572 research outputs found
Aspects of open-flavour mesons in a comprehensive DSBSE study
Open-flavour meson studies are the necessary completion to any comprehensive
investigation of quarkonia. We extend recent studies of quarkonia in the
Dyson-Schwinger-Bethe-Salpeter-equation approach to explore their results for
all possible flavour combinations. Within the inherent limitations of the
setup, we present the most comprehensive results for meson masses and leptonic
decay constants currently available and put them in perspective with respect to
experiment and other approaches.Comment: 38 pages, 26 figures, 2 tables, revised according to reviewer
comment
Form factors of heavy-light systems in point-form relativistic quantum mechanics: the Isgur-Wise function
We investigate electromagnetic and weak form factors of heavy-light mesons in
the context of point-form relativistic quantum mechanics. To this aim we treat
the physical processes from which such electroweak form factors are extracted
by means of a coupled channel approach which accounts for the dynamics of the
intermediate gauge bosons. It is shown that heavy-quark symmetry is respected
by this formulation. A simple analytical expression is obtained for the
Isgur-Wise function in the heavy-quark limit. Breaking of heavy-quark symmetry
due to realistic values of the heavy-quark mass are studied numerically.Comment: Presented at the 21st European Conference on Few-Body Problems in
Physics, Salamanca, Spain, 30 August - 3 September 201
Design and simulation of metropolitan urban growth demands scenarios
La generación y simulación de escenarios exploratorios externos es un instrumento útil en los procesos de planificación y toma de decisiones, de especial relevancia en el ámbito territorial y metropolitano (Peterson et al, 2003; Pettit y Pullar, 2004; Luca, 2007; Carsjens, 2009), cuyo calado en el proceso de planificación en España es escaso hasta la fecha (Valenzuela, Aguilera, Soria y Molero, 2008).
En este artículo se presenta un modelo basado en Dinámica de Sistemas para estimar las demandas de nuevo suelo urbano en ámbitos metropolitanos. El modelo se ha desarrollado concretamente para dos ámbitos metropolitanos españoles (Región Urbana de Madrid y Aglomeración Urbana de Granada) para los cuales se ha realizado un proceso de calibración individual,
Una vez calibrado el modelo para dichos ámbitos, y a través del planteamiento de tres escenarios futuros, se han simulado las posibles tendencias de las demandas de ocupación urbana que podrían derivarse de las premisas establecidas en cada escenario, con unos resultados satisfactorios. Dichos resultados podrán ser empleados en otros trabajos que permitirán localizar espacialmente, mediante modelos de simulación espacial, las demandas estimadas, para mostrar y evaluar posibles consecuencias espaciales y territoriales de los procesos de crecimiento metropolitano.The design and development of future explorative external scenarios are useful tools for the spatial planning and even more for the metropolitan planning (Peterson et al, 2003; Pettit y Pullar, 2004; Luca, 2007; Carsjens, 2009). However, spatial planning policy and practices in Spain lack of this instruments (Valenzuela, Aguilera, Soria y Molero, 2008)
This paper shows a System Dynamics-based model designed to estimate urban growth demands in metropolitan areas. This model has been specifically developed for Madrid and Granada metropolitan areas (Spain), where the model has been calibrated.
