The Complexities of Decision-making Related to Health Risk Assessments

Maine, like the nation, has focused a great deal of recent attention on determining acceptable levels of environmental and human health risk. Barbara discusses the role and uses of scientific information in risk assessment and public policy debate. Similar to Kevin Boyle\u27s previous article (featured in the December 1994 issue of Maine Policy Review), Knuth discusses the 1992 Maine Board of Environmental Protection hearings which focused on the human consumption of fish potentially contaminated with dioxin

Rolling Contact Fatigue of Low Hardness Steel for Slewing Ring Application

This thesis discusses the rolling contact fatigue of steel utilized in anti-friction bearings, also referred to as slewing bearings. These slewing bearings are utilized in cranes, excavators, wind turbines and other similar applications. Five materials composed of two different material types were tested. The two material types were high carbon steel and medium carbon alloy steel. The test specimens were processed from forged rolled rings. Two machines were evaluated a ZF-RCF and 3-Ball test machine. The evaluation was to determine which machine can best simulate the application in which the slewing bearing is utilized. Initially, each specimen will be pretested to determine the appropriate testing direction from within the forged rolled rings. Pretesting is needed in order to establish consistent failure modes between samples. The primary goal of the test is to understand the life differences and failure modes between high carbon steel and medium carbon alloy steel. The high carbon steel ring was cut into two sections, one of which was stress relieved and the other was quenched and tempered. The medium carbon alloy steel was cut into three sections, all of which were quenched and tempered to different hardness levels. The test program was dynamically adjusted based upon the previous sample\u27s life and load. An S-N curve was then established from the 5 materials tested at two target loads. The samples were run until the first sign of a crack was detected by an eddy current. At the completion of the rolling contact test, select sample\u27s microstructure was evaluated for crack initiation location. The selected samples were divided into four groups which represent different maximum shear stress levels. These samples displayed indications of material deformation in which the high carbon steel experienced an increased amount of cold work when compared to medium carbon alloy steel. The life of the high carbon steel was nearly equivalent to the expected life of the medium carbon alloy. The work hardening of the high carbon steel increased the surface hardness that exceeded the medium carbon alloy steel surface hardness

A personal professional vision for elementary principalship : a reflective essay

The business of running public schools to prepare our youngsters to be productive members of society is a very complex task. It is not enough to simply have a vision based on values and beliefs, but one must also possess the necessary skills to · transform that vision into reality. Dr. Lorraine Monroe, a successful leader in the field of educational leadership, sums this up by saying, Most important is that the leader continue not only to believe in the dream and the need to pursue it but also to do the hard brain work of never doubting its importance, (Monroe, 1997, p. 32). It is with this goal in mind that I will first examine my values and beliefs and determine how they will help guide my work as a school leader. I will then examine the knowledge and skills that I believe will be necessary for me to provide effective leadership. Finally, I will articulate my personal professional vision for administrative practice based on a synthesis of my values and the knowledge I have gained through my study of educational leadership

Information-Based Physics: An Observer-Centric Foundation

It is generally believed that physical laws, reflecting an inherent order in the universe, are ordained by nature. However, in modern physics the observer plays a central role raising questions about how an observer-centric physics can result in laws apparently worthy of a universal nature-centric physics. Over the last decade, we have found that the consistent apt quantification of algebraic and order-theoretic structures results in calculi that possess constraint equations taking the form of what are often considered to be physical laws. I review recent derivations of the formal relations among relevant variables central to special relativity, probability theory and quantum mechanics in this context by considering a problem where two observers form consistent descriptions of and make optimal inferences about a free particle that simply influences them. I show that this approach to describing such a particle based only on available information leads to the mathematics of relativistic quantum mechanics as well as a description of a free particle that reproduces many of the basic properties of a fermion. The result is an approach to foundational physics where laws derive from both consistent descriptions and optimal information-based inferences made by embedded observers.Comment: To be published in Contemporary Physics. The manuscript consists of 43 pages and 9 Figure

