8,923 research outputs found
Fixed base simulator study of an externally blown flap STOL transport airplane during approach and landing
A fixed-base simulator study was conducted to determine the flight characteristics of a representative STOL transport having a high wing and equipped with an external-flow jet flap in combination with four high-bypass-ratio fan-jet engines during the approach and landing. Real-time digital simulation techniques were used. The computer was programed with equations of motion for six degrees of freedom and the aerodynamic inputs were based on measured wind-tunnel data. A visual display of a STOL airport was provided for simulation of the flare and touchdown characteristics. The primary piloting task was an instrument approach to a breakout at a 200-ft ceiling with a visual landing
Self-Referential Noise and the Synthesis of Three-Dimensional Space
Generalising results from Godel and Chaitin in mathematics suggests that
self-referential systems contain intrinsic randomness. We argue that this is
relevant to modelling the universe and show how three-dimensional space may
arise from a non-geometric order-disorder model driven by self-referential
noise.Comment: Figure labels correcte
Indium In-111 pentetreotide scintigraphy: Application to carotid body tumors
AbstractPurpose: This study was conducted to investigate and illustrate the use of Indium In-111 pentetreotide scintigraphy as it applies to carotid body tumors (CBT). Localization has relied primarily on ultrasonography, computed tomography, and magnetic resonance imaging with angiographic confirmation. These methods only assess the cervical bifurcation without providing an evaluation of metastasis in patients without symptoms or recurrence in patients after surgery.Methods: Indium In-111 pentetreotide scintigraphy was used in five patients with a diagnosis of CBT. Four patients were evaluated after surgical excision for evidence of tumor recurrence. One patient was evaluated before excision for diagnostic confirmation.Results: No evidence of tumor recurrence was demonstrated in the four patients who had undergone previous CBT excision. One of these patients had increased activity in the pituitary, later confirmed as an enlarged pituitary without evidence of an adenoma with computed tomography. The diagnosis of CBT was confirmed in the patient evaluated before surgery. This patient also had increased activity in the occipital region, confirmed as the site of previous ischemia on computed tomography.Conclusion: Indium In-111 pentetreotide scintigraphy is a new innovative method for viewing neuroendocrine tumors. Its potential lies not only in tumor localization but also in identification of recurrent tumor at the operative site and metastatic disease. (J Vasc Surg 1997;25:905-8.
A compilation, tabulation and analysis of spelling errors made by pupils in grades four, five, and six in free writing of sentences using given stimuli words
Thesis (M.A.)--Boston Universit
Rare Earth Doped Yttrium Aluminum Garnet (YAG) Selective Emitters
As a result of their electron structure, rare earth ions in crystals at high temperature emit radiation in several narrow bands rather than in a continuous blackbody manner. This study presents a spectral emittance model for films and cylinders of rare earth doped yttrium aluminum garnets. Good agreement between experimental and theoretical film spectral emittances was found for erbium and holmium aluminum garnets. Spectral emittances of films are sensitive to temperature differences across the film. For operating conditions of interest, the film emitter experiences a linear temperature variation whereas the cylinder emitter has a more advantageous uniform temperature. Emitter efficiency is also a sensitive function of temperature. For holminum aluminum garnet film the efficiency is 0.35 at 1446K but only 0.27 at 1270 K
Changing Ionization Conditions in SDSS Galaxies with AGN as a Function of Environment from Pairs to Clusters
We study how AGN activity changes across environments from galaxy pairs to
clusters using galaxies with from the Sloan Digital Sky
Survey (SDSS). Using a refined technique, we apply a continuous measure of AGN
activity, characteristic of the ionization state of the narrow-line emitting
gas. Changes in key emission-line ratios ([NII]/H,
[OIII]/H) between different samples allow us to disentangle
different environmental effects while removing contamination. We confirm that
galaxy interactions enhance AGN activity. However, conditions in the central
regions of clusters are inhospitable for AGN activity even if galaxies are in
pairs. These results can be explained through models of gas dynamics in which
pair interactions stimulate the transfer of gas to the nucleus and clusters
suppress gas availability for accretion onto the central black hole.Comment: Accepted for publication in Ap
Challenges and opportunities for promoting physical activity in health care: a qualitative enquiry of stakeholder perspectives
Background: Evidence suggests that physical activity (PA) programmes promoted via healthcare settings worldwide may not currently meet the needs of many patients and healthcare professionals (HCPs). This paper describes the outcomes of a qualitative enquiry into the perspectives of patients and professionals from multiple healthcare services regarding the role of PA. Materials and Methods: 19 patients and 22 HCPs were purposively recruited from physiotherapy, podiatry, chronic pain, diabetes and continence services at a community-based healthcare clinic in the United Kingdom. Participants’ views were explored using semi-structured interviews and analysed using thematic analysis. Results: Results identified five themes: differences between the social and medical rationales underpinning PA promotion; the impact of the patient-professional relationship on patient activation, self-management and PA; a risk culture surrounding PA; challenges to meet variation in patients’ needs and preferences; and lack of formal role for PA as a core part of routine healthcare. Conclusions: The study highlights tensions between needs and aspirations, and the reality of delivering advice and support for PA. Challenges resonated with patients and HCPs across different care groups and were not condition-specific. This highlights a need for sharing good practice across healthcare services and system-level interventions to address organisational barriers to the promotion of PA
NCI-MATCH Arms N & P: Phase II study of PI3K beta inhibitor GSK2636771 in patients (pts) with cancers (ca) with PTEN mutation/deletion (mut/del) or PTEN protein loss
Background: The NCI-MATCH trial is the largest national study (1173 sites) for ptswith relapsed/ refractory solid tumors, lymphomas and myeloma, which assigns tar-geted therapies based on individual tumor molecular alterations detected using theadapted Oncomine AmpliSeq panel (143 genes) and immunohistochemistry (IHC).We hypothesized that patients with PTEN-deficient cancers enrolled to Arms N and Pmay benefit from treatment with the PI3K beta-selective inhibitor GSK2636771.