After the calibration, three future urban growth demands scenarios has been designed and simulated using the model developed. The urban growth demands obtained may be used in later research to spatially locate that demands using spatial simulation models.Peer Reviewe
Aportación de la densitometría ósea en las artroplastias de rodilla
El presente trabajo consiste en una revisión clínica y radiológica de 84 artroplastias
modulares de rodilla de las cuales, en 19 se ha estudiado la masa ósea periprotésica
(7 cementadas y 12 sin cementar) antes, al mes y a los seis meses de la intervención mediante
un densitómetro de doble fotón. Aparte, se ha probado la correlación directa entre la indicación
peroperatoria de no cementar y una mayor masa ósea en todas las zonas periprotésicas;
por otro lado, se ha observado una diferente distribución de la densidad mineral ósea en la
tibia tras la intervención, según se haya utilizado o no cemento. Estos hallazgos confirman el
estudio densitométrico previo a la intervención como un método complementario útil en la
indicación de la cementación de la artroplastia total de rodilla.A clinical and radiological revision of 84 modular knee arthroplasties is
presented. Periprosthesis bone mineral content was studied in 19 prostheses (7 cemented
and 12 uncemented) before, surgery one and 6 months after the intervention using a densitometer
of double energy. A direct correlation between the implantation of a non-cemented
prosthesis and the growth of the bone mass in all the periprosthesis areas was found, existing
a different distribution of the mineral bone density of the tibia after the intervention
depending on the use of cement. These findings show that the densitometric study previous
to an intervention as a useful complementary method in the indication of cemented total
knee arthroplasty
The Globular Cluster System of NGC4374
We study the globular cluster system (GCS) of the giant elliptical NGC4374
(M84) in the Virgo cluster using B and R photometry. The colour distribution is
bimodal with peaks at B-R=1.11 and B-R=1.36, fitting well to those found in
other early-type galaxies. The radial profile of the cluster number density is
flatter than the galaxy light. Using the luminosity function we derive a
distance modulus of , which within the uncertainty agrees with
the distance from surface brightness fluctuations. Blue and red clusters show
similar radial concentrations and azimuthal distributions. The total number of
clusters is , which together with our distance modulus leads to a
specific frequency of . This value is surprisingly low for a
giant elliptical, but resembles the case of merger remnants like NGC1316, where
the low specific frequency is probably caused by the luminosity contribution of
an intermediate-age population. A further common property is the high rate of
type Ia supernovae which also may indicate the existence of a younger
population. However, unlike in the case of NGC1316, one cannot find any further
evidence that NGC4374 indeed hosts younger populations. The low specific
frequency would also fit to a S0 galaxy seen face-on.Comment: Accepted for publication in Astronomy & Astrophysics. 11 page
Occurrence of antibiotics and bacterial resistance in wastewater and sea water from the Antarctic
The potential presence of introduced antibiotics in the aquatic environment is a hot topic of concern, particularly in the Antarctic, a highly vulnerable area protected under the Madrid protocol. The increasing presence of human population, especially during summer, might led to the appearance of pharmaceuticals in wastewater. The previous discovery of Escherichia coli strains resistant to antibiotics in sea water and wastewater collected in King George Island motivated our investigation on antibiotics occurrence in these samples. The application of a multi-residue LCMS/MS method for 20 antibiotics, revealed the presence of 8 compounds in treated wastewater, mainly the quinolones ciprofloxacin and norfloxacin (92% and 54% of the samples analyzed, average concentrations 0.89 μg/L and 0.75 μg/L, respectively) and the macrolides azithromycin and clarithromycin (15% positive samples, and average concentrations near 0.4 μg/L), and erythromycin (38% positive samples, average concentration 0.003 μg/L). Metronidazole and clindamycin were found in one sample, at 0.17 and 0.1 μg/L, respectively; and trimethoprim in two samples, at 0.001 μg/L. Analysis of sea water collected near the outfall of the wastewater discharges also showed the sporadic presence of 3 antibiotics (ciprofloxacin, clindamycin, trimethoprim) at low ng/L level, illustrating the impact of pharmaceuticals consumption and the poor removal of these compounds in conventional WWTPs. The most widespread antibiotic in sea water was ciprofloxacin, which was found in 15 out of 34 sea water samples analyzed, at concentrations ranging from 4 to 218 ng/L. Bacteria resistance was observed for some antibiotics identified in the samples (e.g. trimetropim and nalidixic acid –a first generation quinolone). However, resistance to some groups of antibiotics could not be correlated to their presence in the water samples due to analytical limitations (penicillins, tetraciclines). On the contrary, for some groups of antibiotics detected in samples (macrolides), the antibacterial activity against E. Coli was not investigated because these antibiotics do not include this bacterial species in their spectrum of activity.
Our preliminary data demonstrate that antibiotics occurrence in the Antarctic aquatic environment is an issue that needs to be properly addressed. Periodical monitoring of water samples and the implementation of additional treatments in the WWTPs are recommended as a first step to prevent potential problems related to the presence of antibiotics and other emerging contaminants in the near future in Antarctica
Experiencia a medio plazo con prótesis total de rodilla semiconstreñida
Revisamos 25 prótesis totales de rodilla semiconstreñidas tipo Endo-Model Waldemar-
Link implantadas en 23 pacientes con una edad media de 69,5 años y un seguimiento medio
de 32 meses. Para la evaluación de los resultados clínicos hemos utilizado el protocolo de la Academia
Americana en el que se incluyen los parámetros de: dolor, capacidad para la marcha, facilidad
para subir y bajar escaleras, necesidad o no de bastones y flexoextensión de la articulación,
tanto antes como después de la intervención. Asimismo hemos realizado un estudio radiológico de
las prótesis en el que se ha valorado el centraje de los componentes protésicos en dos planos AP y
L y las imágenes líticas periprotésicas. Los resultados obtenidos han sido satisfactorios observando
en la totalidad de los pacientes una disminución del dolor y un aumento de su capacidad funcional.
