835 research outputs found

    Geometric Stability Analysis for Periodic Solutions of the Swift-Hohenberg Equation

    Full text link
    In this paper we describe invariant geometrical ~structures in the phase space of the Swift-Hohenberg equation in a neighborhood of its periodic stationary states. We show that in spite of the fact that these states are only marginally stable (i.e., the linearized problem about these states has continuous spectrum extending all the way up to zero), there exist finite dimensional invariant manifolds in the phase space of this equation which determine the long-time behavior of solutions near these stationary solutions. In particular, using this point of view, we obtain a new demonstration of Schneider's recent proof that these states are nonlinearly stable.Comment: 44 pages, plain tex, 0 figure

    Dynamic general equilibrium analysis of improved weed management in Australia's winter cropping systems

    Get PDF
    A recent analysis indicated that the direct financial cost of weeds to Australia’s winter grain sectorwas approximately A1.2bnin19981999.Costsofthismagnituderepresentalargerecurringproductivitylossinanagriculturalsectorthatissufficienttoimpactsignificantlyonregionaleconomies.Usingamultiregionaldynamiccomputablegeneralequilibriummodel,wesimulatethegeneralequilibriumeffectsofahypotheticalsuccessfulcampaigntoreducetheeconomiccostsofweeds.WeassumethatanadditionalA1.2bn in 1998–1999. Costs of thismagnitude represent a large recurring productivity loss in an agricultural sector that is sufficient to impact significantly on regional economies.Using amulti-regional dynamic computable general equilibrium model, we simulate the general equilibrium effects of a hypothetical successful campaign to reduce the economic costs of weeds. We assume that an additional 50m of R&D spread over five years is targeted at reducing the additional costs and reduced yields arising from weeds in various broadacre crops. Following this R&D effort, one-tenth of the losses arising from weeds is temporarily eliminated, with a diminishing benefit in succeeding years. At the national level, there is a welfare increase of $700m in discounted net present value terms. The regions with relatively high concentrations of winter crops experience small temporary macroeconomic gains.CGE modelling, dynamics, weed management, Crop Production/Industries,

    Physical Models of Atmospheric Boundary Layer Flows: Some Developments and Recent Applications

    Get PDF
    Experimental studies on wind engineering require the use of different types of physical models of boundary layer flows. Small-scale models obtained in a wind tunnel, for example, attempt to reproduce real atmosphere phenomena like wind loads on structures and pollutant dispersion by the mean flow and turbulent mixing. The quality of the scale model depends on the similarity between the laboratory-generated flow and the atmospheric flow. Different types of neutral atmospheric boundary layer (ABL) including full-depth and part-depth simulations are experimentally evaluated. The Prof. Jacek Gorecki wind tunnel of the UNNE, Argentina, and the Prof. Joaquim Blessmann closed-return wind tunnel of the UFRGS, Brazil, were used to obtain the experimental data. Finally, some recent wind engineering applications of this type of physical wind models are shown

    Cross-site assessment of road design packages

    Get PDF
    This report develop a concept for evaluating alternative design solutions for urban streets: the Street Performance Assessment Scheme. It should be generally valid and applicable to any redesign task, to compare the performance of a road/street section: (1) with the goals formulated for each case study, (2) in situations before and after the implementation of a redesign solution, and (3) between different case studies in cross-site assessments. In this report, the Street Performance Assessment Scheme is applied to streets in five European cities. These streets have major movement and 'place' functions and have limited space availabilities, and are thus typical examples for the most challenging design tasks that urban street designers face

    Ascorbic acid (Vitamin C) content of tomatoes and apples

    Get PDF
    Report on Department of Horticulture Research Project No. 212, entitled, 'Conservation of nutritive value of foods'--P. [2].Digitized 2007 AES.Includes bibliographical references (pages 21-24)

    A Home-Based, Music-Cued Movement Program Is Feasible and May Improve Gait in Progressive Supranuclear Palsy

