4,303 research outputs found

    Boundary regularity for the Poisson equation in reifenberg-flat domains

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    This paper is devoted to the investigation of the boundary regularity for the Poisson equation {{cc} -\Delta u = f & \text{in} \Omega u= 0 & \text{on} \partial \Omega where ff belongs to some Lp(Ω)L^p(\Omega) and Ω\Omega is a Reifenberg-flat domain of Rn.\mathbb R^n. More precisely, we prove that given an exponent α∈(0,1)\alpha\in (0,1), there exists an ε>0\varepsilon>0 such that the solution uu to the previous system is locally H\"older continuous provided that Ω\Omega is (ε,r0)(\varepsilon,r_0)-Reifenberg-flat. The proof is based on Alt-Caffarelli-Friedman's monotonicity formula and Morrey-Campanato theorem

    Strategic Interaction and Spatial Multiplier Effects in Local Growth Control Policies: The California Housing Market

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    Since the 1970s, growth controls spread across many metropolitan regions in the United States. Several studies address the effects of local growth controls on housing markets, particularly its price effect, which is induced by rising construction cost, constrained housing supply, improved amenities, and market reorientation of homebuilders. However, only few studies explicitly address inter-jurisdictional spatial spillovers and strategic interaction of policy-makers of different jurisdictions in the design of growth control policies. This study focuses on two housing market outcomes, supply of new housing and market orientation, and utilizes a spatial econometric framework to systematically investigate local and global spatial spillovers giving rise to spatial multiplier effects. Preliminary results suggest that market orientation of new home building is primarily influenced by population growth and building permit caps, with positive spillovers at the local level only. For the supply of new housing, however, the models seem to suggest positive global spillover effects. However, there is additional indication of a potential relevance of including spatial heterogeneity in the model specification. Specifically, a north-south disparity or a coastal-inland disparity may have non-negligible impacts with concurrent implications for policy-making.spatial spillovers, growth controls, housing supply, market orientation, Public Economics, C21, H23, H73, R31,

    Pediatric regional anesthesia: A review of the relevance of surface anatomy and landmarks used for peripheral nerve blockades in infants and children

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    In regional anesthesia, accurate knowledge of surface anatomy and landmarks are essential for successful nerve blockades with least possible complications. The long-established anatomical landmarks used for peripheral nerve blockades in adult patients have also gained a place in pediatric anesthesia. Despite the continuing benefits and need for more effective peripheral techniques in pediatrics, there is a paucity of data on pediatric landmarks, and hence the absence of more appropriate techniques for the different age groups of children. Recent advancement in imaging has shown that there is a greater awareness for the different surface projections at various stages of postnatal development, as compared with that of adults. Thus, if adult landmarks are not appropriately adapted for use in children, complication rates may rise due to injuries to anatomical structures. This review evaluated the existing evidence of the pediatric nerve block landmarks in the reported literature, in order to highlight the limitations in our current understanding of pediatric surface anatomy and landmarks. A literature search was done using five databases to obtain 141 references. Only a few of these studies provided detailed reports of the relations of relevant nerves to anatomical landmarks. A few clinical imaging studies have provided new anatomical landmarks in children with reference to their age-related growth and anatomy. Most landmarks need to be standardized in children of various ages, and furthermore, inconsistencies in the current descriptions of the surface landmarks need to be validated and standardized for use in pediatric clinical practice. Clin. Anat. 32:803–823, 2019. © 2019 Wiley Periodicals, Inc

    Magnetic resonance imaging study of the sciatic nerve variation in the pediatric gluteal region: Implications for the posterior approach of the sciatic nerve blockade

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    Introduction: In pediatric patients, the sciatic nerve is one of the most commonly blocked peripheral nerves during orthopedic procedures of the lower limb. Ultrasound guidance is the current standard for a successful localization of the sciatic nerve in the gluteal region. Relevant anatomical landmarks are also used to determine the nerve location when ultrasound is not available or inadequate. However, reports have demonstrated paucity of information regarding the sciatic nerve location and variation in the hip throughout pediatric development. This imaging study aimed to document and analyze the relative morphometric relationship of the sciatic nerve in the pediatric gluteal region throughout development. Methods: The location of the sciatic nerve in relation to bony landmarks was measured in 84 pediatric magnetic resonance imaging of patients aged 0.7–15.8 years. Results: The sciatic nerve was identified medial to the most lateral point of greater trochanter at the level of ischial spine and the tip of coccyx. The strong positive correlation between sciatic nerve to landmark distances and age and stature demonstrated linear variation between sciatic nerve location with age and growth of children. To predict the nerve location in the gluteal region, regression equations using patient age were created, having implications for the posterior approach of the sciatic nerve blockade in children. Clinically significant differences were found between sexes, specifically in the older age group. Conclusion: Despite the small sample size of younger age group, this study is the first to document the morphometric changes of the sciatic nerve in the gluteal region across pediatric development and may be useful for providing confirmatory guidelines for nerve location when ultrasound is not accessible or cannot be utilized for practice

    Thermally enhanced oxygen scavengers including a transition metal and a free radical scavenger

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    An oxygen scavenging system comprising a free radical scavenger (e.g., .alpha.-tocopherol, trimethylhydroquinone, ubiquinol, carotenoids, flavonoids, etc. and mixtures thereof) and a transition metal (e.g., iron (II), copper, manganese, cobalt, etc. and mixtures thereof) in a medium is generally provided. The medium containing the antioxidant and the transition metal has been thermally processed by heating to at least about 150.degree. F. for at least about 10 minutes. Methods of removing oxygen from an environment surrounded by a medium containing the oxygen scavenging system and methods of making the oxygen scavenging system in a medium are also provided

    Wounds That Will Not Heal Pervasive Cellular Reprogramming in Cancer

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    There has been an explosion of articles on epithelial-mesenchymal transition and other modes of cellular reprogramming that influence the tumor microenvironment. Many controversies exist and remain to be resolved. The interest of the pathologists in the molecular and functional parallels between wound healing and the developing tumor stroma has its earliest origin in the writings of Rudolph Virchow in the 19th century. Since then, most of the focus has been primarily on the dynamics of the extracellular matrix; however, new interest has been redirected toward deciphering and understanding the enigmatic, yet elegant, plasticity of the cellular components of the proliferating epithelia and stroma and how they are reciprocally influenced. Citing several examples from breast cancer research, we will trace how these perspectives have unfolded in the pages of The American Journal of Pathology and other investigative journals during the past century, their impact, and where the field is headed
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