Topological Defects as Seeds for Eternal Inflation

We investigate the global structure of inflationary universe both by analytical methods and by computer simulations of stochastic processes in the early Universe. We show that the global structure of the universe depends crucially on the mechanism of inflation. In the simplest models of chaotic inflation the Universe looks like a sea of thermalized phase surrounding permanently self-reproducing inflationary domains. In the theories where inflation occurs near a local extremum of the effective potential corresponding to a metastable state, the Universe looks like de Sitter space surrounding islands of thermalized phase. A similar picture appears even if the state $\phi = 0$ is unstable but the effective potential has a discrete symmetry $\phi \to =-\phi$. In this case the Universe becomes divided into domains containing different phases. These domains will be separated from each other by domain walls. However, unlike ordinary domain walls, these domain walls will inflate, and their thickness will exponentially grow. In the theories with continuous symmetries inflation generates exponentially expanding strings and monopoles surrounded by thermalized phase. Inflating topological defects will be stable, and they will unceasingly produce new inflating topological defects. This means that topological defects may play a role of indestructible seeds for eternal inflation.Comment: 21 pages, 17 figures (not included), Stanford University preprint SU--ITP--94--

The performance of the jet trigger for the ATLAS detector during 2011 data taking

The performance of the jet trigger for the ATLAS detector at the LHC during the 2011 data taking period is described. During 2011 the LHC provided proton–proton collisions with a centre-of-mass energy of 7 TeV and heavy ion collisions with a 2.76 TeV per nucleon–nucleon collision energy. The ATLAS trigger is a three level system designed to reduce the rate of events from the 40 MHz nominal maximum bunch crossing rate to the approximate 400 Hz which can be written to offline storage. The ATLAS jet trigger is the primary means for the online selection of events containing jets. Events are accepted by the trigger if they contain one or more jets above some transverse energy threshold. During 2011 data taking the jet trigger was fully efficient for jets with transverse energy above 25 GeV for triggers seeded randomly at Level 1. For triggers which require a jet to be identified at each of the three trigger levels, full efficiency is reached for offline jets with transverse energy above 60 GeV. Jets reconstructed in the final trigger level and corresponding to offline jets with transverse energy greater than 60 GeV, are reconstructed with a resolution in transverse energy with respect to offline jets, of better than 4 % in the central region and better than 2.5 % in the forward direction

Global, regional, and national age-sex-specific mortality and life expectancy, 1950–2017: a systematic analysis for the Global Burden of Disease Study 2017

