Analytical and Numerical Solutions of Nonlinear Differential Equations Arising in Non-Newtonian Fluid Flows

AbstractSolutions for a class of nonlinear second order differential equations, arising in a viscoelastic fluid flow at a rotating cylinder, are obtained. Furthermore, using the Shauder theory and the perturbation technique existence, uniqueness and analyticity results are established. Moreover, the exact analytical solutions (in integral form) are compared with the corresponding numerical ones

Simultaneous determination of time-dependent coefficients and heat source

This article presents a numerical solution to the inverse problems of simultaneous determination of the time-dependent coefficients and the source term in the parabolic heat equation subject to overspecified conditions of integral type. The ill-posed problems are numerically discretized using the finite-difference method. The resulting system of nonlinear equations is solved numerically using the MATLAB toolbox routine lsqnonlin applied to minimizing the nonlinear Tikhonov regularization functional subject to simple physical bounds on the variables. Numerical examples are presented to illustrate the accuracy and stability of the solution

Hydrography and circulation near the crest of the East Pacific Rise between 9° and 10°N

Author Posting. © The Author(s), 2010. This is the author's version of the work. It is posted here by permission of Elsevier B.V. for personal use, not for redistribution. The definitive version was published in Deep Sea Research Part I: Oceanographic Research Papers 58 (2011): 365-376, doi:10.1016/j.dsr.2011.01.009.Topography has a strong effect on the physical oceanography over the flanks and crests of the global mid-ocean ridge system. Here, we present an analysis of the hydrography and circulation near the crest of the East Pacific Rise (EPR) between 9◦ and 10◦N, which coincides with an integrated study site (ISS) of the RIDGE2000 program. The analysis is based primarily on survey and mooring data collected during the LADDER project, which aimed to investigate oceanographic and topographic influences on larval retention and dispersal in hydrothermal vent communities. Results indicate that the yearly averaged regional mean circulation is characterized by a westward drift of 0.5–1 cm·s−1 across the EPR axis and by north- and southward flows along the western and eastern upper ridge flanks, respectively. The westward drift is part of a basin-scale zonal flow that extends across most of the Pacific ocean near 10◦N, whereas the meridional currents near the ridge crest are a topographic effect. In spite of considerable mesoscale variability, which dominates the regional circulation and dispersal on weekly to monthly time scales, quasi-synoptic surveys carried out during the mooring deployment and recovery cruises indicate subinertial circulations that are qualitatively similar to the yearly averaged flow but associated with significantly stronger velocities. Weekly averaged mooring data indicate that the anticyclonically sheared along-flank flows are associated with core speeds as high as 10 cm·s−1 and extend ≈10 km off axis and 200m above the ridge-crest topography. Near the northern limit of the study region, the Lamont Seamount Chain rises from the western ridge flank and restricts along-EPR flow to five narrow passages, where peak velocities in excess of 20 cm·s−1 were observed. Outside the region of the ridge-crest boundary currents the density field over the EPR near 10◦N is characterized by isopycnals dipping into the ridge flanks. Directly above the EPR axis the ridge-crest boundary currents give rise to an isopycnal dome. During times of strong westward cross-EPR flow isopycnal uplift over the eastern flank causes the cross-ridge density field below the doming isopycnals to be asymmetric, with higher densities over the eastern than over the western flank. The data collected during the LADDER project indicate that dispersal of hydrothermal products from the EPR ISS on long time scales is predominantly to the west, whereas mesoscale variability dominates dispersal on weekly to monthly time scales, which are particularly important in the context of larval dispersal.Co-funding of the LADDER project by the biological and physical oceanography divisions of the National Science Foundation under grants OCE-0425361 and OCE-0424953 is gratefully acknowledged, as is support of J.W. Lavelle by NOAA’s Pacific Marine Environmental Laboratory and by the NOAA Vents Program

Amine Containing Analogs of Sulindac for Cancer Prevention

Background: Sulindac belongs to the chemically diverse family of Non-Steroidal Anti-Inflammatory Drugs (NSAIDs) that effectively prevent adenomatous colorectal polyps and colon cancer, especially in patients with familial adenomatous polyposis. Sulindac sulfide amide (SSA), an amide analog of sulindac sulfide, shows insignificant COX-related activity and toxicity while enhancing anticancer activity in vitro and demonstrating in vivo xenograft activity. Objective: Develop structure-activity relationships in the sulindac amine series and identify analogs with promising anticancer activities. Method: A series of sulindac amine analogs were designed and synthesized and then further modified in a “libraries from libraries” approach to produce amide, sulfonamide and N,N-disubstituted sulindac amine sub-libraries. All analogs were screened against three cancer cell lines (prostate, colon and breast). Results: Several active compounds were identified viain vitro cancer cell line screening with the most potent compound (26) in the nanomolar range. Conclusion: Compound 26 and analogs showing the most potent inhibitory activity may be considered for further design and optimization efforts as anticancer hit scaffolds

The Effect That Project Management Certification Has on Employability: Agent's Perceptions from Spain

