436 research outputs found

    Time dependent partial waves and vortex rings in the dynamics of wave packets

    Get PDF
    We have found a new class of time dependent partial waves which are solutions of time dependent Schr\"odinger equation for three dimensional harmonic oscillator. We also showed the decomposition of coherent states of harmonic oscillator into these partial waves. This decomposition appears perticularly convenient for a description of the dynamics of a wave packet representing a particle with spin when the spin--orbit interaction is present in the hamiltonian. An example of an evolution of a localized wave packet into a torus and backwards, for a particular initial conditions is analysed in analytical terms and shown with a computer graphics.Comment: 10 pages, LaTeX, 6 postscript figures, submitted to J. Phys. A: Math. Ge

    Mathematical modelling long-term effects of replacing Prevnar7 with Prevnar13 on invasive pneumococcal diseases in England and Wales

    Get PDF
    England and Wales recently replaced the 7-valent pneumococcal conjugate vaccine (PCV7) with its 13-valent equivalent (PCV13), partly based on projections from mathematical models of the long-term impact of such a switch compared to ceasing pneumococcal conjugate vaccination altogether. A compartmental deterministic model was used to estimate parameters governing transmission of infection and competition between different groups of pneumococcal serotypes prior to the introduction of PCV13. The best-fitting parameters were used in an individual based model to describe pneumococcal transmission dynamics and effects of various options for the vaccination programme change in England and Wales. A number of scenarios were conducted using (i) different assumptions about the number of invasive pneumococcal disease cases adjusted for the increasing trend in disease incidence prior to PCV7 introduction in England and Wales, and (ii) a range of values representing serotype replacement induced by vaccination of the additional six serotypes in PCV13. Most of the scenarios considered suggest that ceasing pneumococcal conjugate vaccine use would cause an increase in invasive pneumococcal disease incidence, while replacing PCV7 with PCV13 would cause an overall decrease. However, the size of this reduction largely depends on the level of competition induced by the additional serotypes in PCV13. The model estimates that over 20 years of PCV13 vaccination, around 5000–62000 IPD cases could be prevented compared to stopping pneumococcal conjugate vaccination altogether. Despite inevitable uncertainty around serotype replacement effects following introduction of PCV13, the model suggests a reduction in overall invasive pneumococcal disease incidence in all cases. Our results provide useful evidence on the benefits of PCV13 to countries replacing or considering replacing PCV7 with PCV13, as well as data that can be used to evaluate the cost-effectiveness of such a switch

    Surgical Treatment with Locoregional Flap for the Nose

    Get PDF
    Nonmelanotic skin cancers (NMSCs) are the most frequent of all neoplasms and nasal pyramid represents the most common site for the presentation of such cutaneous malignancies, particularly in sun-exposed areas: ala, dorsum, and tip. Multiple options exist to restore functional and aesthetic integrity after skin loss for oncological reasons; nevertheless, the management of nasal defects can be often challenging and the best "reconstruction" is still to be found. In this study, we retrospectively reviewed a total of 310 patients who presented to our Department of Plastic and Reconstructive Surgery for postoncological nasal reconstruction between January 2011 and January 2016. Nasal region was classified into 3 groups according to the anatomical zones affected by the lesion: proximal, middle, and distal third. We included an additional fourth group for complex defects involving more than one subunit. Reconstruction with loco regional flaps was performed in all cases. Radical tumor control and a satisfactory aesthetic and functional result are the primary goals for the reconstructive surgeon. Despite tremendous technical enhancements in nasal reconstruction techniques, optimal results are usually obtained when "like is used to repair like." Accurate evaluation of the patients clinical condition and local defect should be always considered in order to select the best surgical option

    Glycogen synthesis by hepatocytes from diabetic rats

    Full text link

    Phase I trial of the combination of the Akt inhibitor nelfinavir and chemoradiation for locally advanced rectal cancer

    Get PDF
    PURPOSE: To investigate the toxicity of nelfinavir, administered during preoperative chemoradiotherapy (CRT) in patients with locally advanced cancer. MATERIAL AND METHODS: Twelve patients were treated with to 50.4Gy combined with capecitabine 825mg/m2 BID. Three dose levels nelfinavir were tested: 750mg BID (DL1), 1250mg BID (DL2) and an level of 1000mg BID (DL3). Surgery was performed between 8 and 10weeks completion of CRT. Primary endpoint was dose-limiting toxicity (DLT), any grade 3 or higher non-hematological or grade 4 or higher toxicity. RESULTS: Eleven patients could be analyzed: 5 were treated in DL2 and 3 in DL3. The first 3 patients in DL1 did not develop a DLT. In patient developed gr 3 diarrhea, 1 patient had gr 3 transaminase patient had a gr 3 cholangitis with unknown cause. An intermediate dose tested in DL3. In this group 2 patients developed gr 3 diarrhea and 1 3 transaminase elevation and gr 4 post-operative wound complication. patients achieved a pathological complete response (pCR). CONCLUSIONS: 750mg BID was defined as the recommended phase II dose in combination capecitabine and 50.4Gy pre-operative radiotherapy in rectal cancer. response evaluations are promising, but a further phase II study is more information about efficacy of this treatment regimen

