On polynomials associated to Voronoi diagrams of point sets and crossing numbers

Three polynomials are defined for sets S of n points in general position in the plane: The Voronoi polynomial with coefficients the numbers of vertices of the order-k Voronoi diagrams of S, the circle polynomial with coefficients the numbers of circles through three points of S enclosing k points, and the E=k polynomial with coefficients the numbers of (at most k)-edges of S. We present several formulas for the rectilinear crossing number of S in terms of these polynomials and their roots. We also prove that the roots of the Voronoi polynomial lie on the unit circle if and only if S is in convex position. Further, we present bounds on the location of the roots of these polynomials.Postprint (published version

Measuring cocircularity in a point set

In a given set S of n points in the plane, how close are four points of S to be cocircular? We define several measures to study this question, and present bounds on this almost-cocircularity in a point set. Algorithms for cocircularity are presented as well.Peer ReviewedPostprint (published version

Electrochemical regeneration of a graphite adsorbent loaded with Acid Violet 17 in a spouted bed reactor

A novel spouted bed reactor is evaluated for water treatment by an adsorption and electrochemical regeneration process. The adsorbent is a bisulphate graphite intercalation compound with low specific surface area but high electrical conductivity, suitable for adsorption of contaminants and simultaneous electrochemical regeneration within a single unit. The effects of current density and liquid flow rate on Acid Violet 17 removal were investigated. The hydrodynamic behavior of the liquid spouted bed reactor was characterized by a flow regime map. A four-parameter model has been developed to describe the adsorption and electrochemical regeneration process in the liquid spouted bed reactor. It was found that the experimental data of dye removal agrees well with the modelled simulations

α-Hispanolol Induces Apoptosis and Suppresses Migration and Invasion of Glioblastoma Cells Likely via Downregulation of MMP-2/9 Expression and p38MAPK Attenuation

α-Hispanolol (α-H) is a labdane diterpenoid that has been shown to induce apoptosis in several human cancer cells. However, the effect of α-H in human glioblastoma cells has not been described. In the present work, we have investigated the effects of α-H on apoptosis, migration, and invasion of human glioblastoma cells with the aim of identifying the molecular targets underlying its mechanism of action. The results revealed that α-H showed significant cytotoxicity against human glioma cancer cell lines U87 and U373 in a concentration- and time-dependent manner. This effect was higher in U87 cells and linked to apoptosis, as revealed the increased percentage of sub-G1 population by cell cycle analysis and acquisition of typical features of apoptotic cell morphology. Apoptosis was also confirmed by significant presence of annexin V-positive cells and caspase activation. Pretreatment with caspase inhibitors diminishes the activities of caspase 8, 9, and 3 and maintains the percentage of viable glioblastoma cells, indicating that α-H induced cell apoptosis through both the extrinsic and the intrinsic pathways. Moreover, we also found that α-H downregulated the anti-apoptotic Bcl-2 and Bcl-xL proteins and activated the pro-apoptotic Bid and Bax proteins. On the other hand, α-H exhibited inhibitory effects on the migration and invasion of U87 cells in a concentration-dependent manner. Furthermore, additional experiments showed that α-H treatment reduced the enzymatic activities and protein levels of matrix metalloproteinase MMP-2 and MMP-9 and increased the expression of TIMP-1 inhibitor, probably via p38MAPK regulation. Finally, xenograft assays confirmed the anti-glioma efficacy of α-H. Taken together, these findings suggest that α-H may exert anti-tumoral effects in vitro and in vivo through the inhibition of cell proliferation and invasion as well as by the induction of apoptosis in human glioblastoma cells. This research describes α-H as a new drug that may improve the therapeutic efficacy against glioblastoma tumors.This study was supported by grant PI11/00036, PI14/00055, and PI17/00012 from the FIS, MPY 1410/09 from ISCIII and Spanish Ministry of Health (Instituto de Salud Carlos III; RD12/0036/0059) to SoH and by grants IERPY 1149/16 and IERPY-M 389/18 to AL. L JG was supported by FIS (FI12/00340). SaH was supported by IERPY 1149/16 from ISCIII.S

Análisis termogravimétrico de la descomposición del diente a diferentes temperaturas

Los dientes expuestos al estrés térmico son útiles en estudios de identificación y circunstancias del fuego. Trabajos recientes de investigación forense aplican novedosas técnicas (histológicas, físico-químicas, moleculares) para conocer los cambios producidos en los mismos como consecuencia de la exposición a altas temperaturas. OBJETIVO: conocer el proceso de degradación del diente en relación con la temperatura mediante técnicas físico-químicas (TG-DSC). MATERIAL Y MÉTODOS: Se realizaron dos ensayos TG-DSC con un analizador termogravimétrico modelo TG/DSC1 de Mettler-Toledo. Los gases emitidos se identificaron mediante un espectrómetro de masas (Thermostar de Pfeiffer-Vacuum). El primer ensayo consistió en calentar pulverizado de diente de 30 a 1000 ºC. El segundo ensayo consistió en someter el diente a temperaturas de 50, 100, 150, 200, 250, 300, 350 y 400 ºC durante una hora. La velocidad de calentamiento de ambos ensayos fue de 10 ºC min-1 con atmósfera oxidante, un flujo de aire de 50 ml min-1, 20 mg de muestra en crisoles de alúmina de 70 µl (7 réplicas). RESULTADOS: El inicio de la descomposición de materia orgánica del diente se produce a los 150 ºC hasta los 400 ºC. A 270 ºC se inicia la descomposición de proteínas, se produce emisión de compuestos orgánicos como CH2O y CO2 a los 343.3 y 346.5 ºC respectivamente. La emisión de óxido nitroso procedente de bases nitrogenadas (ADN y colágeno) se produce a los 347.5 ºC. CONCLUSIONES: Según el estudio termogravimétrico, la materia orgánica dental se descompone completamente antes de los 400 ºC.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Determining ‘Age at Death’ for Forensic Purposes using Human Bone by a Laboratory-based Analytical Method