This study analyses the effects that the project management certification has on employability. This analysis started with a participative process in which various groups of experts who are involved in the certification of people were consulted. A personal interview was carried out amongst 106 professionals —certifying bodies, training institutions, the civil service, and international organisations— and amongst professional who are certified in project management by the International Project Management Association in Spain. The results show that the certification emerges as a powerful tool for improving employability. The effects are demonstrated across two complementary aspects: internal company aspects and external aspects relating to the labour market. Finally, by compiling the different agents’ opinions, a series of measures emerge for improving the accreditation processes as an employability tool and increasing the mutual learning between public and private actors

Horizontal Branch Stars: The Interplay between Observations and Theory, and Insights into the Formation of the Galaxy

We review HB stars in a broad astrophysical context, including both variable and non-variable stars. A reassessment of the Oosterhoff dichotomy is presented, which provides unprecedented detail regarding its origin and systematics. We show that the Oosterhoff dichotomy and the distribution of globular clusters (GCs) in the HB morphology-metallicity plane both exclude, with high statistical significance, the possibility that the Galactic halo may have formed from the accretion of dwarf galaxies resembling present-day Milky Way satellites such as Fornax, Sagittarius, and the LMC. A rediscussion of the second-parameter problem is presented. A technique is proposed to estimate the HB types of extragalactic GCs on the basis of integrated far-UV photometry. The relationship between the absolute V magnitude of the HB at the RR Lyrae level and metallicity, as obtained on the basis of trigonometric parallax measurements for the star RR Lyrae, is also revisited, giving a distance modulus to the LMC of (m-M)_0 = 18.44+/-0.11. RR Lyrae period change rates are studied. Finally, the conductive opacities used in evolutionary calculations of low-mass stars are investigated. [ABRIDGED]Comment: 56 pages, 22 figures. Invited review, to appear in Astrophysics and Space Scienc

First narrow-band search for continuous gravitational waves from known pulsars in advanced detector data

Spinning neutron stars asymmetric with respect to their rotation axis are potential sources of continuous gravitational waves for ground-based interferometric detectors. In the case of known pulsars a fully coherent search, based on matched filtering, which uses the position and rotational parameters obtained from electromagnetic observations, can be carried out. Matched filtering maximizes the signalto- noise (SNR) ratio, but a large sensitivity loss is expected in case of even a very small mismatch between the assumed and the true signal parameters. For this reason, narrow-band analysis methods have been developed, allowing a fully coherent search for gravitational waves from known pulsars over a fraction of a hertz and several spin-down values. In this paper we describe a narrow-band search of 11 pulsars using data from Advanced LIGO’s first observing run. Although we have found several initial outliers, further studies show no significant evidence for the presence of a gravitational wave signal. Finally, we have placed upper limits on the signal strain amplitude lower than the spin-down limit for 5 of the 11 targets over the bands searched; in the case of J1813-1749 the spin-down limit has been beaten for the first time. For an additional 3 targets, the median upper limit across the search bands is below the spin-down limit. This is the most sensitive narrow-band search for continuous gravitational waves carried out so far

History of clinical transplantation

How transplantation came to be a clinical discipline can be pieced together by perusing two volumes of reminiscences collected by Paul I. Terasaki in 1991-1992 from many of the persons who were directly involved. One volume was devoted to the discovery of the major histocompatibility complex (MHC), with particular reference to the human leukocyte antigens (HLAs) that are widely used today for tissue matching.1 The other focused on milestones in the development of clinical transplantation.2 All the contributions described in both volumes can be traced back in one way or other to the demonstration in the mid-1940s by Peter Brian Medawar that the rejection of allografts is an immunological phenomenon.3,4 © 2008 Springer New York

Virtual Ontogeny of Cortical Growth Preceding Mental Illness

Background: Morphology of the human cerebral cortex differs across psychiatric disorders, with neurobiology and developmental origins mostly undetermined. Deviations in the tangential growth of the cerebral cortex during pre/perinatal periods may be reflected in individual variations in cortical surface area later in life. Methods: Interregional profiles of group differences in surface area between cases and controls were generated using T1-weighted magnetic resonance imaging from 27,359 individuals including those with attention-deficit/hyperactivity disorder, autism spectrum disorder, bipolar disorder, major depressive disorder, schizophrenia, and high general psychopathology (through the Child Behavior Checklist). Similarity of interregional profiles of group differences in surface area and prenatal cell-specific gene expression was assessed. Results: Across the 11 cortical regions, group differences in cortical area for attention-deficit/hyperactivity disorder, schizophrenia, and Child Behavior Checklist were dominant in multimodal association cortices. The same interregional profiles were also associated with interregional profiles of (prenatal) gene expression specific to proliferative cells, namely radial glia and intermediate progenitor cells (greater expression, larger difference), as well as differentiated cells, namely excitatory neurons and endothelial and mural cells (greater expression, smaller difference). Finally, these cell types were implicated in known pre/perinatal risk factors for psychosis. Genes coexpressed with radial glia were enriched with genes implicated in congenital abnormalities, birth weight, hypoxia, and starvation. Genes coexpressed with endothelial and mural genes were enriched with genes associated with maternal hypertension and preterm birth. Conclusions: Our findings support a neurodevelopmental model of vulnerability to mental illness whereby prenatal risk factors acting through cell-specific processes lead to deviations from typical brain development during pregnancy