Modeling and Mathematical Analysis of the Dynamics of HPV in Cervical Epithelial Cells: Transient, Acute, Latency, and Chronic Infections.

The aim of this paper is to model the dynamics of the human papillomavirus (HPV) in cervical epithelial cells. We developed a mathematical model of the epithelial cellular dynamics of the stratified epithelium of three (basale, intermedium, and corneum) stratums that is based on three ordinary differential equations. We determine the biological condition for the existence of the epithelial cell homeostasis equilibrium, and we obtain the necessary and sufficient conditions for its global stability using the method of Lyapunov functions and a theorem on limiting systems. We have also developed a mathematical model based on seven ordinary differential equations that describes the dynamics of HPV infection. We calculated the basic reproductive number (R 0) of the infection using the next-generation operator method. We determine the existence and the local stability of the equilibrium point of the cellular homeostasis of the epithelium. We then give a sufficient condition for the global asymptotic stability of the epithelial cell homeostasis equilibrium using the Lyapunov function method. We proved that this equilibrium point is nonhyperbolic when R 0 = 1 and that in this case, the system presents a forward bifurcation, which shows the existence of an infected equilibrium point when R 0 > 1. We also study the solutions numerically (i.e., viral kinetic in silico) when R 0 > 1. Finally, local sensitivity index was calculated to assess the influence of different parameters on basic reproductive number. Our model reproduces the transient, acute, latent, and chronic infections that have been reported in studies of the natural history of HPV.

Draft Genome Sequence of Fusarium oxysporum f. sp. cubense Tropical Race 4 from Peru, Obtained by Nanopore and Illumina Hybrid Assembly.

Fusarium oxysporum f. sp. cubense tropical race 4 (Foc TR4) is the causal agent of Fusarium wilt, a major threat to the banana industry worldwide. Here, we report the genome of a Foc TR4 strain from Peru, sequenced using a combination of Illumina and Oxford Nanopore Technologies.

Pinching or stinging? Comparing prey capture among scorpions with contrasting morphologies.

Background: Scorpions can use their pincers and/or stingers to subdue and immobilize their prey. A scorpion can thus choose between strategies involving force or venom, or both, depending on what is required to subdue its prey. Scorpions vary greatly in the size and strength of their pincers, and in the efficacy of their venom. Whether this variability is driven by their defensive or prey incapacitation functionis unknown. In this study, we test if scorpion species with different pincer morphologies and venom efficacies use these weapons differently during prey subjugation. To that end, we observed Opisthacanthus elatus and Chactas sp. with large pincers and Centruroides edwardsii and Tityus sp. with slender pincers. Methods: The scorpion pinch force was measured, and behavioral experiments were performed with hard and soft prey (Blaptica dubia and Acheta domesticus). Stinger use, sting frequency and immobilization time were measured. Results: We found that scorpions with large pincers such as O. elatus produce more force and use the stinger less, mostly subjugating prey by crushing them with the pincers. In C. edwardsii and Tityus sp. we found they use their slender and relatively weak pincers for holding the prey, but seem to predominantly use the stinger to subjugate them. On the other hand, Chactas sp. uses both strategies although it has a high pinch force. Conclusions: Our results show that scorpionspecies with massive pincers and high pinch force as O. elatus use the stinger less for prey subjugation than scorpionspecies with slenderpincers.

3D Low-Cost Equipment for Automated Peritoneal Dialysis Therapy.

A breakthrough in peritoneal dialysis (PD) therapy occurred in 1977 with the development of continuous ambulatory peritoneal dialysis (CAPD). Its simplicity, low cost, and ease with which CAPD could be performed on patients at home contributed to the popularity of this procedure. However, there is a need for continuous improvement in building optimal systems for incident chronic kidney disease (CKD) patients. This research showed the design and construction of a simplified prototype of low-cost automated peritoneal dialysis (APD) equipment that meets international standards to automatically regulate infusion and fluid drainage in and out of a patient with low margins of error. Experimental tests allowed the adjustment of the RPM values concerning the flow rate provided. In addition, thanks to the pressure sensor, it was possible to observe a fluctuation ranging from 9 to 13 kPa, which is within the permissible average specified in the catalogs of medical instruments and equipment. Furthermore, a turbidity sensor was added to decrease the possibility of presenting peritonitis. The results showed absolute values of flow, angular velocity, and pressure that it could deliver for use in APD therapies. Finally, the construction of the APD equipment is presented generally, showing the electronic and mechanical components that constitute it.

