Constrained Dynamics for Quantum Mechanics I. Restricting a Particle to a Surface

We analyze constrained quantum systems where the dynamics do not preserve the constraints. This is done in particular for the restriction of a quantum particle in Euclidean n-space to a curved submanifold, and we propose a method of constraining and dynamics adjustment which produces the right Hamiltonian on the submanifold when tested on known examples. This method we hope will become the germ of a full Dirac algorithm for quantum constraints. We take a first step in generalising it to the situation where the constraint is a general selfadjoint operator with some additional structures.Comment: 49 pages, TEX, input files amssym.def, amssym.te

A simple model of price formation

A simple Ising spin model which can describe the mechanism of price formation in financial markets is proposed. In contrast to other agent-based models, the influence does not flow inward from the surrounding neighbors to the center site, but spreads outward from the center to the neighbors. The model thus describes the spread of opinions among traders. It is shown via standard Monte Carlo simulations that very simple rules lead to dynamics that duplicate those of asset prices.Comment: Version 2: 4 pages, 4 figures; added more stringent statistical analysis; to appear in Int. J. Modern Physics C, Vol. 13, No. 1 (2002

A Healing Echo: Methodological Reflections of a Working-Class Researcher on Class

College students from the working cl ass have interesting stories to tell about the meaning and operation of mobility through education. The author, herself a “working-class academic,” explores some of the issues and dilemmas of uncovering and presenting these stories. Specifically, the author addresses: (1) the effects of interviewing those similar to one’s self; (2) the possibility of losing voice when interviewing too many participants; (3) the responsibility of the researcher to take seriously the importance of renaming interview participants to ensure both anonymity and integrity; (4) the question of audience; and (5) the issue of reliability

ANALYSIS OF FIREARM LEGISLATION AND LAW ENFORCEMENT SUICIDES IN NVDRS-FUNDED STATES

BACKGROUND: The purpose of this study was to evaluate firearm-related suicides among law enforcement members and identify potential differences between decedents and firearm legislation grades from National Violent Death Reporting System (NVDRS) funded states METHODS: Descriptive and regression analyses were conducted using suicide data from 820 decedents who worked within law enforcement at the time of death. Data were collected over a ten-year period (2003-2013) from the NVDRS. Multivariable logistic regression and Pearson’s chi-square were used to identify if differences existed among firearm-related suicides and other means using variables such as age, marital status, occupation, mental health, and firearm legislation scores. Backwards elimination was used to find the best fitting model. RESULTS Due to missing data among the sample, 40 cases were removed, yielding a final sample size of 820. Of reported suicides, 678 (83%) died by firearm while 142 (17%) used other means. Individuals aged 66 and older had more than 2.5 times the odds of dying by suicide with a firearm compared to those aged 36-50. Occupation, while not statistically significant, showed a protective effect among corrections officers and those listed as “other” compared to members in leadership positions. Mental health status displayed a protective effect among law enforcement suicides. Analysis of the key variable of interest, firearm legislation scores, showed a statistical association between firearm suicides and the lowest firearm legislation score (OR=1.83, p-value\u3c0.05). CONCLUSIONS No statistically significant correlation was identified between occupation and firearm-related suicides. Findings indicate that states with the lowest scores on firearm legislation increased the odds of firearm suicides versus use of other methods. Recommendations include: (1) review of current regulations among states with low firearm regulations to prevent firearm access, (2) increase and improve mental health services provided to law enforcement members, and (3) regulate reporting mechanisms for NVDRS data entry

In Vitro and In Vivo Comparison of the Pathogenicity of Four Influenza Virus Strains

