781 research outputs found
Weak formulation for singular diffusion equation with dynamic boundary condition
In this paper, we propose a weak formulation of the singular diffusion
equation subject to the dynamic boundary condition. The weak formulation is
based on a reformulation method by an evolution equation including the
subdifferential of a governing convex energy. Under suitable assumptions, the
principal results of this study are stated in forms of Main Theorems A and B,
which are respectively to verify: the adequacy of the weak formulation; the
common property between the weak solutions and those in regular problems of
standard PDEs.Comment: 23 page
Probability of Trypanosoma cruzi transmission by Triatoma infestans (Hemiptera: Reduviidae) to the opossum Didelphis albiventris (Marsupialia: Didelphidae)
The probability of Trypanosoma cruzi transmission to opossums by independent events of predation and fecal contamination during feeding ("biting") with positive Triatoma infestans was estimated. Negative female opossums were challenged for 23 hr with 10 infected third and fourth instars of T. infestans, and tests for positivity for T. cruzi by xenodiagnosis were performed at 30, 60, and 90 days. From these data, seven probability parameters were estimated by maximum likelihood, and likelihood ratio statistics confidence intervals were calculated. Simultaneous estimation of p1 (probability that a "bite" will infect an opossum), p3 (probability that a bug that has been eaten by an opossum will infect it), and p6 (probability that the opossum will become infected if faced with an infected triatomine), resulted in p̂1 = 0.06, p̂3 = 0.075, and p̂6 = 0.059. On average, each opossum should be exposed to an average of 700 encounters with bugs during its life, resulting in about eight potentially infective contacts, to produce the 35% opossum prevalence found in the field.Facultad de Ciencias Naturales y Muse
Probability of Trypanosoma cruzi transmission by Triatoma infestans (Hemiptera: Reduviidae) to the opossum Didelphis albiventris (Marsupialia: Didelphidae)
The probability of Trypanosoma cruzi transmission to opossums by independent events of predation and fecal contamination during feeding ("biting") with positive Triatoma infestans was estimated. Negative female opossums were challenged for 23 hr with 10 infected third and fourth instars of T. infestans, and tests for positivity for T. cruzi by xenodiagnosis were performed at 30, 60, and 90 days. From these data, seven probability parameters were estimated by maximum likelihood, and likelihood ratio statistics confidence intervals were calculated. Simultaneous estimation of p1 (probability that a "bite" will infect an opossum), p3 (probability that a bug that has been eaten by an opossum will infect it), and p6 (probability that the opossum will become infected if faced with an infected triatomine), resulted in p̂1 = 0.06, p̂3 = 0.075, and p̂6 = 0.059. On average, each opossum should be exposed to an average of 700 encounters with bugs during its life, resulting in about eight potentially infective contacts, to produce the 35% opossum prevalence found in the field.Facultad de Ciencias Naturales y Muse
Tools for energy and environmentally sustainable planning of urban areas: definition of Local Climate Zones in MMA
El trabajo tiene por objetivo generar una zonificación climática para el Área Metropolitana de Mendoza (AMM) que permita estandarizar el estudio del clima urbano y disponer de una base teórica sólida para la planificación y manejo de la ciudad. El modelo desarrollado es el de Zonas Climáticas Locales (LCZ) propuesto por Stewart y Oke, y para ello se ha utilizado la herramienta WUDAPT (World Urban Database Access Portal Tools).Los resultados muestran que, las zonas climáticas identificadas dentro del área de análisis exponen correlación con el paisaje de los distintos sectores de la ciudad.The work aims to generate a climatic zoning for the Mendoza Metropolitan Area (AMM) that allows to standardize the study of urban climate and to have a solid theoretical basis for planning and management of the city. The model to be developed is the Local Climate Zones (LCZ) proposed by Stewart and Oke and for this purpose it has been used as a WUDAPT (World Urban Database Access Portal Tools) tool. The results show that, overcoming the tool limitations, the climatic zones identified within the analysis area show correlation with the landscape in different city sectors.Fil: Colli, María Florencia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Ambiente, Hábitat y Energía; ArgentinaFil: Correa, Erica N.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Ambiente, Hábitat y Energía; ArgentinaFil: Martinez, Claudia. F.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Ambiente, Hábitat y Energía; ArgentinaV Jornadas de Intercambio y Difusión de los Resultados de Investigaciones de los Doctorandos en IngenieríaCiudad Autónoma de Buenos AiresArgentinaUniversidad Tecnológica Naciona
Probability of Trypanosoma cruzi transmission by Triatoma infestans (Hemiptera: Reduviidae) to the opossum Didelphis albiventris (Marsupialia: Didelphidae)
The probability of Trypanosoma cruzi transmission to opossums by independent events of predation and fecal contamination during feeding ("biting") with positive Triatoma infestans was estimated. Negative female opossums were challenged for 23 hr with 10 infected third and fourth instars of T. infestans, and tests for positivity for T. cruzi by xenodiagnosis were performed at 30, 60, and 90 days. From these data, seven probability parameters were estimated by maximum likelihood, and likelihood ratio statistics confidence intervals were calculated. Simultaneous estimation of p1 (probability that a "bite" will infect an opossum), p3 (probability that a bug that has been eaten by an opossum will infect it), and p6 (probability that the opossum will become infected if faced with an infected triatomine), resulted in p̂1 = 0.06, p̂3 = 0.075, and p̂6 = 0.059. On average, each opossum should be exposed to an average of 700 encounters with bugs during its life, resulting in about eight potentially infective contacts, to produce the 35% opossum prevalence found in the field.Facultad de Ciencias Naturales y Muse
Transapical off-pump echo-guided mitral valve repair with neochordae implantation mid-term outcomes
Background: The NeoChord echo-guided transapical beating heart repair is a promising early-stage
minimally invasive surgical procedure for degenerative mitral valve (MV) regurgitation (DMR) correction.
