275 research outputs found
The NASA aircraft noise prediction program improved propeller analysis system
The improvements and the modifications of the NASA Aircraft Noise Prediction Program (ANOPP) and the Propeller Analysis System (PAS) are described. Comparisons of the predictions and the test data are included in the case studies for the flat plate model in the Boundary Layer Module, for the effects of applying compressibility corrections to the lift and pressure coefficients, for the use of different weight factors in the Propeller Performance Module, for the use of the improved retarded time equation solution, and for the effect of the number grids in the Transonic Propeller Noise Module. The DNW tunnel test data of a propeller at different angles of attack and the Dowty Rotol data are compared with ANOPP predictions. The effect of the number of grids on the Transonic Propeller Noise Module predictions and the comparison of ANOPP TPN and DFP-ATP codes are studied. In addition to the above impact studies, the transonic propeller noise predictions for the SR-7, the UDF front rotor, and the support of the enroute noise test program are included
Analog Circuits for Computing
This project entails designing, simulating, and verifying analog circuits that can perform essential computing functions for power systems applications. The project aims to remedy critical challenges associated with handling calculations digitally, namely, time and power. This project\u27s scope includes creating a library of circuits in SPICE that can be used to model and simulate complex mathematical equations. From these SPICE models, the circuit can be constructed physically, where the solution can be generated in less time using less power than doing the computation digitally. The performance and efficiency of analog computing will be measured and compared to conventional digital methods
Mice with an induced mutation in collagen 8A2 develop larger eyes and are resistant to retinal ganglion cell damage in an experimental glaucoma model
PURPOSE: To study susceptibility to glaucoma injury as it may be affected by mutations in ocular connective tissue components. METHODS: Mice homozygous for an N-ethyl-N-nitrosourea induced G257D exchange (Gly to Asp) missense mutation (Aca23) in their collagen 8A2 gene were studied to measure intraocular pressure (IOP), axial length and width, number of retinal ganglion cells (RGC), and inflation responses. Three month old homozygous Aca23 mutant and wild type (WT) mice had 6 weeks exposure to elevated IOP induced by polystyrene microbead injection. Additional Aca23 and matched controls were studied at ages of 10 and 18 months. RESULTS: Aca23 mice had no significant difference from WT in IOP level, and in both strains IOP rose with age. In multivariable models, axial length and width were significantly larger in Aca23 than WT, became larger with age, and were larger after exposure to glaucoma (n=227 mice). From inflation test data, the estimates of scleral stress resultants in Aca23 mice were similar to age-matched and younger WT C57BL/6 (B6) mice, while the strain estimates for Aca23 were significantly less than those for either WT group in the mid-sclera and in some of the more anterior scleral measures (p<0.001; n=29, 22, 20 eyes in Aca23, older WT, younger WT, respectively). With chronic IOP elevation, Aca23 eyes increased 9% in length and 7% in width, compared to untreated fellow eyes (p<0.05, <0.01). With similar elevated IOP exposure, WT eyes enlarged proportionately twice as much as Aca23, increasing in length by 18% and in nasal-temporal width by 13% (both p<0.001, Mann-Whitney test). In 4 month old control optic nerves, mean RGC axon number was not different in Aca23 and WT (46,905±7,592, 43,628±11,162, respectively; p=0.43, Mann-Whitney test, n=37 and 29). With chronic glaucoma, Aca23 mice had a mean axon loss of only 0.57±17%, while WT mice lost 21±31% (median loss: 1% versus 10%, n=37, 29, respectively; p=0.001; multivariable model adjusting for positive integral IOP exposure). CONCLUSIONS: The Aca23 mutation in collagen 8α2 is the first gene defect found to alter susceptibility to experimental glaucoma, reducing RGC loss possibly due to differences in mechanical behavior of the sclera. Detailed study of the specific changes in scleral connective tissue composition and responses to chronic IOP elevation in this strain could produce new therapeutic targets for RGC neuroprotection
The effect of 3D-stereogram mobile AR on engineering drawing course outcomes among first-year vocational high schoolers with different spatial abilities: a Bloom�s taxonomy perspective
ABSTRACT
Engineering drawing is valuable in capturing geometric features,
conveying engineering ideas, and creating a blueprint of the intended
product. Engineering students usually perform orthographic projections,
