Open Access. Powered by Scholars. Published by Universities.®
Physical Sciences and Mathematics Commons™
Open Access. Powered by Scholars. Published by Universities.®
- Discipline
-
- Astrophysics and Astronomy (26)
- Earth Sciences (13)
- Physics (10)
- Stars, Interstellar Medium and the Galaxy (10)
- External Galaxies (8)
-
- Life Sciences (7)
- Medicine and Health Sciences (6)
- Oceanography and Atmospheric Sciences and Meteorology (6)
- Environmental Sciences (5)
- Glaciology (5)
- Statistics and Probability (5)
- Cosmology, Relativity, and Gravity (4)
- Mathematics (4)
- Chemistry (3)
- Climate (3)
- Computer Sciences (3)
- Geophysics and Seismology (3)
- Social and Behavioral Sciences (3)
- Applied Mathematics (2)
- Atmospheric Sciences (2)
- Biogeochemistry (2)
- Biology (2)
- Biostatistics (2)
- Engineering (2)
- Environmental Studies (2)
- Genetics and Genomics (2)
- Hydrology (2)
- Instrumentation (2)
- Medical Specialties (2)
- Keyword
-
- Astrophysics (13)
- Cosmology and astronomy (8)
- Humans (7)
- Galaxies (5)
- Active galaxies (4)
-
- X-rays (4)
- Algorithms (3)
- General relativity and quantum cosmology (3)
- Helium (3)
- Physics (3)
- Quantum physics (3)
- Star evolution (3)
- Velocity (3)
- Absorption (2)
- Absorption spectra (2)
- Absorption spectroscopy (2)
- Animals (2)
- Astrophysics of galaxies (2)
- Atoms (2)
- Computational biology (2)
- Computer simulation (2)
- Condensed matter (2)
- Cosmology and nongalactic astrophysics (2)
- Detection (2)
- Diffuse (2)
- Emission spectra (2)
- Female (2)
- Galaxy evolution (2)
- Heliosphere (2)
- High energy astrophysical phenomena (2)
Articles 61 - 67 of 67
Full-Text Articles in Physical Sciences and Mathematics
(3+2)-Cycloaddition Reactions Of Oxyallyl Cations, Jimmy Wu, Hui Li
(3+2)-Cycloaddition Reactions Of Oxyallyl Cations, Jimmy Wu, Hui Li
Dartmouth Scholarship
The (3+2)-cycloaddition reaction involving oxyallyl cations has proven to be a versatile and efficient approach for the construction of five-membered carbo- and heterocycles, which are prevalent frameworks in natural products and pharmaceuticals. The following article will provide a brief summary of recent disclosures on this process featuring chemo-, regio- and diastereoselective oxyallyl cycloadditions with both electron-rich and electron-deficient 2π partners.
Gene Expression Changes Reflect Clinical Response In A Placebo-Controlled Randomized Trial Of Abatacept In Patients With Diffuse Cutaneous Systemic Sclerosis, Eliza F. Chakravarty, Viktor Martyanov, David Fiorentino, Tammara A. Wood, David J. Haddon, Justin A. Jarrell, Paul Utz, Mark Genovese, Michael Whitfield, Lorinda Chung
Gene Expression Changes Reflect Clinical Response In A Placebo-Controlled Randomized Trial Of Abatacept In Patients With Diffuse Cutaneous Systemic Sclerosis, Eliza F. Chakravarty, Viktor Martyanov, David Fiorentino, Tammara A. Wood, David J. Haddon, Justin A. Jarrell, Paul Utz, Mark Genovese, Michael Whitfield, Lorinda Chung
Dartmouth Scholarship
Systemic sclerosis is an autoimmune disease characterized by inflammation and fibrosis of the skin and internal organs. We sought to assess the clinical and molecular effects associated with response to intravenous abatacept in patients with diffuse cutaneous systemic.
