5,201 research outputs found
Imaging through turbulence with a quadrature-phase optical interferometer
We present an improved technique for imaging through turbulence at visible wavelengths using a rotation shearing pupil-plane interferometer, intended for astronomical and terrestrial imaging applications. While previous astronomical rotation shearing interferometers have made only visibility modulus measurements, this interferometer makes four simultaneous measurements on each interferometric baseline, with phase differences of π/2 between each measurement, allowing complex visibility measurements (modulus and phase) across the entire input pupil in a single exposure. This technique offers excellent wavefront resolution, allowing operation at visible wavelengths on large apertures, is potentially immune to amplitude fluctuations (scintillation), and may offer superior calibration capabilities to other imaging techniques. The interferometer has been tested in the laboratory under weakly aberrating conditions and at Palomar Observatory under ordinary astronomical observing conditions. This research is based partly on observations obtained at the Hale Telescope
Single-kernel ionomic profiles are highly heritable indicators of genetic and environmental influences on elemental accumulation in maize grain (Zea mays)
Peer reviewedPublisher PD
Water-Cased Kicker Charges for Use in Explosive Demolition
Demolition Projects Involving Explosives Often Incorporate Cutting Charges to Sever Columns in Conjunction with Kicker Charges that Move the Columns Out of Alignment. Traditional Kicker Charges Use Dynamite Secured to the Column above a Linear-Shaped Cutting Charge. This Study Investigates the Use of Water-Cased Kicker Charges for Use in Explosive Demolition. the Goal is to Reduce the Fragmentation of Steel Members and the Quantity of Explosive Needed Due to the Increased Density, Incompressibility, and Impedance Mismatch Water Provides. Simulations and Experimental Tests Were Utilized to Determine What Type of Charges Provide the Optimal Column Movement and Water Placement. Water Charges and Traditional Charges Were Placed on Hanging Steel Columns that Swung Freely from a Top Pivot and Analyzed for the Fragmentation and Velocity of the Column. Tests Were Recorded with High-Speed Video to Calculate Velocity and Impulse. Simulations Showed the Same Results as Experimental Tests, with Water-Cased Charges Moving the Column Faster and with More Impulse Than Traditional Charges. Experimental Testing Showed that Water-Cased Charges Moved the Column 53% Faster Than Traditional in Contact Charges While Simulations Showed that Water-Cased Charges Moved the Column 43% Faster Than Traditional in Contact Charges. Simulations Showed the Water Tamped Behind the Charge Increased Beam Velocity 32% While Water in Front of the Charge Reduced Pressure 38% through Dispersion
Belimumab : a technological advance for systemic lupus erythematosus patients? Report of a systematic review and meta-analysis
Objectives: To undertake a systematic review and meta-analysis to investigate clinical effectiveness of belimumab for patients with systemic lupus erythematosus (SLE) and antinuclear and/or anti-double-stranded DNA (dsDNA) autoantibodies.
Methods: We searched eight electronic databases and reference lists for randomised controlled trials (RCTs) of belimumab against placebo or best supportive care. Quality assessment and random effects meta-analysis were undertaken.
Design: A meta-analysis of RCTs.
Participants: 2133 SLE patients.
Primary and secondary outcome measures: SLE Responder Index (SRI) at week 52.
Results: Three double-blind placebo-controlled RCTs (L02, BLISS-52 BLISS-76) investigated 2133 SLE patients. BLISS-52 and BLISS-76 trials recruited patients with antinuclear and/or anti-dsDNA autoantibodies and demonstrated belimumab effectiveness for the SRI at week 52. Ethnicity and geographical location of participants varied considerably between BLISS trials. Although tests for statistical heterogeneity were negative, BLISS-52 results were systematically more favourable for all measured outcomes. Meta-analysis of pooled 52-week SRI BLISS results showed benefit for belimumab (OR 1.63, 95% CI 1.27 to 2.09). By week 76, the primary SRI outcome in BLISS-76 was not statistically significant (OR 1.31, 95% CI 0.919 to 1.855)
A Unique Case of Autoimmune Retinopathy Associated with Anti-Alpha-Enolase Antibodies
Background. We report a case of autoimmune retinopathy associated with anti-alpha-enolase antibodies with unique manifestations. Methods. A case report. Results. A 30-year-old male experienced recurrent, primarily peripheral visual field disturbances and minimal photopsia, with interval symptom resolution. Fundus changes subsequently developed in areas corresponding to the previous visual field symptoms. Electroretinogram showed bilaterally symmetric abnormalities of light-adapted responses and suggested loss of photoreceptor function. Only anti-alpha-enolase antibodies were detected on Western blot. Our patient noted cutaneous symptoms at the time of both episodes of visual symptoms, but not in the interim. Biomicroscopy revealed subtle small reddish spots in areas of the peripheral retina corresponding to the areas of the patient's visual field where he noted symptoms. To our knowledge these reddish spots have not been reported in autoimmune retinopathy and may clinically support in vitro and in vivo evidence that anti-alpha-enolase antibodies may target photoreceptors. Conclusions. Our patient demonstrates some unique features adding to the known characteristics of autoimmune retinopathy associated with anti-alpha-enolase antibodies. As more cases are reported, further understanding of the features and pathophysiology of this rare condition will hopefully be elucidated
