566 research outputs found
Study of Side Ditch Liners for Highway Application
Over the past few years, the INDOT new materials department has received numerous erosion control products (mostly geosynthetics) to evaluate as alternatives to riprap and concrete in ditch liners. Potential benefits include lower construction costs and better aesthetics over current products. Unfortunately, no specification, design methodology, or classification system currently exists for these erosion control blankets.
In this project\u27s phase I, existing information and knowledge on erosion control materials used to line highway side drainage ditches were investigated. From the available technical1iterature (journal and conference publications, other DOTs specifications, manufacturer documentation, independent test laboratory test data), design methodologies, classification system, product approval procedures, and installation methods were reviewed for temporary and permanent geosynthetic erosion control materials. Based on the synthesis of these reviews a design methodology was proposed including design aids (tables, flow charts, and graphs) necessary to perform flexible liner computations. A classification system based on product performance was also proposed. In addition, current design procedures for hard armor materials (fabric formed revetments, concrete block systems, gabions, and riprap) were reviewed. A tentative specification for both flexible and hard armor ditch liners was drafted
Identifying short motifs by means of extreme value analysis
The problem of detecting a binding site -- a substring of DNA where
transcription factors attach -- on a long DNA sequence requires the recognition
of a small pattern in a large background. For short binding sites, the matching
probability can display large fluctuations from one putative binding site to
another. Here we use a self-consistent statistical procedure that accounts
correctly for the large deviations of the matching probability to predict the
location of short binding sites. We apply it in two distinct situations: (a)
the detection of the binding sites for three specific transcription factors on
a set of 134 estrogen-regulated genes; (b) the identification, in a set of 138
possible transcription factors, of the ones binding a specific set of nine
genes. In both instances, experimental findings are reproduced (when available)
and the number of false positives is significantly reduced with respect to the
other methods commonly employed.Comment: 6 pages, 5 figure
Richness of IT Use Operationalization: A Conceptual Replication
Use of information technology (IT) remains a key concern for organizations. This article presents a conceptual replication of Burton-Jones and Straub’s (2006) study, exploring the effect of IT Use operationalization richness – lean and rich – on Performance. We used 352 valid responses from Amazon MTurk through an online survey. Consistent with the original study, the hypothesis was tested by using the Structural Equation Modeling technique. Our results – which indicated support for the same hypothesis in the original study – suggest that the richer the IT use operationalization, the higher the individual Performance
Chromomagnetism in nuclear matter
Quarks are color charged particles. Due to their motion there is a strong
possibility of generation of color magnetic field. It is shown that however
hadrons are color singlet particles they may have non-zero color magnetic
moment. Due to this color magnetic moment hadrons can show color interaction.
In this paper we have studied the chromomagnetic properties of nuclear matter.Comment: 6 pages, 1 figure, accepted for publication in Int. J. Theor. Phy
Calbindin-D28k gene expression in the developing mouse kidney
Calbindin-D28k gene expression in the developing mouse kidney. Calbindin-D28k appears in the metanephric kidney during embryogenesis. We studied the temporal appearance and spatial distribution of calbindin-D28k mRNA in the developing kidneys of 12-day fetal through 21-day postnatal mice by in situ hybridization. 35S-UTP-labeled antisense (cRNA) probe to calbindin-D28k mRNA hybridized to the ureteric buds of 12-day embryos, whereas adjacent metanephrogenic tissue was unlabeled. By embryonic day 13, Y-shaped bodies of “advancing” ureteric buds were labeled intensely. In 16-day embryos, ampullae of ureteric buds were located immediately beneath the renal capsule and labeled strongly, in contrast to metanephric tubules and S-shaped bodies. The former were unlabeled and the latter were labeled only at points of contact with the ampullae. Subsequently, the ampullae of the metanephric ureteric buds hybridized with the cRNA probe, and from the 18th embryonic to the 21st postnatal day, this labeling was intense. The cRNA probe did not hybridize with the renal vesicles, proximal tubules, or tubular segments of Henle's loop derived from nephrogenic blastema, but it did label distal nephron segments. By the 21st postnatal day, collecting ducts and ureter no longer were labeled. In conclusion, calbindin-D28k mRNA is present in the developing mouse kidney, and its distribution during nephrogenesis is identical to that of calbindin-D28k per se. Collectively, these findings show that the calbindin-D28k gene is transcribed and its message is translated by the cells of the ureteric bud during the initial stage of renal morphogenesis
Path integrals on a flux cone
This paper considers the Schroedinger propagator on a cone with the conical
singularity carrying magnetic flux (``flux cone''). Starting from the operator
formalism and then combining techniques of path integration in polar
coordinates and in spaces with constraints, the propagator and its path
integral representation are derived. "Quantum correction" in the Lagrangian
appears naturally and no a priori assumption is made about connectivity of the
configuration space.Comment: LaTeX file, 9 page
Aspects of classical and quantum motion on a flux cone
Motion of a non-relativistic particle on a cone with a magnetic flux running
