142 research outputs found
Uniform WKB approximation of Coulomb wave functions for arbitrary partial wave
Coulomb wave functions are difficult to compute numerically for extremely low
energies, even with direct numerical integration. Hence, it is more convenient
to use asymptotic formulas in this region. It is the object of this paper to
derive analytical asymptotic formulas valid for arbitrary energies and partial
waves. Moreover, it is possible to extend these formulas for complex values of
parameters.Comment: 5 pages, 2 figure
FooPar: A Functional Object Oriented Parallel Framework in Scala
We present FooPar, an extension for highly efficient Parallel Computing in
the multi-paradigm programming language Scala. Scala offers concise and clean
syntax and integrates functional programming features. Our framework FooPar
combines these features with parallel computing techniques. FooPar is designed
modular and supports easy access to different communication backends for
distributed memory architectures as well as high performance math libraries. In
this article we use it to parallelize matrix matrix multiplication and show its
scalability by a isoefficiency analysis. In addition, results based on a
empirical analysis on two supercomputers are given. We achieve close-to-optimal
performance wrt. theoretical peak performance. Based on this result we conclude
that FooPar allows to fully access Scala's design features without suffering
from performance drops when compared to implementations purely based on C and
MPI
Asymptotic equivalence of discretely observed diffusion processes and their Euler scheme: small variance case
This paper establishes the global asymptotic equivalence, in the sense of the
Le Cam -distance, between scalar diffusion models with unknown drift
function and small variance on the one side, and nonparametric autoregressive
models on the other side. The time horizon is kept fixed and both the cases
of discrete and continuous observation of the path are treated. We allow non
constant diffusion coefficient, bounded but possibly tending to zero. The
asymptotic equivalences are established by constructing explicit equivalence
mappings.Comment: 21 page
Splenectomy through the laparoscopic approach and how I do it
Scopul lucrării. Studierea cazurilor de splenectomie prin abord laparoscopic și clasic în vederea stabilirii cauzalității tip procedurăincidente
perioperatorii și demonstrării superiorității abordului laparoscopic.
Materiale și metode. Au fost selectate cazurile de splenectomie efectuate prin abord clasic și laparoscopic în Clinica de Chirurgie
Colțea, perioada 01.01.2019-31.12.2022. Am revăzut filmările intraoperatorii, am evaluat factorii generali și locali asociați abordului
chirurgical preferat.
Rezultate. Au fost selectate 29 de cazuri, vârsta medie 54.8 ani, 72.4% femei, 27.6% barbati, 55.2% (16) cu multiple comorbidități:
antecedente chirurgicale majore, insuficiența cardiacă, asmul bronșic sever etc. Cazurile au fost împărțite în 2 grupe: Gr. I- cu abord
laparoscopic 34.5% (10), Gr. II- cu abord clasic 65.5% (19). Incidența comorbidităților a fost de 10% (1) în Gr.I, cu dimensiunea medie
a splinei de 13.2 cm (min 8.5 cm, max 21 cm) și 84.2 % (16) în Gr.II cu dimensiunea medie a splinei de 20.4 cm (min 10 cm, max 34
cm). Doar în Gr.II au fost înregistrate sângerări intraoperatorii în 78.9% (15), iar in 15.8% (3) au fost complicații postoperatorii. Pacienții
din Gr.I au avut o perioadă de spitalizare postoperatorie medie de 4 zile, iar cei din Gr. II de 7 zile și au fost externați cu o evoluție
postoperatorie favorabilă.
Concluzie. Abordul laparoscopic are aceleași indicații ca abordul clasic conform EAES, cu avantajul complicațiilor perioperatorii mult
reduse și o spitalizare postoperatorie mai mică comparativ cu abordul clasic, iar în cazul echipelor experimentate este posibil abordul
laparoscopic inclusiv la pacienții cu splenomegalii masive (>20cm), care poate fi asistat manual.Aim of study. Study of cases of splenectomy by laparoscopic and classic approach in order to establish causality type procedureperioperative
incidents and demonstrate the superiority of the laparoscopic approach.
Materials and methods. The cases of splenectomy performed by classical and laparoscopic approach in the Colțea Surgery Clinic,
period 01.01.2019-31.12.2022, were selected. We reviewed intraoperative films, assessed general and local factors associated with
the preferred surgical approach.
Results. 29 cases were selected, average age 54.8 years, 72.4% women, 27.6% men, 55.2% (16) with multiple comorbidities: major
surgical antecedents, heart failure, severe bronchial asthma, etc. The cases were divided into 2 groups: Gr. I- with laparoscopic approach 34.5% (10), Gr. II- with classic approach 65.5% (19). The incidence of comorbidities was 10% (1) in Gr.I, with mean spleen
size of 13.2 cm (min 8.5 cm, max 21 cm) and 84.2% (16) in Gr.II with mean spleen size of 20.4 cm (min 10 cm, max 34 cm). Only in
Gr.II, intraoperative bleeding was recorded in 78.9% (15), and in 15.8% (3) there were postoperative complications. The patients in Gr.
I had an average postoperative hospitalization period of 4 days, and those in Gr. II of 7 days, and were discharged with a favorable
postoperative evolution.
