4,073 research outputs found

    Blockchain, Leadership And Management: Business AS Usual Or Radical Disruption?

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    The Internet provided the world with interconnection. However, it did not provide it with trust. Trust is lacking everywhere in our society and is the reason for the existence of powerful intermediaries aggregating power. Trust is what prevents the digital world to take over. This has consequences for organisations: they are inefficient because time, energy, money and passion are wasted on verifying everything happens as decided. Managers play the role of intermediaries in such case: they connect experts with each others and instruct them of what to do. As a result, in our expert society, people's engagement is low because no one is there to inspire and empower them. In other words, our society faces an unprecedented lack of leadership. Provided all those shortcomings, the study imagines the potential repercussions, especially in the context of management, of implementing a blockchain infrastructure in any type of organisation. Indeed, the blockchain technology seems to be able to remedy to those issues, for this distributed and immutable ledger provides security, decentralisation and transparency. In the context of a blockchain economy, the findings show that value creation will be rearranged, with experts directly collaborating with each others, and hierarchy being eliminated. This could, in turn, render managers obsolete, as a blockchain infrastructure will automate most of the tasks. As a result, only a strong, action-oriented, leadership would maintain the organisation together. This leadership-in-action would consist in igniting people to take action; coach members of the organisations so that their contribution makes sense in the greater context of life

    A 10-year Study of Factors Associated with Alcohol Treatment Use and Non-use in a U.S. Population Sample

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    Background This study seeks to identify changes in perceived barriers to alcohol treatment and predictors of treatment use between 1991–92 and 2001–02, to potentially help understand reported reductions in treatment use at this time. Social, economic, and health trends during these 10 years provide a context for the study. Methods Subjects were Whites, Blacks, and Hispanics. The data were from the National Longitudinal Alcohol Epidemiologic Survey (NLAES) and the National Epidemiologic Survey on Alcohol and Related Conditions (NESARC). We conducted two analyses that compared the surveys on: 1) perceived treatment barriers for subjects who thought they should get help for their drinking, and 2) variables predicting past-year treatment use in an alcohol use disorder subsample using a multi-group multivariate regression model. Results In the first analysis, those barriers that reflected negative beliefs and fears about seeking treatment as well as perceptions about the lack of need for treatment were more prevalent in 2001–02. The second analysis showed that survey year moderated the relationship between public insurance coverage and treatment use. This relationship was not statistically significant in 1991–92 but was significant and positive in 2001–02, although the effect of this change on treatment use was small. Conclusions Use of alcohol treatment in the U.S. may be affected by a number of factors, such as trends in public knowledge about treatment, social pressures to reduce drinking, and changes in the public financing of treatment

    Initial investigation of the wavelength dependence of optical properties measured with a new multi-pass Aerosol Extinction Differential Optical Absorption Spectrometer (AE-DOAS)

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    Atmospheric aerosols directly affect climate by scattering and absorbing radiation. The magnitude of the impact is dependent upon the wavelength of light, but is often estimated near 550 nm. When light scattering and absorption by aerosols is approximated, the wavelength dependence of the refractive index for specific components is lost. As a result, climate models would have inherent uncertainties for aerosol contributions to radiative forcing when considering the entire solar spectrum. An aerosol extinction differential optical absorption spectrometer has been developed to directly measure aerosol extinction at mid-ultraviolet to near infrared wavelengths. The instrument consists of a spectrometer coupled to a closed White-type multi-pass gas cell with an adjustable path length of up to approximately 20 m. Laboratory measurements of various gases are compared with known absorption cross sections. Additionally, the extinction of monodisperse samples of polystyrene latex spheres are measured and compared to Mie theory generated with refractive index values from the literature to validate the new instrument. The polystyrene experiments also emphasize the ability of the new instrument to retrieve the wavelength dependent refractive index, especially in the ultraviolet wavelength regions where variability is expected. The spectrometer will be a significant advancement for determining wavelength dependent complex refractive indices in future laboratory studies as well as provide the ability to monitor ambient aerosol light extinction

    Hispanic Subgroups, Acculturation, and Substance Abuse Treatment Outcomes

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    This study explored Hispanic subgroup differences in substance use treatment outcomes, and the relationship of acculturation characteristics to these outcomes. Data were from a multisite randomized clinical trial of motivational enhancement therapy versus treatment as usual in a sample of Spanish-speaking substance abusers. Participants were Cuban American (n = 34), Mexican American (n = 209), Puerto Rican (n = 78), and other Hispanic American (n = 54). Results suggested that Cuban Americans and individuals with more connection to Hispanic culture had lower treatment retention. Hispanics born in the U.S and those who spoke English at home had a lower percentage of days abstinent during weeks 5–16, although Puerto Ricans born in the U.S. and Cuban Americans living more years in the U.S. had a higher percentage of days abstinent in weeks 1–4 and 5–16, respectively. Results may inform future hypothesis-driven studies in larger Hispanic treatment seeking samples of the relationship between acculturation and treatment outcome

