Simple computations for near-optimum ascent and abort maneuver targets and deorbit ignition time

Closed-form solutions are presented for a two-burn orbit insertion, AOA, and ATO maneuver targets, and for time of ignition of a one-burn deorbit. Based on the assumption that the orbits involved deviate only to the first order about a reference circular orbit, these solutions are nearly fuel-minimum. They are expressed in terms of linear terminal velocity constraint shuttle guidance targets and, thus, are readily applicable to both ground and onboard software use. In addition to potential application to real-time targeting, the equations may be used as a mission design aid in preliminary definition of target loads and definition of abort mode boundaries

An interactive three dimensional approach to anatomical description—the jaw musculature of the Australian laughing kookaburra (Dacelo novaeguineae)

The investigation of form-function relationships requires a detailed understanding of anatomical systems. Here we document the 3-dimensional morphology of the cranial musculoskeletal anatomy in the Australian Laughing Kookaburra Dacelo novaeguineae, with a focus upon the geometry and attachments of the jaw muscles in this species. The head of a deceased specimen was CT scanned, and an accurate 3D representation of the skull and jaw muscles was generated through manual segmentation of the CT scan images, and augmented by dissection of the specimen. We identified 14 major jaw muscles: 6 in the temporal group (M. adductor mandibulae and M. pseudotemporalis), 7 in the pterygoid group (M. pterygoideus dorsalis and M. pterygoideus ventralis), and the single jaw abductor M. depressor mandibulae. Previous descriptions of avian jaw musculature are hindered by limited visual representation and inconsistency in the nomenclature. To address these issues, we: (1) present the 3D model produced from the segmentation process as a digital, fully interactive model in the form of an embedded 3D image, which can be viewed from any angle, and within which major components can be set as opaque, transparent, or hidden, allowing the anatomy to be visualised as required to provide a detailed understanding of the jaw anatomy; (2) provide a summary of the nomenclature used throughout the avian jaw muscle literature. The approach presented here provides considerable advantages for the documentation and communication of detailed anatomical structures in a wide range of taxa

New Faculty Mentoring in Respiratory Care Programs

Introduction: The purpose of this study was to identify mentoring practices of new faculty members in Commission on Accreditation for Respiratory Care (CoARC) accredited respiratory care programs in the U.S. and to identify the perceptions of program directors regarding the observed impact of program mentoring practices. Methods: The method for the study was quantitative non-experimental survey research. The survey instrument was an electronic questionnaire titled Respiratory Care Faculty (RCF) Mentoring Survey. The 25-item survey was divided into three dimensions: mentoring practices, mentor/mentee relationship, and perceptions of the impact of new faculty mentoring. Of the 410 possible program director participants, 126 (30%) responded to the survey. Data from the survey were used to analyze three primary research questions on four independent variables (12 total research questions). Results: Testing of the null hypotheses associated with the 12 research questions resulted in three significant findings and 9 findings that were not significant. Significant findings included female program directors reported greater opportunities for mentoring within their programs and greater levels of expectation concerning mentoring as compared to male program directors. Program directors from associate degree programs also reported a higher level of expectation concerning mentoring than program directors in bachelor’s degree programs. There was overwhelming agreement regarding the potential impact and benefit of mentoring new faculty to improve job performance, reduce turnover, improve job satisfaction, and organizational commitment. Conclusion: The results of this study may benefit administrators and educators in respiratory care in efforts to support new faculty who possibly feel underprepared or overwhelmed in the new role. Because other allied health fields of study are similar in nature to respiratory care, the findings of the study could have potential implications across a range of health-related professions

Evaluating Adults With Idiopathic Pancreatitis for Genetic Predisposition: Higher Prevalence of Abnormal Results With Use of Complete Gene Sequencing

OBJECTIVES: In adults with unexplained pancreatitis, the yield of complete gene versus select exosome sequencing on mutation detection and distinguishing clinical characteristics associated with mutations requires clarification. We sought to (1) compare frequency of mutations identified using different techniques and (2) compare clinical characteristics between adults with and without mutations. METHODS: This is a cohort study of adults with unexplained pancreatitis who underwent genetic testing between January 2008 and December 2012. We compare probabilities of having a positive mutation with complete gene sequencing versus alternatives and describe differences in characteristics among patients with and without mutations. RESULTS: Of the 370 patients, 67 (18%) had a genetic mutation; 24 (6%) were of high risk. Mutations were significantly more prevalent with use of complete sequencing (42%) versus other approaches (8%, P < 0.0001). Most (44/67, 66%) with a mutation had no family history. Those with high-risk mutations were more likely to have a family history of chronic pancreatitis (21% vs 4%, P = 0.002). Patients with pancreas divisum were more likely to have mutations (27% vs 14%, P = 0.0007). CONCLUSION: Among individuals with adult-onset pancreatic disease, the probability of finding any mutation, including high risk, is significantly higher using complete gene sequencing. The impact on patients and providers requires further investigation