Bone Fractures Numerical Analysis in a Femur Affected by Osteogenesis Imperfecta.

This work presents a non-invasive methodology to obtain a three-dimensional femur model of three-year-old infants affected with Osteogenesis Imperfecta (OI) type III. DICOM® Files of a femur were processed to obtain a finite element model to assess the transverse, the oblique, and the comminuted fractures. The model is evaluated under a normal walking cycle. The loads applied were considered the most critical force generated on the normal walking cycle, and the analyses considered anisotropic bone conditions. The outcome shows stress concentration areas in the central zone of the diaphysis of the femur, and the highest levels of stress occur in the case of the comminuted fracture, while the transverse fracture presents the lowest values. Thus, the method can be helpful for determining the bone fracture behavior of certain pathologies, such as osteogenesis imperfecta, osteopenia, and osteoporosis.

Design of an Automated Multiposition Dynamic Wheelchair.

This work presents a design for an automatized multiposition dynamic wheelchair used to transport quadriplegic patients by reconfiguring a manual wheelchair structure. An electric actuator is attached to a four-bar mechanism fixed to each side of a wheelchair's backrest to reach multiposition. The entire device is actuated through a PID controller. An experimental test is carried out in a simplified wheelchair structure. Finally, the structure of the wheelchair is evaluated through the Dynamic analysis and Finite Element Method under the payload computed with the most critical position reached by the mechanism.

Application of udder surface temperature by infrared thermography for diagnosis of subclinical mastitis in Holstein cows located in tropical highlands.

Several reports have indicated that udder surface temperature (UST) can be a useful indicator of subclinical mastitis (SCM). The objective was to evaluate UST by infrared thermography (IRT) as a diagnostic tool for SCM and intramammary infection (IMI), and to assess the influence of environmental conditions in the potential diagnosis of this disease in dairy cows located at high-altitude tropical regions. A total of 105 cows (397 quarters) from 3 dairy farms with mechanical and manual milking methods were enrolled in the study. Subclinical mastitis was diagnosed when quarter samples had a somatic cell count (SCC) ≥200 × 103 cells/mL, microbial growth (MG) was defined when a major pathogen (≥1 cfu/plate) or Corynebacterium spp. (≥10 cfu/plate) was isolated, and IMI was defined as the presence of MG and SCC ≥100 × 103 cells/mL. Infrared images were taken with a thermal camera placed 1 m away from the udder, and shots of the rear and left and right lateral view were made during the morning milking, before any manipulation of the udder and employing dark cardboard on the contralateral side to avoid artifacts in the background. A multilevel mixed effects linear regression model clustered within cows and herd was performed to evaluate the associations with UST. Clinical performance was evaluated using the Youden index to establish the optimum UST thresholds, which were set at 32.6°C for any case definition when milking was by hand, at 33.7°C for MG, and at 34°C for SCM and IMI in machine-milked quarters. Sensitivity (Se), specificity (Sp), area under curve (AUC), and positive likelihood ratio (+LR) were also assessed. Test agreement was assessed by kappa coefficient (κ). The UST of healthy quarters ranged between (95% CI) 32.4 and 32.6°C, lower than SCM quarters (n = 88) at 32.9°C (95% CI: 32.7-33.1 °C), MG quarters (n = 56) at 33.5°C (95% CI: 33.3-33.7°C), and IMI quarters (n = 50) at 33.5°C (95% CI: 33.2-33.7 °C). The UST was also related to the milking method: higher temperatures were observed for hand milking (n = 90) compared with machine milking (n = 185). No relation between environmental conditions such as wind speed, atmospheric temperature, relative humidity, and temperature-humidity index and UST were observed during this study. For hand milking, the optimal UST threshold was 32.6°C; for SCM, Se = 0.53, Sp = 0.89, AUC = 0.71, κ = 0.4; for MG, Se = 0.83, Sp = 0.93, AUC = 0.88, κ = 0.77; and for IMI, Se = 0.82, Sp = 0.92, AUC = 0.87, κ = 0.74. The machine milking threshold for SCM resulted in Se = 0.42, Sp = 0.97, AUC = 0.70, κ = 0.47; for MG, Se = 0.82, Sp = 0.89, AUC = 0.85, κ = 0.60; and for IMI, Se = 0.82, Sp = 0.98, AUC = 0.90, κ = 0.79. These findings suggest that UST determined by IRT is higher in machine-milked cows and in quarters with MG and IMI than in healthy quarters; therefore, UST by IRT is a reliable, clinically useful method for MG and IMI diagnosis.

