3,417 research outputs found
Considerations for a design and operations knowledge support system for Space Station Freedom
Engineering and operations of modern engineered systems depend critically upon detailed design and operations knowledge that is accurate and authoritative. A design and operations knowledge support system (DOKSS) is a modern computer-based information system providing knowledge about the creation, evolution, and growth of an engineered system. The purpose of a DOKSS is to provide convenient and effective access to this multifaceted information. The complexity of Space Station Freedom's (SSF's) systems, elements, interfaces, and organizations makes convenient access to design knowledge especially important, when compared to simpler systems. The life cycle length, being 30 or more years, adds a new dimension to space operations, maintenance, and evolution. Provided here is a review and discussion of design knowledge support systems to be delivered and operated as a critical part of the engineered system. A concept of a DOKSS for Space Station Freedom (SSF) is presented. This is followed by a detailed discussion of a DOKSS for the Lyndon B. Johnson Space Center and Work Package-2 portions of SSF
A Cluster of Class I/f/II YSOs Discovered Near the Cepheid SU Cas
Preliminary constraints are placed on a cluster of YSOs (J2000 02:54:31.4
+69:20:32.5) discovered in the field of the classical Cepheid SU Cas. WISE 3.4,
4.6, 12, and 22 um images reveal that the cluster deviates from spherical
symmetry and exhibits an apparent diameter of 3x6'. SEDs constructed using
2MASS Ks (2.2 um) and WISE photometry indicate that 19 (36%) class I, 21 (40%)
class f, and 13 (25%) class II objects lie r<3' from the cluster center.
Conversely, 11 (18%) class I, 13 (21%) class f, and 37 (61%) class II objects
were detected for r>3'. Approximately 50% of the class I sources within r<3'
were classified solely using WISE photometry owing to the absence of detections
by 2MASS.Comment: Accepted for Publication (MNRAS
Effect of Soil Chemistry on Microbial Biodiversity and Functionality in Grassland and Tilled Soils
Microorganisms are excellent indicators of soil health, because of their rapid response to environmental change. Traditional microbiology is ineffective for the study of soil, as \u3c 1% of microorganisms are currently culturable (Torsvik et al., 1996). Nucleic acid based methods, however, allow rapid detection of organisms, or particular genes, directly from soil samples. This work investigated, using polymerase chain reaction (PCR)-based approaches, the relationship between key chemical properties and bacterial biodiversity in grassland and tilled soils, with particular emphasis on the abundance and diversity of ammonium oxidisers
Effectiveness of Gaming in Creating Cultural Awareness
Despite the emphasis on cultural competency education in the United States for the past three decades, inequities and disparities in healthcare continue to persist, particularly among minority populations. With the current growing gap in provider and patient cultural congruence, how effectively we train students to work with diverse populations in healthcare settings warrants attention. This article presents the results of a qualitative study on the effectiveness of experiential learning, in the form of the game BaFa’ BaFa,’ in raising cultural awareness among students of health professions. Using thematic analysis, the authors analyzed written reflections from student participants. The findings support earlier studies, conducted mainly outside of healthcare, on the effectiveness of gaming in nurturing cultural awareness
Characterization Of Individual Submicron Perfluorocarbon Gas Bubbles By Ultrasonic Backscatter
Measurements were undertaken to determine the unknown microbubble-size distribution of a dodecafluoropentane (DDFP) emulsion consisting of in surfactant-stabilized water. The acoustic backscatter of 2-microsecond-duration tonebursts of 30-MHz focused ultrasound was measured from the emulsion as it moved in a coaxial flow. Calibration for the system was accomplished using 3-μm-radius polystyrene spheres, using a linear scattering model and literature values for polystyrene. Applying viscous linear scattering theory to the backscatter data from individual DDFP bubbles allowed inversion of the radius–backscatter relation. A mean microbubble radius of 130 nm was inferred for the DDFP population. © 2005 Acoustical Society of America
Expression of Cadherin-11 during Organogenesis in the Chick Embryo
Cadherin-11 (cad-11) is primarily a mesenchymal cadherin that appears in delaminating neural crest cells. Its expression correlates with morphogenetic events and the pattern has been studied in mouse, rat and Xenopus embryos, but not during avian organogenesis. Our purpose was to investigate this pattern in the chick embryo during organogenesis using immunolocalization and in situ hybridization. Cad-11 was expressed in mesenchyme around the pharynx and aortic arches, eyes, auditory vesicles, lung buds, stomach, and nasal placodes. Neural expression included some cranial ganglia and also new neuroepithelium within the tail bud region undergoing secondary neurulation. We also found expression in epithelia of the developing circulatory and digestive organs. The limb buds, pineal rudiment and mesonephros were also positive. Cad-11 expression became more widespread with development. Our findings support the role of cad-11 as a mesenchymal cadherin, but provide evidence for a wider role that includes epithelial morphogenesis and secondary neurulation
Volume preserving multidimensional integrable systems and Nambu--Poisson geometry
In this paper we study generalized classes of volume preserving
multidimensional integrable systems via Nambu--Poisson mechanics. These
integrable systems belong to the same class of dispersionless KP type equation.
