Investigation of a HA/PDLGA/Carbon Foam Material System for Orthopedic Fixation Plates Based on Time-Dependent Properties

While there is continuing interest in bioresorbable materials for orthopedic fixation devices, the major challenge in utilizing these materials in load-bearing applications is creating materials sufficiently stiff and strong to sustain loads throughout healing while maintaining fracture stability. The primary aim of this study is to quantify the degradation rate of a bioresorbable material system, then use this degradation rate to determine the material response of an orthopedic device made of the same material as healing progresses. The present research focuses on the development and characterization of a material system consisting of carbon foam infiltrated with hydroxyapatite (HA) reinforced poly(D,L-lactide)-co-poly(glycolide) (PDLGA). A processing technique is developed to infiltrate carbon foam with HA/PDLGA and material morphology is investigated. Additionally, short-term rat osteoblast cell studies are undertaken to establish a starting point for material biocompatibility. Degradation experiments are conducted to elicit the time-dependent properties of the material system at the material scale. These properties are then incorporated into computational models of an internal plate attached to a fractured human femur to design and predict the material response to applied physiological loads. Results from this work demonstrate the importance of material dissolution rate as well as material strength when designing internal fixation plates

Retained Free Energy with Enhanced Nucleation during Electrostatic Levitation of Undercooled Fe-Co Alloys

Double recalescence in many ferrous alloy systems involves rapid solidification of metastable ferrite from the undercooled melt with subsequent transformation to stable austenite. Containerless processing is used to monitor the process using pyrometry and high-speed cinematography such that delay behavior can be predicted based on the application of the retained damage model (RDM). When comparing Fe-Cr-Ni alloys to Fe-Co alloys, the cluster attachment rate is enhanced while free energy retention is reduced. These trends are tied to specific alloy properties. A retained free energy criterion is proposed based on the ratio of thermophysical properties used to define the transformation driving force such that the thermodynamic limit for energy retention may be predicted. Surprisingly, at long delay times, healing occurs such that much of the retained free energy is not available to enhance the transition from metastable to stable phases. At delay times less than one second, no healing is observed and the RDM correctly predicts transformation delay behavior over a wide range of alloy compositions

Modelling the Inorganic Bromine Partitioning in the Tropical Tropopause over the Pacific Ocean

The stratospheric inorganic bromine burden (Bry) arising from the degradation of brominated very short-lived organic substances (VSL org ), and its partitioning between reactive and reservoir species, is needed for a comprehensive assessment of the ozone depletion potential of brominated trace gases. Here we present modelled inorganic bromine abundances over the Pacific tropical tropopause based on aircraft observations of VSL org of two campaigns of the Airborne Tropical TRopopause EXperiment (ATTREX 2013 carried out over eastern Pacific and ATTREX 2014 carried out over the western Pacific) and chemistry-climate simulations (along ATTREX flight tracks) using the specific meteorology prevailing. Using the Community Atmosphere Model with Chemistry (CAM-Chem), we model that BrO and Br are the daytime dominant species. Integrated across all ATTREX flights BrO represents ~ 43 % and 48 % of daytime Bry abundance at 17 km over the Western and Eastern Pacific, respectively. The results also show zones where Br/BrO >1 depending on the solar zenith angle (SZA), ozone concentration and temperature. On the other hand, BrCl and BrONO 2 were found to be the dominant night-time species with ~ 61% and 56 % of abundance at 17 km over the Western and Eastern Pacific, respectively. The western-to-eastern differences in the partitioning of inorganic bromine are explained by different abundances of ozone (O3), nitrogen dioxide (NO2) , and total inorganic chlorine (Cly).Fil: Navarro, María A.. University of Miami; Estados UnidosFil: Saiz-lopez, Alfonso. Consejo Superior de Investigaciones Científicas. Instituto de Química Física; EspañaFil: Cuevas, Carlos Alberto. Consejo Superior de Investigaciones Científicas. Instituto de Química Física; EspañaFil: Fernandez, Rafael Pedro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza; Argentina. Universidad Nacional de Cuyo. Facultad de Ciencias Exactas y Naturales; Argentina. Universidad Tecnologica Nacional. Facultad Regional Mendoza. Secretaría de Ciencia, Tecnología y Postgrado; ArgentinaFil: Atlas, Elliot. University of Miami; Estados UnidosFil: Rodriguez Lloeveras, Xavier. Consejo Superior de Investigaciones Científicas. Instituto de Química Física; EspañaFil: Kinnison, Douglas E.. National Center For Atmospheric Research. Amospheric Chemistry División; Estados UnidosFil: Lamarque, Jean Francois. National Center For Atmospheric Research. Amospheric Chemistry División; Estados UnidosFil: Tilmes, Simone. National Center For Atmospheric Research. Amospheric Chemistry División; Estados UnidosFil: Thornberry, Troy. State University of Colorado at Boulder; Estados Unidos. Earth System Research Laboratory; Estados UnidosFil: Rollins, Andrew. State University of Colorado at Boulder; Estados Unidos. Earth System Research Laboratory; Estados UnidosFil: Elkins, James W.. Earth System Research Laboratory; Estados UnidosFil: Hintsa, Eric J.. State University of Colorado at Boulder; Estados Unidos. Earth System Research Laboratory; Estados UnidosFil: Moore, Fred L.. State University of Colorado at Boulder; Estados Unidos. Earth System Research Laboratory; Estados Unido

