Régimen de consolidación fiscal

Tesis (Maestría en Contaduría Pública Especialidad en Impuestos) UANLUANLhttp://www.uanl.mx

Feasibility analysis and performance evaluation and optimization of a DXSAHP water heater based on the thermal capacity of the system: a case study

The present work conducts an evaluation of the feasibility and the overall performance and consequent optimization of a direct expansion solar assisted heat pump (DXSAHP) employed for domestic water heating. For the study conducted R134a, R404A, R407C and R410A working fluids were evaluated as well as the use of four, six and eight flat-plate solar collectors and a worktime ranging from 1 to 6 h. The case study is based in Mexico City with a 300 L container and a hot water outlet temperature of 51 °C. The paper introduces a new evaluation criterion based on the thermal capacity and all the evaluations conducted throughout this research revolve around this performance metric. The results show that, the system would require at least 4 h of operation to achieve the outlet temperature. Additionally, it was found that the R410A refrigerant has the best heat transfer properties; with an average condensation heat rate of 6.31 kW, followed by the R407C with 5.72 kW, the R404A with 5.42 kW and the R134a with 5.18 kW. Diversely, the R134a refrigerant requires 0.402 kW of compression work, 62% less than the R410A, which requires 1.06 kW. Consequently, R134a delivers the highest COP, which ranges from 7 to 14, followed by the R407C and R404A refrigerants, which present a similar behaviour between them, with COP ranging from 5 to 9 and 4 to 8, respectively, and finally the R410A, achieving the lowest COP, ranging from 3.5 to 6.5. Moreover, it was found that the R134a presents a higher dispersion regarding the energy exchange rate, which reveals that it is the fluid most susceptible to external factors, such as the weather. Contrarily, the remaining refrigerants present a more consistent performance. Finally, the optimization revealed that the R407C refrigerant is the most suitable given that it requires 20% less compression work than the R404A. This provides the heat pump system with a steadier behaviour, a COP ranging from 7 to 8, 30% higher than R410A, a worktime decrease of 1.5 h and heat transfer area of 5.5 flat-plate solar collectors, equivalent to a 31% reduction, both compared to R134a.The research work described in this paper was fully supported by the grants from the National Council ofScience and Technology of Mexico and the resources provided by the Applied Thermal and Hydraulic EngineeringLaboratory of the National Polytechnic Institute of Mexico.Peer ReviewedPostprint (published version

Efficacy and safety of arthroscopy in femoroacetabular impingement syndrome: a systematic review and meta-analysis of randomized clinical trials

This study aimed to compare the efficacy and safety of arthroscopy with physiotherapy or joint lavage in patients with femoroacetabular impingement (FAI). A meta-analysis using PubMed, Embase, Scopus, and the Cochrane Collaboration Library databases was performed in September 2022. We included studies focusing on patients with FAI who underwent arthroscopic surgery versus those who underwent physiotherapy or arthroscopic lavage. The outcomes were functional scores (iHOT-33 and HOS ADL) and adverse events. Randomized clinical trials were included in the study. The risk of bias in each study was assessed according to Cochrane guidelines for clinical trials. The data were combined using Review Manager version 5.4. (PROSPERO CRD42022375273). Six RCTs were included, from a pool of 839 patients (407 females). The iHOT-33 and HOS ADL scales showed significant differences at 12 months in favor of the arthroscopy group (MD, 10.65; 95% CI 6.54–4.76) and (MD, 8.09; 95% CI 3.11–13.07). MCID was not achieved through arthroscopy in functional variables. The rates of osteoarthritis (OR, 6.18; 95% CI 1.06–36.00) and numbness (OR, 73.73; 95% CI 10.00–43.92) were significantly higher in the arthroscopy group. Arthroscopic surgery showed statistical superiority over the control group without exceeding the MCID in most studies; however, the results might have been influenced by secondary variables. Finally, arthroscopic surgery results in a high rate of conversion to osteoarthritis.Medicin

Por alusiones. Referencias personales a inmigrantes en grupos de discusión con españoles sobre la recuperación económica