Sex Differences in the Relationship Between Baroreflex Effectiveness Index and Spontaneous Cardiac Baroreflex Sensitivity
Baroreflex effectiveness index (BEI) is a relatively new measure used to assess cardiac baroreflex function. It is unclear whether BEI provides independent or complementary information compared to traditional spontaneous cardiac baroreflex sensitivity (BRS) measures. PURPOSE: The purpose of this project was to begin to explore the relationship between BEI and BRS in young adults and to investigate the impact of sex on these potential relationships. We hypothesized that there would be a positive correlation between BEI and BRS in both males and females. METHODS: We studied 45 young healthy adults, 17 males (24 ± 4 years) and 28 females (23 ± 4 years). Heart rate (ECG) and beat-to-beat arterial blood pressure (finger photoplethysmography) were continuously recorded during a five-minute resting baseline. Spontaneous cardiac BRS was measured using the Sequence Method, by identifying the gain of the relationship between systolic blood pressure and RRI from sequence(s) of three or more consecutive heartbeats in which systolic blood pressure and RRI change in the same direction. BEI was quantified as the ratio of the number of baroreflex-driven ramps relative to all systolic blood pressure ramps. RESULTS: BEI (Male: 0.65 ± 0.14, Female: 0.61 ± 0.13; mean ± SD, p=0.27) and BRS (Male: 21.3 ± 8.4, Female: 27.27 ± 12.6, p=0.09) between groups was not different. There was no significant relationship between BEI and BRS among all participants (r= 0.13, p= 0.36). However, sex-specific analysis data revealed a positive correlation in our male group (r= 0.57, p=0.01), and no relationship in our female group (r= 0.03, p=0.84). CONCLUSION: These preliminary data suggest that the relationship between BEI and BRS may be sex-dependent
A novel FRET-based screen in high-throughput format to identify inhibitors of malarial and human glucose transporters
The glucose transporter PfHT is essential to the survival of the malaria parasite Plasmodium falciparum and has been shown to be a druggable target with high potential for pharmacological intervention. Identification of compounds against novel drug targets is crucial to combating resistance against current therapeutics. Here, we describe the development of a cell-based assay system readily adaptable to high-throughput screening that directly measures compound effects on PfHT-mediated glucose transport. Intracellular glucose concentrations are detected using a genetically encoded fluorescence resonance energy transfer (FRET)-based glucose sensor. This allows assessment of the ability of small molecules to inhibit glucose uptake with high accuracy (Z′ factor of >0.8), thereby eliminating the need for radiolabeled substrates. Furthermore, we have adapted this assay to counterscreen PfHT hits against the human orthologues GLUT1, -2, -3, and -4. We report the identification of several hits after screening the Medicines for Malaria Venture (MMV) Malaria Box, a library of 400 compounds known to inhibit erythrocytic development of P. falciparum. Hit compounds were characterized by determining the half-maximal inhibitory concentration (IC(50)) for the uptake of radiolabeled glucose into isolated P. falciparum parasites. One of our hits, compound MMV009085, shows high potency and orthologue selectivity, thereby successfully validating our assay for antimalarial screening
Matching for Several Sparse Nominal Variables in a Case-Control Study of Readmission Following Surgery.
Matching for several nominal covariates with many levels has usually been thought to be difficult because these covariates combine to form an enormous number of interaction categories with few if any people in most such categories. Moreover, because nominal variables are not ordered, there is often no notion of a close substitute when an exact match is unavailable. In a case-control study of the risk factors for read-mission within 30 days of surgery in the Medicare population, we wished to match for 47 hospitals, 15 surgical procedures grouped or nested within 5 procedure groups, two genders, or 47 × 15 × 2 = 1410 categories. In addition, we wished to match as closely as possible for the continuous variable age (65-80 years). There were 1380 readmitted patients or cases. A fractional factorial experiment may balance main effects and low-order interactions without achieving balance for high-order interactions. In an analogous fashion, we balance certain main effects and low-order interactions among the covariates; moreover, we use as many exactly matched pairs as possible. This is done by creating a match that is exact for several variables, with a close match for age, and both a near-exact match and a finely balanced match for another nominal variable, in this case a 47 × 5 = 235 category variable representing the interaction of the 47 hospitals and the five surgical procedure groups. The method is easily implemented in R
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