Successful Case of Extirpation of the Uterus

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Simulation comparison of a decoupled longitudinal control system and a velocity vector control wheel steering system during landings in wind shear

A simulator comparison of the velocity vector control wheel steering (VCWS) system and a decoupled longitudinal control system is presented. The piloting task was to use the electronic attitude direction indicator (EADI) to capture and maintain a 3 degree glide slope in the presence of wind shear and to complete the landing using the perspective runway included on the EADI. The decoupled control system used constant prefilter and feedback gains to provide steady state decoupling of flight path angle, pitch angle, and forward velocity. The decoupled control system improved the pilots' ability to control airspeed and flight path angle during the final stages of an approach made in severe wind shear. The system also improved their ability to complete safe landings. The pilots preferred the decoupled control system in severe winds and, on a pilot rating scale, rated the approach and landing task with the decoupled control system as much as 3 to 4 increments better than use of the VCWS system

Residential Grief Camps: An Initial Phenomenological Study of Staff Perspectives

Research has focused primarily on the impact of death on family functioning and the stages and tasks of grief, though little attention has been given to grief camps or the experiences of those who work there. This study explored the experiences of staff at a four-day overnight children’s grief camp. Eight participants reported their experience of camp in two major categories: connection to others and independence in grief and five themes. Camp provides the opportunity for campers to connect to others while finding their own path to healing. Clinical implications and future research directions are also discussed

Exact results for Casimir interactions between dielectric bodies: The weak-coupling or van der Waals Limit

In earlier papers we have applied multiple scattering techniques to calculate Casimir forces due to scalar fields between different bodies described by delta function potentials. When the coupling to the potentials became weak, closed-form results were obtained. We simplify this weak-coupling technique and apply it to the case of tenuous dielectric bodies, in which case the method involves the summation of van der Waals (Casimir-Polder) interactions. Once again exact results for finite bodies can be obtained. We present closed formulas describing the interaction between spheres and between cylinders, and between an infinite plate and a retangular slab of finite size. For such a slab, we consider the torque acting on it, and find non-trivial equilibrium points can occur.Comment: 4 pages, 3 figure

Exact Casimir Interaction Between Semitransparent Spheres and Cylinders

A multiple scattering formulation is used to calculate the force, arising from fluctuating scalar fields, between distinct bodies described by $\delta$-function potentials, so-called semitransparent bodies. (In the limit of strong coupling, a semitransparent boundary becomes a Dirichlet one.) We obtain expressions for the Casimir energies between disjoint parallel semitransparent cylinders and between disjoint semitransparent spheres. In the limit of weak coupling, we derive power series expansions for the energy, which can be exactly summed, so that explicit, very simple, closed-form expressions are obtained in both cases. The proximity force theorem holds when the objects are almost touching, but is subject to large corrections as the bodies are moved further apart.Comment: 5 pages, 4 eps figures; expanded discussion of previous work and additional references added, minor typos correcte

The heat kernel coefficients for the dielectric cylinder

We calculate the \hkks for the \elm field in the background of a dielectric cylinder with non equal speeds of light inside and outside. The coefficient $a_{2}$ whose vanishing makes the vacuum energy of a massless field unique, turns out to be zero in dilute order, i.e., in order (\ep-1)^{2}, and nonzero beyond. As a consequence, the vanishing of the vacuum energy in the presence of a dielectric cylinder found by Casimir-Polder summation must take place irrespectively of the methods by which it might be calculated.Comment: 14 pages, 1 figur

The Soaring of Birds

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Physiological serum 25-hydroxyvitamin D concentrations are associated with improved thyroid function—observations from a community-based program

Purpose: Vitamin D deficiency has been associated with an increased risk of hypothyroidism and autoimmune thyroid disease. Our aim was to investigate the influence of vitamin D supplementation on thyroid function and anti-thyroid antibody levels. Methods: We constructed a database that included 11,017 participants in a health and wellness program that provided vitamin D supplementation to target physiological serum 25-hydroxyvitmain D [25(OH)D] concentrations (>100 nmol/L). Participant measures were compared between entry to the program (baseline) and follow-up (12 ± 3 months later) using an intent-to-treat analysis. Further, a nested case-control design was utilized to examine differences in thyroid function over 1 year in hypothyroid individuals and euthyroid controls. Results: More than 72% of participants achieved serum 25(OH)D concentrations >100 nmol/L at follow-up, with 20% above 125 nmol/L. Hypothyroidism was detected in 2% (23% including subclinical hypothyroidism) of participants at baseline and 0.4% (or 6% with subclinical) at follow-up. Serum 25(OH)D concentrations ≥125 nmol/L were associated with a 30% reduced risk of hypothyroidism and a 32% reduced risk of elevated anti-thyroid antibodies. Hypothyroid cases were found to have higher mean serum 25(OH)D concentrations at follow-up, which was a significant positive predictor of improved thyroid function. Conclusion: The results of the current study suggest that optimal thyroid function might require serum 25(OH)D concentrations above 125 nmol/L. Vitamin D supplementation may offer a safe and economical approach to improve thyroid function and may provide protection from developing thyroid disease

Teacher Performance Pay: Synthesis of Plans, Research, and Guidelines for Practice

The single salary schedule has ruled the delivery of teacher pay for decades, despite long-standing criticism that it fails to link some portion of teachers\u27pay to their performance. In recent years, there has been some experimentation with performance pay for teachers. Early attempts focused on the development of merit pay, in which pay raises were linked to subjective evaluations of teacher performance. Subsequent evaluations of merit pay plans questioned their effectiveness, especially given their limited survival, though it was acknowledged that the problem was not necessarily merit pay per se, but the way the plans were designed, implemented, and administered (Hatry, Greiner, & Ashford, 1994). Notwithstanding these unsuccessful experiences, national surveys have found that teacher attitudes toward some forms of performance pay are not unfavorable (Ballou, 2001; Ballou & Podgursky, 1993). In the 1990s, other forms of performance pay began to emerge at the state and district levels. Notable were school-based performance awards and knowledge- and skill-based pay plans. Elements from these plans have now been incorporated into combined pay plans. And while none of these plans has been widely adopted, they have drawn intensive national scrutiny and study. This Policy Brief focuses on the nature and effectiveness of these plans. We first provide generic descriptions of three types of plans, followed by a synthesis of research results on their effectiveness. A set of guidelines for effective practice is then provided to help states and districts embarking on these forms of performance pay. We conclude with a look ahead at recent developments in performance pay plans and other deviations from the traditional teacher salary schedule