90 research outputs found
Chaotic oscillations in a nearly inviscid, axisymmetric capillary bridge at 2:1 parametric resonance
We consider the 2:1 internal resonances (such that Ω1>0 and Ω2 ≃ 2Ω1 are natural frequencies) that appear in a nearly inviscid, axisymmetric capillary bridge when the slenderness Λ is such that 0<Λ<π (to avoid the Rayleigh instability) and only the first eight capillary modes are considered. A normal form is derived that gives the slow evolution (in the viscous time scale) of the complex amplitudes of the eigenmodes associated with Ω1 and Ω2, and consists of two complex ODEs that are balances of terms accounting for inertia, damping, detuning from resonance, quadratic nonlinearity, and forcing. In order to obtain quantitatively good results, a two-term approximation is used for the damping rate. The coefficients of quadratic terms are seen to be nonzero if and only if the eigenmode associated with Ω2 is even. In that case the quadratic normal form possesses steady states (which correspond to mono- or bichromatic oscillations of the liquid bridge) and more complex periodic or chaotic attractors (corresponding to periodically or chaotically modulated oscillations). For illustration, several bifurcation diagrams are analyzed in some detail for an internal resonance that appears at Λ ≃ 2.23 and involves the fifth and eighth eigenmodes. If, instead, the eigenmode associated with Ω2 is odd, and only one of the eigenmodes associated with Ω1 and Ω2 is directly excited, then quadratic terms are absent in the normal form and the associated dynamics is seen to be fairly simple
FIBROMYALGIA: A SEARCH FOR MARKERS AND THEIR EVALUATION THROUGHOUT A TREATMENT
Fibromyalgia syndrome (FM) is a complex chronic pain disorder of unknown causation associated with debilitating fatigue, unrefreshing sleep, cognitive and affective symptoms. There is no biological markers to monitor FM progression and no permanent cure for FM. Our aim was to identify markers associated with FM and its progression and to evaluate the efficacy of a battery of treatments. The study is a treatment trial, open label and single centre, with 27 women (41 ± 2 years) diagnosed with FM using the Widespread Pain Index (WPI), the Symptom Severity (SS) Scale and the Fibromyalgia Impact Questionnaire (FIQ). Anthropometric parameters, plasma cytokines values and clinical progression were measured before and after two months of a multi-approach treatment. A significant improvement was observed after two months of treatment as shown by WPI, SS Scale and FIQ. No significant variations were observed, except for the intracellular body water parameters, in anthropometric and body composition characteristics. Food-induced histaminosis release was observed to cow´s milk, egg, fruit, wheat and oily fish. Interleukin-1β (IL-1β) and interleukin-6 (IL-6) plasma cytokine values were significantly higher in FM. A strong positive correlation was observed between the percentage of reduction of cytokine levels and the improvement of health status. We propose: i) the existence of different subsets of FM patients; ii) the use of intracellular body water and plasma cytokine values as positive markers for FM progression; iii) that food-sensitisation could be an important mechanism for FM pathogenesis and iv) the use of a multidisciplinary approach for FM treatment
FIBROMYALGIA: A SEARCH FOR MARKERS AND THEIR EVALUATION THROUGHOUT A TREATMENT
Fibromyalgia syndrome (FM) is a complex chronic pain disorder of unknown causation associated with debilitating fatigue, unrefreshing sleep, cognitive and affective symptoms. There is no biological markers to monitor FM progression and no permanent cure for FM. Our aim was to identify markers associated with FM and its progression and to evaluate the efficacy of a battery of treatments. The study is a treatment trial, open label and single centre, with 27 women (41 ± 2 years) diagnosed with FM using the Widespread Pain Index (WPI), the Symptom Severity (SS) Scale and the Fibromyalgia Impact Questionnaire (FIQ). Anthropometric parameters, plasma cytokines values and clinical progression were measured before and after two months of a multi-approach treatment. A significant improvement was observed after two months of treatment as shown by WPI, SS Scale and FIQ. No significant variations were observed, except for the intracellular body water parameters, in anthropometric and body composition characteristics. Food-induced histaminosis release was observed to cow´s milk, egg, fruit, wheat and oily fish. Interleukin-1β (IL-1β) and interleukin-6 (IL-6) plasma cytokine values were significantly higher in FM. A strong positive correlation was observed between the percentage of reduction of cytokine levels and the improvement of health status. We propose: i) the existence of different subsets of FM patients; ii) the use of intracellular body water and plasma cytokine values as positive markers for FM progression; iii) that food-sensitisation could be an important mechanism for FM pathogenesis and iv) the use of a multidisciplinary approach for FM treatment
Technological and infrastructure collaborative seismic research in Western Mexico
In February and March 2014, Spanish, Mexican and British scientists
and technicians explored the western margin of Mexico, a region with a high occurrence
of large earthquakes (> Mw = 7.5) and tsunami generation, on board the
British Royal Research Ship James Cook. This successful joint cruise, named TSUJAL,
was made possible thanks to a cooperative agreement between NERC and CSIC as
part of the Ocean Facilities Exchange Group (OFEG), a major forum of European
oceanographic institutions for the exchange of ship time, equipment and personnel.
