for future research are outlined
My heart is racing! Psychophysiological dynamics of skilled racecar drivers
Our purpose was to test the multi-action plan (MAP) model assumptions in which athletes’ psychophysiological patterns differ among optimal and suboptimal performance experiences. Nine professional drivers competing in premier race categories (e.g., Formula 3, Porsche GT3 Cup Challenge) completed the study. Data collection involved monitoring the drivers’ perceived hedonic tone, accuracy on core components of action, posture, skin temperature, respiration rate, and heart rate responses during a 40-lap simulated race. Time marks, gathered at three standardized sectors, served as the performance variable. The A1GP racing simulator (Allinsport, Modena) established a realistic race platform. Specifically, the Barcelona track was chosen due to its inherently difficult nature characterized by intermittent deceleration points. Idiosyncratic analyses showed large individual differences in the drivers’ psychophysiological profile, as well as distinct patterns in regards to optimal and suboptimal performance experiences. Limitations and future research avenues are discussed. Action (e.g., attentional control) and emotion (e.g., biofeedback training) centered applied sport psychology implications are advanced
SIMBA: a web tool for managing bacterial genome assembly generated by Ion PGM sequencing technology
Background The evolution of Next-Generation Sequencing (NGS) has considerably reduced the cost per sequenced-base, allowing a significant rise of sequencing projects, mainly in prokaryotes. However, the range of available NGS platforms requires different strategies and software to correctly assemble genomes. Different strategies are necessary to properly complete an assembly project, in addition to the installation or modification of various software. This requires users to have significant expertise in these software and command line scripting experience on Unix platforms, besides possessing the basic expertise on methodologies and techniques for genome assembly. These difficulties often delay the complete genome assembly projects. Results In order to overcome this, we developed SIMBA (SImple Manager for Bacterial Assemblies), a freely available web tool that integrates several component tools for assembling and finishing bacterial genomes. SIMBA provides a friendly and intuitive user interface so bioinformaticians, even with low computational expertise, can work under a centralized administrative control system of assemblies managed by the assembly center head. SIMBA guides the users to execute assembly process through simple and interactive pages. SIMBA workflow was divided in three modules: (i) projects: allows a general vision of genome sequencing projects, in addition to data quality analysis and data format conversions; (ii) assemblies: allows de novo assemblies with the software Mira, Minia, Newbler and SPAdes, also assembly quality validations using QUAST software; and (iii) curation: presents methods to finishing assemblies through tools for scaffolding contigs and close gaps. We also presented a case study that validated the efficacy of SIMBA to manage bacterial assemblies projects sequenced using Ion Torrent PGM. Conclusion Besides to be a web tool for genome assembly, SIMBA is a complete genome assemblies project management system, which can be useful for managing of several projects in laboratories. SIMBA source code is available to download and install in local webservers at http://ufmg-simba.sourceforge.net
Genome Sequence of Corynebacterium pseudotuberculosis MB20 bv. equi Isolated from a Pectoral Abscess of an Oldenburg Horse in California.
The genome of Corynebacterium pseudotuberculosis MB20 bv. equi was sequenced using the Ion Personal Genome Machine (PGM) platform, and showed a size of 2,363,089 bp, with 2,365 coding sequences and a GC content of 52.1%. These results will serve as a basis for further studies on the pathogenicity of C. pseudotuberculosis bv. equi
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