3,198 research outputs found

    Modeling of composite beams and plates for static and dynamic analysis

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    The main purpose of this research was to develop a rigorous theory and corresponding computational algorithms for through-the-thickness analysis of composite plates. This type of analysis is needed in order to find the elastic stiffness constants for a plate and to post-process the resulting plate solution in order to find approximate three-dimensional displacement, strain, and stress distributions throughout the plate. This also requires the development of finite deformation plate equations which are compatible with the through-the-thickness analyses. After about one year's work, we settled on the variational-asymptotical method (VAM) as a suitable framework in which to solve these types of problems. VAM was applied to laminated plates with constant thickness in the work of Atilgan and Hodges. The corresponding geometrically nonlinear global deformation analysis of plates was developed by Hodges, Atilgan, and Danielson. A different application of VAM, along with numerical results, was obtained by Hodges, Lee, and Atilgan. An expanded version of this last paper was submitted for publication in the AIAA Journal

    Response to Review by Terrance Sandalow

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    Mark Twain tried to convey the size and complexity of the Mississippi by explaining to his readers that the river draws its water from every state between Delaware and Idaho, discharges 338 times as much water as the Thames, and is fed by 54 subordinate rivers each of which was large enough for steamboat travel

    Phase transition between d-wave and anisotropic s-wave gaps in high temperature oxides superconductors

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    We study models for superconductivity with two interactions: V>V^> due to antiferromagnetic(AF) fluctuations and V<V^< due to phonons, in a weak coupling approach to the high temperature superconductivity. The nature of the two interactions are considerably different; V>V^> is positive and sharply peaked at (±π\pm\pi,±π \pm\pi) while V<V^< is negative and peaked at (0,00,0) due to weak phonon screening. We numerically find (a) weak BCS attraction is enough to have high critical temperature if a van Hove anomaly is at work, (b) V>V^> (AF) is important to give d-wave superconductivity, (c) the gap order parameter Δ(k)\Delta({\bf k}) is constant(s-wave) at extremely overdope region and it changes to anisotropic s-wave as doping is reduced, (d) there exists a first order phase transition between d-wave and anisotropic s-wave gaps. These results are qualitatively in agreement with preceding works; they should be modified in the strongly underdope region by the presence of antiferromagnetic fluctuations and ensuing AF pseudogap.Comment: 4 pages in RevTex (double column), 4 figure

    Methicillin resistant S. aureus (MRSA) and their antibiotic sensitivity pattern in Kano, Nigeria

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    Background: Nosocomial infection caused by methicillin resistant S. aureus (MRSA) presents with management difficulties in infected patients due to their resistance to a number of other frontline antibiotics and constitutessignificant epidemiological problems. This study was undertaken to determine the prevalence of methicillin resistant S. aureus and antibiotic sensitivity pattern in clinical isolates in Kano. There is dearth of  information onthis subject in Kano.Method: One hundred and eighty five (185) S. aureus isolates from various clinical specimens obtained over a 12-month period in the Microbiology Department of Aminu Kano Teaching Hospital (AKTH) were subjected to methicillin susceptibility testing, while including susceptibility testing to other antibiotics by the disc diffusion methods.Result: Out of 185 S. aureus isolates tested, 53(28.6%) were found to be methicillin resistant. While 38(62%) isolates were obtained from in-patients, 15(28%) were from out-patients. Surgical wound infection had the highest prevalence of 32(60%) isolates. Antibiotics sensitivity results of methicillin susceptible staphylococcus aureus MSSA) and MRSA with the third generation cephalosporins and the quinilones were encouraging. AllMRSA isolates were sensitive to vancomycin.Conclusion: A prevalence of 28.6% MRSA in this environment calls for urgent intervention strategies due to its possible rapid spread and therapeutic problem

    Study of the kinetics of antibodies titres against viral pathogens and detection of rotavirus and parainfluenza 3 infections in captive crias of guanacos (Lama guanicoe)