In Spain, the deep economic crisis that started in 2008 did not lead to a significant increase in the rejection of immigrants among the local population, as might have been expected from group threat theory. Once the economic crisis has been overcome, the question arises of to what extent this majority acceptance of immigration in Spain is maintained, as well as whether it is solid or sustainable over time. In this article we offer some answers to these important questions based on the analysis of the discourses produced in 9 Discussion Groups with Spaniards held in 2019. Specifically, it consists of a microscopic or detailed analysis focused on personal allusions to immigrants, i.e. references to specific persons identified as immigrants, which emerged during in the group conversations. Through this analysis, we aim to detect possible attitudes of rejection which may be hidden or dissembled in the most explicit discursive expressions. The results suggest that rejection of immigrants is very scarce and discursively weak, even in these personal allusions. But more than an unconditional acceptance of immigration, the allusions are ambivalent, with a relatively frequent expression of criticism and reproach, which however did not arrive to overt hostility or animosity. This ambivalence makes these attitudes more a certain precarious or unstable.En España la profunda crisis económica que se inicia en 2008 no supuso un aumento importante del rechazo a los inmigrantes entre la población autóctona, como se habría podido esperar en base a la teoría del conflicto intergrupal. Una vez superada la crisis económica se plantea la pregunta de en qué medida esta aceptación mayoritaria de la inmigración en España se mantiene, así como si es sólida o sostenible en el tiempo. En este artículo ofrecemos algunas respuestas a estas importantes cuestiones a partir del análisis de los discursos producidos en 9 Grupos de Discusión con españoles autóctonos realizados en 2019. En concreto, se trata de un análisis microscópico o de detalle centrado en las alusiones personales a inmigrantes, es decir, referencias a personas concretas identificadas como inmigrantes, que se producen en las conversaciones grupales. Mediante este análisis se pretendió detectar posibles actitudes de rechazo ocultadas o disimuladas en las expresiones discursivas más explícitas. Los resultados apuntan a que el rechazo a los inmigrantes es muy escaso y discursivamente débil incluso en estas alusiones personales. Pero más que una aceptación incondicional de la inmigración las alusiones se muestran ambivalentes, con una relativamente frecuente expresión de críticas y reproches que sin embargo no derivan en hostilidad o animadversión. Esta ambivalencia confiere a estas actitudes un cierto carácter precario o inestable. In Spain, the deep economic crisis that started in 2008 did not lead to a significant increase in the rejection of immigrants among the local population, as might have been expected from group threat theory. Once the economic crisis has been overcome, the question arises of to what extent this majority acceptance of immigration in Spain is maintained, as well as whether it is solid or sustainable over time. In this article we offer some answers to these important questions based on the analysis of the discourses produced in 9 Discussion Groups with Spaniards held in 2019. Specifically, it consists of a microscopic or detailed analysis focused on personal allusions to immigrants, i.e. references to specific persons identified as immigrants, which emerged during in the group conversations. Through this analysis, we aim to detect possible attitudes of rejection which may be hidden or dissembled in the most explicit discursive expressions. The results suggest that rejection of immigrants is very scarce and discursively weak, even in these personal allusions. But more than an unconditional acceptance of immigration, the allusions are ambivalent, with a relatively frequent expression of criticism and reproach, which however did not arrive to overt hostility or animosity. This ambivalence makes these attitudes more a certain precarious or unstable

Modeling arterial pulse waves in healthy aging: a database for in silico evaluation of hemodynamics and pulse wave indexes.

The arterial pulse wave (PW) is a rich source of information on cardiovascular (CV) health. It is widely measured by both consumer and clinical devices. However, the physical determinants of the PW are not yet fully understood, and the development of PW analysis algorithms is limited by a lack of PW data sets containing reference CV measurements. Our aim was to create a database of PWs simulated by a computer to span a range of CV conditions, representative of a sample of healthy adults. The typical CV properties of 25-75 yr olds were identified through a literature review. These were used as inputs to a computational model to simulate PWs for subjects of each age decade. Pressure, flow velocity, luminal area, and photoplethysmographic PWs were simulated at common measurement sites, and PW indexes were extracted. The database, containing PWs from 4,374 virtual subjects, was verified by comparing the simulated PWs and derived indexes with corresponding in vivo data. Good agreement was observed, with well-reproduced age-related changes in hemodynamic parameters and PW morphology. The utility of the database was demonstrated through case studies providing novel hemodynamic insights, in silico assessment of PW algorithms, and pilot data to inform the design of clinical PW algorithm assessments. In conclusion, the publicly available PW database is a valuable resource for understanding CV determinants of PWs and for the development and preclinical assessment of PW analysis algorithms. It is particularly useful because the exact CV properties that generated each PW are known.NEW & NOTEWORTHY First, a comprehensive literature review of changes in cardiovascular properties with age was performed. Second, an approach for simulating pulse waves (PWs) at different ages was designed and verified against in vivo data. Third, a PW database was created, and its utility was illustrated through three case studies investigating the determinants of PW indexes. Fourth, the database and tools for creating the database, analyzing PWs, and replicating the case studies are freely available

