The thermodynamics of metabolism, cardiovascular performance and exercise, in health and diabetes: The objective of clinical markers

Extensive experience in UK National Health Service metabolic syndrome/type 2 diabetes clinics highlights the need for convenient clinical marker(s) which can be readily used to indicate the success or otherwise of alternative therapies. In this paper we study the metabolic context of the healthy and diseased states, which points to the haemodynamics being a possible key in identifying candidate markers. Human metabolism relates to two elemental thermodynamic systems, the individual cell and the human body in its entirety. The fundamental laws of thermodynamics apply to humans, animals, and their individual cells for both healthy and diseased conditions. as they are to classic heat engines. In compliance with the second law enhanced levels of heat are generated under exercise, heat itself being another factor modulating the cardiovascular response to physical exercise. Nutrients and oxygen uptake occurs via the digestive system and lungs, respectively, leading to ATP production by the established metabolic pathways: this is controlled by insulin. These are then delivered to the cells via the haemodynamic system to satisfy local metabolic need. The supply and demand of oxygen are finely regulated, in part, via oxygen-dependent release of ATP from the circulating erythrocytes. Energy supply and demand are regulated to sustain muscle activity resulting in the body’s output of measurable thermodynamic work—i.e. exercise. Recently a dynamic pathway model allowing quantification of ATP release from the erythrocytes and its contribution to oxygen supply regulation has been published. However, metabolic uptake is well known to be greatly affected by disease such as the highly prevalent diabetes type 2 with insulin resistance and beta cell dysfunction having mechanistic roles. In 2010, over 25% of residents above 65 in the USA had diabetes 2. The complexity of the metabolic pathways means that monitoring of patient-specific treatment would be beneficial from a diabetic marker which may be haemodynamic-related and traceable via the local fluid dynamics

Compound orbits break-up in constituents: an algorithm

In this paper decomposition of periodic orbits in bifurcation diagrams are derived in unidimensional dynamics system $x_{n+1}=f(x_{n};r)$, being $f$ an unimodal function. We proof a theorem which states the necessary and sufficient conditions for the break-up of compound orbits in their simpler constituents. A corollary to this theorem provides an algorithm for the computation of those orbits. This process closes the theoretical framework initiated in (Physica D, 239:1135--1146, 2010)

La percepción del estado de forma fisica está asociada a la percepción del peso corporal; análisis sociodemográfico en españa

Introduction: The objective of this study was to analyse the relationship between sociodemographic characteristics, body weight perception and physical fitness perception. Methods: Survey by means of personal interview. The sample consisted of 8,594 participants living in Spain between 15 and 97 years of age. Sampling error was ±1.07%. Results: Of the people who reported having good or excellent physical fitness, there was a proportionally greater prevalence of males, people aged 15 to 34, people with university studies and people from an upper or very upper social class (P < 0.001). It was also inferred that there was a greater possibility of perceiving deficient or very bad physical fitness in cohorts who felt that they should gain a bit of weight (OR = 2.87), lose a bit of weight (OR = 2.31) or lose a lot of weight (OR = 8.78). Conclusion: Perception of physical fitness is associated with perception of body weight, independently of people's sociodemographic characteristics.Introducción: El objetivo del trabajo fue analizar la relación entre características sociodemográficas, percepción de peso corporal y percepción de estado de forma física. Métodos: Encuesta mediante entrevista personal. La muestra estuvo formada por 8.594 participantes residentes en España de entre 15 y 97 años. El error muestral fue ±1,07%. Resultados:Entre las personas que declararon estar bien de peso o tener una forma física buena o excelente hubo, proporcionalmente, mayor prevalencia de hombres, jóvenes de entre 15 y 34 años, personas con estudios universitarios y ciudadanos de clase social alta o muy alta (P < 0,001). Además, se infirió mayor posibilidad de percibir una forma física deficiente o muy mala en las cohortes que consideraron que les vendría bien ganar algo de peso (OR = 2,87), perder unos pocos kilos (OR = 2,31) o perder muchos kilos (OR = 8,78). Conclusión: La percepción del estado de forma física está asociada a la percepción del peso corporal, independientemente de las características sociodemográficas de las persona

Las matemáticas de los alumnos

Presentamos aquí los avances de esta investigación orientada a la obtención de un inventario de preconceptos que tienen los estudiantes de nuevo ingreso al bachillerato y que dificultan su aprendizaje de las Matemáticas, fundamentalmente del Álgebra. Conforme avanzamos en este estudio, obtenemos información sobre las estructuras conceptuales de nuestros pupilos, y las utilizamos para ir elaborando las directrices y criterios que normarán, tanto nuestra intervención pedagógica como el diseño de la didáctica ad-hoc que posibiliten aprendizajes significativos. La construcción del conocimiento puede ser analizada desde dos vertientes: Los procesos psicológicos implicados en el aprendizaje y, los mecanismos de influencia educativa susceptibles de promover, guiar y orientar dicho aprendizaje. Para realizar esta indagación usamos la segunda vía y utilizamos métodos de observación directa (intra-aula), entrevista, clínica y registros escritos por los estudiantes

