A novel approach to bioelectrical impedance plethysmography for the assessment of arterial and venous circulatory problems in the forearm

Peripheral vascular disease (PVD) and/or peripheral arterial disease (PAD) are sicknesses known to inadequate delivery of either arterial or venous blood towards the extremities. Such sickness may trigger complications owing to the lack of transport of oxygen and nutrients, thus causing hypoxic events that may eventually prompt to ischaemic tissue or even the loss of the compromised limb. One of the most prominent indicators of prosperous health is blood volume and flow. The basic information within these health parameters may show cardiovascular problems or the advance of further complications related to other diseases like diabetes. In clinical setting, there effective methods to measure these parameters like Doppler ultrasound, photoplethysmography or venous occlusion plethysmography. These methods take measurements from either single vessels and/or small volume of tissue. However, it is difficult to establish a relation between the obstruction of arterial and/or venous circulation and the amount of blood received by the tissue. Bioelectrical impedance plethysmography (iPG) measures blood changes by driving a small amount of AC current into the body and after measuring the potential created by fluids flowing through tissue. This technique apart from taking measures within defined volumes of tissue, it is easy to use as only needs four electrodes on the skin. Hence, a bespoken bioelectrical impedance device including hardware and software was built ready to measure changes in blood volume/flow in the upper limbs. The system was assessed in an in-vivo controlled environment with 8 participants. The blood flow towards their left arms was altered by constricting the upper arm with a cuff at three levels: 1) below venous pressure 2) amongst venous and arterial pressure and 3) during total occlusion. Simultaneously, measurements from various instruments like ECG, Doppler ultrasound, laser Doppler flowmetry and PPG were taken and compared to the measurements obtained from the iPG instrument and defining its correlation with the impedimetric signal. The results from the experiments showed that the bioelectrical impedance signal changed in basal and arterial pulses showing specific characteristics for each kind of occlusion. The data indicated that it is possible to differentiate between a venous and arterial occlusion by examining both components of the impedance signal. The impedance during venous occlusion dropped in average 0.658±0.230% from the baseline. On the other hand, during arterial occlusion the base impedance dropped in a higher rate approximately 1.13±04.82%, indicating a differentiator during both type of blood flow disruption. Furthermore, the impedance plethysmography waveform morphology also reshaped during these occlusive periods. The whole waveform during artificial venous obstruction increased in magnitude, the systolic peak rose 31.80%, the dicrotic notch 47.73% and the diastolic point 31.92%, where the value of the latter was higher than the dicrotic notch point. In contrast, in the time of partial arterial occlusion the waveform also increased in size at all these points, but its shape was altered. The impedance magnitude at the diastolic point went below the ones at the dicrotic notch. These fluctuations provided additional further information that it might be possible to differentiate amongst venous and arterial occlusions. By consolidating the data obtained by the iPG device, it is possible to produce an index ratio between the basal impedance and these three reference points which may help to identify early circulatory problems in the arterial and/or venous systems

Geminivirus Rep Protein Interferes with the Plant DNA Methylation Machinery and Suppresses Transcriptional Gene Silencing

Viruses are masters at circumventing host defenses and manipulating the cellular environment for their own benefit. The replication of the largest known family of single-stranded DNA viruses, Geminiviridae, is impaired by DNA methylation but the fact that plants might use methylation as a defense against geminiviruses and the impact that viral genome methylation may have during the infection, remain controversial. We have found that geminiviruses reduce the expression of the plant maintenance DNA methyltransferases, MET1 and CMT3, in both, locally and systemically infected tissues. Furthermore, we demonstrated that the virus-mediated repression of these two maintenance DNA methyltransferases is widely spread among different geminivirus species and we have identified Rep as the geminiviral protein responsible for the repression of MET1 and CMT3. The presence of Rep, suppresses transcriptional gene silencing (TGS) of an Arabidopsis transgene and of host loci whose expression is strongly controlled by MET1. Bisulfite sequencing analyses showed that the expression of Rep caused a substantial reduction in the levels of DNA methylation at certain loci at CG sites. The biological relevance of these findings and the role of Rep as a TGS suppressor will be discussed.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Dilaton thin-shell wormholes supported by a generalized Chaplygin gas