Estimating central blood pressure from aortic flow: development and assessment of algorithms

Central blood pressure (cBP) is a highly prognostic cardiovascular (CV) risk factor whose accurate, invasive assessment is costly and carries risks to patients. We developed and assessed novel algorithms for estimating cBP from noninvasive aortic hemodynamic data and a peripheral blood pressure measurement. These algorithms were created using three blood flow models: the two- and three-element Windkessel (0-D) models and a one-dimensional (1-D) model of the thoracic aorta. We tested new and existing methods for estimating CV parameters (left ventricular ejection time, outflow BP, arterial resistance and compliance, pulse wave velocity, and characteristic impedance) required for the cBP algorithms, using virtual (simulated) subjects (n = 19,646) for which reference CV parameters were known exactly. We then tested the cBP algorithms using virtual subjects (n = 4,064), for which reference cBP were available free of measurement error, and clinical datasets containing invasive (n = 10) and noninvasive (n = 171) reference cBP waves across a wide range of CV conditions. The 1-D algorithm outperformed the 0-D algorithms when the aortic vascular geometry was available, achieving central systolic blood pressure (cSBP) errors ≤ 2.1 ± 9.7 mmHg and root-mean-square errors (RMSEs) ≤ 6.4 ± 2.8 mmHg against invasive reference cBP waves (n = 10). When the aortic geometry was unavailable, the three-element 0-D algorithm achieved cSBP errors ≤ 6.0 ± 4.7 mmHg and RMSEs ≤ 5.9 ± 2.4 mmHg against noninvasive reference cBP waves (n = 171), outperforming the two-element 0-D algorithm. All CV parameters were estimated with mean percentage errors ≤ 8.2%, except for the aortic characteristic impedance (≤13.4%), which affected the three-element 0-D algorithm’s performance. The freely available algorithms developed in this work enable fast and accurate calculation of the cBP wave and CV parameters in datasets containing noninvasive ultrasound or magnetic resonance imaging data

Estimating central blood pressure from aortic flow: development and assessment of algorithms

Central blood pressure (cBP) is a highly prognostic cardiovascular (CV) risk factor whose accurate, invasive assessment is costly and carries risks to patients. We developed and assessed novel algorithms for estimating cBP from noninvasive aortic hemodynamic data and a peripheral blood pressure measurement. These algorithms were created using three blood flow models: the two- and three-element Windkessel (0-D) models and a one-dimensional (1-D) model of the thoracic aorta. We tested new and existing methods for estimating CV parameters (left ventricular ejection time, outflow BP, arterial resistance and compliance, pulse wave velocity, and characteristic impedance) required for the cBP algorithms, using virtual (simulated) subjects (n = 19,646) for which reference CV parameters were known exactly. We then tested the cBP algorithms using virtual subjects (n = 4,064), for which reference cBP were available free of measurement error, and clinical datasets containing invasive (n = 10) and noninvasive (n = 171) reference cBP waves across a wide range of CV conditions. The 1-D algorithm outperformed the 0-D algorithms when the aortic vascular geometry was available, achieving central systolic blood pressure (cSBP) errors ≤ 2.1 ± 9.7 mmHg and root-mean-square errors (RMSEs) ≤ 6.4 ± 2.8 mmHg against invasive reference cBP waves (n = 10). When the aortic geometry was unavailable, the three-element 0-D algorithm achieved cSBP errors ≤ 6.0 ± 4.7 mmHg and RMSEs ≤ 5.9 ± 2.4 mmHg against noninvasive reference cBP waves (n = 171), outperforming the two-element 0-D algorithm. All CV parameters were estimated with mean percentage errors ≤ 8.2%, except for the aortic characteristic impedance (≤13.4%), which affected the three-element 0-D algorithm’s performance. The freely available algorithms developed in this work enable fast and accurate calculation of the cBP wave and CV parameters in datasets containing noninvasive ultrasound or magnetic resonance imaging data. NEW & NOTEWORTHY First, our proposed methods for CV parameter estimation and a comprehensive set of methods from the literature were tested using in silico and clinical datasets. Second, optimized algorithms for estimating cBP from aortic flow were developed and tested for a wide range of cBP morphologies, including catheter cBP data. Third, a dataset of simulated cBP waves was created using a three-element Windkessel model. Fourth, the Windkessel model dataset and optimized algorithms are freely available.This work was supported by a PhD Fellowship awarded by the King’s College London and Imperial College London EPSRC Centre for Doctoral Training in Medical Imaging [EP/L015226/1], the British Heart Foundation (BHF) [PG/15/104/31913], and the Wellcome EPSRC Centre for Medical Engineering at King’s College London [WT 203148/Z/16/Z]. The authors acknowledge financial support from the Department of Health through the National Institute for Health Research (NIHR) Cardiovascular MedTech Co-operative at Guy’s and St Thomas’ NHS Foundation Trust (GSTT)