Redesign of a Piston for a Diesel Combustion Engine to Use Biodiesel Blends.

Biofuels represent an energy option to mitigate polluting gases. However, technical problems must be solved, one of them is to improve the combustion process. In this study, the geometry of a piston head for a diesel engine was redesigned. The objective was to improve the combustion process and reduce polluting emissions using biodiesel blends as the fuel. The methodology used was the mechanical engineering design process. A commercial piston (base piston) was selected as a reference model to assess the piston head's redesign. Changes were applied to the profile of the piston head based on previous research and a new model was obtained. Both models were evaluated and analyzed using the finite element method, where the most relevant physical conditions were temperature and pressure. Numerical simulations in the base piston and the new piston redesign proposal presented similar behaviors and results. However, with the proposed piston, it was possible to reduce the effort and the material. The proposed piston profile presents adequate results and behaviors. In future, we suggest continuing conducting simulations and experimental tests to assess its performance.

Recognizing Decision-Making Using Eye Movement: A Case Study With Children.

The use of visual attention for evaluating consumer behavior has become a relevant field in recent years, allowing researchers to understand the decision-making processes beyond classical self-reports. In our research, we focused on using eye-tracking as a method to understand consumer preferences in children. Twenty-eight subjects with ages between 7 and 12 years participated in the experiment. Participants were involved in two consecutive phases. The initial phase consisted of the visualization of a set of stimuli for decision-making in an eight-position layout called Alternative Forced-choice. Then the subjects were asked to freely analyze the set of stimuli, they needed to choose the best in terms of preference. The sample was randomly divided into two groups balanced by gender. One group visualized a set of icons and the other a set of toys. The final phase was an independent assessment of each stimulus viewed in the initial phase in terms of liking/disliking using a 7-point Likert scale. Sixty-four stimuli were designed for each of the groups. The visual attention was measured using a non-obstructive eye-tracking device. The results revealed two novel insights. Firstly, the time of fixation during the last four visits to each stimulus before the decision-making instant allows us to recognize the icon or toy chosen from the eight alternatives with a 71.2 and 67.2% of accuracy, respectively. The result supports the use of visual attention measurements as an implicit tool to analyze decision-making and preferences in children. Secondly, eye movement and the choice of liking/disliking choice are influenced by stimuli design dimensions. The icon observation results revealed how gender samples have different fixation and different visit times which depend on stimuli design dimension. The toy observations results revealed how the materials determinate the largest amount fixations, also, the visit times were differentiated by gender. This research presents a relevant empirical data to understand the decision-making phenomenon by analyzing eye movement behavior. The presented method can be applied to recognize the choice likelihood between several alternatives. Finally, children's opinions represent an extra difficulty judgment to be determined, and the eye-tracking technique seen as an implicit measure to tackle it.

Continuous Microalgal Cultivation for Antioxidants Production.