Anomalous far infrared monochromatic transmission through a film of type-II superconductor in magnetic field

Anomalous far infrared monochromatic transmission through a lattice of Abrikosov vortices in a type-II superconducting film is found and reported. The transmitted frequency corresponds to the photonic mode localized by the defects of the Abrokosov lattice. These defects are formed by extra vortices placed out of the nodes of the ideal Abrokosov lattice. The extra vortices can be pinned by crystal lattice defects of a superconductor. The corresponding frequency is studied as a function of magnetic field and temperature in the framework of the Dirac-type two-band model. While our approach is valid for all type-II superconductors, the specific calculations have been performed for the YBa$_{2}$Cu$_{3}$O$_{7-\delta}$ (YBCO). The control of the transmitted frequency by varying magnetic field and/or temperature is analyzed. It is suggested that found anomalously transmitted localized mode can be utilized in the far infrared monochromatic filters.Comment: 9 pages, 2 figure

Nano granular metallic Fe - oxygen deficient TiO2−δ_{2-\delta} composite films: A room temperature, highly carrier polarized magnetic semiconductor

Nano granular metallic iron (Fe) and titanium dioxide (TiO$_{2-\delta}$) were co-deposited on (100) lanthanum aluminate (LaAlO$_3$) substrates in a low oxygen chamber pressure using a pulsed laser ablation deposition (PLD) technique. The co-deposition of Fe and TiO$_2$ resulted in $\approx$ 10 nm metallic Fe spherical grains suspended within a TiO$_{2-\delta}$ matrix. The films show ferromagnetic behavior with a saturation magnetization of 3100 Gauss at room temperature. Our estimate of the saturation magnetization based on the size and distribution of the Fe spheres agreed well with the measured value. The film composite structure was characterized as p-type magnetic semiconductor at 300 K with a carrier density of the order of $10^{22} /{\rm cm^3}$. The hole carriers were excited at the interface between the nano granular Fe and TiO$_{2-\delta}$ matrix similar to holes excited in the metal/n-type semiconductor interface commonly observed in Metal-Oxide-Semiconductor (MOS) devices. From the large anomalous Hall effect directly observed in these films it follows that the holes at the interface were strongly spin polarized. Structure and magneto transport properties suggested that these PLD films have potential nano spintronics applications.Comment: 6 pages in Latex including 8 figure

Critical currents, flux-creep activation energy and potential barriers for the vortex motion from the flux creep experiments

We present an experimental study of thermally activated flux creep in a superconducting ring-shaped epitaxial YBCO film as well as a new way of analyzing the experimental data. The measurements were made in a wide range of temperatures between 10 and 83 K. The upper temperature limit was dictated by our experimental technique and at low temperatures we were limited by a crossover to quantum tunneling of vortices. It is shown that the experimental data can very well be described by assuming a simple thermally activated hopping of vortices or vortex bundles over potential barriers, whereby the hopping flux objects remain the same for all currents and temperatures. The new procedure of data analysis also allows to establish the current and temperature dependencies of the flux-creep activation energy U, as well as the temperature dependence of the critical current Ic, from the flux-creep rates measured at different temperatures. The variation of the activation energy with current, U(I/Ic), is then used to reconstruct the profile of the potential barriers in real space.Comment: 12 pages, 13 Postscript figures, Submitted to Physical Review

The influence of pressure on the phase stability of nanocomposite Fe_(89)Zr_7B_4 during heating from energy dispersive x-ray diffraction

Nanocomposite materials consisting of small crystalline grains embedded within an amorphous matrix show promise for many soft magnetic applications. The influence of pressure is investigated by in situ diffraction of hammer milled Fe_(89)Zr_(7)B_4 during heating through the α → γ Fe transition at 0.5, 2.2, and 4.9 GPa. The changes in primary and secondary crystallization onset are described by diffusion and the energy to form a critical nucleus within the framework of classical nucleation theory