BACKGROUND: Assessments of age-specific mortality and life expectancy have been done by the UN Population Division, Department of Economics and Social Affairs (UNPOP), the United States Census Bureau, WHO, and as part of previous iterations of the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD). Previous iterations of the GBD used population estimates from UNPOP, which were not derived in a way that was internally consistent with the estimates of the numbers of deaths in the GBD. The present iteration of the GBD, GBD 2017, improves on previous assessments and provides timely estimates of the mortality experience of populations globally. METHODS: The GBD uses all available data to produce estimates of mortality rates between 1950 and 2017 for 23 age groups, both sexes, and 918 locations, including 195 countries and territories and subnational locations for 16 countries. Data used include vital registration systems, sample registration systems, household surveys (complete birth histories, summary birth histories, sibling histories), censuses (summary birth histories, household deaths), and Demographic Surveillance Sites. In total, this analysis used 8259 data sources. Estimates of the probability of death between birth and the age of 5 years and between ages 15 and 60 years are generated and then input into a model life table system to produce complete life tables for all locations and years. Fatal discontinuities and mortality due to HIV/AIDS are analysed separately and then incorporated into the estimation. We analyse the relationship between age-specific mortality and development status using the Socio-demographic Index, a composite measure based on fertility under the age of 25 years, education, and income. There are four main methodological improvements in GBD 2017 compared with GBD 2016: 622 additional data sources have been incorporated; new estimates of population, generated by the GBD study, are used; statistical methods used in different components of the analysis have been further standardised and improved; and the analysis has been extended backwards in time by two decades to start in 1950. FINDINGS: Globally, 18·7% (95% uncertainty interval 18·4–19·0) of deaths were registered in 1950 and that proportion has been steadily increasing since, with 58·8% (58·2–59·3) of all deaths being registered in 2015. At the global level, between 1950 and 2017, life expectancy increased from 48·1 years (46·5–49·6) to 70·5 years (70·1–70·8) for men and from 52·9 years (51·7–54·0) to 75·6 years (75·3–75·9) for women. Despite this overall progress, there remains substantial variation in life expectancy at birth in 2017, which ranges from 49·1 years (46·5–51·7) for men in the Central African Republic to 87·6 years (86·9–88·1) among women in Singapore. The greatest progress across age groups was for children younger than 5 years; under-5 mortality dropped from 216·0 deaths (196·3–238·1) per 1000 livebirths in 1950 to 38·9 deaths (35·6–42·83) per 1000 livebirths in 2017, with huge reductions across countries. Nevertheless, there were still 5·4 million (5·2–5·6) deaths among children younger than 5 years in the world in 2017. Progress has been less pronounced and more variable for adults, especially for adult males, who had stagnant or increasing mortality rates in several countries. The gap between male and female life expectancy between 1950 and 2017, while relatively stable at the global level, shows distinctive patterns across super-regions and has consistently been the largest in central Europe, eastern Europe, and central Asia, and smallest in south Asia. Performance was also variable across countries and time in observed mortality rates compared with those expected on the basis of development. INTERPRETATION: This analysis of age-sex-specific mortality shows that there are remarkably complex patterns in population mortality across countries. The findings of this study highlight global successes, such as the large decline in under-5 mortality, which reflects significant local, national, and global commitment and investment over several decades. However, they also bring attention to mortality patterns that are a cause for concern, particularly among adult men and, to a lesser extent, women, whose mortality rates have stagnated in many countries over the time period of this study, and in some cases are increasing

Laser Doppler Anemometry Measurements Of Steady Flow Through Two Bi-leaflet Prosthetic Heart Valves [velocimetria Laser De Escoamento Permanente Através De Duas Próteses Cardíacas De Duplo Folheto]