through the cone axis (a ``flux cone'') is studied. It is expressed as the
motion of a particle moving on the Euclidean plane under the action of a
velocity-dependent force. Probability fluid (``quantum flow'') associated with
a particular stationary state is studied close to the singularity,
demonstrating non trivial Aharonov-Bohm effects. For example, it is shown that
near the singularity quantum flow departs from classical flow. In the context
of the hydrodynamical approach to quantum mechanics, quantum potential due to
the conical singularity is determined and the way it affects quantum flow is
analysed. It is shown that the winding number of classical orbits plays a role
in the description of the quantum flow. Connectivity of the configuration space
is also discussed.Comment: LaTeX file, 21 pages, 8 figure
Recovery of adrenal insufficiency is frequent after adjuvant mitotane therapy in patients with adrenocortical carcinoma
Mitotane is a steroidogenesis inhibitor and adrenolytic drug used for treatment of adrenocortical cancer (ACC). Mitotane therapy causes adrenal insufficiency requiring glucocorticoid replacement in all patients. However, it is unclear whether chronic therapy with mitotane induces complete destruction of zona fasciculata and whether hypothalamic-pituitary-adrenal (HPA) axis can recover after treatment cessation. Our objective was to assess the HPA axis recovery in a cohort of patients after cessation of adjuvant mitotane therapy for ACC. We retrospectively reviewed patient files with stage I-II-III ACC in two referral centers in Canada and Italy. Data on demographics, tumor characteristics, hormonal profile, and HPA axis were collected. Data from 23 patients with pathologically proven ACC treated with adjuvant mitotane for a minimum of two years were analyzed. Eight patients were males and 15 were females and the median age was 41 years old (range 18 to 73). After mitotane cessation, 18/23 (78.3%) patients achieved a complete HPA axis recovery while 3/23 (13.0%) were unable to tolerate glucocorticoid withdrawal despite having normal hormonal test values and 2/23 (8.7%) never achieved recovery. The mean time interval between mitotane cessation and HPA axis recovery was 2.7 years. A high proportion of patients achieved HPA axis recovery following cessation of mitotane adjuvant therapy. However, complete recovery was often delayed up to 2.5 years and regular assessment of the hormonal profile is required
Treatment of nephrotic syndrome with adrenocorticotropic hormone (ACTH) gel
Andrew S Bomback1, James A Tumlin2, Joel Baranski3, James E Bourdeau4, Anatole Besarab5, Alice S Appel1, Jai Radhakrishnan1, Gerald B Appel11Department of Medicine, Division of Nephrology, Columbia University College of Physicians and Surgeons, New York, NY, USA; 2Department of Internal Medicine, Division of Nephrology, University of Tennessee College of Medicine in Chattanooga, Chattanooga, TN, USA; 3Balboa Nephrology Medical Group, San Diego, CA, USA; 4Nephrology Specialists of Oklahoma, Tulsa, OK, USA; 5Department of Medicine, Division of Nephrology and Hypertension, Henry Ford Health System, Detroit, MI, USAPurpose: A synthetic adrenocorticotropin (ACTH) analog has shown efficacy in Europe as primary and secondary therapy for nephrotic syndrome, but there is no published experience using the natural, highly purified ACTH gel formulation, available in the United States, for nephrotic syndrome. We therefore investigated the use of ACTH gel for nephrotic syndrome in the United States.Patients and methods: Twenty-one patients with nephrotic syndrome treated with ACTH gel outside of research settings in the United States, with initiation of therapy by December 31, 2009, allowing a minimum 6 months follow-up. We defined complete remission as stable renal function with proteinuria falling to <500 mg/day, and partial remission as stable renal function with >50% reduction in proteinuria from 500 to 3500 mg/day.Results: Twenty-one patients with nephrotic syndrome were treated: 11 with idiopathic membranous nephropathy (iMN), 4 with membranoproliferative glomerulonephritis (MPGN), 1 with focal segmental glomerulosclerosis (FSGS), 1 with minimal change disease (MCD), 1 with immunoglobulin A (IgA) nephropathy, 1 with class V systemic lupus erythematosus (SLE) glomerulonephritis, 1 with monoclonal diffuse proliferative glomerulonephritis, and 1 with unbiopsied nephrotic syndrome. ACTH was used as primary therapy for 3 patients; the remaining patients had previously failed a mean 2.3 immunosuppressive regimens. Eleven patients achieved a complete or partial remission, with 4 (19%) in complete remission. Of the 11 patients who achieved remission, 9 had iMN, 1 had FSGS, and 1 had IgA nephropathy. Of the 11 patients with iMN, 3 (27%) achieved complete remission and 6 (55%) achieved partial remission despite having previously failed a mean 2.4 therapies. Five patients reported steroid-like adverse effects, but there were no severe infections. The limitations were retrospective data analysis with short-term follow-up.Conclusion: ACTH gel may be a viable treatment option for resistant nephrotic syndrome due to membranous nephropathy. Short-term data suggest that remission rates may approach 80%.Keywords: nephrotic syndrome, membranous nephropathy, chronic kidney diseas
Finite-size anyons and perturbation theory
We address the problem of finite-size anyons, i.e., composites of charges and
finite radius magnetic flux tubes. Making perturbative calculations in this
problem meets certain difficulties reminiscent of those in the problem of
pointlike anyons. We show how to circumvent these difficulties for anyons of
arbitrary spin. The case of spin 1/2 is special because it allows for a direct
application of perturbation theory, while for any other spin, a redefinition of
the wave function is necessary. We apply the perturbative algorithm to the
N-body problem, derive the first-order equation of state and discuss some
examples.Comment: 18 pages (RevTex) + 4 PS figures (all included); a new section on
equation of state adde
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