Caracterización de los sistemas de producción familiar ovina en la Mixteca Oaxaqueña, México

Family sheep production is common in rural Mexico. It is an important element of subsistence systems in these areas but is generally rustic. Better understanding of rustic sheep production is a first step in developing strategies and programs to support family producers. Family sheep production units in two municipalities in the Mixteca region of Oaxaca, Mexico, were characterized in terms of production system, market access and land use. A mixed methodology was applied, employing a structured questionnaire addressing socioeconomic and productive variables, and participatory observation in 29 family sheep producers. All the surveyed producers see sheep farming as their main income source. Most (86 %) use a subsistence system, and all use family labor. The main feeding strategy was grazing of communal land, and production was largely intended for sale of live animals to intermediaries or in local markets for eventual processing for meat, and/or for self-use. Most (83 %) of the production units included a pen built from regional materials, and these pens were most frequently on the family property. Implementation of management plans and animal health and safety measures were minimal. Analysis of these productive systems identified how producers manage sheep production. Management strategies respond to the environmental services available on communal lands, and involve family-type production which fulfills economic, social, environmental and cultural functions, but provides low productivity. Unit productivity and producer livelihood could be improved by implementing measures such as pasture rotation and adopting technological innovations. Broadening producer access to government programs and creating public policy that promotes development in marginal rural areas could greatly improve productivity and consequently reduce poverty and food insecurity.El objetivo fue analizar las características de las unidades de producción familiar ovina de dos municipios de la Mixteca Oaxaqueña teniendo como referencia el sistema de producción, acceso al mercado y el uso del territorio. Se usó una metodología mixta, empleando un cuestionario estructurado donde se analizaron variables de carácter socioeconómico y productivo; y observación participativa en 29 ovinocultores familiares. Los resultados señalan que el 100 % de los productores ven a la ovinocultura como principal fuente de ingresos, 86 % produce bajo un sistema de subsistencia, 100 % emplea la mano de obra familiar, la estrategia alimentaria principal es el pastoreo debido a las características del territorio y el tipo de tenencia de la tierra comunal en un 90 %, la función zootécnica es producción de carne destinada al comercio local y autoconsumo, 83 % de los productores cuentan con corral de encierro construido con material de la región, 86.7 % de los productores mantienen su corral dentro del predio familiar, se aplican escasas medidas de manejo y sanitarias. El análisis de los sistemas productivos permitió identificar formas de gestión de su producción la cual está ligada a los servicios dentro de su territorio, desarrollando una producción de tipo familiar que cumple con funciones económicas, sociales, ambientales y culturales, sin embargo, se cuenta con una baja productividad. Por lo cual, se considera necesario la adopción de tecnología e innovación a través de estrategias y políticas públicas que impulsen el desarrollo rural en zonas marginales tendientes a disminuir el nivel de pobreza e inseguridad alimentaria

El aprendizaje jurídico basado en un modelo multipolar de trabajo de fin de grado

El presente Proyecto de Innovación y Mejora de la Calidad Docente tiene como objeto el diseño de un modelo “multipolar” de trabajo de fin de grado. Entendida la multipolaridad en el sentido de que el trabajo debe ser multidisciplinar, interfacultativo y plurianual. Para ello, se ha trabajado un tema de gran actualidad política, social y jurídica, como es el análisis de los efectos que producirá la despenalización generalizada de las faltas en la reciente reforma del Código Penal y su transformación en ilícitos administrativos en la Ley Orgánica de Protección de la Seguridad Ciudadana. Se propone un modelo de trabajo fin de grado en el que el propio alumno es el gestor y arquitecto de su trabajo y en el que se la interdisciplinariedad y el diverso enfoque de cada alumno integrado en el grupo de trabajo permite un intercambio constante de información, materiales y de intenso debate entre los alumnos