Introduction: In vitro hydrodynamic characterization of prosthetic heart valves provides important information regarding their operation, especially if performed by noninvasive techniques of anemometry. Once velocity profiles for each valve are provided, it is possible to compare them in terms of hydrodynamic performance. In this first experimental study using laser doppler anemometry with mechanical valves, the simulations were performed at a steady flow workbench. Objective: To compare unidimensional velocity profiles at the central plane of two bi-leaflet aortic prosthesis from St. Jude (AGN 21-751 and 21 AJ-501 models) exposed to a steady flow regime, on four distinct sections, three downstream and one upstream. Methods: To provide similar conditions for the flow through each prosthesis by a steady flow workbench (water, flow rate of 17L/min.) and, for the same sections and sweeps, to obtain the velocity profiles of each heart valve by unidimensional measurements. Results: It was found that higher velocities correspond to the prosthesis with smaller inner diameter and instabilities of flow are larger as the section of interest is closer to the valve. Regions of recirculation, stagnation of flow, low pressure, and flow peak velocities were also found. Conclusions: Considering the hydrodynamic aspect and for every section measured, it could be concluded that the prosthesis model AGN 21-751 (RegentTM) is superior to the 21 AJ-501 model (Master Series). Based on the results, future studies can choose to focus on specific regions of the these valves.284462469Yoganathan, A.P., He, Z., Casey, J.S., Fluid mechanics of heart valves (2004) Ann Rev Biomed Eng, 6, pp. 331-362Dasi, L.P., Simon, H.A., Sucosky, P., Yoganathan, A.P., Fluid mechanics of artificial heart valves (2009) Clin Exp Pharmacol Physiol, 36 (2), pp. 225-237Chew, Y.T., Chew, T.C., Low, H.T., Lim, W.L., Techniques in the determination of the flow effectiveness of prosthetic heart valves. In: Cardiovascular techniques: Biomechanical systems: Techniques and applications. vol. II. London:Cornelius Leondes CRC Press LLC, 2001, pp. 70-117Yoganathan, A.P., Chandran, K.B., Sotiropoulus, F., Flow in prosthetic heart valves: State-of-the-art and future directions (2005) Ann Biomed Eng, 33 (12), pp. 1689-1694Grigioni, M., Daniele, C., D'Avenio, G., Morbiducci, U., Del Gaudio, C., Abbate, M., Innovative technologies for the assessment of cardiovascular medical devices: State-of-the-art techniques for artificial heart valve testing (2004) Expert Rev Med Devices, 1 (1), pp. 81-93Meyer, R.S., Deutsch, S., Bachmann, C.B., Tarbell, J.M., Laser Doppler velocimetry and flow visualization studies in the regurgitant leakage flow region of three mechanical mitral valves (2001) Artif Organs, 25 (4), pp. 292-299Pinotti, M., Is there correlation between the turbulent eddies size and mechanical hemolysis? (2000) J Braz Soc Mech Sci, 22. , http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-73862000000400006, Available from: URLMeyer, R.S., Deutsch, S., Maymir, J.C., Geselowitz, D.B., Tarbell, J.M., Three-component laser Doppler velocimetry measurements in the regurgitant flow region of a Björk-Shiley monostrut mitral valve (1997) Ann Biomed Eng, 25 (6), pp. 1081-1091Lu, P.C., Lai, H.C., Liu, J.S., A reevaluation and discussion on the threshold limit for hemolysis in a turbulent shear flow (2001) J Biomech, 34 (10), pp. 1361-1364Woo, Y.R., Yoganathan, A.P., Pulsatile flow velocity and shear stress measurements on the St. Jude bileaflet valve prosthesis (1986) Scand J Thorac Cardiovasc Surg, 20 (1), pp. 15-28(2005) Cardiovascular Implants-cardiac Valve Prostheses, , American National Standard, ISO 5840Cheade, E.L., (2008) Atualização De Sistema Duplicador De Pulsos Para Teste De Válvulas Cardíacas [Dissertação De Mestrado], p. 120. , Campinas: UNICAMP, Faculdade de Engenharia Elétrica e de ComputaçãoBazan, O., Ortiz, J.P., Design conception and experimental setup for in vitro evaluation of mitral prosthetic valves (2011) Rev Bras Cir Cardiovasc, 26 (2), pp. 197-204Bazan, O., Ortiz, J.P., Sistema Duplicador De Pulsos Para Análise In Vitro De Próteses De Válvulas Cardíacas-testes Preliminares De Validação, , www.metallum.com.br/7colaob/resumos/trabalhos_completos/02-015.docx, em: 7o Congresso Latino Americano de Órgãos Artificiais e Biomateriais, COLAOB 2012, 2012, Natal/ RN, Proceedings of COLAOB 2012, disponível emde Paulis, R., Schmitz, C., Scaffa, R., Nardi, P., Chiariello, L., Reul, H., In vitro evaluation of aortic valve prosthesis in a novel valved conduit with pseudosinuses of Valsalva (2005) J Thorac Cardiovasc Surg, 130 (4), pp. 1016-1021Dasi, L.P., Ge, L., Simon, H.A., Sotiropoulo, S.F., Yoganathan, A.P., Vorticity dynamics of a bileaflet mechanical heart valve in an axisymmetric aorta (2007) Phys Fluids, 19 (6), pp. 067105-067117Medical, S.J., (2010) Cardiac Surgery, , U.S. Product Catalog, AprilBlais, C., Pibarot, P., Dumesnil, J.G., Garcia, D., Chen, D., Durand, L.-G., Comparison of valve resistance with effective orifice area regarding flow dependence (2001) Am J Cardiol, 88 (1), pp. 45-52Dotta, F., Torres, M., Manfroi, W., Guaragna, J.C.V.C., Caramoni, P., Albuquerque, L.C., Desproporção prótese aórtica-paciente: Definição, impacto e prevenção (2007) Rev Bras Ecocardiogr, 20 (4), pp. 34-38Zhang, M., Wu, Q.C., Intra-supra annular aortic valve and complete supra annular aortic valve: A literature review and hemodynamic comparison (2010) Scand J Surg, 99 (1), pp. 28-31Seitelberger, R., Bialy, J., Gottardi, R., Seebacher, G., Moidl, R., Mittelöck, M., Relation between size of prosthesis and valve gradient: Comparison of two aortic bioprosthesis (2004) Eur J Cardiothorac Surg, 25 (3), pp. 358-363Guenzinger, R., Eichinger, W.B., Hettich, I., Bleiziffer, S., Ruzicka, D., Bauernschimitt, R., A prospective randomized comparison of the Medtronic Advantage Supra and St Jude Medical Regent mechanical heart valves in the aortic position: Is there an additional benefit of supra-annular valve positioning? (2008) J Thorac Cardiovasc Surg, 136 (2), pp. 462-47