In this article, we construct spherical thin-shell wormholes with charge in dilaton gravity. The exotic matter required for the construction is provided by a generalized Chaplygin gas. We study the stability under perturbations preserving the symmetry. We find that the increase of the coupling between the dilaton and the electromagnetic fields reduces the range of the parameters for which stable configurations are possible.Comment: 14 pages, 6 figures. v3: typos correcte

Importance of the temperature in the interaction plant-geminivirus

Introduction. Geminivirusare plant viruses that have circular single-stranded DNA (ssDNA) genome encapsidated in twinned quasi-icosahedral (geminate) virionsand are a serious threat to diverse economically important crops such as tomato, pepper and cassava. TYLCV (Tomato yellow leaf curl virus) belongs to the genus begomovirus which is by far, the largest of the seven genera in the family Geminiviridae and it is a pathogen that induces a devastating disease in tomato in the Mediterranean region. Cultured tomatoes are often exposed to a combination of extreme heat and infection with TYLCV and this combination leads to intense disease symptoms and yield losses.The impact of temperature over the interaction tomato- TYLCVhas been characterized (Ghandi et al., 2016) but these results seem to be contradictory to our findings. Objective. The main objective of this work is to improve our understanding of the impact that high temperature has in the interaction plant-geminivirus.Material and methods. Nicotianabenthamiana plants were infected with TYLCV and growth in a chamber at 21 ºC or at 35 ºC. The amount of virus, symptoms, plant height and number of leaves were monitored at 14, 21 and 28 dpi (days post-infection). Three biological replicates were performed, each containing 15 infected plants and 10 non-infected plants (mock). Results. No differences were observed between non-infected and infected plants at both temperatures, in plant height or in the number of leaves, but the amount of virus and the severity of symptoms were significantly reduced in plants at high temperature. Conclusions. We conclude that TYLCV yield decreases in N. benthamiana due to high temperature and ongoing experiments in tomato TYLCV-infected plants will let us determine the importance of this finding in an agronomical important crop and to compare our results with the published data.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

The perception of indole negatively modulates biocontrol activities in the plant beneficial Rhizobacterium Lysobacter capsici AZ78

The rhizosphere is a dynamic environment characterised by multiple and complex microbial interactions where diffusible communication signals (DCS) continuously influence the expression patterns of the microbiome, hence regulating fundamental traits for adaptation to the rhizosphere. In particular, plant-associated bacteria release indole, a Volatile Organic Compound (VOC) that acts as an interkingdom signal able to influence antibiotic resistance, motility, biofilm formation and virulence. Lysobacter spp. are commonly found in the rhizosphere and have been frequently associated to disease suppression. For instance, the biocontrol activity of the plant beneficial bacterium Lysobacter capsici AZ78 (AZ78) has been reported against the phytopathogenic oomycetes Phytophthora infestans, Plasmopara viticola, Pythium ultimum and the Gram-positive bacterium Rhodococcus fascians. However, there is scarce information about Lysobacter spp. ecology and how DCS, and in particular indole, may affect their behaviour in the rhizosphere. To investigate the aspects determining rhizosphere competence and functioning of Lysobacter spp., this work presents a functional and transcriptomic analysis performed on AZ78, which was grown in the presence indole. The presence of indole significantly reduced the inhibition capacity of AZ78 against P. ultimum and R. fascians by 47 and 31%, respectively. Moreover, RNA-Seq analysis revealed that nearly 12% of all genes in AZ78 genome were modulated by indole. In particular, indole downregulated the expression of the heat-stable antifungal factor (HSAF) biosynthetic gene cluster, which may affect AZ78 antioomycete and antimicrobial activity. Moreover, in the presence of indole, AZ78 downregulated several signal transduction pathways responsible for nutrients uptake, resulting in reduced growth. Finally, indole downregulated several genes related to type IV pilus functionality, which might lead to impaired twitching motility. This study sheds light on the key role of DCS such as indole in shaping AZ78 behaviour in the rhizosphere and suggests that, manipulating DCS levels may alter the persistence and functioning of several plant-beneficial rhizobacteria, such as Lysobacter strains

Análisis de la infección por geminivirus en plantas con la maquinaria de metilación del DNA alterada.

