Righting an injustice or American Taliban? the removal of Confederate statues

In recent years, several racial instances have occurred in the United States that have reinvigorated and demanded action concerning Confederate flags, statues and symbology. The Charleston massacre in 2015 prompted South Carolina to finally remove the Confederate battle flag from state grounds. The Charlottesville riots in 2017 accelerated the removal of Confederate statues from the public square. However, the controversy has broadened the discussion of how the Civil War monuments are to be viewed, especially in the public square. Many of the monuments were not built immediately following the Civil War, but later, during the era of Jim Crow and the disenfranchisement of African Americans during segregation in the South. Are they tributes to heroes or are they relics of a racist past that sought not to remember as much as to intimidate and bolster white supremacy? This work seeks to break up the eras of Confederate monument building and demonstrate that different monuments were built at different times (and are still being built). The monuments reflect other events in the country happening at the time, as well as the thinking of those who built them. This author hopes that these nuances will add to the general discussion and the usual three responses toward the statues of either taking them down to either destroy them, keep them, but add context, or place them in museums, cemeteries or private property. These nuances are important, possibly rendering all three as valid decisions. This author will use multiple lenses, including Union, Confederate, and African American lenses as interpreters for the various eras discussed. (Author abstract)Reif, A.W. (2018). Righting an injustice or American Taliban? the removal of Confederate statues. Retrieved from http://academicarchive.snhu.eduMaster ArtsHistoryCollege of Online and Continuing Educatio

Coordination under threshold uncertainty in a public goods game

We explored experimentally how threshold uncertainty affects coordination success in a threshold public goods game. Whereas all groups succeeded in providing the public good when the exact value of the threshold was known, uncertainty was generally detrimental for the public good provision. The negative effect of threshold uncertainty was particularly severe when it took the form of ambiguity, i.e. when players were not only unaware of the value of the threshold but also of its probability distribution. Early signaling of willingness to contribute and share the burden equitably helped groups in coping with threshold uncertainty.public good, threshold uncertainty, ambiguity, experiment

Coordination under threshold uncertainty in a public goods game

We explored experimentally how threshold uncertainty affects coordination success in a threshold public goods game. Whereas all groups succeeded in providing the public good when the exact value of the threshold was known, uncertainty was generally detrimental for the public good provision. The negative effect of threshold uncertainty was particularly severe when it took the form of ambiguity, i.e. when players were not only unaware of the value of the threshold but also of its probability distribution. Early signaling of willingness to contribute and share the burden equitably helped groups in coping with threshold uncertainty. --Public good,threshold uncertainty,ambiguity,experiment

Computational analysis of shock-induced flow through stationary particle clouds

We investigate the shock-induced flow through random particle arrays using particle-resolved Large Eddy Simulations for different incident shock wave Mach numbers, particle volume fractions and particle sizes. We analyze trends in mean flow quantities and the unresolved terms in the volume averaged momentum equation, as we vary the three parameters. We find that the shock wave attenuation and certain mean flow trends can be predicted by the opacity of the particle cloud, which is a function of particle size and particle volume fraction. We show that the Reynolds stress field plays an important role in the momentum balance at the particle cloud edges, and therefore strongly affects the reflected shock wave strength. The Reynolds stress was found to be insensitive to particle size, but strongly dependent on particle volume fraction. It is in better agreement with results from simulations of flow through particle clouds at fixed mean slip Reynolds numbers in the incompressible regime, than with results from other shock wave particle cloud studies, which have utilized either inviscid or two-dimensional approaches. We propose an algebraic model for the streamwise Reynolds stress based on the observation that the separated flow regions are the primary contributions to the Reynolds stress.Comment: 33 pages, 23 figures, 3 table

Improving voluntary public good provision by a non-governmental, endogenous matching mechanism : experimental evidence

Social norms can help to foster cooperation and to overcome the free-rider problem in private provision of public goods. This paper focuses on the enforcement of social norms by a self-introduced punishment and reward scheme. We analyse if subjects achieve to implement a norm-enforcement mechanism at their own expense by applying the theory of non-governmental norm-enforcement by Buchholz et al. (2014) in a laboratory experiment. Based on their theory without central authority and endogenously determined enforcement mechanism, we implement a two-stage public good game: At the first stage subjects determine the strength of penalty/reward on their own and in the second stage they decide on their contributions to the public good. We find that the mechanism by Buchholz et al. (2014) leads to a higher public good contribution than without the use of any mechanism. Only in a few cases groups end up with a zero enforcement mechanism. This result indicates that subjects are apparently willing to contribute funds for implementing an enforcement mechanism. Moreover, higher enforcement parameters lead to higher public good contributions in the second stage, although too high enforcement parameters lead to unreachable theoretical optima

How does radial growth of water-stressed populations of european beech (Fagus sylvatica l.) trees vary under multiple drought events?