Impact Of Spatial Aliasing On Sea-Ice Thickness Measurements, Cathleen Geiger, Hans-Reinhard Müller, Jesse P. Samluk, E Rachel Bernstein, Jacqueline Richter-Menge
Impact Of Spatial Aliasing On Sea-Ice Thickness Measurements, Cathleen Geiger, Hans-Reinhard Müller, Jesse P. Samluk, E Rachel Bernstein, Jacqueline Richter-Menge
Dartmouth Scholarship
We explore spatial aliasing of non-Gaussian distributions of sea-ice thickness. Using a heuristic model and >1000 measurements, we show how different instrument footprint sizes and shapes can cluster thickness distributions into artificial modes, thereby distorting frequency distribution, making it difficult to compare and communicate information across spatial scales. This problem has not been dealt with systematically in sea ice until now, largely because it appears to incur no significant change in integrated thickness which often serves as a volume proxy. Concomitantly, demands are increasing for thickness distribution as a resource for modeling, monitoring and forecasting air–sea fluxes and growing human …
On The Uncertainty Of Sea-Ice Isostasy, Cathleen Geiger, Peter Wadhams, Hans-Reinhard Müller, Jacqueline Richter-Menge
On The Uncertainty Of Sea-Ice Isostasy, Cathleen Geiger, Peter Wadhams, Hans-Reinhard Müller, Jacqueline Richter-Menge
Dartmouth Scholarship
During late winter 2007, coincident measurements of sea ice were collected using various sensors at an ice camp in the Beaufort Sea, Canadian Arctic. Analysis of the archived data provides new insight into sea-ice isostasy and its related R-factor through case studies at three scales using different combinations of snow and ice thickness components. At the smallest scale (<1 m; point scale), isostasy is not expected, so we calculate a residual and define this as �� (‘zjey’) to describe vertical displacement due to deformation. From 1 to 10 m length scales, we explore traditional isostasy and identify a specific sequence of thickness calculations which minimize freeboard and elevation uncertainty. An effective solution exists when the R-factor is allowed to vary: ranging from 2 to 12, with mean of 5.17, mode of 5.88 and skewed distribution. At regional scales, underwater, airborne and spaceborne platforms are always missing thickness variables from either above or below sea level. For such situations, realistic agreement is found by applying small-scale skewed ranges for the R-factor. These findings encourage a broader isostasy solution as a function of potential energy and length scale. Overall, results add insight to data collection strategies and metadata characteristics of different thickness products.
The Action Cycle/Structural Context Framework: A Fisheries Application, D. G. Webster
The Action Cycle/Structural Context Framework: A Fisheries Application, D. G. Webster
Dartmouth Scholarship
There is a growing consensus that environmental governance is a wicked problem that requires understanding of the many linkages and feedbacks between human and natural systems. Here, I propose an action cycle/structural context (AC/SC) framework that is based on the concept of responsive governance, in which individuals and decision makers respond to problems rather than working to prevent them. By linking agency and structure, the AC/SC framework points out two key problems in the realm of environmental governance: the profit disconnect, whereby economic signals of environmental harm are dampened by endogenous or exogenous forces, and the power disconnect, whereby those …
Robust And Efficient Solution Of The Drum Problem Via Nyström Approximation Of The Fredholm Determinant, Lin Zhao, Alex Barnett
Robust And Efficient Solution Of The Drum Problem Via Nyström Approximation Of The Fredholm Determinant, Lin Zhao, Alex Barnett
Dartmouth Scholarship
The “drum problem''---finding the eigenvalues and eigenfunctions of the Laplacian with Dirichlet boundary condition---has many applications, yet remains challenging for general domains when high accuracy or high frequency is needed. Boundary integral equations are appealing for large-scale problems, yet certain difficulties have limited their use. We introduce the following two ideas to remedy this: (1) We solve the resulting nonlinear eigenvalue problem using Boyd's method for analytic root-finding applied to the Fredholm determinant, and we show that this is many times faster than the usual iterative minimization of a singular value. (2) We fix the problem of spurious exterior resonances …
Spectrally Accurate Quadratures For Evaluation Of Layer Potentials Close To The Boundary For The 2d Stokes And Laplace Equations, Alex Barnett, Bowei Wu, Shravan Veerapaneni
Spectrally Accurate Quadratures For Evaluation Of Layer Potentials Close To The Boundary For The 2d Stokes And Laplace Equations, Alex Barnett, Bowei Wu, Shravan Veerapaneni
Dartmouth Scholarship
Dense particulate flow simulations using integral equation methods demand accurate evaluation of Stokes layer potentials on arbitrarily close interfaces. In this paper, we generalize techniques for close evaluation of Laplace double-layer potentials in [J. Helsing and R. Ojala, J. Comput. Phys., 227 (2008), pp. 2899--2921]. We create a “globally compensated” trapezoid rule quadrature for the Laplace single-layer potential on the interior and exterior of smooth curves. This exploits a complex representation, a product quadrature (in the style of Kress) for the sawtooth function, careful attention to branch cuts, and second-kind barycentric-type formulae for Cauchy integrals and their derivatives. Upon …