Determination of age-at-death (AAD) is an important and frequent requirement in contemporary forensic science and in the reconstruction of past populations and societies from their remains. Its estimation is relatively straightforward and accurate (±3 years) for immature skeletons by using morphological features and reference tables within the context of forensic anthropology. However, after skeletal maturity (>35 yrs) estimates become inaccurate, particularly in the legal context. In line with the general migration of all the forensic sciences from reliance upon empirical criteria to those which are more evidence-based, AAD determination should rely more-and-more upon more quantitative methods. We explore here whether well-known changes in the biomechanical properties of bone and the properties of bone matrix, which have been seen to change with age even after skeletal maturity in a traceable manner, can be used to provide a reliable estimate of AAD. This method charts a combination of physical characteristics some of which are measured at a macroscopic level (wet & dry apparent density, porosity, organic/mineral/water fractions, collagen thermal degradation properties, ash content) and others at the microscopic level (Ca/P ratios, osteonal and matrix microhardness, image analysis of sections). This method produced successful age estimates on a cohort of 12 donors of age 53–85 yr (7 male, 5 female), where the age of the individual could be approximated within less than ±1 yr. This represents a vastly improved level of accuracy than currently extant age estimation techniques. It also presents: (1) a greater level of reliability and objectivity as the results are not dependent on the experience and expertise of the observer, as is so often the case in forensic skeletal age estimation methods; (2) it is purely laboratory-based analytical technique which can be carried out by someone with technical skills and not the specialised forensic anthropology experience; (3) it can be applied worldwide following stringent laboratory protocols. As such, this technique contributes significantly to improving age estimation and therefore identification methods for forensic and other purposes

Utilidad del espectrofotómetro en la estimación de la temperatura en huesos calcinados

El cambio morfológico y de color producido en los huesos quemados puede verse influenciado por la temperatura y tiempo de exposición. El objetivo principal de este estudio fue medir los cambios los cambios de color con el espectrofotómetro y correlacionar los mismos con la temperatura y tiempo a las que habían sido expuestos. Metodología: Un total de 32 fragmentos de 5 cm de huesos largos humanos, fueron sometidos a 200, 400, 600 y 800 ºC en un horno de mufla. Para cada rango de temperatura, se establecieron 2 grupos de 4 fragmentos; unos se exponían durante 30 minutos y otros 60 minutos. Además, otros 4 fragmentos se utilizaron como control. Se realizó un examen visual tanto de la cortical como de la médula ósea con lupas y fotografías; describiendo cambios estructurales. Posteriormente, se midió el color con un espectrofotómetro. Resultados: Los huesos sometidos a 200 °C presentaban un color marrón. A 400 presentaban color negro y gris en el 100% de los casos. Los huesos sometidos a 600 y 800 °C viraban de gris y blanco a un tono azulado. No se encontraron diferencias visuales entre los diferentes tiempos (30 y 60 minutos). El espectrofotómetro mostró determinaciones significativas de cambios de color en los valores de Blanqueamiento (WI) y Tonalidad/Crominancia (Z e y). Además, se observa correlación significativa entre el color y la temperatura tanto en los huesos sometidos durante 30 como a 60 minutos en los mismos valores de espectrofotómetro mencionados. Conclusión: De acuerdo con estos resultados, Blanqueamiento es el parámetro que mejor predice la temperatura a la que han sido expuestos los huesos. Por todo ello, el análisis colorimétrico de los huesos incinerados puede ayudar a estimar la temperatura, siendo ésta más influyente que el tiempo de exposición.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

A modular cell-based biosensor using engineered genetic logic circuits to detect and integrate multiple environmental signals

AbstractCells perceive a wide variety of cellular and environmental signals, which are often processed combinatorially to generate particular phenotypic responses. Here, we employ both single and mixed cell type populations, pre-programmed with engineered modular cell signalling and sensing circuits, as processing units to detect and integrate multiple environmental signals. Based on an engineered modular genetic AND logic gate, we report the construction of a set of scalable synthetic microbe-based biosensors comprising exchangeable sensory, signal processing and actuation modules. These cellular biosensors were engineered using distinct signalling sensory modules to precisely identify various chemical signals, and combinations thereof, with a quantitative fluorescent output. The genetic logic gate used can function as a biological filter and an amplifier to enhance the sensing selectivity and sensitivity of cell-based biosensors. In particular, an Escherichia coli consortium-based biosensor has been constructed that can detect and integrate three environmental signals (arsenic, mercury and copper ion levels) via either its native two-component signal transduction pathways or synthetic signalling sensors derived from other bacteria in combination with a cell-cell communication module. We demonstrate how a modular cell-based biosensor can be engineered predictably using exchangeable synthetic gene circuit modules to sense and integrate multiple-input signals. This study illustrates some of the key practical design principles required for the future application of these biosensors in broad environmental and healthcare areas