Microalgae, including cyanobacteria, represent a valuable source of natural compounds that have remarkable bioactive properties. Each microalga species produces a mixture of antioxidants with different amounts of each compound. Three aspects are important in the production of bioactive compounds: the microalga species, the medium composition including light supplied and the photobioreactor design, and operation characteristics. In this study, the antioxidant content and productivity performance of four microalgae were assessed in batch and continuous cultures. Biomass productivity by the four microalgae was substantially enhanced under continuous cultivation by 5.9 to 6.3 times in comparison with batch cultures. The energetic yield, under the experimental conditions studied, ranged from 0.03 to 0.041 g biomass kJ-1. Phenols, terpenoids, and alkaloids were produced by Spirulinaplatensis, Isochrysisgalbana, and Tetraselmissuecica, whereas tocopherols and carotenoids were produced by the four microalgae, except for phycocyanin and allophycocyanin, which were only produced by S. platensis and Porphyridiumcruentum. The findings demonstrate that the continuous cultivation of microalgae in photobioreactors is a convenient method of efficiently producing antioxidants.

Prey and Venom Efficacy of Male and Female Wandering Spider, Phoneutria boliviensis (Araneae: Ctenidae).

Spiders rely on venom to catch prey and few species are even capable of capturing vertebrates. The majority of spiders are generalist predators, possessing complex venom, in which different toxins seem to target different types of prey. In this study, we focused on the trophic ecology and venom toxicity of Phoneutria boliviensis F. O. Pickard-Cambridge, 1897, a Central American spider of medical importance. We tested the hypothesis that its venom is adapted to catch vertebrate prey by studying its trophic ecology and venom toxicity against selected vertebrate and invertebrate prey. We compared both trophic ecology (based on acceptance experiments) and toxicity (based on bioassays) among sexes of this species. We found that P. boliviensis accepted geckos, spiders, and cockroaches as prey, but rejected frogs. There was no difference in acceptance between males and females. The venom of P. boliviensis was far more efficient against vertebrate (geckos) than invertebrate (spiders) prey in both immobilization time and LD50. Surprisingly, venom of males was more efficient than that of females. Our results suggest that P. boliviensis has adapted its venom to catch vertebrates, which may explain its toxicity to humans.

An LMS Programming Scheme and Floating-Gate Technology Enabled Trimmer-Less and Low Voltage Flame Detection Sensor.

In this paper, a Least Mean Square (LMS) programming scheme is used to set the offset voltage of two operational amplifiers that were built using floating-gate transistors, enabling a 0.95 VRMS trimmer-less flame detection sensor. The programming scheme is capable of setting the offset voltage over a wide range of values by means of electron injection. The flame detection sensor consists of two programmable offset operational amplifiers; the first amplifier serves as a 26 µV offset voltage follower, whereas the second amplifier acts as a programmable trimmer-less voltage comparator. Both amplifiers form the proposed sensor, whose principle of functionality is based on the detection of the electrical changes produced by the flame ionization. The experimental results show that it is possible to measure the presence of a flame accurately after programming the amplifiers with a maximum of 35 LMS-algorithm iterations. Current commercial flame detectors are mainly used in absorption refrigerators and large industrial gas heaters, where a high voltage AC source and several mechanical trimmings are used in order to accurately measure the presence of the flame.

El discurso sobre lo gremial / Discourse on the Labor Union

En este artículo se comparte una reflexión en torno a la lectura de diferentes ensayos de colegas-psiquiatras españoles, como Guillermo Rendueles Olmedo, Manuel Desviat, Teresa Cabruja, Iván de la Mata Ruiz y Alberto Ortiz Lobo, quienes denuncian enérgicamente la psicologización e individualización del malestar, como forma de despolitización y de socialización del sufrimiento, el cual es inseparablemente individual y social. Se alude también a lo que se consideran las causas del malestar del psiquiatra y, finalmente, a partir de las reflexiones del filosofo francés Jean Paul Sartre y del filosofo alemán Arthur Schopenhauer se habla sobre el ser político y social...

In this paper, I want to share reflections that stem from reading the essays of several Spanish Colleagues, psychiatrists Guillermo Rendueles Olmedo, Manuel Desviat, Teresa Cabruja, Ivan de la Mata Ruiz, and Alberto Ortiz Lobo, who strongly denounce the psychologization and individualization of discomfort, as a way to de-politicize and de-socialize suffering, which is inseparably personal and social. I will also refer to what I consider are the causes of the malaise of the psychiatrist and finally, based on the ideas of French philosopher Jean Paul Sartre and German philosopher Arthur Schopenhauer, I will talk about being political and social...

