Evaluation of advanced lift concepts and potential fuel conservation for short-haul aircraft

The effect of different field lengths, cruise requirements, noise level, and engine cycle characteristics on minimizing fuel consumption and minimizing operating cost at high fuel prices were evaluated for some advanced short-haul aircraft. The conceptual aircraft were designed for 148 passengers using the upper surface-internally blown jet flap, the augmentor wing, and the mechanical flap lift systems. Advanced conceptual STOL engines were evaluated as well as a near-term turbofan and turboprop engine. Emphasis was given to designs meeting noise levels equivalent to 95-100 EPNdB at 152 m (500 ft) sideline

Database Search Strategies for Proteomic Data Sets Generated by Electron Capture Dissociation Mass Spectrometry

Large data sets of electron capture dissociation (ECD) mass spectra from proteomic experiments are rich in information; however, extracting that information in an optimal manner is not straightforward. Protein database search engines currently available are designed for low resolution CID data, from which Fourier transform ion cyclotron resonance (FT-ICR) ECD data differs significantly. ECD mass spectra contain both z-prime and z-dot fragment ions (and c-prime and c-dot); ECD mass spectra contain abundant peaks derived from neutral losses from charge-reduced precursor ions; FT-ICR ECD spectra are acquired with a larger precursor m/z isolation window than their low-resolution CID counterparts. Here, we consider three distinct stages of postacquisition analysis: (1) processing of ECD mass spectra prior to the database search; (2) the database search step itself and (3) postsearch processing of results. We demonstrate that each of these steps has an effect on the number of peptides identified, with the postsearch processing of results having the largest effect. We compare two commonly used search engines: Mascot and OMSSA. Using an ECD data set of modest size (3341 mass spectra) from a complex sample (mouse whole cell lysate), we demonstrate that search results can be improved from 630 identifications (19% identification success rate) to 1643 identifications (49% identification success rate). We focus in particular on improving identification rates for doubly charged precursors, which are typically low for ECD fragmentation. We compare our presearch processing algorithm with a similar algorithm recently developed for electron transfer dissociation (ETD) data

Learning styles in vertically integrated teaching.

This item is under embargo for a period of 12 months from the date of publication, in accordance with the publisher's policy.Background: With vertical integration, registrars and medical students attend the same educational workshops. It is not known whether these learners have similar or different learning styles related to their level of education within the medical training schema. This study aims to collect information about learning styles with a view to changing teaching strategies. If a significant difference is demonstrated this will impact on required approaches to teaching. Methods: The VARK learning inventory questionnaire was administered to 36 general practice registrars and 20 medical students. The learning styles were compared as individuals and then related to their level of education within the medical training schema. Results: Students had a greater preference for multimodal learning compared with registrars (62.5 per cent versus 33.3 per cent, respectively). More than half of the registrars preferred uni or bimodal learning modalities, compared with one-third of the medical students. Discussion: The present work- shop format based on visual and aural material will not match the learning needs of most learners. This small study has shown that the majority of medical students and registrars could have their learning preferences better met by the addition of written material to the workshop series. Surprisingly, a significantly larger number of medical students than registrars appeared to be broadly multi- modal in their learning style, and this warrants further research

Fast magnetic reconnection in the plasmoid-dominated regime

A conceptual model of resistive magnetic reconnection via a stochastic plasmoid chain is proposed. The global reconnection rate is shown to be independent of the Lundquist number. The distribution of fluxes in the plasmoids is shown to be an inverse square law. It is argued that there is a finite probability of emergence of abnormally large plasmoids, which can disrupt the chain (and may be responsible for observable large abrupt events in solar flares and sawtooth crashes). A criterion for the transition from magnetohydrodynamic to collisionless regime is provided.Comment: 4 pages, 1 figur

