Speed Dating y el mercado de solteros

Encontrar tu media naranja ocupa recursos, es un hecho crucial en el ser humano ser capaz de optimizarlos y hacer una elección que, como demostraremos, es racional aunque parezca que el amor sea ilógico.Considerando los posibles candidatos parte de la oferta y/o la demanda, los economistas crean modelos para explicar un mercadomatrimonial en el que la base de estudio son los clientes de Speed Dating, un sistema de citas rápidas. Siendo ésta la base principal,nuestro objetivo es realizar un proyecto en el que seamos capaces de establecer un prototipo de cliente, tanto femenino como masculino observando los posibles sesgos que tal población pueda mostrar para estudios de inferencia estadística sobre la población de los solteros.Las diferencias entre sexos son una motivación esencial, preguntarnos si puede marcar una diferencia en el punto de partida también. Éstas y demás preguntas las resolveremos en las siguientes páginas, ¿sabéis que en realidad nos unen más aspectos que el estado civil?, ¿no essospechoso que seamos aparentemente tan iguales?Si realmente la guerra de sexos existe aquí demostramos que avanzamos en aras de la igualdad: Los solteros del Speed Dating tienen altos niveles de estudios, dedican su tiempo de ocio a actividades culturales y de entretenimiento y disponen de una mentalidad abierta.La paz es posible pero no deja de implicar la incertidumbre sobre si una diferencia es positiva o negativa, cuestiones morales a parte. Si los candidatos de un sexo determinado superan al contrario, es lógico que, al haber mayor competencia busquen la diferenciación como ventaja comparativa para acceder a mejores términos de comercio, así que si no existe tal diferencia puede ser por dos motivos: realmente la igualdad impera en la sociedad como estudios sociológicos determinan, resaltando la homogamia, concepto propio de un mercado matrimonial “sin restricciones” o quizás, la heterogamia en las uniones está quedando en segundo lado, perdiendo en términos de apertura social.

Effect of obesity onset on pendular energy transduction at spontaneous walking speed: Prader-Willi versus nonsyndromal obese individuals.

OBJECTIVE: To compare the mechanical external work (Wext ) and pendular energy transduction (Rstep ) at spontaneous walking speed (Ss ) in individuals with Prader-Willi syndrome (PWS) versus subjects with nonsyndromal obesity (OB) to investigate whether the early onset of obesity allows PWS subjects to adopt energy conserving gait mechanics. DESIGN AND METHODS: Wext and Rstep were computed using kinematic data acquired by an optoelectronic system and compared in 15 PWS (BMI = 39.5 ± 1.8 kg m(-2) ; 26.7 ± 1.5 year) and 15 OB (BMI = 39.3 ± 1.0 kg m(-2) ; 28.7 ± 1.9 year) adults matched for gender, age and BMI and walking at Ss . RESULTS: Ss was significantly lower in PWS (0.98 ± 0.03 m s(-1) ) than in OB (1.20 ± 0.02 m s(-1) ; P < 0.001). There were no significant differences in Wext per kilogram between groups (PWS: 0.37 ± 0.04 J kg(-1) m(-1) ; OB: 0.40 ± 0.05 J kg(-1) m(-1) ; P = 0.66) and in Rstep (PWS: 69.9 ± 2.9%; OB: 67.7 ± 2.4%; P = 0.56). However, Rstep normalized to Froude number (Rstep /Fr) was significantly greater in PWS (6.0 ± 0.6) than in OB (3.8 ± 0.2; P = 0.001). Moreover, Rstep /Fr was inversely correlated with age of obesity onset (r = -0.49; P = 0.006) and positively correlated with obesity duration (r = 0.38; P = 0.036). CONCLUSION: Individuals with PWS seem to alter their gait to improve pendular energy transduction as a result of precocious and chronic adaptation to loading.

Assessing High-Speed Internet Access in the State of Iowa: Fifth Assessment, May 2006

The primary objective of the Fifth Assessment is to evaluate the level of progress in the deployment of high-speed Internet technologies in the State of Iowa.

Error and attack tolerance of layered complex networks.