Influenza viruses cause between 3 and 5 million cases of respiratory infection each year and are responsible for between 250 and 500 thousand deaths. There are principally two avenues for the treatment and prevention of influenza. They are vaccination and antiviral regimens. Prevention of infection is largely accomplished through vaccination. While vaccines remain the preferred method for controlling the spread of influenza, treatment with antiviral drugs is important for treatment of severe infections that are caused by viruses that are different from the vaccination strains. The two major classes of antiviral drugs for influenza treatment are the adamantanes and the neuraminidase inhibitors. While most viruses have become resistant to the adamantanes, the neuraminidase inhibitors remain the primary choice for treatment of infections. Oseltamivir is the most important of the neuraminidase inhibitors. Data from an experiment run at Utah State University displayed a characteristic that is reflected in other published data. Oseltamivir, which has been shown to be effective against influenza virus strains in vitro, is unable to sufficiently protect mice from lethal infections. The focus of the present research was to identify viral differences that might explain for this discrepancy. Four viral strains were chosen that display differing susceptibilities to oseltamivir in mice. The viruses used were Influenza A/Duck/MN/1525/81 (H5N1), A/Victoria/3/75 (H3N2), A/NWS/33 (H1N1) and A/California/04/2009 (Pandemic H1N1). Oseltamivir was unable to protect mice that were infected with the A/Duck/MN/1525/81 and A/Victoria/3/75 viruses. These two viruses, along with the A/NWS/33 and the A/California/04/2009 viruses, were compared in vitro using virus replication kinetics, neuraminidase inhibition assays, and antiviral assays in cell culture. The viruses were studied in vivo by comparing survival, weight loss, lung scores and weights, lung virus titers, complete blood counts, cytokine assays, and histopathology. A second in vivo experiment was run to determine the effects of oseltamivir on survival, weight loss, lung scores and weights, lung virus titers, and histopathology. The two in vivo experiments summarized in this study confirmed previous data since oseltamivir was unable to protect mice infected with the influenza A/Duck and A/Victoria viruses. Overall, the virus infections behaved remarkably similar. The most interesting difference was that the A/Duck/MN/1525/81 and A/Victoria/3/75 viruses were able to induce more severe histopathological damage in mouse lungs earlier in the infection. The ability to cause severe disease more quickly might explain why the A/Duck/MN/1525/81 and A/Victoria/3/75 viruses remain lethal, despite oseltamivir treatment

Abradable compressor and turbine seals, volume 1

The application and advantages of abradable coatings as gas-path seals in a general aviation turbine engine were evaluated for use on the high-pressure compressor, the high-pressure turbine, and the low-pressure turbine shrouds. Topics covered include: (1) the initial selection of candidate materials for interim full-scale engine testing; (2) interim engine testing of the initially selected materials and additional candidate materials; (3) the design of the component required to adapt the hardware to permit full-scale engine testing of the most promising materials; (4) finalization of the fabrication methods used in the manufacture of engine test hardware; and (5) the manufacture of the hardware necessary to support the final full-scale engine tests

Abradable compressor and turbine seals, volume 2

The applications and advantages of abradable coatings as gas path seals in a general aviation turbofan engine were investigated. Abradable materials were evaluated for the high pressure radial compressor and the axial high and low pressure turbine shrouds

Physical activity barriers in the workplace : an exploration of factors contributing to non-participation in a UK workplace physical activity intervention

Purpose– The purpose of this paper is to explore factors contributing to non-participation in a workplace physical activity (PA) intervention in a large UK call centre. Design/methodology/approach – In total, 16 inactive individuals (nine male/seven female), aged 27±9 years, who had not taken part in the intervention were interviewed to explore their perceptions of PA, the intervention and factors which contributed to their non-participation. Transcripts were analysed using thematic analysis. Findings – Six superordinate themes were identified: self-efficacy for exercise; attitudes towards PA; lack of time and energy; facilities and the physical environment; response to the PA programme and PA culture. Barriers occurred at multiple levels of influence, and support the use of ecological or multilevel models to help guide future programme design/delivery. Research limitations/implications – The 16 participants were not selected to be representative of the workplace gender or structure. Future intentions relating to PA participation were not considered and participants may have withheld negative opinions about the workplace or intervention despite use of an external researcher. Practical implications – In this group of employees education about the importance of PA for young adults and providing opportunities to gain social benefits from PA would increase perceived benefits and reduce perceived costs of PA. Workplace cultural norms with respect to PA must also be addressed to create a shift in PA participation. Originality/value – Employees’ reasons for non-participation in workplace interventions remain poorly understood and infrequently studied. The study considers a relatively under-studied population of employed young adults, providing practical recommendations for future interventions