4,988 research outputs found
Examining Pre-Service Teacher Candidates’ Sources and Levels of Knowledge about Autism Spectrum Disorders
This study was designed to identify what pre-service teacher candidates knew about autism spectrum disorder (ASD) and how they had acquired that knowledge in order to design more effective preparation courses. Teacher candidates (N=87) from three teacher preparation programs completed questionnaires during, or prior to, their first special education course. The findings indicate a relationship between sources of knowledge about ASD and actual levels of knowledge. Based on the findings, the authors argue that there is a need for coursework that focuses on effective intervention strategies and utilizes direct opportunities for teacher candidates to work with students with ASD
Associations of TNFR1 with kidney function outcomes by age, gender, and baseline kidney function status: Data from the Heart and Soul Study.
Tumor necrosis factor receptor type 1 (TNFR1) is associated with kidney disease and mortality risk in various populations [1], [2]. We evaluated associations of TNFR1 with mortality and mediators of this relationship in doi: 10.1016/j.atherosclerosis.2017.05.021. Whether or not these associations are influenced by age, gender, or baseline kidney function are not known. We evaluated associations of TNFR1 levels with measures of kidney function stratifying by these variables. Our outcomes included estimated glomerular filtration rate (eGFR) < 60Â ml/min/1.73Â m2, albumin to creatinine ratio (ACR) >30Â mg/g, and rapid kidney function loss, defined as a change in eGFR of greater than 3% per year
Modeling radiation belt radial diffusion in ULF wave fields: 2. Estimating rates of radial diffusion using combined MHD and particle codes
[1] Quantifying radial transport of radiation belt electrons in ULF wave fields is essential for understanding the variability of the trapped relativistic electrons. To estimate the radial diffusion coefficients (DLL), we follow MeV electrons in realistic magnetospheric configurations and wave fields calculated from a global MHD code. We create idealized pressure-driven MHD simulations for controlled solar wind velocities (hereafter referred to as pressure-driven Vx simulations) with ULF waves that are comparable to GOES data under similar conditions, by driving the MHD code with synthetic pressure profiles that mimic the pressure variations of a particular solar wind velocity. The ULF wave amplitude, in both magnetic and electric fields, increases at larger radial distance and during intervals with higher solar wind velocity and pressure fluctuations. To calculate DLL as a function of solar wind velocity (Vx = 400 and 600 km/s), we follow 90 degree pitch angle electrons in magnetic and electric fields of the pressure-driven Vx simulations. DLL is higher at larger radial distance and for the case with higher solar wind velocity and pressure variations. Our simulated DLL values are relatively small compared to previous studies which used larger wave fields in their estimations. For comparison, we scale our DLL values to match the wave amplitudes of the previous studies with those of the idealized MHD simulations. After the scaling, our DLL values for Vx = 600 km/s are comparable to theDLL values derived from Polar measurements during nonstorm intervals. This demonstrates the use of MHD models to quantify the effect of pressure-driven ULF waves on radiation belt electrons and thus to differentiate the radial diffusive process from other mechanisms
Applications of ADS-B in General Aviation
ADS-B Applications for General Aviation Airports—ADS-B (Automatic Dependent Surveillance–Broadcast) Out will soon be required for aircraft operating in most assigned airspace categories. ADS-B data are more accessible for analysis than data from flight data monitoring devices and can potentially be used to improve airport operations. General aviation airports need low-cost, effective solutions. In this session we explore data from ADS-B technologies that support operations counting, landing/takeoff cycle characterization, and landing fee assessment, and that potentially identify areas of operational concern
Estimating Operations and Airport-Specific Landing & Take-off Cycles at GA Airports
Estimating Operations and AirportSpecific Landing Take-off Cycles at GA Airports—Estimating greenhouse gas and particulate emissions around airports is important when seeking to understand the impact on a community of existing or increasing aviation operations. Environmental consultants prepare models, and these models need estimates of the number of operations and landing/take-off (LTO) cycle characteristics. This information is difficult for GA airport managers to obtain. This presentation shows how to estimate LTO characteristics and the number of operations more easily by using sampling methods
MicroRNA-23a promotes myelination in the central nervous system.
