Price Destabilizing Speculation

It is sometimes asserted that rational speculative activity must result in more stable prices because speculators buy when prices are low and sell when they are high. This is incorrect. Speculators buy when the chances of price appreciation are high, selling when the chances are low. Speculative activity in an economy in which all agents are rational, have identical priors, and have access to identical information may destabilize prices, under any reasonable definition of destabilization. It takes extremely strong conditions to ensure that speculative activity (of the commodity storage variety) "stabilizes" prices, even in a very weak sense.Economic

Tradición, continuidad y modernidad en el derecho consuetudinario islámico: ejemplos del Marruecos beréber y de las agencias tribales pujtunes de Pakistán

El derecho consuetudinario beréber, nucleado en torno a un corpus de tradición oral, tiene, sin embargo, importantes manifestaciones escritas —en lengua árabe— en al menos tres sociedades bereberófonas —los rífenos del Norte de Marruecos, los ishilhayen o swasa del Alto Atlas occidental/Sus/Anti-Atlas, y, los kabylios de Argelia— caracterizadas por una base social de agricultores sedentarios. Estos auténticos archivos locales custodian los documentos llamados qanun-es, testimonios de las vicisitudes de las interrelaciones sociales en todos los ámbitos. En el marco de los impactos desde los puntos de vista de la tradición, la continuidad y la modernidad, la visión de la antropología social, testimoniada por los trabajos de campo, realza papel jugado desde la época precolonial por los vínculos generados por el derecho consuetudinario, ahora considerado en un cuadro comparativo que engloba a las relaciones jurídicas en el antiguo espacio de las agencias tribales de la frontera Noroeste de la India Británica, el actual estado de Pakistán

Infiltration/cure modeling of resin transfer molded composite materials using advanced fiber architectures

A model was developed which can be used to simulate infiltration and cure of textile composites by resin transfer molding. Fabric preforms were resin infiltrated and cured using model generated optimized one-step infiltration/cure protocols. Frequency dependent electromagnetic sensing (FDEMS) was used to monitor in situ resin infiltration and cure during processing. FDEMS measurements of infiltration time, resin viscosity, and resin degree of cure agreed well with values predicted by the simulation model. Textile composites fabricated using a one-step infiltration/cure procedure were uniformly resin impregnated and void free. Fiber volume fraction measurements by the resin digestion method compared well with values predicted using the model

Numerical modelling of a 1.5 MW tidal turbine in realistic coupled wave–current sea states for the assessment of turbine hub-depth impacts on mechanical loads

This paper considers hub-depth impacts on mechanical loads for a tidal turbine operating in realistic coupled wave–current sea states. A novel medium-fidelity actuator-line CFD model for simulating tidal turbine non-steady hydrodynamic rotor load responses in the presence of turbulence, shear, and surface waves is developed. The model is validated using tank testing data from a lab-scale turbine. The validated model is then upscaled, to a power rating of 1.5 MW, and simulated in realistic wave–current conditions consistent with those of the MeyGen site. Mean torque and thrust are found to increase with turbine hub height, and the presence of waves is shown to increase mean torque and thrust values by up to 22% and 11%, respectively. The effect on standard deviations and maximum values for these variables is more pronounced, with increases of up to 2500% and 1700% in signal standard deviations, and up to 80% and 30% in maximum values for torque and thrust, respectively. The presence of longer period waves is also shown to reduce mean torque levels, while the corresponding standard deviations and maximum values remained relatively unchanged. In such circumstances, the turbine is operating with an undesirable combination of low-power and high-fatigue. Tidal turbine hub loading characteristics and sensitivities, in the context of the operational loads which subsequently enter the drivetrain and turbine support structure, are also analysed. The magnitude of out-of-plane rotor moments are found to increase with the hub height and wave height. Complex flow interactions are shown to play an important role in this context, leading to what is termed “wave-driven moment-type dominance” effects. Overall, both the rotor location and wave composition are found to significantly impact the turbine’s rotor mechanical load response

Interactive deep maps and spatial narratives for landscape conservation and public engagement

Landscape conservation science and practice has increasingly embraced a “people and nature” paradigm that recognizes the dynamic complexity and bidirectional relationships in social-ecological systems. Conservation research remains heavily biased toward the ecological dimensions of conservation, with socially focused research taking up a relatively small fraction. The digital revolution and accompanying geospatial web inspired platforms and methods that provide a significant opportunity for closing this divide. This article focuses on potential contributions to conservation science and practices from one such integrative platform—interactive deep maps and their resulting spatial narratives— that digitally combine the qualitative and experiential essence(s) of place with the quantitative capabilities of Cartesian space. By critically exploring emerging work, we propose that interactive deep maps and spatial narratives are uniquely positioned for integrating social and ecological dimensions of place-based conservation by linking the lived experiences of people with the spatially represented ecological characteristics of nature

Development of a National Anthropogenic Heating Database with an Extrapolation for International Cities

