Mass & secondary structure propensity of amino acids explain their mutability and evolutionary replacements

Why is an amino acid replacement in a protein accepted during evolution? The answer given by bioinformatics relies on the frequency of change of each amino acid by another one and the propensity of each to remain unchanged. We propose that these replacement rules are recoverable from the secondary structural trends of amino acids. A distance measure between high-resolution Ramachandran distributions reveals that structurally similar residues coincide with those found in substitution matrices such as BLOSUM: Asn Asp, Phe Tyr, Lys Arg, Gln Glu, Ile Val, Met → Leu; with Ala, Cys, His, Gly, Ser, Pro, and Thr, as structurally idiosyncratic residues. We also found a high average correlation (\overline{R} R = 0.85) between thirty amino acid mutability scales and the mutational inertia (I X ), which measures the energetic cost weighted by the number of observations at the most probable amino acid conformation. These results indicate that amino acid substitutions follow two optimally-efficient principles: (a) amino acids interchangeability privileges their secondary structural similarity, and (b) the amino acid mutability depends directly on its biosynthetic energy cost, and inversely with its frequency. These two principles are the underlying rules governing the observed amino acid substitutions. © 2017 The Author(s)

Observational Δν\Delta\nu-ρˉ\bar\rho relation for δ\delta Sct stars using eclipsing binaries and space photometry

Delta Scuti ($\delta$ Sct) stars are intermediate-mass pulsators, whose intrinsic oscillations have been studied for decades. However, modelling their pulsations remains a real theoretical challenge, thereby even hampering the precise determination of global stellar parameters. In this work, we used space photometry observations of eclipsing binaries with a $\delta$ Sct component to obtain reliable physical parameters and oscillation frequencies. Using that information, we derived an observational scaling relation between the stellar mean density and a frequency pattern in the oscillation spectrum. This pattern is analogous to the solar-like large separation but in the low order regime. We also show that this relation is independent of the rotation rate. These findings open the possibility of accurately characterizing this type of pulsator and validate the frequency pattern as a new observable for $\delta$ Sct stars.Comment: 11 pages, including 2 pages of appendix, 2 figures, 2 tables, accepted for publication in ApJ

Mandibular advancement devices in the treatment of obstructive sleep apnea syndrome

La apnea del sueño es un trastorno respiratorio, con consecuencias no deseables para la salud, que ocurre durante el sueño cuando se obstruyen o colapsan las vías aéreas superiores. El fenómeno es bien conocido clínicamente, con diagnosis y tratamientos médicos contrastados, pero no existe una metodología sencilla ni los instrumentos y técnicas de análisis necesarias para conocer y valorar cualitativa y cuantitativamente la respuesta física y clínica de una actuación mandibular concreta. En este trabajo se muestra como las técnicas digitales de tratamiento de imágenes, la dinámica de fluidos y la implementación de criterios ingenieriles de diseño importados de otros campos de actividad permiten, a partir de unas imágenes médicas convencionales, establecer una metodología de análisis sencilla útil clínicamente para decidir las actuaciones, de presión o mecánicas, mandibulares más convenientes. La metodología se aplica a un paciente que sufre el síndrome y se estudia el efecto de un dispositivo mandibular (DAM® ), especialmente innovador, premiado científica y empresarialmente en varias ocasiones, que por medio de un avance de la mandíbula, variable y distinto para cada paciente según las necesidades clínicas, provoca una apertura significativa de las vías aéreas superiores.Obstructive sleep apnea syndrome (OSAS) consists in the occurrence of recurrent episodes of airflow limitation during sleep, with undesirable consequences for the health. The phenomenon is well known from a medical point of view (prognosis, diagnosis and treatment), but there is not a methodology or analysis tools for the quantification of the clinical response using Mandibular Advancement Devices (MAD). This paper shows how combining image processing, fluid dynamics and engineering design criteria, imported from other fields, allow to establish a simple analysis method clinically useful to decide the more convenient positioning of the MAD based on the pressure or mechanical movement of the jaw. This methodology is applied to a patient suffering OSAS which the objective to evaluate the changes provoked in the upper-airways due to an innovative mandibular device.Peer Reviewe

Salvage surgery for squamous cell carcinoma of the head and neck in the era of immunotherapy: Is it time to clarify our guidelines?

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/146561/1/cncr31717_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/146561/2/cncr31717.pd

Babesia Bovis Ligand-Receptor Interaction: AMA-1 Contains Small Regions Governing Bovine Erythrocyte Binding