Demyelinating disorders including leukodystrophies are devastating conditions that are still in need of better understanding, and both oligodendrocyte differentiation and myelin synthesis pathways are potential avenues for developing treatment. Overexpression of lamin B1 leads to leukodystrophy characterized by demyelination of the central nervous system, and microRNA-23 (miR-23) was found to suppress lamin B1 and enhance oligodendrocyte differentiation in vitro. Here, we demonstrated that miR-23a-overexpressing mice have increased myelin thickness, providing in vivo evidence that miR-23a enhances both oligodendrocyte differentiation and myelin synthesis. Using this mouse model, we explored possible miR-23a targets and revealed that the phosphatase and tensin homologue/phosphatidylinositol trisphosphate kinase/Akt/mammalian target of rapamycin pathway is modulated by miR-23a. Additionally, a long noncoding RNA, 2700046G09Rik, was identified as a miR-23a target and modulates phosphatase and tensin homologue itself in a miR-23a-dependent manner. The data presented here imply a unique role for miR-23a in the coordination of proteins and noncoding RNAs in generating and maintaining healthy myelin
Vascular remodeling of the mouse yolk sac requires hemodynamic force
The embryonic heart and vessels are dynamic and form and remodel while functional. Much has been learned about the genetic
mechanisms underlying the development of the cardiovascular system, but we are just beginning to understand how changes in
heart and vessel structure are influenced by hemodynamic forces such as shear stress. Recent work has shown that vessel
remodeling in the mouse yolk sac is secondarily effected when cardiac function is reduced or absent. These findings indicate that
proper circulation is required for vessel remodeling, but have not defined whether the role of circulation is to provide mechanical
cues, to deliver oxygen or to circulate signaling molecules. Here, we used time-lapse confocal microscopy to determine the role of
fluid-derived forces in vessel remodeling in the developing murine yolk sac. Novel methods were used to characterize flows in
normal embryos and in embryos with impaired contractility (Mlc2a^(–/–)). We found abnormal plasma and erythroblast circulation in
these embryos, which led us to hypothesize that the entry of erythroblasts into circulation is a key event in triggering vessel
remodeling. We tested this by sequestering erythroblasts in the blood islands, thereby lowering the hematocrit and reducing shear
stress, and found that vessel remodeling and the expression of eNOS (Nos3) depends on erythroblast flow. Further, we rescued
remodeling defects and eNOS expression in low-hematocrit embryos by restoring the viscosity of the blood. These data show that
hemodynamic force is necessary and sufficient to induce vessel remodeling in the mammalian yolk sa
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IL-17A produced by αβ T cells drives airway hyper-responsiveness in mice and enhances mouse and human airway smooth muscle contraction.
Emerging evidence suggests that the T helper 17 (T(H)17) subset of αβ T cells contributes to the development of allergic asthma. In this study, we found that mice lacking the αvβ8 integrin on dendritic cells did not generate T(H)17 cells in the lung and were protected from airway hyper-responsiveness in response to house dust mite and ovalbumin sensitization and challenge. Because loss of T(H)17 cells inhibited airway narrowing without any obvious effects on airway inflammation or epithelial morphology, we examined the direct effects of T(H)17 cytokines on mouse and human airway smooth muscle function. Interleukin-17A (IL-17A), but not IL-17F or IL-22, enhanced contractile force generation of airway smooth muscle through an IL-17 receptor A (IL-17RA)-IL-17RC, nuclear factor κ light-chain enhancer of activated B cells (NF-κB)-ras homolog gene family, member A (RhoA)-Rho-associated coiled-coil containing protein kinase 2 (ROCK2) signaling cascade. Mice lacking integrin αvβ8 on dendritic cells showed impaired activation of this pathway after ovalbumin sensitization and challenge, and the diminished contraction of the tracheal rings in these mice was reversed by IL-17A. These data indicate that the IL-17A produced by T(H)17 cells contributes to allergen-induced airway hyper-responsiveness through direct effects on airway smooth muscle
Weak interactions of supersymmetric staus at high energies
Neutrino telescopes may have the potential to detect the quasi-stable staus
predicted by supersymmetric models. Detection depends on stau electromagnetic
energy loss and weak interactions. We present results for the weak interaction
contribution to the energy loss of high energy staus as they pass through rock.
We show that the neutral current weak interaction contribution to the energy
loss increases with energy, but it is much smaller than the photonuclear energy
loss, however, the charged current contribution may become the dominant process
above the energy of GeV, depending on the parameters of the model.
As a consequence, the stau range may be reduced above GeV as
compared to the range neglecting weak interactions. We contrast this with the
tau range which is barely changed with the inclusion of charged current
interactions.Comment: 7 pages, 8 figures, version to be publishe
Non-Gaussian Hybrid Transfer Functions: Memorizing Mine Survivability Calculations
Hybrid algorithms and models have received significant interest in recent years and are increasingly used to solve real-world problems. Different from existing methods in radial basis transfer function construction, this study proposes a novel nonlinear-weight hybrid algorithm involving the non-Gaussian type radial basis transfer functions. The speed and simplicity of the non-Gaussian type with the accuracy and simplicity of radial basis function are used to produce fast and accurate on-the-fly model for survivability of emergency mine rescue operations, that is, the survivability under all conditions is precalculated and used to train the neural network. The proposed hybrid uses genetic algorithm as a learning method which performs parameter optimization within an integrated analytic framework, to improve network efficiency. Finally, the network parameters including mean iteration, standard variation, standard deviation, convergent time, and optimized error are evaluated using the mean squared error. The results demonstrate that the hybrid model is able to reduce the computation complexity, increase the robustness and optimize its parameters. This novel hybrid model shows outstanding performance and is competitive over other existing models
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