En ningún caso se han observado infecciones profundas de la prótesis. Se ha comprobado un
aumento en el arco de flexión en las prótesis en que la punta del vástago femoral estaba desviada
hacia la cortical anterior, sin que esto se acompañase de un déficit en la extensión.We have reviewed 25 total knee prosthesis (Endo-Model type, Waldemar-Link) performed
in 23 patients with an age average of 69,5 years-old and a average follow-up of 32 months.
The clinical assessment applied was the AAOS protocol including the parameters of: pain, ability to go
up and down the stairs, to need of sticks, flexion and extension of the joint, before and after the operation.
In the radiological study we have evaluated the correct alignment of the components in two
planes A-P and L, and the periprosthetic lucencies. The results obtained have been satisfying in all the
patients with a diminution of the pain and better function of the joint. No deep infection was observed
and the flexion was better in prosthesis with anterior deviation of the femoral rod in the lateral plane
Biosensors to diagnose Chagas disease: A review
International audienceChagas disease (CD), which mostly affects underprivileged people, has turned into one 9 of Latin America's main public health problems. Prevention of the disease requires early diagnosis, 10 initiation of therapy, and regular blood monitoring of the infected individual. However, the majority 11 of the infections go undiagnosed because of general mild symptoms and lack of access to medical 12 care. Therefore, more affordable and accessible detection technologies capable of providing early 13 diagnosis and parasite load measurements in settings where CD is prevalent are needed to enable 14 enhanced intervention strategies. This review discusses currently available detection technologies 15 and emerging biosensing technologies for a future application to CD. Even if biosensing 16 technologies still require further research efforts to develop portable systems, we arrive to the 17 conclusion that biosensors could improve diagnosis and the patients' treatment follow-up, in terms 18 of rapidity, small sample volume, high integration, ease of use, real-time and low cost detection 19 compared to current conventional technologies. 2
Enhanced proliferation of pre-osteoblastic cells by dynamic piezoelectric stimulation
[EN] This work reports on the influence of the polarization of electroactive poly(vinylidene fluoride), PVDF, on the biological response of cells cultivated under static and dynamic conditions. Non-poled and "poled +" beta-PVDF with and without a titanium layer were thus prepared. A thin titanium layer was deposited on PVDF films in order to obtain a more homogeneous surface charge. The MC3T3-E1 osteoblast cell culture exhibited different responses in the presence of PVDF films. The positively charged beta-PVDF films promote higher osteoblast adhesion and proliferation, which is higher under dynamic conditions on poled samples, showing that the surface charge under mechanical stimulation improves the osteoblast growth. Therefore, electroactive membranes and scaffolds can provide the necessary electrical stimuli for the growth and proliferation of specific cells.JLGR acknowledge the support of the Spanish Ministry of Education through project No. MAT2010-21611-C03-01 (including the FEDER financial support) and project EUI2008-00126.Ribeiro, C.; Moreira, S.; Correia, V.; Sencadas, V.; Rocha, JG.; Gama, FM.; Gómez Ribelles, JL.... (2012). Enhanced proliferation of pre-osteoblastic cells by dynamic piezoelectric stimulation. RSC Advances. 2(30):11504-11509. https://doi.org/10.1039/c2ra21841k115041150923
Form Factors of Few-Body Systems: Point Form Versus Front Form
We present a relativistic point-form approach for the calculation of
electroweak form factors of few-body bound states that leads to results which
resemble those obtained within the covariant light-front formalism of Carbonell
et al. Our starting points are the physical processes in which such form
factors are measured, i.e. electron scattering off the bound state, or the
semileptonic weak decay of the bound state. These processes are treated by
means of a coupled-channel framework for a Bakamjian-Thomas type mass operator.
A current with the correct covariance properties is then derived from the
pertinent leading-order electroweak scattering or decay amplitude. As it turns
out, the electromagnetic current is affected by unphysical contributions which
can be traced back to wrong cluster properties inherent in the Bakamjian-Thomas
construction. These spurious contributions, however, can be separated uniquely,
as in the covariant light-front approach. In this way we end up with form
factors which agree with those obtained from the covariant light-front
approach. As an example we will present results for electroweak form factors of
heavy-light systems and discuss the heavy-quark limit which leads to the famous
Isgur-Wise function.Comment: Presented at LIGHTCONE 2011, Dallas, USA, 23 - 27 May, 201
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