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    A longitudinal study was conducted to investigate the presence of antibodies (Ab) to Rotavirus (RV), Parainfluenza-3 virus (PI-3), Bovine Herpesvirus-1 (BoHV-1), Bovine Viral Diarrhoea virus (BVDV-1) and Bluetongue virus (BTV) in eleven guanaco's crias (chulengos) relocated from Rio Negro to Buenos Aires Province (Argentina) and reared in captivity for a year in an experimental field. Serum samples were collected periodically to detect the evidence of viral infections. Faecal samples were collected to investigate RV shedding. We detected the evidence of Ab to RV from the beginning of the experience, suggesting the presence of maternal Ab against the virus. RV infection was detected in seven of the eleven chulengos, by seroconversion (4), virus shedding in stools (1) or both (2). In all cases, the RV strain was typed as [P1]G8, the same G/P type combination detected in captive chulengos with acute diarrhoea sampled in Rio Negro, in 2001. In contrast, we could not detect antibodies against PI-3, BoHV-1, BVDV or BT in any of initial samples. No Abs against BoHV-1, BVDV or BTV were detected in the chulengos throughout the study. However, all the chulengos became asymptomatically seropositive to PI-3 by the 7 month after arrival. This study suggest that wild-born guanacos raised in captivity can be relatively susceptible to common livestock viral infections, such as RV and PI-3, which are easily spread among chulengos.Fil: Marcoppido, G.. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Virología; ArgentinaFil: Olivera, Valeria. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Patobiología; ArgentinaFil: Bok, Karin. Dirección Nacional de Instituto de Investigación.Administración Nacional de Laboratorios e Institutos de Salud "Dr. Carlos G. Malbrán"; ArgentinaFil: Parreño, Gladys Viviana. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Virología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

    Argentinean agid test for diagnosis of equine infectious anemia: six years of history

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    Equine infectious anemia (EIA) is a disease of high economic impact on the equine industry worldwide. Since horses are frequent travelers, EIA falls under strict regulatory control programs in many countries. In Argentina the national animal health authority (SENASA) states that all horses imported, moving within the country, or congregating at public assemblies must have a negative EIA report conducted within the previous 2 months. The agent causing EIA is a RNA virus from the Retroviridae family and its major capsid protein named p26 is the most immunogenic protein in the viral particle. Thus, the detection of specific antibodies directed to p26 is the aim of most diagnosis tests available in the world. The agar gel immunodifusion (AGID) is the officially accepted method to certify the diagnosis of EIA in Argentina. Since 2009 IncuINTA was working on the scaling up and production of the KIT AIE IDGA RP26, an Argentinean AGID test entirely developed in the laboratory containing a recombinant p26 protein to detect EIA antibodies in horses’ serum. Until 2015 IncuINTA produced two pilot batches and six commercial batches (one per year) containing from 24000 determinations in 2011 to 39600 determinations in 2015. Since the product was launched in 2011, the sales were increased 109%. Up to date we have placed on the market 170640 determinations. As expected, the number of laboratories buying the KIT AIE IDGA RP26 was also increasing through time being 26 in 2011 and 36 in 2015. This number of clients represents 17% of the 207 laboratories authorized by SENASA to diagnose EIA in Argentina. These laboratories are located mostly in Buenos Aires, Santa Fe, Entre Ríos, Formosa, La Pampa, Rio Negro, Cordoba, Corrientes, Salta and Tucum an provinces. Until 2009 there was no Argentinean EIA test available in our market being the imported ones very expensive. IncuINTA, which is a R&D laboratory, could scale up, produce and sell the KIT AIE IDGA RP26 during six consecutive years. After this success, IncuINTA perspective is to increase the number of batches each year to be able to attend the demand of most diagnosis laboratories in the country.Fil: Bok, Marina. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Virología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Asenzo, G.. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Virología; ArgentinaFil: Vena, M. M.. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Virología; ArgentinaFil: Parreño, V.. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Virología; ArgentinaFil: Wigdorovitz, A.. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Virología; Argentina10th International Equine Infectious Diseases ConferenceBuenos AiresArgentinaUniversity of Kentuck

    Spin-triplet superconductivity in quasi-one dimension

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    We consider a system with electron-phonon interaction, antiferromagnetic fluctuations and disconnected open Fermi surfaces. The existence of odd-parity superconductivity in this circumstance is shown for the first time. If it is applied to the quasi-one-dimensional systems like the organic conductors (TMTSF)_2X we obtain spin-triplet superconductivity with nodeless gap. Our result is also valid in higher dimensions(2d and 3d).Comment: 2 page

    How Cereal Grass Shoots Perceive And Respond To Gravity

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    Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/141646/1/ajb208758.pd
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