Los geminivirus son virus de plantas pertenecientes a la familia Geminiviridae. Poseen un genoma compuesto por una o dos moléculas de DNA circular de cadena simple y una cápside compuesta de 2 partes icosaédricas gemelas, de ahí el nombre de geminivirus. Uno de los geminivirus más estudiados es el virus del rizado amarillo de la hoja de tomate (TYLCV, Tomato yellow leaf curl virus), causante de importantes pérdidas en las cosechas en zonas templadas, subtropicales y tropicales. Este geminivirus codifica 6 proteínas, de las cuales sólo la proteína Rep es esencial para su replicación. La metilación del DNA es una marca epigenética que promueve el silenciamiento génico a nivel transcripcional (TGS) y juega un importante papel en el mantenimiento de la integridad del genoma mediante el silenciamiento de transposones. Diversos estudios sugieren que participa de manera relevante en la defensa de la planta frente a virus de DNA como los geminivirus (Raja et al, 2008; Yang et al, 2011, Zhang et al, 2011). Los geminivirus son capaces de interferir en el mecanismo de TGS propio de la planta; una de las proteínas implicadas en la supresión de dicho mecanismo es Rep, la cual induce una disminución en los niveles de expresión de las metiltransferasas de mantenimiento MET1 y CMT3 de Arabidopsis thaliana y Nicotiana benthamiana, revierte el silenciamiento génico transcripcional de loci endógenos y transgenes e induce la hipometilación de loci cuya metilación es esencialmente dependiente de MET1 (Rodríguez-Negrete et al., 2013). Considerando que los datos previos sugieren que los geminivirus suprimen el mecanismo de TGS como un mecanismo de contra-defensa, nos popusimos evaluar la importancia de la metilación del DNA como mecanismo de defensa frente a los geminivirus. Para ello se midieron los niveles del geminivus TYLCV-Mld (Tomato yellow leaf curl virus, aislado Mld) tras la infección de mutantes de A. thaliana deficientes en la maquinaria de metilación: met1-3 (mutante en MET1), ros1-4 (mutante en la desmetilasa ROS1) y ddc (triple mutante DRM1, DRM2 y CMT3, siendo DRM1 y DRM2 metiltransferasas de novo). Por otro lado se midieron niveles del mismo geminivirus en plantas infectadas de N. benthamiana que presentan reducidos niveles de expresión de MET1, CMT3 o ROS1; la reducción de la expresión de estos genes de N. benthamiana fue generada mediante silenciamiento génico inducido por virus (VIGS). Se presentarán y discutirán dichos resultados.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

MINLP-based hybrid strategy for operating mode selection of TES-backed-up refrigeration systems

Es la versión aceptada del artículo. Se puede consultar la versión final en https://onlinelibrary.wiley.com/doi/10.1002/rnc.4674This brief deals with the satisfaction of the daily cooling demand by a hybrid system that consists of a vapor-compression refrigeration cycle and a thermal energy storage (TES) unit, based on phase change materials. The addition of the TES tank to the original refrigeration plant allows to schedule the cooling production regardless of the instantaneous demand, given that the TES tank can store cold energy and release it whenever deemed appropriate. The scheduling problem is posed as an optimization problem based on mixed-integer nonlinear programming (MINLP) since it includes both discrete and continuous variables. The latter corresponds to the references on the main cooling powers involved in the problem (cooling production at the evaporator and TES charging/discharging), whereas the discrete variables define the operating mode scheduling. Therefore, in addition to the hybrid features of the physical plant, a hybrid optimal control strategy is also proposed. A receding horizon approach is applied, similar to model predictive control (MPC) strategies, while economic criteria are imposed in the objective function, as well as feasibility issues. The TES state estimation is also addressed since its instantaneous charge ratio is not measurable. The proposed strategy is applied in simulation to a challenging cooling demand profile, and the main advantages of the MINLP-based strategy over a nonlinear MPC-based scheduling strategy previously developed are highlighted, regarding operating cost, ease of tuning, and ability to adapt to cooling demand variations.Ministerio de Ciencia e InnovaciónFCT (Portugal)POR Lisbo