Many complex systems may be described by not one but a number of complex networks mapped on each other in a multi-layer structure. Because of the interactions and dependencies between these layers, the state of a single layer does not necessarily reflect well the state of the entire system. In this paper we study the robustness of five examples of two-layer complex systems: three real-life data sets in the fields of communication (the Internet), transportation (the European railway system), and biology (the human brain), and two models based on random graphs. In order to cover the whole range of features specific to these systems, we focus on two extreme policies of system's response to failures, no rerouting and full rerouting. Our main finding is that multi-layer systems are much more vulnerable to errors and intentional attacks than they appear from a single layer perspective.

The Speed of the Financial Revolution: Evidence from Hoare’s Bank

Finance is important for development, yet the onset of modern economic growth in Britain lagged the British financial revolution by over a century. We present evidence from a new West-End London private bank to explain this delay. Hoare’s Bank loaned primarily to a highly select and well-born clientele, although it did not discriminate against “unknown” borrowers in the early 18th century. It could not extend credit more generally because of government restrictions (usury limits) and policies (frequent wars). Britain’s financial development could have aided growth substantially, had it not been for the rigidities and turmoil introduced by government interference.

Speed of convergence of recursive least squares learning with ARMA perceptions

This paper fills a gap in the existing literature on least squareslearning in linear rational expectations models by studying a setup inwhich agents learn by fitting ARMA models to a subset of the statevariables. This is a natural specification in models with privateinformation because in the presence of hidden state variables, agentshave an incentive to condition forecasts on the infinite past recordsof observables. We study a particular setting in which it sufficesfor agents to fit a first order ARMA process, which preserves thetractability of a finite dimensional parameterization, while permittingconditioning on the infinite past record. We describe how previousresults (Marcet and Sargent [1989a, 1989b] can be adapted to handlethe convergence of estimators of an ARMA process in our self--referentialenvironment. We also study ``rates'' of convergence analytically and viacomputer simulation.

Country asymmetries, endogenous product choice and the speed of trade liberalization

In a world with two countries which differ in size, we study theimpact of (the speed of) trade liberalization on firms' profitsand total welfare of the countries involved. Firms correctlyanticipate the pace of trade liberalization and take it intoaccount when deciding on their product choices, which areendogenously determined at the beginning of the game. Competitionin the marketplace then occurs either on quantities or on prices.As long as the autarkic phase continues, local firms are nationalmonopolists. When trade liberalization occurs, firms compete in aninternational duopoly. We analyze trade effects by using twodifferent models of product differentiation. Across all thespecifications adopted (and independently of the price v. quantitycompetition hypothesis), total welfare always unambiguously riseswith the speed of trade liberalization: Possible losses by firmsare always outweighed by consumers' gains, which come under theform of lower prices, enlarged variety of higher average qualitiesavailable. The effect on profits depends on the type of industryanalyzed. Two results in particular seem to be worth of mention.With vertical product differentiation and fixed costs of qualityimprovements, the expected size of the market faced by the firmsdetermines the incentive to invest in quality. The longer the periodof autarky, the lower the possibility that the firm from the smallcountry would be producing the high quality and be the leader in theinternational market when it opens. On the contrary, when trade opensimmediately, national markets do not play any role and firms fromdifferent countries have the same opportunity to become the leader.Hence, immediate trade liberalization might be in the interest ofproducers in the small country. In general, the lower the size of thesmall country, the more likely its firm will gain from tradeliberalization. Losses from the small country firm can arise when itis relegated to low quality good production and the domestic marketsize is not very small. With horizontal product differentiation (thehomogeneous good case being a limit case of it when costs ofdifferentiation tend to infinity), investments in differentiationbenefit both firms in equal manner. Firms from the small country do notrun the risk of being relegated to a lower competitive position undertrade. As a result, they would never lose from it. Instead, firms fromthe large country may still incur losses from the opening of trade whenthe market expansion effect is low (i.e. when the country is very largerelative to the other).