    Asymptotic solvers for ordinary differential equations with multiple frequencies

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    We construct asymptotic expansions for ordinary differential equations with highly oscillatory forcing terms, focusing on the case of multiple, non-commensurate frequencies. We derive an asymptotic expansion in inverse powers of the oscillatory parameter and use its truncation as an exceedingly effective means to discretize the differential equation in question. Numerical examples illustrate the effectiveness of the method

    Reducing the Effects of Unequal Number of Games on Rankings

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    Ranking is an important mathematical process in a variety of contexts such as information retrieval, sports and business. Sports ranking methods can be applied both in and beyond the context of athletics. In both settings, once the concept of a game has been defined, teams (or individuals) accumulate wins, losses, and ties, which are then factored into the ranking computation. Many settings involve an unequal number of games between competitors. This paper demonstrates how to adapt two sports rankings methods, the Colley and Massey ranking methods, to settings where an unequal number of games are played between the teams. In such settings, the standard derivations of the methods can produce nonsensical rankings. This paper introduces the idea of including a super-user into the rankings and considers the effect of this fictitious player on the ratings. We apply such techniques to rank batters and pitchers in Major League baseball, professional tennis players, and participants in a free online social game. The ideas introduced in this paper can further the scope that such methods are applied and the depth of insight they offer

    Alcohol availability and neighborhood poverty and their relationship to binge drinking and related problems among drinkers in committed relationships

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    The authors examined the relationship of alcohol outlet density (AOD) and neighborhood poverty with binge drinking and alcohol-related problems among drinkers in married and cohabitating relationships and assessed whether these associations differed across sex. A U.S. national population couples survey was linked to U.S. Census data on AOD and neighborhood poverty. The 1,784 current drinkers in the survey reported on their binge drinking, alcohol-related problems, and other covariates. AOD was defined as the number of alcohol outlets per 10,000 persons and was obtained at the zip code level. Neighborhood poverty was as having a low (\u3c20%) or high (≥20%) proportion of residents living in poverty at the census tract level. We used logistic regression for survey data to estimate odds ratios and 95% confidence intervals and tested for differences of associations by sex. Associations of neighborhood poverty with binge drinking were stronger for male than for female drinkers. The association of neighborhood poverty with alcohol-related problems was also stronger for men than for women. We observed no relationships between AOD and binge drinking or alcohol-related problems in this couples survey. Efforts to reduce binge drinking or alcohol-related problems among partners in committed relationships may have the greatest impact if targeted to male drinkers living in high-poverty neighborhoods. Binge drinking and alcohol-related problems, as well as residence in an impoverished neighborhood are risk factors for intimate partner violence (IPV) and other relationship conflicts

    A micropillar for cavity optomechanics

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    We present a new micromechanical resonator designed for cavity optomechanics. We have used a micropillar geometry to obtain a high-frequency mechanical resonance with a low effective mass and a very high quality factor. We have coated a 60-μ\mum diameter low-loss dielectric mirror on top of the pillar and are planning to use this micromirror as part of a high-finesse Fabry-Perot cavity, to laser cool the resonator down to its quantum ground state and to monitor its quantum position fluctuations by quantum-limited optical interferometry

    Tracer diffusion in colloidal suspensions under dilute and crowded conditions with hydrodynamic interactions

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    We consider tracer diffusion in colloidalsuspensions under solid loading conditions, where hydrodynamic interactions play an important role. To this end, we carry out computer simulations based on the hybrid stochastic rotation dynamics-molecular dynamics (SRD-MD) technique. Many details of the simulation method are discussed in detail. In particular, our choices for the SRD-MD parameters and for the different scales are adapted to simulating colloidalsuspensions under realistic conditions. Our simulation data are compared with published theoretical, experimental and numerical results and compared to Brownian dynamics simulation data. We demonstrate that our SRD-MD simulations reproduce many features of the hydrodynamics in colloidal fluids under finite loading. In particular, finite-size effects and the diffusive behavior of colloids for a range of volume fractions of the suspension show that hydrodynamic interactions are correctly included within the SRD-MD technique.Peer reviewe
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