Occupational kidney disease among young populations in northwest Nicaragua

Chronic kidney disease of undetermined aetiology (CKDu) is mainly responsible for the deaths of young males in agricultural lowland regions of Central America. The aim of this thesis was to advance the understanding of the causes of CKDu by conducting several different epidemiological research studies. The systematic review identified a number of cross-sectional studies and occupational cohort studies with limited follow-up periods, but the findings were inconclusive regarding the causes of CKDu. The cohort study described in this PhD thesis is the first community-based cohort study in the region to evaluate the natural history of disease in apparently healthy people aged 18-30 years. It collected information about a wide range of exposure conditions with a questionnaire, biological samples, and water samples. There was an unparalleled, asymptomatic and very rapid decline in renal function among 10% of males and 3.5% of females who had normal renal function at baseline. Meanwhile, the group displaying established renal dysfunction (mean estimated glomerular filtration rate, eGFR: 58 mL/min/1.73 m2) at baseline showed a slower subsequent decline in kidney function (3.6 mL/min/1.73 m2/year). A rapid decrease in eGFR was associated with outdoor work, agricultural work, and a lack of shade during work breaks. The nested case-control study measured eGFR, and urinary neutrophil gelatinase-associated lipocalin (uNGAL) at baseline. After adjusting for eGFR, uNGAL did not improve prediction a rapid decline in kidney function among individuals who initially presented a normal eGFR. This is the first study to show that in northwest Nicaragua, 10% of the male and 3.5% of the female population aged 18-30 years showed a very strong decline in kidney function. Larger community-based and occupational longitudinal studies with more detailed analyses of exposure data are needed to identify the cause(s) of CKDu

Detecting vapour bubbles in simulations of metastable water

International audienceThe investigation of cavitation in metastable liquids with molecular simulations requires an appropriate definition of the volume of the vapour bubble forming within the metastable liquid phase. Commonly used approaches for bubble detection exhibit two significant flaws: first, when applied to water they often identify the voids within the hydrogen bond network as bubbles thus masking the signature of emerging bubbles and, second, they lack thermodynamic consistency. Here, we present two grid-based methods, the M-method and the V-method, to detect bubbles in metastable water specifically designed to address these shortcomings. The M-method incorporates information about neighbouring grid cells to distinguish between liquid- and vapour-like cells, which allows for a very sensitive detection of small bubbles and high spatial resolution of the detected bubbles. The V-method is calibrated such that its estimates for the bubble volume correspond to the average change in system volume and are thus thermodynamically consistent. Both methods are computationally inexpensive such that they can be used in molecular dynamics and Monte Carlo simulations of cavitation. We illustrate them by computing the free energy barrier and the size of the critical bubble for cavitation in water at negative pressure

El discurso generado en el aula de español como lengua extranjera: ¿Un discurso con características propias?.

El discurso que se genera en el aula de español como lengua extranjera por el contexto en el que se realiza académico y por la situación en la que se produce el aula en presencia de los alumnos como destinatarios presenta unos rasgos que dificultan su clasificación dentro de los esquemas elaborados hasta la fecha para el análisis de los diferentes tipos de discurso. Si repasamos la bibliografía existente sobre el tema, tradicionalmente se ha partido de la dicotomía oral/escrito por lo que estos se han caracterizado según su grado de elaboración y según el canal de transmisión; pero observamos que difícilmente el discurso didáctico encaja en las clasificaciones existentes. Es por todo ello por lo que se propone establecer un marco teórico a partir de los estudios del español conversacional que permita caracterizar el discurso didáctico atendiendo a los rasgos que comparte con este

One-vortex moduli space and Ricci flow

The metric on the moduli space of one abelian Higgs vortex on a surface has a natural geometrical evolution as the Bradlow parameter, which determines the vortex size, varies. It is shown by various arguments, and by calculations in special cases, that this geometrical flow has many similarities to Ricci flow.Comment: 20 page

The complete HEFT Lagragian after the LHC Run I

The complete effective chiral Lagrangian for a dynamical Higgs is presented and constrained by means of a global analysis including electroweak precision data together with Higgs and triple gauge-boson coupling data from the LHC Run I. The operators' basis up to next-to-leading order in the expansion consists of 148 (188 considering right-handed neutrinos) flavour universal terms and it is presented here making explicit the custodial nature of the operators. This effective Lagrangian provides the most general description of the physical Higgs couplings once the electroweak symmetry is assumed, and it allows for deviations from the SU(2)L doublet nature of the Standard Model Higgs. The comparison with the effective linear Lagrangian constructed with an exact SU(2)L doublet Higgs and considering operators with at most canonical dimension six is presented. A promising strategy to disentangle the two descriptions consists in analysing (i) anomalous signals present only in the chiral Lagrangian and not expected in the linear one, that are potentially relevant for LHC searches, and (ii) decorrelation effects between observables that are predicted to be correlated in the linear case and not in the chiral one. The global analysis presented here, which includes several kinematic distributions, is crucial for reducing the allowed parameter space and for controlling the correlations between parameters. This improves previous studies aimed at investigating the Higgs Nature and the origin of the electroweak symmetry breaking