imagining a 3D situation and sketching its 2D representation. That
requires imagination and mental visualization, determined by the
learner�s spatial ability. This study proposes the infusion of an AR
stereogram mobile application into an engineering drawing course to
establish how it influences learning outcomes among students with
different spatial abilities. The quantitative experimental study involved
two mechanical engineering classes in northern Taiwan, N = 69 first-year
vocational high schoolers. Statistical analysis revealed that the
experimental group with high spatial ability recorded better results and
excellent drawing skills. Bloom�s taxonomy categorization reported that
spatial ability influenced �understanding� and �applying� levels, with
the strongest effect on �understanding.� Although no significant
interaction existed, learning outcomes were highly affected by spatial
ability in �understanding� and �applying� levels and AR in the overall
performance. The findings and discussions show AR holds great
potential to enhance students� spatial ability for real-time visualization
and enables better concept comprehension by improving their
understanding of engineering topics. Future studies should consider
these implications in creating effective and immersive learning
environments for different courses in engineering education
Toxicity report of once weekly radiation therapy for low-risk prostate adenocarcinoma: preliminary results of a phase I/II trial
<p>Abstract</p> <p>Background</p> <p>Increasing clinical data supports a low α/β ratio for prostate adenocarcinoma, potentially lower than that of surrounding normal tissues. A hypofractionated, weekly radiation therapy (RT) schedule should result in improved tumour control, reduced acute toxicity, and similar or decreased late effects. We report the toxicity profile of such treatment.</p> <p>Materials and Methods</p> <p>We conducted a multi-institution phase I/II trial of three-dimensional conformal radiation therapy (3D-CRT) for favourable-risk prostate cancer (T1a-T2a, Gleason ≤ 6 and PSA < 10 ng/ml). RT consisted of 45 Gy in nine 5 Gy fractions, once weekly. Primary end-points were feasibility and late gastrointestinal (GI) toxicity (RTOG scale), while secondary end-points included acute GI toxicity, acute and late genitourinary (GU) toxicity, biochemical control, and survival.</p> <p>Results</p> <p>Between 2006 and 2008, 80 patients were treated. No treatment interruptions occurred. The median follow-up is 33 months (range: 20-51). Maximal grade 1, 2, and 3 acute (< 3 months) GU toxicity was 29%, 31% and 5% respectively (no grade 4). Acute GI grade 1 toxicity was reported in 30% while grade 2 occurred in 14% (no grade 3 or 4). Crude late grade ≥ 3 toxicity rates at 31 months were 2% for both GU and GI toxicity. Cumulative late grade ≥ 3 GI toxicity at 3 years was 11%. Two patients had PSA failure according to the Phoenix definition. The three-year actuarial biochemical control rate is 97%.</p> <p>Conclusions</p> <p>Weekly RT with 45 Gy in 9 fractions is feasible and results in comparable toxicity. Long term tumour control and survival remain to be assessed.</p
Programmable bio-nanochip-based cytologic testing of oral potentially malignant disorders in Fanconi anemia
Fanconi anemia (FA) is caused by mutations of DNA repair genes. The risk of oral squamous cell carcinoma (OSCC) among FA patients is 800-folds higher than in the general population. Early detection of OSCC, preferably at it precursor stage, is critical in FA patients to improve their survival. In an ongoing clinical trial, we are evaluating the effectiveness of the programmable bio-nanochip (p-BNC)-based oral cytology test in diagnosing oral potentially malignant disorders (OPMD) in non-FA patients. We used this test to compare cytomorphometric and molecular biomarkers in OSCC cell lines derived from FA and non-FA patients to brush biopsy samples of a FA patient with OPMD and normal mucosa of healthy volunteers. Our data showed that expression patterns of molecular biomarkers were not notably different between sporadic and FA-OSCC cell lines. The p-BNC assay revealed significant differences in cytometric parameters and biomarker MCM2 expression between cytobrush samples of the FA patient and cytobrush samples of normal oral mucosa obtained from healthy volunteers. Microscopic examination of the FA patient's OPMD confirmed the presence of dysplasia. Our pilot data suggests that the p-BNC brush biopsy test recognized dysplastic oral epithelial cells in a brush biopsy sample of a FA patient
The first recorded outbreak of cryptosporidiosis due to Cryptosporidium cuniculus (formerly rabbit genotype), following a water quality incident
Background: We report the first identified outbreak of cryptosporidiosis with Cryptosporidium cuniculus following a water quality incident in Northamptonshire, UK.