Given increasing utility of numerical models to examine urban impacts on meteorology and climate, there exists an urgent need for accurate representation of seasonally and diurnally varying anthropogenic heating data, an important component of the urban energy budget for cities across the world. Incorporation of anthropogenic heating data as inputs to existing climate modeling systems has direct societal implications ranging from improved prediction of energy demand to health assessment, but such data are lacking for most cities. To address this deficiency we have applied a standardized procedure to develop a national database of seasonally and diurnally varying anthropogenic heating profiles for 61 of the largest cities in the United Stated (U.S.). Recognizing the importance of spatial scale, the anthropogenic heating database developed includes the city scale and the accompanying greater metropolitan area. Our analysis reveals that a single profile function can adequately represent anthropogenic heating during summer but two profile functions are required in winter, one for warm climate cities and another for cold climate cities. On average, although anthropogenic heating is 40% larger in winter than summer, the electricity sector contribution peaks during summer and is smallest in winter. Because such data are similarly required for international cities where urban climate assessments are also ongoing, we have made a simple adjustment accounting for different international energy consumption rates relative to the U.S. to generate seasonally and diurnally varying anthropogenic heating profiles for a range of global cities. The methodological approach presented here is flexible and straightforwardly applicable to cities not modeled because of presently unavailable data. Because of the anticipated increase in global urban populations for many decades to come, characterizing this fundamental aspect of the urban environment – anthropogenic heating – is an essential element toward continued progress in urban climate assessment

Becoming The Boss: Discretion And Postsuccession Success In Family Firms

Family firms can enjoy substantial longevity. Ironically, however, they are often imperiled by the very process that is essential to this longevity. Using the concept of managerial discretion as a starting point, we use a human agency lens to introduce the construct of successor discretion as a factor that affects the family business succession process. While important in general, successor discretion is positioned as a particularly relevant factor for productively managing organizational renewal in family businesses. This study represents a foundation for future empirical research investigating the role of agency in entrepreneurial action in the family business context, which consequently can contribute to the larger research literature on succession and change

Physical characteristics explain ball-carrying capability in sub-elite rugby union players.

The aims of the present study were two-fold: (i) to investigate the relationship between physical characteristics and the game statistics associated with ball-carrying capability amongst sub-elite rugby union players; and (ii) to predict the level of change in these physical characteristics required to improve the associated game statistic via regression analysis. Thirty-eight senior professional players (forwards, n = 22; backs, n = 16) were assessed for body mass (BM), back squat (BS) single-repetition maximum (1RM) normalised to BM (1RM/BM), 10 m sprint velocity (S10), 10 m sprint momentum (SM10), and the game statistics from 22 games within the 2019/20 RFU Championship season. The relationship between these measures and the predicted level of change in a physical measure required to improve the total number of the associated game statistic by one were assessed by Pearson's correlation coefficient and simple regression analyses. In forwards, an ~ 11.5% reduction in BM, an ~ 11.8% improvement in BS 1RM/BM, or an ~ 11.5% increase in S10 was required to improve the game statistics associated with ball-carrying capability. In backs, a ~ 19.3% increase in BM or a ~ 15.6% improvement in SM10 was required. These findings demonstrate that improvements in lower-body relative strength, acceleration performance, and position-specific alterations in body mass are required to maximise the ball-carrying capability and therefore match outcome of sub-elite rugby union players

The effects of extended public transport operating hours and venue lockout policies on drinking-related harms in Melbourne, Australia: Results from SimDrink, an agent-based simulation model.

Background: The late-night accessibility of entertainment precincts is a contributing factor to acute drinking-related harms. Using computer simulation we test the effects of improved public transport (PT) and venue lockouts on verbal aggression, consumption-related harms and transport-related harms among a population of young adults engaging in heavy drinking in Melbourne. Methods: Using an agent-based model we implemented: a two-hour PT extension/24-hour PT; 1 am/3 am venue lockouts; and combinations of both. Outcomes determined for outer-urban (OU) and inner-city (IC) residents were: the number of incidents of verbal aggression inside public and private venues; the number of people ejected from public venues for being intoxicated; and the percentage of people experiencing verbal aggression, consumption-related harms and transport-related harms. Results: All-night PT reduced verbal aggression in the model by 21% but displaced some incidents among OU residents from private to public settings. Comparatively, 1 am lockouts reduced verbal aggression in the model by 19% but led to IC residents spending more time in private rather than public venues where their consumption-related harms increased. Extending PT by 2 h had similar outcomes to 24-hour PT except with fewer incidents of verbal aggression displaced. Although 3 am lockouts were inferior to 1 am lockouts, when modelled in combination with any extension of PT both policies were similar. Conclusions: A two-hour extension of PT is likely to be more effective in reducing verbal aggression and consumption-related harms than venue lockouts. Modelling a further extension of PT to 24 h had minimal additional benefits but the potential to displace incidents of verbal aggression among OU residents from private to public venues