2,332 research outputs found
Time Pressure and the Development of Integrative Agreements in Bilateral Negotiations
A laboratory experiment examined the effects of time pressure on the process and outcome of integrative bargaining. Time pressure was operationalized in terms of the amount of time available to negotiate. As hypothesized, high time pressure produced nonagreements and poor negotiation outcomes only when negotiators adopted an individualistic orientation; when negotiators adopted a cooperative orientation, they achieved high outcomes regardless of time pressure. In combination with an individualistic orientation, time pressure produced greater competitiveness, firm negotiator aspirations, and reduced information exchange. In combination with a cooperative orientation, time pressure produced greater cooperativeness and lower negotiator aspirations. The main findings were seen as consistent with Pruitt’s strategic-choice model of negotiation
Systematic chemotherapy of febrile cases : a substitute strategy for malaria control in rural areas of Africa
Diversity, palaeoecology and palaeoenvironmental significance of the Eocene chondrichthyan assemblages of the Bolca Lagerstätte, Italy
Ballistic aggregation: a solvable model of irreversible many particles dynamics
The adhesive dynamics of a one-dimensional aggregating gas of point particles
is rigorously described. The infinite hierarchy of kinetic equations for the
distributions of clusters of nearest neighbours is shown to be equivalent to a
system of two coupled equations for a large class of initial conditions. The
solution to these nonlinear equations is found by a direct construction of the
relevant probability distributions in the limit of a continuous initial mass
distribution. We show that those limiting distributions are identical to those
of the statistics of shocks in the Burgers turbulence. The analysis relies on a
mapping on a Brownian motion problem with parabolic constraints.Comment: 23 pages, 6 figures include
Individual Differences in Need for Cognition and Decision-Making Competence among Leaders
When making decisions, people sometimes deviate from normative standards. While such deviations may appear to be alarmingly common, examining individual differences may reveal a more nuanced picture. Specifically, the personality factor of need for cognition (i.e., the extent to which people engage in and enjoy effortful cognitive activities; Cacioppo & Petty, 1982) may moderate decision makers’ susceptibility to bias, as could personality factors associated with being a leader. As part of a large-scale assessment of high-level leaders, participants completed a battery of decision-making competence and personality scales. Leaders who scored higher on need for cognition performed better on two of four components of a decision-making competence measure: framing and honoring sunk costs. In addition, the leader sample performed better than published controls. Thus, both individual differences in need for cognition and leadership experience moderate susceptibility to decision biases. Implications for broader theories of individual differences and bias are discussed
The College Payoff: Education, Occupations, Lifetime Earnings
Examines lifetime earnings by educational attainment, occupation, age, gender, and race/ethnicity; variations in earnings at the same degree level by occupation and in the same occupation by degree level; and top-earning occupations by degree level
Le paludisme urbain à Yaoundé, Cameroun : 1. Etude entomologique dans deux quartiers centraux
Une étude entomologique longitudinale sur les moustiques agressifs pour l'homme et la transmission du paludisme a été réalisée dans deux quartiers centraux de la ville de Yaoundé (Cameroun) d'avril 1989 à mars 1990. Le quartier Essos borde un bas-fond marécageux. Le quartier Obili est comparable à Essos, mais il y a beaucoup de bassins de pisciculture mal entretenus et couverts de végétation aquatique. Les moustiques furent échantillonnés de nuit, dans les maisons, sur appât humain, deux fois par mois dans chaque quartier. A Essos, un habitant reçoit annuellement près de 4000 piqûres de moustiques. Quatre espèces de moustiques sont capturées : #Culex #quinquefasciatus (84%), #Mansonia #gambiae. #Funestus. #gambiae. #Funestus est absent et la proportion d'#A. #gambiae. #gambiae (49% de la faune culicidienne agressive) est liée à l'abondance de la végétation aquatique due au manque d'entretien des bassins. (Résumé d'auteur
A Cross-Over in the Enstrophy Decay in Two-Dimensional Turbulence in a Finite Box
The numerical simulation of two-dimensional decaying turbulence in a large
but finite box presented in this paper uncovered two physically different
regimes of enstrophy decay. During the initial stage, the enstrophy, generated
by a random Gaussian initial condition, decays as t^{-gamma} with gamma
approximately 0.7-0.8. After that, the flow undergoes a transition to a gas or
fluid composed of distinct vortices. Simultaneously, the magnitude of the decay
exponent crosses over to gamma approximately 0.4. An exact relation for the
total number of vortices, N(t), in terms of the mean circulation of an
individual vortex is derived. A theory predicting that N(t) is proportional to
t^{-xi} and the magnitudes of exponents gamma=2/5 and xi=4/5 is presented and
the possibility of an additional very late-time cross-over to gamma=1/3 and
xi=2/3 is also discussed.Comment: 11 pages, 7 figure
Neural dynamics of perceptual detection under temporal uncertainty
Tesis doctoral inédita leída en la Universidad Autónoma de Madrid, Facultad de Ciencias, Departamento de Física Teórica. Fecha de lectura: 17-10-2014Among the large number of functions that compose our mental life,
perception is arguably the most fundamental one. Perception is the
cognitive process by which external sensory signals are transformed
into meaningful information that represents our environment and guide
decisions and behavior. What is the neural basis of this transformation?