Methods: A standardised, enhanced Cryptosporidium exposure questionnaire was administered to all cases of cryptosporidiosis after the incident. Stool samples, water testing, microscopy slides and rabbit gut contents positive for Cryptosporidium were typed at the Cryptosporidium Reference Unit, Singleton Hospital, Swansea.
Results: Twenty-three people were microbiologically linked to the incident although other evidence suggests an excess of 422 cases of cryptosporidiosis above baseline. Most were adult females; unusually for cryptosporidiosis there were no affected children identified under the age of 5 years. Water consumption was possibly higher than in national drinking water consumption patterns. Diarrhoea duration was negatively correlated to distance from the water treatment works where the contamination occurred. Oocyst counts were highest in water storage facilities.
Conclusions: This outbreak is the first caused by C. cuniculus infection to have been noted and it has conclusively demonstrated that this species can be a human pathogen. Although symptomatically similar to cryptosporidiosis from C. parvum or C. hominis, this outbreak has revealed some differences, in particular no children under 5 were identified and females were over-represented. These dissimilarities are unexplained although we postulate possible explanations
Occupational, physical, sexual and mental health and violence among migrant and trafficked commercial fishers and seafarers from the Greater Mekong Subregion (GMS): systematic review.
BACKGROUND: Little is known about the health of GMS commercial fishers and seafarers, many of whom are migrants and some trafficked. This systematic review summarizes evidence on occupational, physical, sexual and mental health and violence among GMS commercial fishers/seafarers. METHODS: We searched 5 electronic databases and purposively searched grey literature. Quantitative or qualitative studies reporting prevalence or risk of relevant outcomes were included. Two reviewers independently screened articles. Data were extracted on nationality and long/short-haul fishing where available. RESULTS: We identified 33 eligible papers from 27 studies. Trafficked fishers/seafarers were included in n=12/13 grey literature and n=1/20 peer-reviewed papers. Among peer-reviewed papers: 11 focused on HIV/AIDS/sexual health; nine on occupational/physical health; one study included mental health of trafficked fishers. Violence was quantitatively measured in eight papers with prevalence of: 11-26% in port convenience samples; 68-100% in post-trafficking service samples. Commercial fishers/seafarers whether trafficked or not worked extremely long hours; trafficked long-haul fishers had very limited access to care following injuries or illness. Lesser-known risks reported among fishers included penile oil injections and beriberi. We found just one work safety intervention study and inconclusive evidence for differences in the outcomes by nationality. Findings are limited by methodological weaknesses of primary studies. CONCLUSION: Results show an absence of high-quality epidemiological studies beyond sexual health. Formative and pilot intervention research on occupational, physical and mental health among GMS commercial fishers and seafarers is needed. Future studies should include questions about violence and exploitation. Ethical and reporting standards of grey literature should be improved. TRIAL REGISTRATION: Review registration number: PROSPERO 2014: CRD42014009656
Pretreatment with ibrutinib reduces cytokine secretion and limits the risk of obinutuzumab-induced infusion-related reactions in patients with CLL : analysis from the iLLUMINATE study
The online version contains supplementary material available at 10.1007/s00277-021-04536-6
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