    Get PDF
    Objectives: To understand the benefits and feasibility of using supervised, home-based, music-cued training to improve gait speed and stability in community-dwelling people with Progressive Supranuclear Palsy.Design: Feasibility trial incorporating a single group repeated-measures design.Setting: Human movement laboratory and participants' homes.Interventions:Two training sessions per week, conducted by experienced physiotherapists over 4 weeks. Each home training session consisted of a range of activities in standing or walking, with, and without auditory cues. Rhythmic auditory cues were played via a portable digital music player and consisted of metronome beats and individually chosen, commercially available rhythmic music tracks.Main Outcome Measures: Spatiotemporal gait measures were recorded using an 8 m long GAITRite® mat. Participants walked without cues at self-selected comfortable pace. The Progressive Supranuclear Palsy and Unified Parkinson's Disease Rating Scales were administered at baseline. Addenbrooke's Cognitive Examination-III, Geriatric Depression Scale, Assessment of Personal Music Preference Scale, and Physiological Profile Assessment were administered at baseline and retest.Results: At baseline, two of the five community-dwelling participants with Progressive Supranuclear Palsy walked with normal speed and low gait variability. Of the remainder who walked with slower, more variable patterns, two walked faster at retest, one by a clinically meaningful amount. Four participants reduced their timing variability at retest and three reduced step length variability. All participants reported high satisfaction levels with the program.Conclusions: When delivered at home with the support of caregivers, music-cued gait training can provide a feasible approach to improving disorders of gait stability in people with this rare, degenerative condition. Movement to music is engaging and enjoyable which can facilitate adherence to therapy.Clinical Trial Registration : ANZCTR 12616000851460. http://www.anzctr.org.au

    Few-cycle pulses from a graphene mode-locked all-fiber laser

    Get PDF
    We combine a graphene mode-locked oscillator with an external compressor and achieve~29fs pulses with~52mW average power. This is a simple, low-cost, and robust setup, entirely fiber based, with no free-space optics, for applications requiring high temporal resolution

    Impact of cerebral hypoperfusion-reperfusion on optic nerve integrity and visual function in the DBA/2J mouse model of glaucoma.

    Get PDF
    OBJECTIVE One of the most important risk factors for developing a glaucomatous optic neuropathy is elevated intraocular pressure. Moreover, mechanisms such as altered perfusion have been postulated to injure the optical path. In a mouse model, we compare first negative effects of cerebral perfusion/reperfusion on the optic nerve structure versus alterations by elevated intraocular pressure. Second, we compare the alterations by isolated hypoperfusion-reperfusion and isolated intraocular pressure to the combination of both. METHODS AND ANALYSIS Mice were divided in four groups: (1) controls; (2) perfusion altered mice that underwent transient bi-common carotid artery occlusion (BCCAO) for 40 min; (3) glaucoma group (DBA/2J mice); (4) combined glaucoma and altered perfusion (DBA/2J mice with transient BCCAO). Optic nerve sections were stereologically examined 10-12 weeks after intervention. RESULTS All experimental groups showed a decreased total axon number per optic nerve compared with controls. In DBA/2J and combined DBA/2J & BCCAO mice the significant decrease was roughly 50%, while BCCAO leaded to a 23% reduction of axon number, however reaching significance only in the direct t-test. The difference in axon number between BCCAO and both DBA/2J mice was almost 30%, lacking statistical significance due to a remarkably high variation in both DBA/2J groups. CONCLUSION Elevated intraocular pressure in the DBA/2J mouse model of glaucoma leads to a much more pronounced optic nerve atrophy compared with transient forebrain hypoperfusion and reperfusion by BCCAO. A supposed worsening effect of an altered perfusion added to the pressure-related damage could not be detected

    Detection of monoclonal immunoglobulin heavy chain gene rearrangement (FR3) in Thai malignant lymphoma by High Resolution Melting curve analysis