Several key issues limit our understanding of the neurobiology
of perception and perceptual decision-making. First, the neural codes
used by the brain to represent sensory information are still unclear.
Second, perceptual decisions presumably arise from the coordinated
activity of populations of neurons. However, the analytical tools best
suited to study decision signals in neuronal populations remain unknown.
Third, perception is not a passive process. On the contrary,
external stimuli and internal brain states dynamically interact to give
rise to percepts. In this thesis, I address these questions using computational
simulations and neural data recorded while monkeys perform
a vibrotactile detection task. Three fundamental issues are examined:
(1) the dynamics of correlated variability, (2) the decoding of decisions
from neural population's activity and (3) the neural mechanisms underlying
the use of temporal expectations. I study the dynamics of
choice-conditioned noise correlations and show that they reveal an internal
component of the decision-making process. By developing novel
statistical measures, I quantify how predictive is the activity of populations
of cortical neurons about the subject's decision. As a result,
I nd that a speci c subset of premotor cortex neurons unequivocally
predict the animal's decision report. The vibrotactile detection
task studied in this work requires subjects to make decisions under
temporal uncertainty. I nd that subjects bene t from temporal expectations
by modulating their response criterion over the course of
a trial. I show that this modulation is represented by the population
dynamics of premotor cortex neurons. A trained recurrent neural
network reproduces the experimental ndings and reveals the dynamical
mechanism implementing a
exible response criterion. Knowledge
about the probability of stimulation over time, acquired during training,
is intrinsically encoded in the neural population activity, allowing
a dynamic control of the response criterion to improve performanceEntre el gran número funciones cognitivas que componen nuestra vida
mental, la percepción es, quizá, la más fundamental. La percepción es
el proceso mediante el cual el cerebro interpreta, organiza y da sentido
a la gran cantidad de señales sensoriales que recibe del mundo exterior.
De esta forma, la información sensorial es transformada en una representaci
ón relevante de nuestro entorno, útil para guíar nuestro comportamiento.
¿Cuál es el correlato neuronal de esta transformación?
Hay varias cuestiones clave que limitan nuestro entendimiento de la
neurobiología de la percepción y de las decisiones perceptuales. En
primer lugar, el código neuronal que el cerebro utiliza para representar
información sensorial no es del todo claro. En segundo lugar, las
decisiones presumiblemente emergen de la actividad conjunta de un
gran número de neuronas. Sin embargo, las herramientas analíticas
más adecuadas para estudiar estas señales poblacionales todava no
son enteramente conocidas. En tercer lugar, la percepción no es un
proceso pasivo. Por el contrario, los estímulos externos y los estados
internos del cerebro interactúan dinámicamente para construir
nuestra experiencia subjetiva. En esta tesis, abordo estos asuntos
utilizando simulaciones computacionales y analizando registros neuronales
obtenidos en monos mientras realizan una tarea de detección
vibrotáctil. Tres cuestiones fundamentales son examinadas: (1) la
dinámica de la variabilidad neuronal correlacionada, (2) la decodi_-
cación de señales de decisión a partir de la actividad de poblaciones
de neuronas y (3) los mecanismos neuronales que subyacen a la incorporaci
ón de expectativas temporales en el proceso de decisión. Estudiando
la dinámica de las correlaciones del ruido, muestro que éstás
revelan una componente interna del proceso de decisión. Mediante
el desarrollo de nuevas medidas estadísticas, cuantifico el poder predictivo
de la actividad de conjuntos de neuronas acerca de las decisiones
del sujeto. Como resultado, encuentro que la decisión del
animal puede predecirse inequívocamente a partir de la actividad de
poblaciones específicas de neuronas de la corteza premotora. La tarea
de detección estudiada en esta tesis require que los animales tomen
decisiones en un contexto de incertidumbre temporal. En esta tesis
muestro que los sujetos construyen y utilizan expectativas temporales
para aumentar su rendimiento mediante la modulación de su criterio
de respuesta a través del tiempo. Además, encuentro que la actividad
de las neuronas de la corteza premotora es consistente con un mecanismo
neuronal específico para implementar esta modulación. Finalmente,
derivo un modelo de red recurrente que reproduce los resultados
experimentales y permite estudiar la estructura dinámica subyacente.
El conocimiento previo acerca de la probabilidad de estimulación
como función del tiempo, adquirido durante el entrenamiento,
puede ser intrínsecamente codificado por una población de neuronas,
permitiendo el control dinámico del criterio de durante el proceso de
decisión
Toronto Augmented Reality Map: Enhancing citizen engagement with open government data using contemporary media platforms
This thesis investigates how visualization strategies and media platforms affect citizen engagement with urban public data. There is currently an international movement towards government transparency and accessible information as developed nations become more urbanized and information technology more ubiquitous. Concurrently, new media platforms (e.g., virtual and augmented reality) are evolving rapidly and show promise of mass adoption. These factors together offer design researchers a unique opportunity to develop new forms of citizen-facing media. I therefore developed an interactive augmented reality application that works with a printed map of the city of Toronto to overlay open government data as visualized digital content. An iterative practice-based research approach was used. Usability tests demonstrated that a strength of augmented reality is its facilitation of multi-user engagement. This thesis concludes by discussing how the Toronto augmented reality map can be made into an interactive citizen-facing installation in the public sphere
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