2,984 research outputs found
Local Mismatch Location and Spatial Scale Detection in Image Registration
Image registration is now a well understood problem and several techniques using a combination of cost functions,
transformation models and optimizers have been reported in medical imaging literature. Parametric methods
often rely on the efficient placement of control points in the images, that is, depending on the location and scale
at which images are mismatched. Poor choice of parameterization results in deformations not being modeled
accurately or over parameterization, where control points may lie in homogeneous regions with low sensitivity to
cost. This lowers computational efficiency due to the high complexity of the search space and might also provide
transformations that are not physically meaningful, and possibly folded.
Adaptive methods that parameterize based on mismatch in images have been proposed. In such methods, the
cost measure must be normalized, heuristics such as how many points to pick, resolution of the grids, choosing
gradient thresholds and when to refine scale would have to be ascertained in addition to the limitation of working
only at a few discrete scales.
In this paper we identify mismatch by searching the entire image and a wide range of smooth spatial scales.
The mismatch vector, containing location and scale of mismatch is computed from peaks in the local joint
entropy. Results show that this method can be used to quickly and effectively locate mismatched regions in
images where control points can be placed in preference to other regions speeding up registration.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/85931/1/Fessler223.pd
Fatty acid transport protein 4 is required for incorporation of saturated ultralong-chain fatty acids into epidermal ceramides and monoacylglycerols
Fatty acid transport protein 4 (FATP4) is an acyl-CoA synthetase that is required for normal permeability barrier in mammalian skin. FATP4 (SLC27A4) mutations cause ichthyosis prematurity syndrome, a nonlethal disorder. In contrast, Fatp4-/- mice die neonatally from a defective barrier. Here we used electron microscopy and lipidomics to characterize defects in Fatp4-/- mice. Mutants showed lamellar body, corneocyte lipid envelope, and cornified envelope abnormalities. Lipidomics identified two lipids previously speculated to be present in mouse epidermis, sphingosine ÎČ-hydroxyceramide and monoacylglycerol; mutants displayed decreased proportions of these and the two ceramide classes that carry ultralong-chain, amide-linked fatty acids (FAs) thought to be critical for barrier function, unbound Ï-O-acylceramide and bound Ï-hydroxyceramide, the latter constituting the major component of the corneocyte lipid envelope. Other abnormalities included elevated amounts of sphingosine α-hydroxyceramide, phytosphingosine non-hydroxyceramide, and 1-O-acylceramide. Acyl chain length alterations in ceramides also suggested roles for FATP4 in esterifying saturated non-hydroxy and ÎČ-hydroxy FAs with at least 25 carbons and saturated or unsaturated Ï-hydroxy FAs with at least 30 carbons to CoA. Our lipidomic analysis is the most thorough such study of the Fatp4-/- mouse skin barrier to date, providing information about how FATP4 can contribute to barrier function by regulating fatty acyl moieties in various barrier lipids
Epithelial laminin α5 is necessary for distal epithelial cell maturation, VEGF production, and alveolization in the developing murine lung
AbstractLaminin α5 is prominent in the basement membrane of alveolar walls, airways, and pleura in developing and adult lung. Targeted deletion of laminin α5 in mice causes developmental defects in multiple organs, but embryonic lethality has precluded examination of the latter stages of lung development. To identify roles for laminin α5 in lung development, we have generated an inducible lung epithelial cell-specific Lama5 null (SP-CLama5fl/â) mouse through use of the Cre/loxP system, the human surfactant protein C promoter, and the reverse tetracycline transactivator. SP-CLama5fl/â embryos exposed to doxycycline from E6.5 died a few hours after birth. Compared to control littermates, SP-CLama5fl/â lungs had dilated, enlarged distal airspaces, but basement membrane ultrastructure was preserved. Distal epithelial cell differentiation was perturbed, with a marked reduction of alveolar type II cells and a virtual absence of type I cells. Cell proliferation was reduced and apoptosis was increased. Capillary density was diminished, and this was associated with a decrease in total lung VEGF production. Overall, these findings indicate that epithelial laminin α5, independent of its structural function, is necessary for murine lung development, and suggest a role for laminin α5 in signaling pathways that promote alveolar epithelial cell differentiation and VEGF expression
2016 â 2017 Kentucky Agricultural Economic Situation and Outlook
Topics: U.S. Agricultural Economy; Kentuckyâs Agricultural Economy
Spallation of Iron in Black Hole Accretion Flows
In the local Galactic interstellar medium there is approximate energy
equipartition between cosmic rays, magnetic fields and radiation. If this holds
in the central regions of AGN, in particular Seyfert galaxies, then consideral
nuclear spallation of Fe occurs, resulting in enhanced abundances of the sub-Fe
elements Ti, V, Cr and Mn. These elements produce a cluster of X-ray
flourescence lines at energies just below the 6.4 keV Fe-K line. It is
suggested that the red wings on the Fe lines observed with ASCA from various
Seyfert AGN are due to the unresolved line emission from these elements. Future
observations with more sensitive X-ray instruments should resolve these lines.