Lost Branches on the Tree of Life

Failure to archive published data can impede reproducibility and inhibit downstream synthesis. Alarmingly, we estimate that ∼70% of existing DNA sequence alignments/phylogenetic trees, representing much of the underpinning of modern phylogenetic analysis, are no longer accessible. The evolutionary biology community needs to adopt policies ensuring that data are publicly archived upon publication

Non-Critical String Duals of N=1 Quiver Theories

We construct N=1 non-critical strings in four dimensions dual to strongly coupled N=1 quiver gauge theories in the Coulomb phase, generalizing the string duals of Argyres-Douglas points in N=2 gauge theories. They are the first examples of superstrings vacua with an exact worldsheet description dual to chiral N=1 theories. We identify the dual of the non-critical superstring using a brane setup describing the field theory in the classical limit. We analyze the spectrum of chiral operators in the strongly coupled regime and show how worldsheet instanton effects give non-perturbative information about the gauge theory. We also consider aspects of D-branes relevant for the holographic duality.Comment: JHEP style; 40 pages, 3 figures; v2: minor corrections, refs added, version to appear in JHE

Injection of iodine to the stratosphere

© 2015. American Geophysical Union. All Rights Reserved. We report a new estimation of the injection of iodine into the stratosphere based on novel daytime (solar zenith angle < 45°) aircraft observations in the tropical tropopause layer and a global atmospheric model with the most recent knowledge about iodine photochemistry. The results indicate that significant levels of total reactive iodine (0.25-0.7 parts per trillion by volume), between 2 and 5 times larger than the accepted upper limits, can be injected into the stratosphere via tropical convective outflow. At these iodine levels, modeled iodine catalytic cycles account for up to 30% of the contemporary ozone loss in the tropical lower stratosphere and can exert a stratospheric ozone depletion potential equivalent to, or even larger than, that of very short-lived bromocarbons. Therefore, we suggest that iodine sources and chemistry need to be considered in assessments of the historical and future evolution of the stratospheric ozone layer.Peer Reviewe