Steady Hall Magnetohydrodynamics Near a X-type Magnetic Neutral Line

Hall magnetohydrodynamics (MHD) properties near a two-dimensional (2D) X-type magnetic neutral line in the steady state are considered via heuristic and rigorous developments. Upon considering the steady-state as the asymptotic limit of the corresponding \textit{time-dependent} problem and using a rigorous development, Hall effects are shown to be able to sustain the hyperbolicity of the magnetic field (and hence a more open X-point configuration) near the neutral line in the steady state. The heuristic development misses this subtle connection of the steady state with the corresponding \textit{time-dependent} problem and predicts only an elongated current-sheet configuration (as in resistive MHD). However, the heuristic development turns out to be useful in providing insight into the lack of dependence of the reconnection rate on the mechanism breaking the frozen-in condition of the magnetic field lines. The latter result can be understood in terms of the ability of the ions and electrons to transport equal amounts of magnetic flux per unit time out of the reconnection region.Comment: 1-10 page

A Model for Patchy Reconnection in Three Dimensions

We show, theoretically and via MHD simulations, how a short burst of reconnection localized in three dimensions on a one-dimensional current sheet creates a pair of reconnected flux tubes. We focus on the post-reconnection evolution of these flux tubes, studying their velocities and shapes. We find that slow-mode shocks propagate along these reconnected flux tubes, releasing magnetic energy as in steady-state Petschek reconnection. The geometry of these three-dimensional shocks, however, differs dramatically from the classical two-dimensional geometry. They propagate along the flux tube legs in four isolated fronts, whereas in the two-dimensional Petschek model, they form a continuous, stationary pair of V-shaped fronts. We find that the cross sections of these reconnected flux tubes appear as teardrop shaped bundles of flux propagating away from the reconnection site. Based on this, we argue that the descending coronal voids seen by Yohkoh SXT, LASCO, and TRACE are reconnected flux tubes descending from a flare site in the high corona, for example after a coronal mass ejection. In this model, these flux tubes would then settle into equilibrium in the low corona, forming an arcade of post-flare coronal loops.Comment: 27 pages plus 16 figure

Native Hawaiian Grandparents: Exploring Benefits and Challenges in the Caregiving Experience

Background: Increasingly, U.S. grandparents are raising their grandchildren. In Hawai‘i, 12% of Native Hawaiian grandparents live with grandchildren, compared to 7% of grandparents in all races combined in the state, and to 3.6% of grandparents in the total U.S. Although strong family-centric cultural values may provide Native Hawaiian grandparents with caregiving benefits, a generally poor health profile suggests they may also face challenges in this role. In this study, we talked to Native Hawaiian grandparents raising grandchildren (GRG) about the benefits and challenges of their caregiving experiences. Method: Three focus groups were conducted with Native Hawaiian grandparents (n=33) in Hawai‘i who were 55 years of age or older and caregivers to their grandchildren. Findings: The most prevalent themes voiced by grandparents spoke of the benefits of being a grandparent caregiver (the greatest being the experience of mutual, unconditional love) and the enjoyment of passing on “life lessons” to their grandchildren. Grandparents identified concrete examples of what they provided to grandchildren and also spoke of their role in transmission of Native Hawaiian cultural values, practices, and stories to their grandchildren. A number of challenges pertaining to grandparent caregiving were identified along with needed services—respite care, financial assistance, children’s programs, and information on grandparent legal rights. Despite these challenges, grandparents preferred to seek help from extended family rather than from formal supports. Our results support previous research on a number of universal GRG needs and services (i.e., legal rights of GRG) but also suggest potential directions to meeting the needs of Native Hawaiian GRG that are responsive to indigenous cultural values and preferences. Given the number of unmet needs expressed, further research is needed to design interventions for this population of grandparents raising grandchildren

The Economic Resource Receipt of New Mothers

U.S. federal policies do not provide a universal social safety net of economic support for women during pregnancy or the immediate postpartum period but assume that employment and/or marriage will protect families from poverty. Yet even mothers with considerable human and marital capital may experience disruptions in employment, earnings, and family socioeconomic status postbirth. We use the National Survey of Families and Households to examine the economic resources that mothers with children ages 2 and younger receive postbirth, including employment, spouses, extended family and social network support, and public assistance. Results show that many new mothers receive resources postbirth. Marriage or postbirth employment does not protect new mothers and their families from poverty, but education, race, and the receipt of economic supports from social networks do