Stochastic models for atomic clocks

For the atomic clocks used in the National Bureau of Standards Time Scales, an adequate model is the superposition of white FM, random walk FM, and linear frequency drift for times longer than about one minute. The model was tested on several clocks using maximum likelihood techniques for parameter estimation and the residuals were acceptably random. Conventional diagnostics indicate that additional model elements contribute no significant improvement to the model even at the expense of the added model complexity

Developing an Academic Library Assessment Plan: A Case Study

Purpose – The purpose of this paper is to analyze the process of developing an academic library assessment plan and its relation to the furtherance of a culture of assessment. Design/methodology/approach – Qualitative study of a university library’s assessment planning process; findings based on documentary evidence as well as an employee survey; analysis framed in relationship to relevant literature. Findings – Planning for the future of assessment offered the Jerry Falwell Library a significant opportunity for organizational change. Evaluations of the planning process were mixed, but generally revealed evidence of conditions associated with the development of a culture of assessment. Participants saw planning as the product of both external and internal factors. The plan’s orientation toward value and impact, though clearly understood, was not universally appreciated. Implementation of the plan remains a substantial challenge. Research limitations/implications – Reliability is subject to the limitations inherent to qualitative methods. Single case study design limits generalizability to different contexts. Practical implications – The goal of developing a culture of assessment is not to be achieved easily or quickly. Library employees may be most inclined to support an assessment agenda when it is driven by internal factors such as quality improvement and the pursuit of efficiency and effectiveness. Originality/value – The study emphasizes the process of developing an assessment plan at a university with a strong teaching mission. Additionally, it provides insight into the relationship between assessment planning and a culture of assessment

Uncharted Waters: Treating Trauma Symptoms in the Context of Early Psychosis.

Psychosis is conceptualized in a neurodevelopmental vulnerability-stress framework, and childhood trauma is one environmental factor that can lead to psychotic symptoms and the development of psychotic disorders. Higher rates of trauma are associated with higher psychosis risk and greater symptom frequency and severity, resulting in increased hospitalization rates and demand on outpatient primary care and mental health services. Despite an estimated 70% of individuals in the early stages of psychosis reporting a history of experiencing traumatic events, trauma effects (post-traumatic anxiety or depressive symptoms) are often overlooked in psychosis treatment and current interventions typically do not target commonly comorbid post-traumatic stress symptoms. We presented a protocol for Trauma-Integrated Cognitive Behavioral Therapy for Psychosis (TI-CBTp), an approach to treating post-traumatic stress symptoms in the context of early psychosis care. We provided a brief summary of TI-CBTp as implemented in the context of Coordinated Specialty Care and presented preliminary data supporting the use of TI-CBTp in early psychosis care. The preliminary results suggest that individuals with comorbid psychosis and post-traumatic stress symptoms can be appropriately and safely treated using TI-CBTp within Coordinated Specialty Care

Carbon release from submarine seeps at the Costa Rica fore arc: implications for the volatile cycle at the Central America convergent margin

We report total dissolved inorganic carbon (DIC) abundances and isotope ratios, as well as helium isotope ratios (3He/4He), of cold seep fluids sampled at the Costa Rica fore arc in order to evaluate the extent of carbon loss from the submarine segment of the Central America convergent margin. Seep fluids were collected over a 12 month period at Mound 11, Mound 12, and Jaco Scar using copper tubing attached to submarine flux meters operating in continuous pumping mode. The fluids show minimum 3He/4He ratios of 1.3 RA (where RA is air 3He/4He), consistent with a small but discernable contribution of mantle-derived helium. At Mound 11, δ13C∑CO2 values between −23.9‰ and −11.6‰ indicate that DIC is predominantly derived from deep methanogenesis and is carried to the surface by fluids derived from sediments of the subducting slab. In contrast, at Mound 12, most of the ascending dissolved methane is oxidized due to lower flow rates, giving extremely low δ13C∑CO2 values ranging from −68.2‰ to −60.3‰. We estimate that the carbon flux (CO2 plus methane) through submarine fluid venting at the outer fore arc is 8.0 × 105 g C km−1 yr−1, which is virtually negligible compared to the total sedimentary carbon input to the margin and the output at the volcanic front. Unless there is a significant but hitherto unidentified carbon flux at the inner fore arc, the implication is that most of the carbon being subducted in Costa Rica must be transferred to the (deeper) mantle, i.e., beyond the depth of arc magma generation