European beech (Fagus sylvatica L.) trees are becoming vulnerable to drought, with a warming climate. Existing studies disagree on how radial growth varies in European beech in response to droughts. We aimed to find the impact of multiple droughts on beech trees’ annual radial growth at their ecological drought limit created by soil water availability in the forest. Besides, we quantified the influence of competition and canopy openness on the mean basal area growth of beech trees. We carried out this study in five near-natural temperate forests in three localities of Germany and Switzerland. We quantified available soil water storage capacity (AWC) in plots laid in the transition zone from oak to beech dominated forests. The plots were classified as ‘dry’ (AWC 60 mL). We performed dendroecological analyses starting from 1951 in continuous and discontinuous series to study the influence of climatic drought (i.e., precipitation-potential evapotranspiration) on the radial growth of beech trees in dry and less-dry plots. We used observed values for this analysis and did not use interpolated values from interpolated historical records in this study. We selected six drought events to study the resistance, recovery, and resilience of beech trees to drought at a discontinuous level. The radial growth was significantly higher in less-dry plots than dry plots. The increase in drought had reduced tree growth. Frequent climatic drought events resulted in more significant correlations, hence, increased the dependency of tree growth on AWC. We showed that the recovery and resilience to climatic drought were higher in trees in less-dry plots than dry plots, but it was the opposite for resistance. The resistance, recovery, and resilience of the trees were heterogeneous between the events of drought. Mean growth of beech trees (basal area increment) were negatively impacted by neighborhood competition and positively influenced by canopy openness. We emphasized that beech trees growing on soil with low AWC are at higher risk of growth decline. We concluded that changes in soil water conditions even at the microsite level could influence beech trees’ growth in their drought limit under the changing climate. Along with drought, neighborhood competition and lack of light can also reduce beech trees’ growth. This study will enrich the state of knowledge about the ongoing debate on the vulnerability of beech trees to drought in Europe

Studying dietary intake in daily life through multilevel two-part modelling: a novel analytical approach and its practical application

Background Understanding which factors influence dietary intake, particularly in daily life, is crucial given the impact diet has on physical as well as mental health. However, a factor might influence whether but not how much an individual eats and vice versa or a factor’s importance may differ across these two facets. Distinguishing between these two facets, hence, studying dietary intake as a dual process is conceptually promising and not only allows further insights, but also solves a statistical issue. When assessing the association between a predictor (e.g. momentary affect) and subsequent dietary intake in daily life through ecological momentary assessment (EMA), the outcome variable (e.g. energy intake within a predefined time-interval) is semicontinuous. That is, one part is equal to zero (i.e. no dietary intake occurred) and the other contains right-skewed positive values (i.e. dietary intake occurred, but often only small amounts are consumed). However, linear multilevel modelling which is commonly used for EMA data to account for repeated measures within individuals cannot be applied to semicontinuous outcomes. A highly informative statistical approach for semicontinuous outcomes is multilevel two-part modelling which treats the outcome as generated by a dual process, combining a multilevel logistic/probit regression for zeros and a multilevel (generalized) linear regression for nonzero values. Methods A multilevel two-part model combining a multilevel logistic regression to predict whether an individual eats and a multilevel gamma regression to predict how much is eaten, if an individual eats, is proposed. Its general implementation in R, a widely used and freely available statistical software, using the R-package brms is described. To illustrate its practical application, the analytical approach is applied exemplary to data from the Eat2beNICE-APPetite-study. Results Results highlight that the proposed multilevel two-part model reveals process-specific associations which cannot be detected through traditional multilevel modelling. Conclusions This paper is the first to introduce multilevel two-part modelling as a novel analytical approach to study dietary intake in daily life. Studying dietary intake through multilevel two-part modelling is conceptually as well as methodologically promising. Findings can be translated to tailored nutritional interventions targeting either the occurrence or the amount of dietary intake