Methods: Eligibility: relapsed/refractory ca, good end-organ function, and ECOG PS ≤ 1. Pts were screened for molecular alterations by centralized testing on fresh tumor biopsy and had deleterious PTEN mut/del without loss of expression (Arm N) or complete loss of cytoplasmic and nuclear PTEN staining on IHC (Arm P), and no other aberrations activating the PI3K/MTOR and MAPK pathways (mut in PIK3CA, PIK3R1, BRAF, KRAS, AKT1, TSC1/2, mTOR, RHEB, NF2, NRAS, HRAS). Pts received GSK2636771 400mg/day (28-days cycles). RECIST 1.1 overall response rate (ORR) was the primary endpoint.
Results: Of 59 enrolled pts, 56 were eligible and received treatment. Of 22 pts with PTEN mut/del (Arm N: 6 uterine, 2 breast, 2 prostate, 2 head/neck ca, 10 other), all are off treatment as of analysis (14 disease progression, 4 for adverse events [AEs], 4 other). One pt (4.5%) with prostate ca (PTEN deletion, MPRSS2-ERG fusion) attained a partial response (-42%). Of 7 (32%) pts with stable disease (SD), 2 had SD \u3e 6 months (uterine leiomyosarcoma; endometrial carcinoma). Of 34 pts with loss of PTEN protein by IHC (Arm P: 7 prostate, 6 breast, 3 squamous anal ca, 2 cholangiocarcinoma, 16 other), all are off treatment as of analysis (26 disease progression, 4 for AE, 4 other). Of 9 (37.5%) pts with SD, 3 had SD \u3e 6 months (prostate cancer; squamous bladder cancer, squamous anal cancer). Median progression-free survival was 1.8 months for both arms. Gr ≥ 3 treatment-related (tr) reversible toxicities were experienced by 30% (7) and 20% (7) of pts in arms N and P, respectively. No tr Gr 5 toxicities were observed in either arm.
Conclusions: Single agent GSK2636771 has very modest activity in ca with PTEN gene mutation/deletion and/or PTEN protein loss
Photothermal Absorption Spectroscopy of Individual Semiconductor Nanocrystals
Photothermal heterodyne detection is used to record the first
room-temperature absorption spectra of single CdSe/ZnS semiconductor
nanocrystals. These spectra are recorded in the high cw excitation regime, and
the observed bands are assigned to transitions involving biexciton and trion
states. Comparison with the single nanocrystals photoluminescence spectra leads
to the measurement of spectral Stokes shifts free from ensemble averaging
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Hydrological Conditions at the 317/319 Area at Argonne National Laboratory
This study examined the hydrological conditions of the glacial till underlying the 317/319 Area at Argonne National Laboratory (ANL) near Lemont, Illinois. The study's purpose was to review and summarize hydrological data collected by ANL's Environment, Safety, and Health Department and to characterize, based on these data, the groundwater movement and migration of potential contaminants in the area. Recommendations for further study have been made based on the findings of this review. The 317/319 Area is located between Meridian Road and the southern border of ANL. The 317 Area was commissioned in the late 1940s for the temporary storage of radioactive waste. Low- and high-level solid radioactive waste is stored in partially buried concrete vaults. Low-level radioactive waste awaiting shipment for off-site disposal is stored in aboveground steel bins north of the vaults. The 319 Area is an inactive landfill, located east of the 317 Area that was used for the disposal of general refuse, demolition debris, and laboratory equipment. Fluorescent light bulbs, chemical containers, and suspect waste were also placed in the landfill. Liquid chemical wastes were disposed of at each site in gravel-filled trenches called French drains.'' The 317/319 Area is underlain by a silty clay glacial till. Dolomite bedrock underlies the till at an average depth of about 19.5m. Organic contaminants and radionuclides have been detected in groundwater samples from wells completed in the till. Fractures in the clay as well as sand and gravel lenses present in the till could permit these contaminants to migrate downward to the dolomite aquifer. At the time of this report, no chemical quality analyses had been made on groundwater samples from the dolomite. The study found that existing information about subsurface characteristics at the site is inadequate to identify potential pathways for contaminant migration. 14 refs., 13 figs., 6 tabs
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