Speculations on the postnatural: Restoration, accumulation, and sacrifice at the Salton Sea

Using a regional political ecology lens, this paper explores emerging geographies and politics of a “postnatural” ecomodernist turn in mainstream environmentalism. We examine the unfolding case of ecological restoration and renewable energy development at Southern California’s Salton Sea. Ambitious proposals to restore the massive, increasingly degraded lake (and finance restoration) by reengineering it as a hub for geothermal energy generation and high-tech green industry hinge upon the ambiguity and malleability of restoration in an environment long classified as postnatural. These plans coincide with a broader rush on renewable energy sites in the California desert, and mounting conflicts over water and land with legacy agro-industrial interests. The case illustrates significant problems within postnatural environmentalism. First, it demonstrates how theorizations of the postnatural can intersect with green capitalist projects of re(e)valuation and development, as the Sea’s managers manipulate environmental framings to support accumulation-minded projects, and accumulation imperatives swamp other functionalities of restoration. Meanwhile, despite the flourishing of postnatural discourses, the “pristine” is shown to do continued work as the Sea becomes a sacrifice zone for development deflected from better-protected spaces. This postnatural positioning has rendered the Salton Sea vulnerable to neoliberal austerity and speculation in ways that compromise its future existence

Noncooperative algorithms in self-assembly

We show the first non-trivial positive algorithmic results (i.e. programs whose output is larger than their size), in a model of self-assembly that has so far resisted many attempts of formal analysis or programming: the planar non-cooperative variant of Winfree's abstract Tile Assembly Model. This model has been the center of several open problems and conjectures in the last fifteen years, and the first fully general results on its computational power were only proven recently (SODA 2014). These results, as well as ours, exemplify the intricate connections between computation and geometry that can occur in self-assembly. In this model, tiles can stick to an existing assembly as soon as one of their sides matches the existing assembly. This feature contrasts with the general cooperative model, where it can be required that tiles match on \emph{several} of their sides in order to bind. In order to describe our algorithms, we also introduce a generalization of regular expressions called Baggins expressions. Finally, we compare this model to other automata-theoretic models.Comment: A few bug fixes and typo correction

New Variants of Pattern Matching with Constants and Variables

Given a text and a pattern over two types of symbols called constants and variables, the parameterized pattern matching problem is to find all occurrences of substrings of the text that the pattern matches by substituting a variable in the text for each variable in the pattern, where the substitution should be injective. The function matching problem is a variant of it that lifts the injection constraint. In this paper, we discuss variants of those problems, where one can substitute a constant or a variable for each variable of the pattern. We give two kinds of algorithms for both problems, a convolution-based method and an extended KMP-based method, and analyze their complexity.Comment: 15 pages, 2 figure

Effects of Aerobic Exercise Modality on Cognition and Fitness in Breast Cancer Survivors

International Journal of Exercise Science 12(3): 1023-1033, 2019. Although cognitive dysfunction is a common occurrence among breast cancer survivors, there is no widely recognized intervention for this debilitating condition. The purpose of this study was to determine whether floor/step aerobics (FSA) and/or treadmill walking (TMW) interventions can improve outcomes when compared to standard care (STC). Recent breast cancer survivors participated in 12 weeks of FSA (n=8), TMW (n=7), or STC (n=10) with pre/post assessments of cognition and fitness. Interaction effects between group and time were assessed with repeated measures ANOVA. Throughout the extent of cognitive and fitness assessments, there were found to be no statistically significant interactions between group and time. Because of the small sample size, these results should not be taken to mean that exercise cannot improve cognition in recent breast cancer survivors, but this study should be used as a baseline for designing similar studies with a longer intervention, more intense exercise program, or another alteration that might increase effectiveness of the intervention. More research is needed in this area, but until more specific study results are available, healthcare providers should continue to encourage breast cancer survivors to regularly participate in aerobic exercise to maintain physical function