CITY MANAGERS: Do They Promote Fiscal Efficiency?

ABSTRACT: Debate over the virtues of one or another form of municipal government has raged since the early days of the reform movement. Proponents of professional municipal management have based their argument on the virtues of having a person trained and practiced in the skills needed to manage the diverse operations and functions that make up the modern city. This line of reasoning encompasses the premise that professional management brings efficiency to municipal management. However, little research has focused on this aspect of professional management. This study uses data from a nationwide survey of cities to test the hypothesis that cities with professional management achieve measurable efficiencies compared to cities without such management. These efficiencies include reduced levels of municipal expenditures and property taxes. The results of this analysis provide significant new information for both scholars and practitioners.     

用于改善5GHz以上信号传输完整性的多层板用材料

对于高速数字和其它类似的系统来说,能够提供低的Dk值和低损耗特性的材料已经成为一个基本要素。对原始设备制造商而言,在某种意义上,在一个高层数板设计中得到一个能够提供完美的信号完整性的解决方案已经成为“神圣之杯”。在很多新设计中,传统的环氧/玻纤材料已经不能满足电气特性的要求。生产高速光学路由器、开关、网络、服务器等的原始设备制造商都需要具有低介电常数(Dk)和损耗因子(Df)的材料来进一步提高产品性能。通过用更薄的介质层厚度来保证特性阻抗值,更低的介电常数可以允许更快的信号传输速度和更高的封装密度。更高的损耗…     

SHAPE OPTIMIZATION WITH ADAPTIVE MESH REFINEMENT: TARGET ERROR SELECTION STRATEGIES

The multi-point approximation method in conjunction with Adaptive Mesh Refinement (AMR) for shape optimization of thin-walled structures is studied. Application of AMR is done in such a manner that in the beginning of an optimization process large discretization errors are accepted, while finite element discretizations become more accurate as the optimization process progresses. In this paper several strategies for selecting the target discretization errors are investigated. Special attention is paid to both the overall computational effort and the convergence of the optimization processes.     

INVESTORS: THE MISSING PIECE IN THE FORECLOSURE RACIAL GAP DEBATE

ABSTRACT: Foreclosures have become one of the most important problems facing cities and the U.S. economy. However, not all communities are affected equally. Our goal is to better understand factors that affect variation in neighborhood foreclosures in a typical, mid‐sized U.S. city—Louisville, Kentucky. While previous findings indicate that a key explanatory variable leading to rising neighborhood foreclosures is the proportion of racial minorities, our analysis finds that in a fully specified model, race does not predict differences between black and white homeowners. On the other hand, an analysis of investors predicts high foreclosure rates in African‐American neighborhoods. The effect of percent nonwhite is caused by several key intervening variables, including the presence of investor foreclosures, the absence of neighborhood walkability, and the prevalence of high‐cost loans. In the past, walkability and investor behavior have largely been ignored by social scientists studying neighborhood variation in foreclosures and the role of race in rising foreclosures. In this article, we examine how speculation by investors in majority African‐American neighborhoods along with degree of walkability and the concentration of high‐priced loans have contributed to recent increases in foreclosures and variation across neighborhoods. Together, the findings demonstrate that these three factors help to better explain the contemporary causes of greater foreclosures in African‐American neighborhoods.     

A Method for the Analysis of ATP Metabolites in Beef Skeletal Muscle by HPLC

A method to determine inosine, hypoxanthine, NAD, AMP, IMP, IDP, ADP, adenylosuccinic acid, ITP and ATP contents in postmortem muscle by HPLC has been developed. The method consists of an homogenization of the muscle in 0.5M HClO₄ or 10% TCA, extraction of the compound with 0.5M tri-n-octylamine/Freon 113 and single injection chromatography on a Whatman Partisil-10/25 SAX column.     

INDUSTRIAL WASTEWATER CONTROL1

The reduction or elimination of industrial wastes at their in-plant sources is a more economical and more effective practice than their treatment at the plant outfall. Examples described, all selected from the food industries, are the hot gas blanching of vegetables, the dry peeling of fruits and vegetables by application of caustic, the recovery of useful by-products from whey, the reuse of poultry processing wastewaters and reduced water usage in the poultry industry, and material recovery from brewery, citrus, and fishery operations. All of these result in a smaller quantity of wastewater and pollutants going to treatment or discharge. End-of-pipe treatment is frequently required, even after all practical in-plant clean-up. Discharge into municipal sewers is discussed, as are the basic operations and processes available for pretreatment as well as for final treatment prior to discharge to a waterway. The author's premise is a plea for sharing of knowledge among different industries.     

Removal of Oxide Contamination from Silicon Carbide Powders

The removal of oxide (SiO₂) contamination from SiC powders by treatment with BCl₃(g) or with HF(g) has been demonstrated. Hydrogen fluoride is more effective and does not present corrosion problems with the container materials used.     

Quantifying the search space for multi-agent system decision-making organizations

When a group comes together to pursue a goal, how should the group interact? Both theory and practice show no single organization always performs best; the best organization depends on context. Therefore, a group should adapt how it interacts to fit the situation. In a multi-agent system (MAS), a decision-making framework (DMF) specifies the allocation of decision-making and action-execution responsibilities for a set of goals among agents within the MAS. Adaptive decision-making frameworks (ADMFs) is the ability to change the DMF, changing which agents are responsible for decision-making and action-execution for a set of goals. Interesting questions remain about the ability of an agent to find the 'best,' or 'near optimal' or 'sufficient' DMF among all the possible DMFs. This paper presents initial exploration of this investigation by asking, 'How does the state space of MAS decision-making organizations scale with growth in the number of agents, number of goals and complexity of the organization structure?' This paper presents tight computational bounds on the size of the search space for DMFs by applying combinatorial mathematics. The DMF representation is also shown to be a factor in the size of this search space.     

Changes in Connective Tissue Histology in Freeze-Thaw Cycled and Refrigerated Pork Liver

Alterations in the connective tissue of pork liver during storage were examined histologically. The connective tissue outlining the lobule of pork liver was apparently unaltered during refrigerated storage (R-S), but showed extensive crimping or waviness during freeze-thaw (F-T) cycling. Intralobular connective tissue (reticulin) disappeared during R-S but was still visible after six F-T cycles. The existence of a proteolytic enzyme active against Type III collagen at refrigerator temperatures but irreversibly inactivated by freezing was postulated.     

ROLE OF HOST PLANT VOLATILES IN MATE LOCATION FOR THREE SPECIES OF LONGHORNED BEETLES

Stressed woody plants represent an ephemeral and unpredictable resource for larvae of some species of longhorned beetles (Coleoptera: Cerambycidae) because prime subcortical tissues are rapidly degraded by a guild of xylophagous competitors. Selection favors efficient mechanisms of host and mate location to expedite colonization of hosts by larvae. Based on previous research, we hypothesize that mate location in some species of the subfamily Cerambycinae involves three sequential behavioral stages: (1) both sexes are attracted to larval hosts by plant volatiles; (2) males attract females over shorter distances with pheromones; and (3) males recognize females by contact pheromones in their epicuticular wax layer. We already have evidence of second-stage and third-stage behaviors in three species in this subfamily whose xylophagous larvae feed in hardwood trees: Xylotrechus colonus, Megacyllene caryae, and Neoclytus mucronatus mucronatus. In this report, we evaluate the first behavioral stage of mate location behavior (i.e., independent response of both sexes to host plant volatiles) for the same three species. Supporting our hypothesis, both males and females responded to volatiles emanating from hickory logs in Y-tube olfactometer bioassays.