A dense geophysical data set was acquired using for the first time 6 km length
seismic streamer facilities from Spain’s Consejo Superior de Investigaciones Cientificas
(CSIC), usually operating in the Spanish RV Sarmiento de Gamboa, onboard
the British RRS James Cook by solving all mechanical, electrical and electronic
problems. The RRS James Cook in turn provides the seismic source and the acoustic,
hullmounted echosounder operated by the British Natural Environment Research
Council (NERC). Multiscale seismic and echosounder images unravel the subduction
geometry, nature of the crust, and evidence faults and mass wasting processes. The
data are crucial to estimating fault seismic parameters, and these parameters are
critical to carrying out seismic hazard in Mexico, especially when considering largemagnitude
earthquakes (Mw 8.0), and to constrain tsunami models.Peer Reviewe
LCDM halo substructure properties revealed with high resolution and large volume cosmological simulations
We investigate the structural properties, distribution and abundance of LCDM
dark matter subhaloes using the Phi-4096 and Uchuu suite of N-body cosmological
simulations. Thanks to the combination of their large volume, high mass
resolution and superb statistics, we are able to quantify -- for the first time
consistently over more than seven decades in ratio of subhalo-to-host-halo mass
-- dependencies of subhalo properties with mass, maximum circular velocity,
Vmax, host halo mass and distance to host halo centre. We also dissect the
evolution of these dependencies over cosmic time. We provide accurate fits for
the subhalo mass and velocity functions, both exhibiting decreasing power-law
slopes in the expected range of values and with no significant dependence on
redshift. We also find subhalo abundance to depend weakly on host halo mass. We
explore the distribution of subhaloes within their hosts and its evolution over
cosmic time for subhaloes located as deep as ~0.1 per cent of the host virial
radius. Subhalo structural properties are codified via a concentration
parameter, cV, that does not depend on any specific, pre-defined density
profile and relies only on Vmax. We derive the cV-Vmax relation in the range
7-1500 km/s and find an important dependence on distance of the subhalo to the
host halo centre, as already described in Molin\'e et al. (2017).
Interestingly, we also find subhaloes of the same mass to be significantly more
concentrated into more massive hosts. Finally, we investigate the redshift
evolution of cV, and provide accurate fits that take into account all mentioned
dependencies. Our results offer an unprecedented detailed characterization of
the subhalo population, consistent over a wide range of subhalo and host halo
masses, as well as cosmic times. Our work enables precision work in any future
research involving dark matter halo substructure.Comment: 17 pages, 15 figures, 5 tables. Submitted to the journal. Comments
welcome
Archivos, posicionada en la senda del impacto
Con este bagaje, comenzamos 2023, un año en el que nuestra revista cumple un cuarto de siglo llevando a cabo la misión para la que fue concebida, misión que los distintos comités editoriales que hemos participado consideramos un acierto: contribuir a la transferencia de conocimiento útil para avanzar en la mejora de la salud de las personas trabajadora
Impacto de la variabilidad intrapaciente en la concentración sanguínea de anticalcineurínicos en los resultados del trasplante cardiaco
[Abstract]
Introduction and objectives.
Intrapatient blood level variability (IPV) of calcineurin inhibitors has been associated with poor outcomes in solid-organ transplant, but data for heart transplant are scarce. Our purpose was to ascertain the clinical impact of IPV in a multi-institutional cohort of heart transplant recipients.
Methods.
We retrospectively studied patients aged ≥ 18 years, with a first heart transplant performed between 2000 and 2014 and surviving ≥ 1 year. IPV was assessed by the coefficient of variation of trough levels from posttransplant months 4 to 12. A composite of rejection or mortality/graft loss or rejection and all-cause mortality/graft loss between years 1 to 5 posttransplant were analyzed by Cox regression analysis.
Results.
The study group consisted of 1581 recipients (median age, 56 years; women, 21%). Cyclosporine immediate-release tacrolimus and prolonged-release tacrolimus were used in 790, 527 and 264 patients, respectively. On multivariable analysis, coefficient of variation > 27.8% showed a nonsignificant trend to association with 5-year rejection-free survival (HR, 1.298; 95%CI, 0.993-1.695; P = .056) and with 5-year mortality (HR, 1.387; 95%CI, 0.979-1.963; P = .065). Association with rejection became significant on analysis of only those patients without rejection episodes during the first year posttransplant (HR, 1.609; 95%CI, 1.129-2.295; P = .011). The tacrolimus-based formulation had less IPV than cyclosporine and better results with less influence of IPV.
Conclusions.
IPV of calcineurin inhibitors is only marginally associated with mid-term outcomes after heart transplant, particularly with the tacrolimus-based immunosuppression, although it could play a role in the most stable recipients.[Resumen]
Introducción y objetivos.
