Rocket propulsion research at Lewis Research Center

A small contingent of engineers at NASA LeRC pioneered the basic research on liquid propellants for rockets shortly after World War 2. Carried on through the 1950s, this work influenced the important early decisions made by Abe Silverstein when he took charge of the Office of Space Flight Programs for NASA. He strongly supported the development of liquid hydrogen as a propulsion fuel in the face of resistance from Wernher von Braun. Members of the LeRC staff played an important role in bringing liquid hydrogen technology to the point of reliability through their management of the Centaur Program. This paper demonstrates how the personality and engineering intuition of Abe Silverstein shaped the Centaur program and left a lasting imprint on the laboratory research tradition. Many of the current leaders of LeRC received their first hands-on engineering experience when they worked on the Centaur program in the 1960s

Who Can Win a Single-Elimination Tournament?

A single-elimination (SE) tournament is a popular way to select a winner in both sports competitions and in elections. A natural and well-studied question is the tournament fixing problem (TFP): given the set of all pairwise match outcomes, can a tournament organizer rig an SE tournament by adjusting the initial seeding so that their favorite player wins? We prove new sufficient conditions on the pairwise match outcome information and the favorite player, under which there is guaranteed to be a seeding where the player wins the tournament. Our results greatly generalize previous results. We also investigate the relationship between the set of players that can win an SE tournament under some seeding (so called SE winners) and other traditional tournament solutions. In addition, we generalize and strengthen prior work on probabilistic models for generating tournaments. For instance, we show that \emph{every} player in an $n$ player tournament generated by the Condorcet Random Model will be an SE winner even when the noise is as small as possible, $p=\Theta(\ln n/n)$; prior work only had such results for $p\geq \Omega(\sqrt{\ln n/n})$. We also establish new results for significantly more general generative models.Comment: A preliminary version appeared in Proceedings of the 30th AAAI Conference on Artificial Intelligence (AAAI), 201

Depression and Anxiety in Roman Catholic Secular Clergy

A nationally selected random sample of Roman Catholic secular priests was investigated using the Center for Epidemiological Studies-Depression scale and the State-Trait Anxiety Inventory Form Y. Additionally, a Self-Report Inventory requested information regarding participants\u27 demographics as well as four categories of predictor variables (i.e., Vocational Satisfaction, Social Support, Spiritual Activities, Physical Environment) potentially associated with depression and anxiety. The study yielded a return rate of 64%. Secular clergy reported significantly greater depression and anxiety (both state and trait) than are reported in the general population. Low Vocational Satisfaction was found to be predictive of depression as well as both state and trait anxiety. Additionally, low Social Support was found to be predictive of state and trait anxiety. When the significant predictor variables were conceptually collapsed, it appeared that both people and place were significantly related to Roman Catholic secular priests\u27 experience of depression and anxiety

Depression and Contributors to Vocational Satisfaction in Roman Catholic Secular Clergy

A nationally selected, random sample of Roman Catholic secular (i.e., diocesan) priests was examined using the Center for Epidemiological Studies-Depression scale and an instrument developed for this study to assess contributors to priests’ vocational satisfaction. In addition, a self-report inventory gathered information regarding participants’ demographics as well as four categories of predictor variables (i.e., overall level of vocational satisfaction, social support, spiritual activities, physical environment). The study yielded a response rate of 45%. Secular clergy reported rates of depression approximately seven times greater than are found in the general population, and also indicated that the recent sexual abuse scandal in the Roman Catholic church had negatively affected their mood. Priests’ engagement in sacramental activities contributed greatly to their vocational satisfaction, and low levels of vocational satisfaction were found to be most predictive of depression. Factors comprising priests’ vocational satisfaction were External Manifestations (e.g., preaching, teaching), Internal Manifestations (e.g., prayer life, affirmation of God’s call), and Social Manifestations (e.g., relationships with parishioners, appreciation from others)

Cruces discursivos de la memoria pública y la privada : Memorias curiosas de Juan Manuel Beruti y la Gaceta de Buenos Aires