Gall midge attack intensity and host-plant response in a Neotropical coastal ecosystem

The gall inducer Clusiamyia nitida Maia, 1996 (Diptera, Cecidomyiidae) often infests the shrub Clusia lanceolata (Camb.) (Clusiaceae) in the Neotropical vegetation of restinga of Rio de Janeiro State, Brazil. Leaves of Clusia lanceolata host up to 20 spheroid galls and show variation in their shape. We aimed to evaluate the effect of gall's intensity on leaves of Clusia lanceolata, and the extension of gall's impact on adjacent non-galled leaves. We analyzed the effect of the number of galls on leaf area, biomass, specific area and leaf appearance from 509 leaves of 14 individual plants. The results showed that differences of individual plants, pairs of leaves, and gall presence were responsible for more then 90% of variation on infested leaves. Variation on parasitic intensity level created differences in leaf response. Under moderate gall attack characterized by scattered galls on a leaf, the increase of the number of galls caused an increase of leaf biomass and area, and a decrease of specific area. The specific area was smaller also under high attack intensity, characterized by coalescent galls on a leaf. In those cases of extremely high parasitic intensity, galled leaves became deformed and the surface area was severely reduced. Leaf deformation due to gall attack led to early leaf abscission, indicated by the 90% of deformed leaves found in the youngest leaf pair of the branch. There was insufficient evidence that the impact of galls on leaf morpho-physiological parameters extended beyond the attacked leaves, because ungalled leaves did not change significantly when their opposite leaf had been galled.

Pattern of attack of a galling insect reveals an unexpected preference-performance linkage on medium-sized resources

Pattern of attack of a galling insect reveals an unexpected preference-performance linkage on medium-sized resources. The Plant Vigor Hypothesis (PVH) predicts oviposition preference and higher offspring performance on longer and fast-growing shoots, and although several studies have tested its predictions, long-term studies concerning the patterns of host selection by galling species are still lacking. The PVH was tested in this study using Bauhinia brevipes (Fabaceae) as the host of a leaf gall midge, Asphondylia microcapillata (Diptera, Cecidomyiidae) during three consecutive years. Shoots were collected from the same 80 plants between 2001 and 2003 and shoot length, number of healthy and galled leaves, gall number, and mortality factors were recorded. Nearly 600 galls were found on the 5,800 shoots collected. Medium-sized shoots supported from 46 to 70% of all galls, with greater gall survival rate in 2002 and 2003. A decrease in parasitism rate coupled with an increase in gall predation lead to a constant similar gall survivorship rate in all years (x = 22.7%). Although gall abundance varied among years (122 in 2001, 114 in 2002 and 359 in 2003) preference for longer shoots was not observed because the percentage of galled shoots and galled leaves were higher on medium shoot length classes in all years. The observed distribution of gall abundance and galled shoots were always greater than the expected distribution on medium shoot length classes. These findings do not support the PVH, and show that A. microcapillata can maximize the female preference and larval performance on medium-sized shoots of B. brevipes.

Assessment of speed of human locomotion using a differential satellite global positioning system.

PURPOSE: The objective was to explore whether a satellite-based navigation system, global positioning system used in differential mode (DGPS), could accurately assess the speed of running in humans. METHODS: A subject was equipped with a portable GPS receptor coupled to a receiver for differential corrections, while running outdoors on a straight asphalt road at 27 different speeds. Actual speed (reference method) was assessed by chronometry. RESULTS: The accuracy of speed prediction had a standard deviation (SD) of 0.08 km x h(-1) for walking, 0.11 km x h(-1) for running, yielding a coefficient of variation (SD/mean) of 1.38% and 0.82%, respectively. There was a highly significant linear relationship between actual and DGPS speed assessment (r2 = 0.999) with little bias in the prediction equation, because the slope of the regression line was close to unity (0.997). CONCLUSION: the DGPS technique appears to be a valid and inconspicuous tool for "on line" monitoring of the speed of displacement of individuals located on any field on earth, for prolonged periods of time and unlimited distance, but only in specific environmental conditions ("open sky"). Furthermore, the accuracy of speed assessment using the differential GPS mode was improved by a factor of 10 as compared to non-differential GPS.

Does the aggressiveness of the prey modify the attack behavior of the predator Supputius cincticeps (Stål) (Hemiptera, Pentatomidae)?