Injection of iodine to the stratosphere

We report a new estimation of the injection of iodine into the stratosphere based on novel daytime (solar zenith angle < 45°) aircraft observations in the tropical tropopause layer and a global atmospheric model with the most recent knowledge about iodine photochemistry. The results indicate that significant levels of total reactive iodine (0.25-0.7 parts per trillion by volume), between 2 and 5 times larger than the accepted upper limits, can be injected into the stratosphere via tropical convective outflow. At these iodine levels, modeled iodine catalytic cycles account for up to 30% of the contemporary ozone loss in the tropical lower stratosphere and can exert a stratospheric ozone depletion potential equivalent to, or even larger than, that of very short-lived bromocarbons. Therefore, we suggest that iodine sources and chemistry need to be considered in assessments of the historical and future evolution of the stratospheric ozone layer.Fil: Saiz López, Alfonso. Consejo Superior de Investigaciones Científicas. Instituto de Química Física; España. National Center For Atmospheric Research. Amospheric Chemistry División; Estados Unidos. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Baidar, S.. Cooperative Institute For Research In Environmental Science; Estados Unidos. State University of Colorado at Boulder; Estados UnidosFil: Cuevas, Carlos Alberto. Consejo Superior de Investigaciones Científicas. Instituto de Química Física; EspañaFil: Koening, T. K.. State University of Colorado at Boulder; Estados UnidosFil: Fernandez, Rafael Pedro. Consejo Superior de Investigaciones Científicas. Instituto de Química Física; España. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Dix, Barbara. State University of Colorado at Boulder; Estados UnidosFil: Douglas E. KINNISON. National Center For Atmospheric Research. Amospheric Chemistry División; Estados UnidosFil: Jean-Francoise LAMARQUE. National Center For Atmospheric Research. Amospheric Chemistry División; Estados UnidosFil: Xavier Rodriguez-Lloeveras. Consejo Superior de Investigaciones Científicas. Instituto de Química Física; EspañaFil: Campos, T.L.. National Center For Atmospheric Research. Amospheric Chemistry División; Estados UnidosFil: Volkamer, Rainer. Cooperative Institute For Research In Environmental Science; Estados Unidos. State University of Colorado at Boulder; Estados Unido

Performance of the Ultra-High Rate Germanium (UHRGe) System

Performance of the Ultra-High Rate Germanium (UHRGe) System client repor

YY1 haploinsufficiency causes an intellectual disability syndrome featuring transcriptional and chromatin dysfunction

Yin and yang 1 (YY1) is a well-known zinc-finger transcription factor with crucial roles in normal development and malignancy. YY1 acts both as a repressor and as an activator of gene expression. We have identified 23 individuals with de novo mutations or deletions of YY1 and phenotypic features that define a syndrome of cognitive impairment, behavioral alterations, intrauterine growth restriction, feeding problems, and various congenital malformations. Our combined clinical and molecular data define "YY1 syndrome" as a haploinsufficiency syndrome. Through immunoprecipitation of YY1-bound chromatin from affected individuals' cells with antibodies recognizing both ends of the protein, we show that YY1 deletions and missense mutations lead to a global loss of YY1 binding with a preferential retention at high-occupancy sites. Finally, we uncover a widespread loss of H3K27 acetylation in particular on the YY1-bound enhancers, underscoring a crucial role for YY1 in enhancer regulation. Collectively, these results define a clinical syndrome caused by haploinsufficiency of YY1 through dysregulation of key transcriptional regulators.Michele Gabriele, Anneke T. Vulto-van Silfhout, Pierre-Luc Germain, Alessandro Vitriolo, Raman Kumar, Evelyn Douglas, Eric Haan, Kenjiro Kosaki, Toshiki Takenouchi, Anita Rauch, Katharina Steindl, Eirik Frengen, Doriana Misceo, Christeen Ramane J. Pedurupillay, Petter Stromme, Jill A. Rosenfeld, Yunru Shao, William J. Craigen, Christian P. Schaaf, David Rodriguez-Buritica, Laura Farach, Jennifer Friedman, Perla Thulin, Scott D. McLean, Kimberly M. Nugent, Jenny Morton, Jillian Nicholl, Joris Andrieux, Asbjørg Stray-Pedersen, Pascal Chambon, Sophie Patrier, Sally A. Lynch, Susanne Kjaergaard, Pernille M. Tørring, Charlotte Brasch-Andersen, Anne Ronan, Arie van Haeringen, Peter J. Anderson, Zöe Powis, Han G. Brunner, Rolph Pfundt, Janneke H.M. Schuurs-Hoeijmakers, Bregje W.M. van Bon, Stefan Lelieveld, Christian Gilissen, Willy M. Nillesen, Lisenka E.L.M. Vissers, Jozef Gecz, David A. Koolen, Giuseppe Testa, Bert B.A. de Vrie