Conclusions. The laparoscopic approach has the same indications as the classic one according to EAES, with the advantage
of reduced perioperative complications and a shorter postoperative hospitalization, and in the case of experienced teams, the
laparoscopic approach is possible, including patients with massive splenomegaly (>20cm), being manually assisted
A Comparison of Wood Density between Classical Cremonese and Modern Violins
Classical violins created by Cremonese masters, such as Antonio Stradivari and Giuseppe Guarneri Del Gesu, have become the benchmark to which the sound of all violins are compared in terms of their abilities of expressiveness and projection. By general consensus, no luthier since that time has been able to replicate the sound quality of these classical instruments. The vibration and sound radiation characteristics of a violin are determined by an instrument's geometry and the material properties of the wood. New test methods allow the non-destructive examination of one of the key material properties, the wood density, at the growth ring level of detail. The densities of five classical and eight modern violins were compared, using computed tomography and specially developed image-processing software. No significant differences were found between the median densities of the modern and the antique violins, however the density difference between wood grains of early and late growth was significantly smaller in the classical Cremonese violins compared with modern violins, in both the top (Spruce) and back (Maple) plates (p = 0.028 and 0.008, respectively). The mean density differential (SE) of the top plates of the modern and classical violins was 274 (26.6) and 183 (11.7) gram/liter. For the back plates, the values were 128 (2.6) and 115 (2.0) gram/liter. These differences in density differentials may reflect similar changes in stiffness distributions, which could directly impact vibrational efficacy or indirectly modify sound radiation via altered damping characteristics. Either of these mechanisms may help explain the acoustical differences between the classical and modern violins
Stimuli Thresholds for Isomerization-Induced Molecular Motions in Azobenzene-Containing Materials.
We use large-scale molecular dynamics simulations of the isomerizations of azobenzene molecules diluted inside a simple molecular material to investigate the effect of a modification of the cis isomer shape on the induced diffusion mechanism. To this end we simulate incomplete isomerizations, modifying the amplitude of the trans-to-cis isomerization. We find thresholds in the evolution of the host molecules mobility with the isomerization amplitude, a result predicted by the cage-breaking mechanism hypothesis (Teboul, V.; Saiddine, M.; Nunzi, J. M.; Accary, J. B. J. Chem. Phys. 2011, 134, 114517) and by the gradient pressure mechanism theory (Barrett, C. J.; Rochon, P. L.; Natansohn, A. L. J. Chem. Phys. 1998, 109, 1505–1516.). Above the threshold the diffusion then increases linearly with the variation of the chromophore size induced by the isomerization
Consumer input into research: the Australian Cancer Trials website
<p>Abstract</p> <p>Background</p> <p>The Australian Cancer Trials website (ACTO) was publicly launched in 2010 to help people search for cancer clinical trials recruiting in Australia, provide information about clinical trials and assist with doctor-patient communication about trials. We describe consumer involvement in the design and development of ACTO and report our preliminary patient evaluation of the website.</p> <p>Methods</p> <p>Consumers, led by Cancer Voices NSW, provided the impetus to develop the website. Consumer representative groups were consulted by the research team during the design and development of ACTO which combines a search engine, trial details, general information about trial participation and question prompt lists. Website use was analysed. A patient evaluation questionnaire was completed at one hospital, one week after exposure to the website.</p> <p>Results</p> <p>ACTO's main features and content reflect consumer input. In February 2011, it covered 1, 042 cancer trials. Since ACTO's public launch in November 2010, until the end of February 2011, the website has had 2, 549 new visits and generated 17, 833 page views. In a sub-study of 47 patient users, 89% found the website helpful for learning about clinical trials and all respondents thought patients should have access to ACTO.</p> <p>Conclusions</p> <p>The development of ACTO is an example of consumers working with doctors, researchers and policy makers to improve the information available to people whose lives are affected by cancer and to help them participate in their treatment decisions, including consideration of clinical trial enrolment. Consumer input has ensured that the website is informative, targets consumer priorities and is user-friendly. ACTO serves as a model for other health conditions.</p
An efficient Foxtail mosaic virus vector system with reduced environmental risk
<p>Abstract</p> <p>Background</p> <p>Plant viral vectors offer high-yield expression of pharmaceutical and commercially important proteins with a minimum of cost and preparation time. The use of <it>Agrobacterium tumefaciens </it>has been introduced to deliver the viral vector as a transgene to each plant cell via a simple, nonsterile infiltration technique called "agroinoculation". With agroinoculation, a full length, systemically moving virus is no longer necessary for excellent protein yield, since the viral transgene is transcribed and replicates in every infiltrated cell. Viral genes may therefore be deleted to decrease the potential for accidental spread and persistence of the viral vector in the environment.</p> <p>Results</p> <p>In this study, both the coat protein (CP) and triple gene block (TGB) genetic segments were eliminated from <it>Foxtail mosaic virus </it>to create the "FECT" vector series, comprising a deletion of 29% of the genome. This viral vector is highly crippled and expresses little or no marker gene within the inoculated leaf. However, when co-agroinoculated with a silencing suppressor (p19 or HcPro), FECT expressed GFP at 40% total soluble protein in the tobacco host, <it>Nicotiana benthamiana</it>. The modified FoMV vector retained the full-length replicase ORF, the TGB1 subgenomic RNA leader sequence and either 0, 22 or 40 bases of TGB1 ORF (in vectors FECT0, FECT22 and FECT40, respectively). As well as <it>N. benthamiana</it>, infection of legumes was demonstrated. Despite many attempts, expression of GFP via syringe agroinoculation of various grass species was very low, reflecting the low <it>Agrobacterium</it>-mediated transformation rate of monocots.</p> <p>Conclusions</p> <p>The FECT/40 vector expresses foreign genes at a very high level, and yet has a greatly reduced biohazard potential. It can form no virions and can effectively replicate only in a plant with suppressed silencing.</p
Abstracts of presentations on selected topics at the XIVth international plant protection congress (IPPC) July 25-30, 1999
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