The dynamics of iterated transportation simulations

Iterating between a router and a traffic micro-simulation is an increasibly accepted method for doing traffic assignment. This paper, after pointing out that the analytical theory of simulation-based assignment to-date is insufficient for some practical cases, presents results of simulation studies from a real world study. Specifically, we look into the issues of uniqueness, variability, and robustness and validation. Regarding uniqueness, despite some cautionary notes from a theoretical point of view, we find no indication of ``meta-stable'' states for the iterations. Variability however is considerable. By variability we mean the variation of the simulation of a given plan set by just changing the random seed. We show then results from three different micro-simulations under the same iteration scenario in order to test for the robustness of the results under different implementations. We find the results encouraging, also when comparing to reality and with a traditional assignment result. Keywords: dynamic traffic assignment (DTA); traffic micro-simulation; TRANSIMS; large-scale simulations; urban planningComment: 24 pages, 7 figure

Effect of Media and Estrogen on Morphological Change in Candida albicans

Introduction: Candida albicans (C. albicans), an opportunistic pathogen, lives symbiotically within the intestine of its human host. Temperature and chemical factors have been shown to induce a morphological change in C. albicans from yeast to filamentous form turning C. albicans pathogenic. In this study, we investigated the intestinal cues that might be responsible for the change. We found that different solid media impact the morphological phenotype so we focused on characterizing these before further testing. We tested Estradiol (E2) because of its known linkage to sepsis and higher levels during infections. Experiments were conducted to compare solid agar plates of YEPD, Minimal Media (MM), and Spider Media (SP) for C. albicans growth to choose the best one for further testing with E2 and other factors that could be prone to causing morphological changes. Methods: C. albicans was inoculated through streak method on different solid media (YEPD, MM, SP) and incubated at 30℃. The effect of 0.1nM E2 on C. albicans morphology was also tested. Morphological changes were assayed through bright-field microscopy. Results: Using the three different medias, we found three distinctive phenotypes: A, B, and C. Out of 6 experiments of 14 MM plates, the expressed phenotype was 86% A and 14% inconclusive of the time. 8 experiments of 17 SP plates showed 100% of phenotype B. 6 experiments of 14 YEPD plates presented phenotype C 92% of the time and 8% inconclusive. For E2 trials, 2 experiments, 6 MM plates showed 50% phenotype A and 50% inconclusive. 4 experiments, 10 SP plates had phenotype B 100%. YEPD 2 experiments, 2 plates had phenotype C at 100%. Conclusion: We have established experimental conditions of media controls for further testing whether E2 and other cues, such as inflammatory cytokines, have inhibitory or positive effects on the growth of C. albicans

Effects Of Environmental And Anthropogenic Factors On The Range Contraction Of Bird And Mammal Species

The largest contributor to biodiversity loss is habitat destruction caused by humans. A common consequence of habitat destruction is a reduction in the geographic range of a species. Little research has been done to separate the contribution of anthropogenic and environmental variables to the extinction or persistence of species that have experienced range contraction. In this thesis, I examined the relative effects of several variables (elevation, mean annual precipitation, mean annual temperature, human population density, distance from roads, and proportion of land converted to built-up land, cropland, and rangeland) on the geographic ranges of declining bird and mammal species from all continents except Antarctica. Species were examined separately to determine which variables might have influenced the contraction in the ranges of individual species. The results of each variable were compiled both by individual species and by continent. My results suggest environmental variables have a greater effect on species persistence and extinction than do the anthropogenic variables I tested. Mean annual precipitation was most often identified as having a positive or negative influence on species persistence. The findings of this study provide a comprehensive assessment of the effects of environmental and anthropogenic variables on the persistence of both individual species and all species from each of the 6 continents included in the analyses. These findings could allow conservation biologists to better predict areas where a declining species will persist, thereby enabling the prioritization of areas for the establishment of wildlife reserves

In Present Past: Sun Tunnels and the Historic Reconstruction of Vision

The following study investigates how Nancy Holt’s Sun Tunnels makes effective use of time and land to reprogram the modern viewer’s eye. By utilizing sculpture that is reminiscent of pre-historic observatories as an observational framing device against the landscape topography, the artwork succeeds in presenting a historic reconstruction of vision

Public Sector Labour Relations in the United States: Austerity, Politics and Policy

Public sector unions around the world are under threat from political forces. Combined, the financial crisis and austerity measures have challenged public sector unions' legitimacy. In the U.S., the postrecession assault on public sector unions is rooted in political ideology, with not only a widening polarization along the liberal-conservative spectrum playing a key role, but cultural cognition and economic downturn, too. This research provides a comparative historical analysis of changes in public sector collective bargaining rights at state and local levels in 50 states. The article describes the variations in public sector industrial relations at the state and local levels in the short and medium term. It also proposes a theoretical model to explain similar and diverging patterns which can be observed across the states.Gewerkschaften des öffentlichen Dienstes sehen weltweit ihre Legitimation in Frage gestellt und sind bedroht durch politische Gegner, die Finanzkrise und Sparmaßnahmen. In den USA wurzelt der Angriff auf die Gewerkschaften des öffentlichen Dienstes in politischer Ideologie, insbesondere der zunehmenden Polarisierung im liberal-konservativen Spektrum, dem Feld der kulturellen Kognition und des wirtschaftlichen Abschwungs. Der Beitrag liefert eine historisch-komparative Analyse der Veränderungen Rechte des collective bargaining im öffentlichen Dienst auf staatlicher und lokaler Ebene aller 50 Staaten der USA. Dabei werden die kurz- und mittelfristigen Veränderungen der industriellen Beziehungen des öffentlichen Dienstes auf staatlicher und lokaler Ebene beschrieben und darüber hinaus ein Modell zur Erklärung von Ähnlichkeiten und Abweichungen zwischen den Bundesstaaten vorgeschlagen