Sediment record from the western Arctic Ocean with an improved Late Quaternary age resolution: HOTRAX core HLY0503-8JPC, Mendeleev Ridge

Sediment core HLY0503-8JPC raised by the HOTRAX'05 expedition from the Mendeleev Ridge was analyzed for multiple lithological, paleontological, and stable-isotopic proxies to reconstruct paleoceanographic conditions in the western Arctic Ocean during the Late Quaternary. The core, extensively sampled in the upper 5 m, reveals pronounced changes in sedimentary environments during the ca. 250 kyr interval encompassing Marine Isotopic Stages (MIS) 1 to 7. An estimated average resolution of 500 yr/sample, at least for the last glacial cycle including the last interglacial, provides more detail than seen in other sedimentary records from the western Arctic Ocean. The age control is provided by 14C and amino acid racemization measurements on planktonic foraminifers and correlations with the stratigraphy developed for the central Lomonosov Ridge and with glacial events at the Eurasian Arctic margin. Cyclic variations in lithology combined with foraminiferal abundance and stable-isotopic composition indicate profound changes in hydrographic and depositional environments between interglacial-type and glacial-type periods apparently reflecting a combination of 100-kyr and precessional time scales. This periodicity is complicated by abrupt iceberg- and/or meltwater-discharge events with variable (Laurentide vs. Eurasian) provenance. The proxy record from the interval identified as the last interglacial (MIS 5e), which may aid in understanding the future state of the Arctic Ocean, indicates low ice conditions and possibly enhanced stratification of the water column

Late Quaternary stratigraphy and sedimentation patterns in the western Arctic Ocean

Sediment cores from the western Arctic Ocean obtained on the 2005 HOTRAX and some earlier expeditions have been analyzed to develop a stratigraphic correlation from the Alaskan Chukchi margin to the Northwind and Mendeleev–Alpha ridges. The correlation was primarily based on terrigenous sediment composition that is not affected by diagenetic processes as strongly as the biogenic component, and paleomagnetic inclination records. Chronostratigraphic control was provided by 14C dating and amino-acid racemization ages, as well as correlation to earlier established Arctic Ocean stratigraphies. Distribution of sedimentary units across the western Arctic indicates that sedimentation rates decrease from tens of centimeters per kyr on the Alaskan margin to a few centimeters on the southern ends of Northwind and Mendeleev ridges and just a few millimeters on the ridges in the interior of the Amerasia basin. This sedimentation pattern suggests that Late Quaternary sediment transport and deposition, except for turbidites at the basin bottom, were generally controlled by ice concentration (and thus melt-out rate) and transportation distance from sources, with local variances related to subsurface currents. In the long term, most sediment was probably delivered to the core sites by icebergs during glacial periods, with a significant contribution from sea ice. During glacial maxima very fine-grained sediment was deposited with sedimentation rates greatly reduced away from the margins to a hiatus of several kyr duration as shown for the Last Glacial Maximum. This sedimentary environment was possibly related to a very solid ice cover and reduced melt-out over a large part of the western Arctic Ocean