    Get PDF
    <p>Abstract</p> <p>Malignant lymphoma, especially non-Hodgkin lymphoma, is one of the most common hematologic malignancies in Thailand. The diagnosis of malignant lymphoma is often problematic, especially in early stages of the disease. Detection of antigen receptor gene rearrangement including T cell receptor (TCR) and immunoglobulin heavy chain (IgH) by polymerase chain reaction followed by heteroduplex has currently become standard whereas fluorescent fragment analysis (GeneScan) has been used for confirmation test. In this study, three techniques had been compared: thermocycler polymerase chain reaction (PCR) followed by heteroduplex and polyacrylamide gel electrophoresis, GeneScan analysis, and real time PCR with High Resolution Melting curve analysis (HRM). The comparison was carried out with DNA extracted from paraffin embedded tissues diagnosed as B- cell non-Hodgkin lymphoma. Specific PCR primers sequences for IgH gene variable region 3, including fluorescence labeled IgH primers were used and results were compared with HRM. In conclusion, the detection IgH gene rearrangement by HRM in the LightCycler System showed potential for distinguishing monoclonality from polyclonality in B-cell non-Hodgkin lymphoma.</p> <p>Introduction</p> <p>Malignant lymphoma, especially non-Hodgkin lymphoma, is one of the most common hematologic malignancies in Thailand. The incidence rate as reported by Ministry of Public Health is 3.1 per 100,000 population in female whereas the rate in male is 4.5 per 100,000 population <abbrgrp><abbr bid="B1">1</abbr></abbrgrp>. At Siriraj Hospital, the new cases diagnosed as malignant lymphoma were 214.6 cases/year <abbrgrp><abbr bid="B2">2</abbr></abbrgrp>. The diagnosis of malignant lymphoma is often problematic, especially in early stages of the disease. Therefore, detection of antigen receptor gene rearrangement including T cell receptor (TCR) and immunoglobulin heavy chain (IgH) by polymerase chain reaction (PCR) assay has recently become a standard laboratory test for discrimination of reactive from malignant clonal lymphoproliferation <abbrgrp><abbr bid="B3">3</abbr><abbr bid="B4">4</abbr></abbrgrp>. Analyzing DNA extracted from formalin-fixed, paraffin-embedded tissues by multiplex PCR techniques is more rapid, accurate and highly sensitive. Measuring the size of the amplicon from PCR analysis could be used to diagnose malignant lymphoma with monoclonal pattern showing specific and distinct bands detected on acrylamide gel electrophoresis. However, this technique has some limitations and some patients might require a further confirmation test such as GeneScan or fragment analysis <abbrgrp><abbr bid="B5">5</abbr><abbr bid="B6">6</abbr></abbrgrp>.</p> <p>GeneScan technique or fragment analysis reflects size and peak of DNA by using capillary gel electrophoresis. This technique is highly sensitive and can detect 0.5-1% of clonal lymphoid cells. It measures the amplicons by using various fluorescently labeled primers at forward or reverse sides and a specific size standard. Using a Genetic Analyzer machine and GeneMapper software (Applied Bioscience, USA), the monoclonal pattern revealed one single, sharp and high peak at the specific size corresponding to acrylamide gel pattern, whereas the polyclonal pattern showed multiple and small peak condensed at the same size standard. This technique is the most sensitive and accurate technique; however, it usually requires high technical experience and is also of high cost <abbrgrp><abbr bid="B7">7</abbr></abbrgrp>. Therefore, rapid and more cost effective technique are being sought.</p> <p>LightCycler PCR performs the diagnostic detection of amplicon via melting curve analysis within 2 hours with the use of a specific dye <abbrgrp><abbr bid="B8">8</abbr><abbr bid="B9">9</abbr></abbrgrp>. This dye consists of two types: one known as SYBR-Green I which is non specific and the other named as High Resolution Melting analysis (HRM) which is highly sensitive, more accurate and stable. Several reports demonstrated that this new instrument combined with DNA intercalating dyes can be used to discriminate sequence changes in PCR amplicon without manual handling of PCR product <abbrgrp><abbr bid="B10">10</abbr><abbr bid="B11">11</abbr></abbrgrp>. Therefore, current investigations using melting curve analysis are being developed <abbrgrp><abbr bid="B12">12</abbr><abbr bid="B13">13</abbr></abbrgrp>.</p> <p>In this study, three different techniques were compared to evaluate the suitability of LightCycler PCR with HRM as the clonal diagnostic tool for IgH gene rearrangement in B-cell non-Hogdkin lymphoma, i.e. thermocycler PCR followed by heteroduplex analysis and PAGE, GeneScan analysis and LightCycler PCR with HRM.</p
    corecore