El periodo de transición desde el sistema colonial español a la nueva república trajo aparejado el impulso de la prensa periódica como órgano de difusión y promoción de nuevas propuestas políticas e ideológicas, donde los publicistas se convirtieron en portavoces de una opinión que ellos mismos crearon y movilizaron. Este desarrollo tuvo como contracara el fenómeno inverso: el hombre común se preocupó por registrar los sucesos excepcionales para generaciones posteriores. Nos proponemos analizar las complejas relaciones entre producción memorialística y prensa, a partir de Memorias curiosas, de Juan Manuel Beruti y algunos números de la Gaceta de Buenos Aires (1801-1811

A DNP Nurse-Managed Hepatitis C Clinic, Improving Quality of Life in a Rural Area

Hepatitis C is quickly becoming a national threat, involving 2% of the nation’s population, ranking this as the 11th most prevalent disease in the world. Traditionally, treatment for hepatitis C has been conducted in tertiary care settings, limiting access to care for those residing in rural areas. Improving access to care through the development of a Doctor of Nursing Practice (DNP) nurse-managed clinic in a rural setting will improve health outcomes and quality of life for those treated outside the traditional setting. Caring for those living in less densely populated areas requires an understanding of rural culture. This paper will discuss the development and implementation of a DNP Model of Care for rural patients being treated for hepatitis C. The model of care starts with identifying hepatitis C, treating the patient following established medical guidelines, using the nursing model to monitor clinical progress and managing side-effects caused by the treatment medications. Using the DNP Model of Care, a patient-focused clinic can successfully treat rural patients utilizing the principles of the Effect Theory for management and the Process Theory for ongoing evaluation. Collaboration with other key resources, utilizing a multidisciplinary approach allows the DNP nurse to care for those requiring treatment for chronic hepatitis C, where they live and work with the assistance of family and social support

Ticked Off: An Analysis of the Inadequate Diagnosis and Treatment of Lyme Disease

Lyme disease is the most common vector-borne disease in the United States and has a high prevalence among people in the northeast. Lyme disease can be a debilitating illness if not diagnosed early, and can lead to long-term health problems for many patients. This thesis serves as a review of scientific literature on Lyme disease, with the prevalence, symptomology, the bacterial mechanism of infection, the diagnostic process, transmission, and treatment therapies. Further research and development could lead to better primary care for those suffering with Lyme disease

The signature motif of the Saccharomyces cerevisiae Pif1 DNA helicase is essential in vivo for mitochondrial and nuclear functions and in vitro for ATPase activity

Pif1 family DNA helicases are conserved from bacteria to humans and have critical and diverse functions in vivo that promote genome integrity. Pif1 family helicases share a 23 amino acid region, called the Pif1 signature motif (SM) that is unique to this family. To determine the importance of the SM, we did mutational and functional analysis of the SM from the Saccharomyces cerevisiae Pif1 (ScPif1). The mutations deleted portions of the SM, made one or multiple single amino acid changes in the SM, replaced the SM with its counterpart from a bacterial Pif1 family helicase and substituted an α-helical domain from another helicase for the part of the SM that forms an α helix. Mutants were tested for maintenance of mitochondrial DNA, inhibition of telomerase at telomeres and double strand breaks, and promotion of Okazaki fragment maturation. Although certain single amino acid changes in the SM can be tolerated, the presence and sequence of the ScPif1 SM were essential for all tested in vivo functions. Consistent with the in vivo analyses, in vitro studies showed that the presence and sequence of the ScPif1 SM were critical for ATPase activity but not substrate binding

Active Traffic Management as a Tool for Addressing Traffic Congestion

Recurrent and non-recurrent congestion in urban areas continues to be a major concern due to its adverse impacts on delays, fuel consumption and pollution, driver frustration, and traffic safety. In the U.S., limited public funding for roadway expansion and improvement projects, coupled with continued growth in travel along congested urban freeway corridors, creates a pressing need for innovative congestion management approaches