Hence they bear a close resemblance to the self dual Einstein equation. All
these dispersionless KP and dToda type equations can be studied via twistor
geometry, by using the method of Gindikin's pencil of two forms. Following this
approach we study the twistor construction of our volume preserving systems
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Impact of depth of response on survival in patients treated with cobimetinib ± vemurafenib: pooled analysis of BRIM-2, BRIM-3, BRIM-7 and coBRIM.
BackgroundThis pooled analysis investigated the prognostic value of depth of response in two cohorts of patients with BRAFV600-mutated metastatic melanoma treated with vemurafenib or cobimetinib plus vemurafenib.MethodsThe data were pooled from BRIM-2, BRIM-3, BRIM-7 and coBRIM. Association of depth of response with survival was estimated by Cox proportional hazards regression, adjusted for clinically relevant covariates. Depth of response was analysed in previously identified prognostic subgroups based on disease characteristics and gene signatures.ResultsGreater tumour reduction and longer time to maximal response were significantly associated with longer progression-free survival (PFS) and overall survival (OS) when evaluated as continuous variables. Patients with the deepest responses had long-lasting survival outcomes (median PFS: 14 months; OS: 32 months with vemurafenib; not estimable with cobimetinib plus vemurafenib). Cobimetinib plus vemurafenib improved depth of response versus vemurafenib monotherapy regardless of other prognostic factors, including gene signatures.ConclusionsGreater depth of response was associated with improved survival, supporting its utility as a measure of treatment efficacy in melanoma and further evaluation of its incorporation into existing prognostic models. Cobimetinib plus vemurafenib improved outcomes across quartiles of response regardless of prognostic factors or gene signatures and provided durable survival benefits in patients with deep responses
The G292.0+1.8 pulsar wind nebula in the mid-infrared
G292.0+1.8 is a Cas A-like supernova remnant that contains the young pulsar
PSR J1124-5916 powering a compact torus-like pulsar wind nebula visible in
X-rays. A likely counterpart to the nebula has been detected in the optical VRI
bands. To confirm the counterpart candidate nature, we examined archival
mid-infrared data obtained with the Spitzer Space Telescope. Broad-band images
taken at 4.5, 8, 24, and 70 microns were analyzed and compared with available
optical and X-ray data. The extended counterpart candidate is firmly detected
in the 4.5 and 8 micron bands. It is brighter and more extended in the bands
than in the optical, and its position and morphology agree well with the
coordinates and morphology of the torus-like pulsar wind nebula in X-rays. The
source is not visible in 24 and 70 micron images, which are dominated by bright
emission from the remnant shell and filaments. We compiled the infrared fluxes
of the nebula, which probably contains a contribution from an unresolved pulsar
in its center, with the optical and X-ray data. The resulting unabsorbed
multiwavelength spectrum is described by power laws of significantly steeper
slope in the infrared-optical than in X-rays, implying a double-knee spectral
break between the optical and X-rays. The 24 and 70 microns flux upper limits
suggest a second break and a flatter spectrum at the long wavelength limit.
These features are common to two other pulsar wind nebulae associated with the
remnants B0540-69.3 and 3C 58 and observed in all three ranges. The position,
morphology, and spectral properties of the detected source allow us to comfirm
that it is the infrared-optical counterpart to both the pulsar and its wind
nebula system in the G292.0+1.8 supernova remnant.Comment: 5 pages, 2 figure
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