Apical membrane antigen 1 is a microneme protein which plays an indispensable role during Apicomplexa parasite invasion. The detailed mechanism of AMA-1 molecular interaction with its receptor on bovine erythrocytes has not been completely defined in Babesia bovis. This study was focused on identifying the minimum B. bovis AMA-1-derived regions governing specific and high-affinity binding to its target cells. Different approaches were used for detecting ama-1 locus genetic variability and natural selection signatures. The binding properties of twelve highly conserved 20-residue-long peptides were evaluated using a sensitive and specific binding assay based on radio-iodination. B. bovis AMA-1 ectodomain structure was modelled and refined using molecular modelling software. NetMHCIIpan software was used for calculating B-and T-cell epitopes. The B. bovis ama-1 gene had regions under functional constraint, having the highest negative selective pressure intensity in the Domain I encoding region. Interestingly, B. bovis AMA-1-DI (100YMQKFDIPRNHGSGIYVDLG119 and120GYESVGSKSYRMPVGKCPVV139 ) and DII (302CPMHPVRDAIFGKWSGGSCV321 )-derived peptides had high specificity interaction with erythrocytes and bound to a chymotrypsin and neuraminidase-treatment sensitive receptor. DI-derived peptides appear to be exposed on the protein’s surface and contain predicted B-and T-cell epitopes. These findings provide data (for the first-time) concerning B. bovis AMA-1 functional subunits which are important for establishing receptor-ligand interactions which could be used in synthetic vaccine development

Budgetary impact for the National Health System of Apixaban Prophylaxis of venous thromboembolism in patients undergoing yotal knee or hip replacement

Fundamentos: Debido al elevado coste sanitario del tromboembolismo venoso (TEV) es necesario realizar análisis económicos que determinen la eficiencia de sus diferentes tratamientos farmacológicos. El objetivo del trabajo es estimar el impacto presupuestario para el Sistema Nacional de Salud (SNS) de la prevención del tromboembolismo venoso (TEV) con apixaban en artroplastia total de cadera (ATC) o rodilla (ATR). Métodos: Se consideraron los costes de los diferentes fármacos para la prevención del TEV (apixaban, dabigatrán, enoxaparina, fondaparinux, otras heparinas, rivaroxaban y warfarina) y los de las complicaciones del TEV a corto plazo (90 días) y a 5 años (trombosis venosa profunda, embolismo pulmonar, sangrados y síndrome postrombótico). La eficacia de la prevención se estimó mediante un metaanálisis. Las tasas de TEV y muerte con apixaban fueron inferiores en ATC y ATR a las observadas con enoxaparina (-3,5% y -10,0%, respectivamente) y tuvo menos acontecimientos hemorrágicos (-0,7% y -1,6%, respectivamente). Los datos poblacionales y los costes se obtuvieron de fuentes españolas. Horizonte temporal: 5 años. Todos los costes se descontaron anualmente un 3,5%. Se estimó que a los cinco años de su comercialización el consumo de apixaban supondría el 23% de la prevención del TEV y el de enoxaparina descendería del 60% hasta el 33%. Resultados: La introducción de apixaban para la prevención del TEV produciría un ahorro para el SNS de 547.422 € en un periodo de 5 años. En el caso de considerar sin coste la administración ambulatoria de las heparinas, el ahorro quinquenal para el SNS ascendería a 270.068 €. Conclusiones: La introducción de apixaban podría reducir la tasa de TEV y sangrados en comparación con enoxaparina, reduciéndose el gasto del SNS en la prevención del TEVDue to high health care costs of venous thromboembolism (VTE), economic analyses are needed to determine the efficiency of different drug treatments. Consequently, a study was conducted to estimate the budgetary impact for the National Health System (NHS) with apixaban for prevention of venous thromboembolism (VTE) in total hip (THR) or knee (TKR) replacement. Methods: Cost considered: the drugs for the prevention of VTE (apixaban, dabigatran, enoxaparin, fondaparinux, other heparins, rivaroxaban and warfarin) and the complications of VTE in the short term and in 5 years (deep vein thrombosis, pulmonary embolism, bleedings and the post-thrombotic syndrome). The effectiveness of prophylaxis was estimated using a meta-analysis. The VTE rates and death with apixaban are lower in THR and TKR than enoxaparin (-3.5% and -10.0%, respectively) with less bleeding events (-0.7% and -1.6%, respectively). Population data and unit costs were obtained from Spanish sources. Time horizon: 5 years. All costs were discounted by 3.5% annually. Five years after commercialization, the use of apixaban was estimated to account for 23% of the prophylaxis of VTE and the use of enoxaparin decrease from the 60% to 33%. Results: Apixaban´s introduction for the prophylaxis of VTE would have a significant impact for the NHS, resulting in a saving of 547,422 over a period of 5 years. In the case of outpatient administration of heparin did not have a cost, the savings for the NHS five years amount to Due to high health care costs of venous thromboembolism (VTE), economic analyses are needed to determine the efficiency of different drug treatments. Consequently, a study was conducted to estimate the budgetary impact for the National Health System (NHS) with apixaban for prevention of venous thromboembolism (VTE) in total hip (THR) or knee (TKR) replacement. Methods: Cost considered: the drugs for the prevention of VTE (apixaban, dabigatran, enoxaparin, fondaparinux, other heparins, rivaroxaban and warfarin) and the complications of VTE in the short term and in 5 years (deep vein thrombosis, pulmonary embolism, bleedings and the post-thrombotic syndrome). The effectiveness of prophylaxis was estimated using a meta-analysis. The VTE rates and death with apixaban are lower in THR and TKR than enoxaparin (-3.5% and -10.0%, respectively) with less bleeding events (-0.7% and -1.6%, respectively). Population data and unit costs were obtained from Spanish sources. Time horizon: 5 years. All costs were discounted by 3.5% annually. Five years after commercialization, the use of apixaban was estimated to account for 23% of the prophylaxis of VTE and the use of enoxaparin decrease from the 60% to 33%. Results: Apixaban´s introduction for the prophylaxis of VTE would have a significant impact for the NHS, resulting in a saving of 547,422 over a period of 5 years. In the case of outpatient administration of heparin did not have a cost, the savings for the NHS five years amount to 270,068. Conclusions: According to this study, the introduction of apixaban may reduce the rate of VTE and bleeding compared with enoxaparin, decreasing the expenditure of NHS in VTE prophylaxis Due to high health care costs of venous thromboembolism (VTE), economic analyses are needed to determine the efficiency of different drug treatments. Consequently, a study was conducted to estimate the budgetary impact for the National Health System (NHS) with apixaban for prevention of venous thromboembolism (VTE) in total hip (THR) or knee (TKR) replacement. Methods: Cost considered: the drugs for the prevention of VTE (apixaban, dabigatran, enoxaparin, fondaparinux, other heparins, rivaroxaban and warfarin) and the complications of VTE in the short term and in 5 years (deep vein thrombosis, pulmonary embolism, bleedings and the post-thrombotic syndrome). The effectiveness of prophylaxis was estimated using a meta-analysis. The VTE rates and death with apixaban are lower in THR and TKR than enoxaparin (-3.5% and -10.0%, respectively) with less bleeding events (-0.7% and -1.6%, respectively). Population data and unit costs were obtained from Spanish sources. Time horizon: 5 years. All costs were discounted by 3.5% annually. Five years after commercialization, the use of apixaban was estimated to account for 23% of the prophylaxis of VTE and the use of enoxaparin decrease from the 60% to 33%. Results: Apixaban´s introduction for the prophylaxis of VTE would have a significant impact for the NHS, resulting in a saving of € 547,422 over a period of 5 years. In the case of outpatient administration of heparin did not have a cost, the savings for the NHS five years amount to 270,068. Conclusions: According to this study, the introduction of apixaban may reduce the rate of VTE and bleeding compared with enoxaparin, decreasing the expenditure of NHS in VTE prophylaxis € 270,068. Conclusions: According to this study, the introduction of apixaban may reduce the rate of VTE and bleeding compared with enoxaparin, decreasing the expenditure of NHS in VTE prophylaxisEstudio financiado, sin restricciones, por Bristol-Myers Squibb y Pfize