Does the aggressiveness of the prey modify the attack behavior of the predator Supputius cincticeps (Stål) (Hemiptera, Pentatomidae)? The stink bug Supputius cincticeps (Stål) (Hemiptera, Pentatomidae) is a predator found in several Brazilian regions, which possesses desirable attributes as a natural control agent and in biological control programs. The aim of this study was to test if the attack behavior and predation success of S. cincticeps were affected by prey species. Larvae of Tenebrio molitor (L.) (Coleoptera, Tenebrionidae), Spodoptera frugiperda (J. E. Smith) (Lepidoptera, Noctuidae), and Thyrinteina arnobia (Stoll) (Lepidoptera, Geometridae) were offered to S. cincticeps in laboratory bioassays where predatory attack and prey defensive behaviors were observed for 2-hour periods. The attack behavior of S. cincticeps changed with the prey species offered. More than 25% of T. molitor and S. frugiperda larvae were immediately attacked, but T. arnobia was not immediately attacked by S. cincticeps. Successful attack (i.e., successful insertion of the predator stylets into the prey) depends on the region of the body attacked, with a greater proportion of successful attacks in the anterior than in the median or posterior regions. Larvae of T. arnobia and S. frugiperda displayed a sequence of abrupt head and body movements in response to S. cincticeps attack. Attempts of predation were more successful on T. molitor and S. frugiperda than on T. arnobia. Information about the differential attack behavior of S. cincticeps on different prey species is important for designing successful biological control programs using this hemipteran predator.

Food's visually perceived fat content affects discrimination speed in an orthogonal spatial task.

Choosing what to eat is a complex activity for humans. Determining a food's pleasantness requires us to combine information about what is available at a given time with knowledge of the food's palatability, texture, fat content, and other nutritional information. It has been suggested that humans may have an implicit knowledge of a food's fat content based on its appearance; Toepel et al. (Neuroimage 44:967-974, 2009) reported visual-evoked potential modulations after participants viewed images of high-energy, high-fat food (HF), as compared to viewing low-fat food (LF). In the present study, we investigated whether there are any immediate behavioural consequences of these modulations for human performance. HF, LF, or non-food (NF) images were used to exogenously direct participants' attention to either the left or the right. Next, participants made speeded elevation discrimination responses (up vs. down) to visual targets presented either above or below the midline (and at one of three stimulus onset asynchronies: 150, 300, or 450 ms). Participants responded significantly more rapidly following the presentation of a HF image than following the presentation of either LF or NF images, despite the fact that the identity of the images was entirely task-irrelevant. Similar results were found when comparing response speeds following images of high-carbohydrate (HC) food items to low-carbohydrate (LC) food items. These results support the view that people rapidly process (i.e. within a few hundred milliseconds) the fat/carbohydrate/energy value or, perhaps more generally, the pleasantness of food. Potentially as a result of HF/HC food items being more pleasant and thus having a higher incentive value, it seems as though seeing these foods results in a response readiness, or an overall alerting effect, in the human brain.

Speed Limit Questions? Here’s Your Answer, July 6, 2005

Iowa’s speed regulations are based on the same basic speed law that is used in all 50 states: “Any person driving a motor vehicle on a highway shall drive the same at a careful and prudent speed not greater than nor less than is reasonable and proper, having due regard to the traffic, surface, and width of the highway and of any other conditions then existing, and no person shall drive any vehicle upon a highway at a speed greater than will permit the person to bring it to a stop within the assured clear distance ahead, such driver having the right to assume, however, that all persons using said highway will observe the law.” Statutory limits are based on the concept that uniform categories of highways can be traveled safely at certain preset maximum speeds under ideal conditions. Whether the speed limit is posted or unposted, drivers should reduce their speed below these values in poor weather, heavy traffic, and under other potentially hazardous conditions.

Determination of sea surface salinity and wind speed by L-band microwave radiometry from a fixed platform

The European Space Agency Soil Moisture andOcean Salinity (SMOS) mission aims at obtaining global maps ofsoil moisture and sea surface salinity from space for large-scale andclimatic studies. It uses an L-band (1400–1427 MHz) MicrowaveInterferometric Radiometer by Aperture Synthesis to measurebrightness temperature of the earth’s surface at horizontal andvertical polarizations ( h and v). These two parameters will beused together to retrieve the geophysical parameters. The retrievalof salinity is a complex process that requires the knowledge ofother environmental information and an accurate processing ofthe radiometer measurements. Here, we present recent resultsobtained from several studies and field experiments that were partof the SMOS mission, and highlight the issues still to be solved.

Dispersal probability distributions and the wave-front speed problem

The speed and width of front solutions to reaction-dispersal models are analyzed both analytically and numerically. We perform our analysis for Laplace and Gaussian distribution kernels, both for delayed and nondelayed models. The results are discussed in terms of the characteristic parameters of the models