¿Hablamos de lo mismo? Estudio contrastivo de programas de lenguas para fines específicos en dos universidades de Estados Unidos y España

Language courses for specific purposes vary due to their context and purpose. However, it is possible to find common features between programs in two different countries, with different characteristics and languages in question. It is interesting then toobserve how different courses work according to their specific characteristics to highlight in addition to their similarities their limitations and challenges. In this sense, this paper addresses the cases of Spanish for specific purposes in the Faculty of Foreign Languages of Valdosta State University in the United States and English in the Faculty of Education of the University of Alcalá in Spain. The contrastive study refers to the characteristics of both programs, their courses and students, the methodology and materials used for instruction, the use of the target language and evaluation. The paper concludes that in spite of the different nature of the programs and courses in question, more similarities can be found than differences of substance, so that future studies will address these contrasts in the elaboration of an international common framework.Las asignaturas de idiomas para fines específicos varían debido a su contexto y sus propósitos. Sin embargo, es posible encontrar rasgos comunes entre programas en dos países diferentes, con diferentes características y lenguas en cuestión. Es interesante entonces observar cómo funcionan diferentes asignaturas según sus rasgos específicos para destacar además de sus similitudes sus limitantes y retos. En este sentido, este trabajo aborda los casos de español para fines específicos en la Facultad de Lenguas Extranjeras de la Universidad Estatal de Valdosta en Estados Unidos y de inglés en la Facultad de Educación de la Universidad de Alcalá en España. El estudio contrastivo se refiere a las características de ambos programas, de sus asignaturas y alumnos, la metodología y los materiales utilizados para la instrucción, el uso de la lengua objetivo y la evaluación. El documento concluye que a pesar de la distinta naturaleza de los programas y asignaturas en cuestión se pueden encontrar más similitudes que diferencias de fondo, para que estudios futuros aborden estos contrastes en la elaboración de un marco común internacional

Optimización de la extracción de aceite de semilla de dátil mediante la ayuda de tecnologías hidrotermales y de ultrasonido

The date seed is a by-product from the date industry. Its use as a source of added-value compounds is of great interest. Oil accounts for 5-13% of the seed’s weight. Soxhlet extraction with organic solvents is the traditional method for obtaining oil from seeds. In this work, hydrothermal pre-treatments and sonication are proposed to make the extraction a more environmentally friendly process. Factors such as sonication time and temperature and hexane-to-seed ratio (H/S) have been considered. Response surface methodology was applied for optimization. Hydrothermal treatments increased oil recovery. H/S was the most influential factor, and was close to 7 mL/g seeds for both samples. 71% recovery was achieved for native seeds after 15 min sonication at 45 ºC, and 80% for 180 ºC-treated seeds after 45 min at 35 ºC when compared to Soxhlet extraction. These conditions comply with our initial aim. Pre-treatments seem to have a negative effect on oil stability, although this observation needs to be confirmed.La semilla de dátil es un subproducto de la industria datilera. Su uso como fuente de compuestos de valor añadido sería muy interesante. El aceite representa el 5-13% del peso de la semilla. La extracción mediante Soxhlet con disolventes orgánicos es el método tradicional para obtener aceite de semillas. En este trabajo se proponen pretratamientos hidrotérmicos y sonicación para diseñar un proceso de extracción más respetuoso con el medio ambiente. Se han considerado factores como el tiempo y la temperatura de sonicación y la proporción hexano/semilla (H/S). La optimización del proceso se llevó a cabo por el método de superficie de respuesta. Los tratamientos hidrotérmicos aumentaron el porcentaje de recuperación. El factor más influyente fue H/S, y su valor óptimo estuvo cerca de 7 mL/g para ambas muestras. La recuperación óptima fue del 71% para las semillas sin tratamiento tras 15 min de sonicación a 45 ºC, y del 80% para las semillas tratadas a 180 ºC después de 45 min a 35 ºC. Estos resultados cumplen con nuestro objetivo inicial. Sin embargo, los pretratamientos parecen tener un efecto negativo sobre la estabilidad del aceite, lo que se confirmará en estudios posteriores