¿Cómo pagan los colombianos y por qué?

Este reporte presenta los resultados de dos encuestas, una a consumidores y otra a pequeños comercios, sobre los factores socioeconómicos vinculados al acceso, uso y aceptación de los pagos electrónicos en Colombia. La implementación de estas encuestas en las principales ciudades colombianas en 2016 es el resultado de un esfuerzo conjunto del Banco de la República, la Asociación Bancaria de Colombia, Redeban Multicolor S.A. y la firma Cifras & Conceptos. Entre los mensajes centrales de este reporte se encuentra que aunque los consumidores urbanos han alcanzado un alto grado de acceso a instrumentos de pago electrónicos, estos siguen haciendo un 97% de sus pagos en efectivo debido a la limitada aceptación de estos instrumentos en sus transacciones cotidianas. La renuencia de los comercios a aceptar instrumentos de pago electrónicos se debe a varios aspectos, entre los cuales se destacan sus percepciones respecto a los altos costos de operar con pagos electrónicos frente al efectivo y la perspectiva de mayores cargas impositivas. No obstante, los comercios reconocen las oportunidades que puede traerles el aceptar pagos electrónicos en términos de eficiencia y competitividad. Estos factores no solo están asociados con la decisión de aceptar o no pagos electrónicos sino, de igual relevancia, con sus decisiones de formalizarse y acceder a cuentas de depósito con el sistema financiero

Metacercarias de Digenea en Hyphessobrycon Wajat Almirón & Casciotta, 1999 en la laguna del Parque General Manuel Belgrano, Santa Fe

Los ambientes acuáticos urbanos brindan servicios ecosistémicos valiosos tales como esparcimiento, provisión de agua y control de inundaciones. Sin embargo, muchos de estos servicios entran en riesgo debido a la falta de monitoreo y medidas de manejo que garanticen el mantenimiento de su integridad biológica. El Parque General Manuel Belgrano (PGMB) se encuentra ubicado en la zona sur de la ciudad de Santa Fe y posee una laguna aislada del riacho Santa Fe por un terraplén artificial. Este cuerpo de agua contiene una comunidad de unas 20 especies de peces, con una alta abundancia del pequeño carácido Hyphessobrycon wajat. Este trabajo tuvo como objetivo estudiar los ectoparásitos asociados a la población de H. wajat residente en la laguna del PGMB.Asociación Parasitológica Argentin