The Determinants of Local Government Police Expenditures: A Public Employment Approach

Explanation of the level of local government police expenditures is generally drawn from the results of empirical analyses. However, the assumptions of the underlying statistical model are not realistic for the police function and as a consequence the regression results do not provide useful clues as to the reasons for either the rapid growth in police spending and employment or the wide variation in per capita expenditures among cities. This paper shows—within the context of a traditional consumer maximization model—how the socio-economic characteristics and fiscal capacities of a community determine the level of police expenditures through the effects of these characteristics on the level of police wages and employment. The model is developed by combining an existing body of public finance research with a growing body of labor economics research dealing with the state and local government sector, particularly with estimating the employment demand function and the determinants of the wage rate. Our results suggest that important explanatory variables have been excluded from earlier expenditure determinants studies and have led to serious problems in interpreting statistical results. Moreover, our estimation of a structural model facilitates interpretation of the contributions of supply and demand variables to public expenditure levels as well as enabling us to trace exogenous shocks through the model to their ultimate effects on employment, compensation and expenditure levels

Huntington’s Disease iPSC-Derived Brain Microvascular Endothelial Cells Reveal WNT-Mediated Angiogenic and Blood-Brain Barrier Deficits

Brain microvascular endothelial cells (BMECs) are an essential component of the blood-brain barrier (BBB) that shields the brain against toxins and immune cells. While BBB dysfunction exists in neurological disorders, including Huntington's disease (HD), it is not known if BMECs themselves are functionally compromised to promote BBB dysfunction. Further, the underlying mechanisms of BBB dysfunction remain elusive given limitations with mouse models and post-mortem tissue to identify primary deficits. We undertook a transcriptome and functional analysis of human induced pluripotent stem cell (iPSC)-derived BMECs (iBMEC) from HD patients or unaffected controls. We demonstrate that HD iBMECs have intrinsic abnormalities in angiogenesis and barrier properties, as well as in signaling pathways governing these processes. Thus, our findings provide an iPSC-derived BBB model for a neurodegenerative disease and demonstrate autonomous neurovascular deficits that may underlie HD pathology with implications for therapeutics and drug delivery.American Heart Association (12PRE10410000)American Heart Association (CIRMTG2-01152)National Institutes of Health (U.S.) (NIHNS089076

Macroscopic coherent structures in a stochastic neural network: from interface dynamics to coarse-grained bifurcation analysis

We study coarse pattern formation in a cellular automaton modelling a spatially-extended stochastic neural network. The model, originally proposed by Gong and Robinson (Phys Rev E 85(5):055,101(R), 2012), is known to support stationary and travelling bumps of localised activity. We pose the model on a ring and study the existence and stability of these patterns in various limits using a combination of analytical and numerical techniques. In a purely deterministic version of the model, posed on a continuum, we construct bumps and travelling waves analytically using standard interface methods from neural field theory. In a stochastic version with Heaviside firing rate, we construct approximate analytical probability mass functions associated with bumps and travelling waves. In the full stochastic model posed on a discrete lattice, where a coarse analytic description is unavailable, we compute patterns and their linear stability using equation-free methods. The lifting procedure used in the coarse time-stepper is informed by the analysis in the deterministic and stochastic limits. In all settings, we identify the synaptic profile as a mesoscopic variable, and the width of the corresponding activity set as a macroscopic variable. Stationary and travelling bumps have similar meso- and macroscopic profiles, but different microscopic structure, hence we propose lifting operators which use microscopic motifs to disambiguate them. We provide numerical evidence that waves are supported by a combination of high synaptic gain and long refractory times, while meandering bumps are elicited by short refractory times

Short- and long-term growth effects of special interest groups in the U.S. states: A dynamic panel error-correction approach

The perception of special interest groups as a serious threat to economic growth has strengthened over the years; however, the vast empirical literature surrounding this claim has produced mixed and inconclusive results. This study re-examines the issue incorporating a potentially important aspect that has generally been ignored by previous studies, namely, the implicit suggestion by some of the theoretical works that the extent and the intensity of the growth effects of special interest groups may differ significantly over different time frames. Specifically, this study uses dynamic panel error-correction methods (Pesaran, Shin, and Smith (1999)) to properly determine whether these effects, if they exist, occur mostly in the short run or the long run based on data from a panel of 48 U.S. states for the years 1975 – 2004. The joint Hausman-type test selected the preferred model, which controls for human capital achievement, initial income, income inequality, and the tax burden. This model produced results which are in sharp contrast to the simple linearly negative or positive findings reported in much of the literature by indicating that special interest groups have significant non-linearly inverted U-shaped long-run effects on growth, and that it takes time (about 8 years) for the full effects to become evident. The results provide evidence that U.S. states face a threshold point below which special interest groups’ lobbying and rent-seeking activities boost long-run growth performance but above which they have damaging effects on long-run growth effort. This is confirmed by the Lind and Mehlum (2010) u-test which also suggests that the threshold point is reached when the activities and strength of special interest groups (measured by the percentage of each state’s public and private non-agricultural wage and salary employees who are union members, and which varies from 3.8% to 38.7%)) is at the 15.8% level

Probing the viability of oxo-coupling pathways in iridium-catalyzed oxygen evolution

[Image: see text] A series of Cp*Ir(III) dimers have been synthesized to elucidate the mechanistic viability of radical oxo-coupling pathways in iridium-catalyzed O(2) evolution. The oxidative stability of the precursors toward nanoparticle formation and their oxygen evolution activity have been investigated and compared to suitable monomeric analogues. We found that precursors bearing monodentate NHC ligands degraded to form nanoparticles (NPs), and accordingly their O(2) evolution rates were not significantly influenced by their nuclearity or distance between the two metals in the dimeric precursors. A doubly chelating bis-pyridine–pyrazolide ligand provided an oxidation-resistant ligand framework that allowed a more meaningful comparison of catalytic performance of dimers with their corresponding monomers. With sodium periodate (NaIO(4)) as the oxidant, the dimers provided significantly lower O(2) evolution rates per [Ir] than the monomer, suggesting a negative interaction instead of cooperativity in the catalytic cycle. Electrochemical analysis of the dimers further substantiates the notion that no radical oxyl-coupling pathways are accessible. We thus conclude that the alternative path, nucleophilic attack of water on high-valent Ir-oxo species, may be the preferred mechanistic pathway of water oxidation with these catalysts, and bimolecular oxo-coupling is not a valid mechanistic alternative as in the related ruthenium chemistry, at least in the present system