    Learning through exchange about organic agriculture - case of Europe and Australia

    Get PDF
    LEAFSE is the catch word for an innovative program of exchange study for young Australians and Europeans, with organic agriculture as the focal point of their Masters level studies. Two years ago, the European Commission and the Australian Department of Education, Science and Technology (DEST) came up with the call for applications for a pilot project to support international mobility of tertiary students between the two continents. The grand aims set for the exchange included providing students with an international outlook and a range of perspectives, preparing them for the global marketplace, enable their understanding and empathy for different cultures and traditions and foster exchange of information. A number of us with an interest and an already existing academic network in organic agriculture proposed LEAFSE - Learning through Exchange - Agriculture, Food Systems and Environment, a winning project, which was chosen as the single pilot project from a field of well over a dozen contenders. Within the broader theme of Agriculture, Food Systems and Environment, we named organic farming as the focal point of the exchange, and we were aware of the immense possibilities for learning through exchange inter-continentally in this field. Under this project, Master's level students from EU study for a semester at a partner university in Australia, and students from Australia study for a semester at a partner university in EU. The partners in the programme are, from Europe: • The Royal Veterinary and Agricultural University, Denmark • University of Wales, Aberystwyth, United Kingdom • Wageningen University and Research Centre, The Netherlands • University of Kassel, Witzenhausen, Germany, and from Australia: • University of Western Sydney, New South Wales • University of New England, New South Wales • University of Western Australia, Western Australia • University of Queensland, Queensland The project has an innovative but manageable framework for mobility of the students, a joint programme of study which incorporates many novel elements including holistic thinking, experiential and integrated learning and use of newer tools of communication technologies, and above all, a structure that fosters a high degree of inter-cultural understanding and network building. When completed, the pilot phase of the project would have enabled exchange of 36 students from each continent, nine from each participating institution. The respective government agencies provide the students with an adequate stipend to cover travel and living expenses for six months of study. The project has been running on target and the results of the first year of exchange have been more than impressive. This presentation will be a joint effort by the faculty and a number of participating students to demonstrate the cultural, agricultural, pedagogic, and practical lessons that have been learnt from this exchange in the field of organic farming. It will also highlight some of the challenges which need to be overcome in our efforts towards shaping sustainable agricultural and food systems which are cognizant of our respective environments

    Elliptical Squeezed States and Rydberg Wave Packets

    Get PDF
    We present a theoretical construction for closest-to-classical wave packets localized in both angular and radial coordinates and moving on a keplerian orbit. The method produces a family of elliptical squeezed states for the planar Coulomb problem that minimize appropriate uncertainty relations in radial and angular coordinates. The time evolution of these states is studied for orbits with different semimajor axes and eccentricities. The elliptical squeezed states may be useful for a description of the motion of Rydberg wave packets excited by short-pulsed lasers in the presence of external fields, which experiments are attempting to produce. We outline an extension of the method to include certain effects of quantum defects appearing in the alkali-metal atoms used in experiments.Comment: published in Phys. Rev. A, vol. 52, p. 2234, Sept. 199

    Analytic results for Gaussian wave packets in four model systems: II. Autocorrelation functions

    Full text link
    The autocorrelation function, A(t), measures the overlap (in Hilbert space) of a time-dependent quantum mechanical wave function, psi(x,t), with its initial value, psi(x,0). It finds extensive use in the theoretical analysis and experimental measurement of such phenomena as quantum wave packet revivals. We evaluate explicit expressions for the autocorrelation function for time-dependent Gaussian solutions of the Schrodinger equation corresponding to the cases of a free particle, a particle undergoing uniform acceleration, a particle in a harmonic oscillator potential, and a system corresponding to an unstable equilibrium (the so-called `inverted' oscillator.) We emphasize the importance of momentum-space methods where such calculations are often more straightforwardly realized, as well as stressing their role in providing complementary information to results obtained using position-space wavefunctions.Comment: 18 pages, RevTeX, to appear in Found. Phys. Lett, Vol. 17, Dec. 200

    Keplerian Squeezed States and Rydberg Wave Packets

    Get PDF
    We construct minimum-uncertainty solutions of the three-dimensional Schr\"odinger equation with a Coulomb potential. These wave packets are localized in radial and angular coordinates and are squeezed states in three dimensions. They move on elliptical keplerian trajectories and are appropriate for the description of the corresponding Rydberg wave packets, the production of which is the focus of current experimental effort. We extend our analysis to incorporate the effects of quantum defects in alkali-metal atoms, which are used in experiments.Comment: accepted for publication in Physical Review
    • …
    corecore