El objetivo es estudiar el impacto clínico de la variabilidad intrapaciente (VIP) de la concentración sanguínea de los anticalcineurínicos en el trasplante cardiaco, pues la información actual es escasa.
Métodos.
Se analizó retrospectivamente a pacientes de edad ≥ 18 años con un trasplante cardiaco realizado entre 2000 y 2014 y con supervivencia ≥ 1 año. La VIP se valoró mediante el coeficiente de variación de concentraciones entre los meses 4 a 12 postrasplante. El compuesto de rechazo, mortalidad o pérdida del injerto y la mortalidad o pérdida del injerto 1-5 años tras el trasplante se analizaron mediante regresión de Cox.
Resultados.
Se estudió a 1.581 receptores (edad, 56 años; mujeres, 21%), tratados con ciclosporina (790 pacientes) o tacrolimus (791 pacientes). En el análisis multivariable, un coeficiente de variación > 27,8% tendió a asociarse con el compuesto de rechazo/mortalidad (HR = 1,298; IC95%, 0,993-1,695; p = 0,056) y con la mortalidad (HR = 1,387; IC95%, 0,979-1,963; p = 0,065) a los 5 años. La asociación con el rechazo fue significativa al analizar a la población sin rechazos durante el primer año del trasplante (HR = 1,609; IC95%, 1,129-2,295; p = 0,011). El tacrolimus tuvo menos VIP que la ciclosporina, junto con unos mejores resultados por la menor influencia de la VIP.
Conclusiones.
La VIP de los anticalcineurínicos, especialmente con la inmunosupresión basada en el tacrolimus, se asocia solo marginalmente con los resultados a medio plazo del trasplante cardiaco, aunque puede tener influencia en los pacientes más estables durante el primer año tras el trasplante
Risk factors associated with moderate-to-severe renal dysfunction among heart transplant patients: results from the CAPRI study
[Abstract] The longer survival of patients with heart transplantation (HT) favors calcineurin inhibitor–related chronic kidney disease (CKD). It behoves to identify risk factors. At 14 Spanish centers, data on 1062 adult patients with HT (age 59.2 ± 12.3 yr, 82.5% men) were collected at routine follow-up examinations. Glomerular filtration rate, GFR, was estimated using the four-variable MDRD equation, and moderate-or-severe renal dysfunction (MSRD) was defined as K/DOQI stage 3 CKD or worse. Time since transplant ranged from one month to 22 yr (mean 6.7 yr). At assessment, 26.6% of patients were diabetic and 63.9% hypertensive; 53.9% were taking cyclosporine and 33.1% tacrolimus; and 61.4% had MSRD. Among patients on cyclosporine or tacrolimus at assessment, multivariate logistic regression identified male sex (OR 0.44), pre- and post-HT creatinine (2.73 and 3.13 per mg/dL), age at transplant (1.06 per yr), time since transplant (1.05 per yr), and tacrolimus (0.65) as independent positive or negative predictors of MSRD. It is concluded that female sex, pre- and one-month post-HT serum creatinine, age at transplant, time since transplant, and immunosuppression with cyclosporine rather than tacrolimus may all be risk factors for development of CKD ≥ stage 3 by patients with HT
The impact from survey depth and resolution on the morphological classification of galaxies
We consistently analyse for the first time the impact of survey depth and spatial resolution on the most used morphological parameters for classifying galaxies through non-parametric methods: Abraham and Conselice-Bershady concentration indices, Gini, M20moment of light, asymmetry, and smoothness. Three different non-local data sets are used, Advanced Large Homogeneous Area Medium Band Redshift Astronomical (ALHAMBRA) and Subaru/XMMNewton Deep Survey (SXDS, examples of deep ground-based surveys), and Cosmos Evolution Survey (COSMOS, deep space-based survey). We used a sample of 3000 local, visually classified galaxies, measuring their morphological parameters at their real redshifts (z ~ 0). Then we simulated them to match the redshift and magnitude distributions of galaxies in the non-local surveys. The comparisons of the two sets allow us to put constraints on the use of each parameter for morphological classification and evaluate the effectiveness of the commonly used morphological diagnostic diagrams. All analysed parameters suffer from biases related to spatial resolution and depth, the impact of the former being much stronger. When including asymmetry and smoothness in classification diagrams, the noise effects must be taken into account carefully, especially for ground-based surveys. M20 is significantly affected, changing both the shape and range of its distribution at all brightness levels. We suggest that diagnostic diagrams based on 2-3 parameters should be avoided when classifying galaxies in ground-based surveys, independently of their brightness; for COSMOS they should be avoided for galaxies fainter than F814 = 23.0. These results can be applied directly to surveys similar to ALHAMBRA, SXDS and COSMOS, and also can serve as an upper/lower limit for shallower/deeper ones.Ministerio de Economía y Competitividad AYA2010-15169, AYA2013-42227-P, AYA2013-4318
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