Command-level Police Officers’ Perceptions of the “War on Cops” and De-policing

Policing has been the subject of intense public scrutiny for the better part of two years after several high-profile police killings of unarmed African Americans across the United States. The scrutiny has been so extreme that some contend there is currently a “war on cops”—whereby citizens are emboldened by protests and negative media coverage of the police, and are lashing out by assaulting police officers more frequently. In response, it is argued that officers are de-policing (i.e. avoiding proactive stops). We surveyed command-level police officers from a southeastern state about their attitudes concerning the war on cops and de-policing. The majority of our sample believed there has been a war on cops over the last two years. Moreover, officers who felt strongly about the existence of a war on cops were more likely to believe that de-policing is common among officers in today’s world of law enforcement

Affordable, Energy-Efficient Housing Design for Chile: Achieving Passivhaus Standard with the Chilean State Housing Subsidy

In Chile, it is estimated that the energy demand will continue to increase if substantial energy efficiency measures in housing are not taken. These measures are generally associated with technical and mainly economic difficulties. This paper aims to show the technical and economic feasibility of achieving Passivhaus standard house in Chile, considering the budget of the maximum state subsidy currently available (Chilean Unidad de Fomento (CLF) 2000 ≈ 81,000 USD). The design was simulated in the Passive House Planning Package software to determine if the house could be certified with the selected standard. At the same time, the value of all the items was quantified in order not to exceed the stipulated maximum budget for a house considered as affordable. It was shown that in terms of design it is possible to implement the Passivhaus standard given the current housing subsidy. The designed housing ensures a reduction of 85% in heating demand and a 60% reduction in CO2 emissions during the operation, compared to an average typical Chilean house

Demeanor, Race, and Police Perceptions of Procedural Justice: Evidence from Two Randomized Experiments

President Obama’s Task Force on 21st Century Policing recently endorsed procedural justice as a way to restore trust between police and communities. Yet police–citizen interactions vary immensely, and research has yet to give sufficient consideration to the factors that might affect the importance officers place on exercising procedural justice during interactions. Building on research examining “moral worthiness” judgments and racial stereotyping among police officers, we conducted two randomized experiments to test whether suspect race and demeanor affect officers’ perceptions of the threat of violence and importance of exercising procedural justice while interacting with suspicious persons. We find that suspect race fails to exert a statistically significant effect on either outcome. However, demeanor does—such that officers perceive a greater threat of violence and indicate it is less important to exercise procedural justice with disrespectful suspects. These findings have implications for procedural justice training, specifically, and police–community relations more broadly

Reprogramming the Maternal Zebrafish Genome after Fertilization to Match the Paternal Methylation Pattern

SummaryEarly vertebrate embryos must achieve totipotency and prepare for zygotic genome activation (ZGA). To understand this process, we determined the DNA methylation (DNAme) profiles of zebrafish gametes, embryos at different stages, and somatic muscle and compared them to gene activity and histone modifications. Sperm chromatin patterns are virtually identical to those at ZGA. Unexpectedly, the DNA of many oocyte genes important for germline functions (i.e., piwil1) or early development (i.e., hox genes) is methylated, but the loci are demethylated during zygotic cleavage stages to precisely the state observed in sperm, even in parthenogenetic embryos lacking a replicating paternal genome. Furthermore, this cohort constitutes the genes and loci that acquire DNAme during development (i.e., ZGA to muscle). Finally, DNA methyltransferase inhibition experiments suggest that DNAme silences particular gene and chromatin cohorts at ZGA, preventing their precocious expression. Thus, zebrafish achieve a totipotent chromatin state at ZGA through paternal genome competency and maternal genome DNAme reprogramming

Final Report: Buffalo National River Ecosystems

The objective of this study was to sample the Buffalo River on a seasonal basis for a year, in order to determine whether any potential water quality problems existed

Statistical Model of Heavy-Ion Fusion-Fission Reactions

Cross-section and neutron-emission data from heavy-ion fusion-fission reactions are consistent with the fission of fully equilibrated systems with fission lifetime estimates obtained via a Kramers-modified statistical model which takes into account the collective motion of the system about the ground state, the temperature dependence of the location and height of fission transition points, and the orientation degree of freedom. If the standard techniques for calculating fission lifetimes are used, then the calculated excitation-energy dependence of fission lifetimes is incorrect. We see no evidence to suggest that the nuclear viscosity has a temperature dependence. The strong increase in the nuclear viscosity above a temperature of approximately 1.3 MeV deduced by others is an artifact generated by an inadequate fission model.Comment: Full paper submitted to PRC to accompany our recently published Phys. Rev. Lett. 101, 032702 (2008

Genetic algorithm dynamics on a rugged landscape

The genetic algorithm is an optimization procedure motivated by biological evolution and is successfully applied to optimization problems in different areas. A statistical mechanics model for its dynamics is proposed based on the parent-child fitness correlation of the genetic operators, making it applicable to general fitness landscapes. It is compared to a recent model based on a maximum entropy ansatz. Finally it is applied to modeling the dynamics of a genetic algorithm on the rugged fitness landscape of the NK model.Comment: 10 pages RevTeX, 4 figures PostScrip

Audio source separation using hierarchical phase-invariant models

2009 ISCA Tutorial and Research Workshop on Non-linear Speech Processing (NOLISP)International audienceAudio source separation consists of analyzing a given audio recording so as to estimate the signal produced by each sound source for listening or information retrieval purposes. In the last five years, algorithms based on hierarchical phase-invariant models such as single or multichannel hidden Markov models (HMMs) or nonnegative matrix factorization (NMF) have become popular. In this paper, we provide an overview of these models and discuss their advantages compared to established algorithms such as nongaussianity-based frequency-domain independent component analysis (FDICA) and sparse component analysis (SCA) for the separation of complex mixtures involving many sources or reverberation.We argue how hierarchical phase-invariant modeling could form the basis of future modular source separation systems

Memory effects on descent from nuclear fission barrier

Non-Markovian transport equations for nuclear large amplitude motion are derived from the collisional kinetic equation. The memory effects are caused by the Fermi surface distortions and depend on the relaxation time. It is shown that the nuclear collective motion and the nuclear fission are influenced strongly by the memory effects at the relaxation time $\tau \geq 5\cdot 10^{-23}{\rm s}$. In particular, the descent of the nucleus from the fission barrier is accompanied by characteristic shape oscillations. The eigenfrequency and the damping of the shape oscillations depend on the contribution of the memory integral in the equations of motion. The shape oscillations disappear at the short relaxation time regime at $\tau \to 0$, which corresponds to the usual Markovian motion in the presence of friction forces. We show that the elastic forces produced by the memory integral lead to a significant delay for the descent of the nucleus from the barrier. Numerical calculations for the nucleus $^{236}$U shows that due to the memory effect the saddle-to-scission time grows by a factor of about 3 with respect to the corresponding saddle-to-scission time obtained in liquid drop model calculations with friction forces.Comment: 22 pages, 8 figures, submitted to Phys. Rev.