The technique has been improved since its inception following procedure standardization, patient selection
optimization, and learning curve stabilization. We hereby present the mid-term clinical results through three
years of our large single center experience.
Methods: All consecutive patients with severe symptomatic DMR due to prolapse or flail of one or both
mitral leaflets that underwent the NeoChord procedure between November 2013 and June 2019 were
included. Patients were categorized according to MV anatomy; Type A isolated central posterior leaflet
prolapse and/or flail, Type B posterior multi-segment prolapse and/or flail, Type C anterior and/or bi-leaflet
prolapse or flail, Type D paracommissural prolapse and/or flail and/or significant leaflet and/or annular
calcifications. Patients underwent clinical and echocardiographic follow-up at one, three, six, twelve months
and yearly thereafter. Clinical outcomes and the composite primary endpoint (patient success) were defined
according to Mitral Valve Academic Research Consortium (MVARC) criteria. Mitral regurgitation (MR)
severity was graded as absent, mild, moderate and severe according to American Society of Echocardiography
(ASE) and European Society of Cardiology (ESC) guidelines.
Results: Two hundred and three patients were included; median follow-up was 24 months [interquartile
range (IQR), 9–36]. Median age was 64 years (IQR, 54–74 years), median Society of Thoracic Surgeons
(STS) Predicted Risk of Mortality (PROM) was 0.60% (IQR, 0.32–1.44%). There were 106 Type A patients
(52.2%), 68 Type B (33.5%), 16 Type C (7.9%), and 13 Type D (6.4%). Kaplan-Meier estimate of survival
was 99.0%±0.7% at one and two years and 94.0%±2.9% at three years. At one-year follow-up patient success
was 91.2%±2.0% and 111 patients (74%) presented a residual MR mild or less (1+). At three-year follow-up
patient success was 81.2%±3.8% and 32 patients (64%) had a residual MR mild or less (1+). Patient success
was significantly different according to anatomical type (P=0.001). Echocardiographic analysis showed a
significant acute left ventricle and left atrial reverse remodeling that was maintained up to three years.
Conclusions: The NeoChord echo-guided transapical beating heart repair procedure demonstrated good
clinical outcomes and echocardiographic results up to three-year follow-up
Optimal control for a phase field system with a possibly singular potential
In this paper we study a distributed control problem for a phase field system of Caginalp type with logarithmic potential. The main aim of this work would be to force the location of the diffuse interface to be as close as possible to a prescribed set. However, due to the discontinuous character of the cost functional, we have to approximate it by a regular one and, in this case, we solve the associated control problem and derive the related first order necessary optimality conditions
Post-subduction tectonics induced by extension from a lithospheric drip
Acknowledgements S.P. acknowledges support from the Natural Environmental Research Council (NERC) Grant NE/R013500/1 and from the European Union’s Horizon 2020 Research and Innovation Program under Marie Skłodowska-Curie Grant Agreement 790203. We thank the TanDEM-X Science Communication Team (German Aerospace Center (DLR) e.V.) for providing TanDEM topographic data. We thank the NERC Geophysical Equipment Facility for loan 1038. Numerical simulations were undertaken on the NCI National Facility in Canberra, Australia, which is supported by the Australian Commonwealth Government. A.G. was funded by an Independent Research Fellowship from the Royal Astronomical Society.Peer reviewedPostprin
Compilation of results of the ICPPR non-Apis working group with a special focus on the bumblebee acute oral and contact toxicity ring test 2014 ICPPR Non-Apis Working Group
Although honeybee risk assessment for chemicals has been rigorously revised recently, methods and techniques available for non-apis pollinators are scarce. An ICPPR working group “non-apis” was established in 2013 to address these knowledge gaps. Acute contact tests were designed and performed with solitary bees Osmia sp. but still require further optimization. Ring tests on acute oral and contact toxicity for the bumblebee Bombus sp. were developed and performed in 2014. Thirteen European laboratories participated in the trials and in most cases control mortality was < 10% after 96h, indicating that the developed methodologies were feasible in a variety of laboratories. The oral exposure and the group contact exposure tests were each found to generate more variable LD50 estimates, whereas the endpoints obtained in the single contact tests were more consistent among laboratories. The difference in the two different contact test designs indicates the presence of a ‘housing’ effect, which makes the group housing less favorable. In addition, the use of Tween80 as a wetting agent was found to be unsuccessful
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