The estimated gamma ray emission from nuclear deexcitation and neutral pion
production is calculated and found to be below the sensitivities of any current
instruments. However, very luminous nearby Seyferts displaying Fe lines with
red wings would have MeV continuum emission detectable by future
instruments such as GLAST.Comment: 11 pages, Latex, requires AASTEX macros, 5 postscript figures,
Astrophysical Journal in pres
Dynamic, adaptive changes in MAO-A binding after alterations in substrate availability: an in vivo [11C]-harmine positron emission tomography study
Monoamine oxidase A (MAO-A) is an important target in the pathophysiology and therapeutics of major depressive disorder, aggression, and neurodegenerative conditions. We measured the effect of changes in MAO-A substrate on MAO-A binding in regions implicated in affective and neurodegenerative disease with [11C]-harmine positron emission tomography in healthy volunteers. Monoamine oxidase A VT, an index of MAO-A density, was decreased (mean: 14%±9%) following tryptophan depletion in prefrontal cortex (P<0.031), and elevated (mean: 17%±11%) in striatum following carbidopaâlevodopa administration (P<0.007). These findings suggest an adaptive role for MAO-A in maintaining monoamine neurotransmitter homeostasis by rapidly compensating fluctuating monoamine levels
MicrobiotaâDependent Metabolite Trimethylamine NâOxide and Coronary Artery Calcium in the Coronary Artery Risk Development in Young Adults Study (CARDIA)
BACKGROUND: Clinical studies implicate trimethylamine N-oxide (TMAO; a gut microbiota-dependent nutrient metabolite) in cardiovascular disease risk. There is a lack of population-based data on the role of TMAO in advancing early atherosclerotic disease. We tested the prospective associations between TMAO and coronary artery calcium (CAC) and carotid intima-media thickness (cIMT).
METHODS AND RESULTS: Data were from the Coronary Artery Risk Development in Young Adults Study (CARDIA), a biracial cohort of US adults recruited in 1985-1986 (n=5115). We randomly sampled 817 participants (aged 33-55Â years) who attended examinations in 2000-2001, 2005-2006, and 2010-2011, at which CAC was measured by computed tomography and cIMT (2005-2006) by ultrasound. TMAO was quantified using liquid chromotography mass spectrometry on plasma collected in 2000-2001. Outcomes were incident CAC, defined as Agatston units=0 in 2000-2001 and >0 over 10-year follow-up, CAC progression (any increase over 10-year follow-up), and continuous cIMT. Over the study period, 25% (n=184) of those free of CAC in 2000-2001 (n=746) developed detectable CAC. In 2000-2001, median (interquartile range) TMAO was 2.6 (1.8-4.2) ÎŒmol/L. In multivariable-adjusted models, TMAO was not associated with 10-year CAC incidence (rate ratio=1.03; 95% CI: 0.71-1.52) or CAC progression (0.97; 0.68-1.38) in Poisson regression, or cIMT (beta coefficient: -0.009; -0.03 to 0.01) in linear regression, comparing the fourth to the first quartiles of TMAO.
CONCLUSIONS: In this population-based study, TMAO was not associated with measures of atherosclerosis: CAC incidence, CAC progression, or cIMT. These data indicate that TMAO may not contribute significantly to advancing early atherosclerotic disease risk among healthy early-middle-aged adults
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