Colgajos en la reconstrucción facial en dos pacientes con carcinoma basocelular / Flaps in the facial reconstruction in two patients with basal cell carcinoma

En la cara se encuentran estructuras con una función perfectamente delimitada, además de un componente estético muy importante. Intentamos mostrar la utilidad de colgajos de piel en la reconstrucción facial en dos pacientes con carcinoma basocelular. Se realizó un estudio descriptivo retrospectivo de dos casos en que se practicó resección de lesiones: nasal, en mejilla. En pacientes que acudieron al Centro Clínico Valentina Canabal, entre enero y diciembre 2009. Los dos pacientes tenían diagnóstico de carcinoma basocelular, los procedimientos utilizados fueron: colgajo pediculado y Z plastia, la evolución de los casos fue satisfactoria, sin secuelas funcionales y resultados estéticos excelentes, el tiempo quirúrgico promedio fue de 80 min. y la hospitalización duró un máximo de dos días. En nuestra experiencia se demuestra la gran utilidad de los colgajos en las reconstrucciones faciales con resultados tanto estéticos como funcionales favorables.

In the face the structures are well defined function, and have very important aesthetic component. We try to show the usefulness of skin flaps in facial reconstruction in two patients with diagnostic of basal cell carcinoma. We conducted a retrospective study of two cases in which resection of lesions nasal, and in the cheek. In patients who attended in the Center Clinical Valentina Canabal, between January and December 2009. Both patients had a diagnosis of skin basal cell carcinoma, the procedures used were pedicles flap and Z-plastic, the patient outcome was satisfactory, without complications, functional disability and excellent cosmetic results, the average surgical time was 80 minutes hospitalization lasted a maximum of two days. In our experience we demonstrates the usefulness of the flaps in the facial reconstruction, with favorable results and aesthetic and functional satisfactory to the patients.

Características asociadas al éxito o fracaso de la prueba de parto vaginal en cesareada anterior en el Instituto Materno Perinatal Julio-Diciembre 2010 / Characteristics associated with success or failure of the test of vaginal birth after cesarean at the National Institute Materno Perinatal in July-December 2010

Objetivos: Evaluar la tasa de éxito y los factores asociados al éxito o fracaso de la pacientes cesareadas anteriores sometidas a prueba de parto vaginal (TOLAC).Métodos: Estudio observacional, descriptivo y retrospectivo. Realizado en el Instituto Nacional Materno Perinatal (INMP), donde se incluyeron todas las gestantes a término con el antecedente de cesárea anterior una vez que cumplían los criterios de inclusión y exclusión sometidas a TOLAC en el periodo comprendido de Julio a Diciembre del 2010. Resultados: La población de estudio fue de 151 pacientes. La tasa de éxito de TOLAC fue de 83,4 por ciento. En ambos grupos la mayoría fue adulta y con estudios secundarios. Respecto a los factores anteparto la causa de indicación de la cesárea previa fue sufrimiento fetal agudo (19 por ciento) en el grupo de TOLAC exitoso y distocia funicular (24 por ciento) en el grupo de TOLAC fallido. En ambos grupos la mayoría de pacientes no tuvieron el antecedente de parto vaginal antes o después de la cesárea. El IMC > 30 estuvo asociado a TOLAC fallido. Respecto a la patología asociada la obesidad guardo relación con la falla de la prueba de parto. En relación a los factores intraparto estudiados un Bishop favorable (>6) estuvo asociado al éxito del TOLAC, la mayor tasa de falla de TOLAC se presento en pacientes sometidas a manejo activo (p<0.05), el trabajo de parto disfuncional fue la indicación más frecuente en ambos grupos para inducción de trabajo de parto, la perdida de bienestar fetal expresada por el MEF categoría II al final de trabajo de parto estuvo relacionado con TOLAC fallido. La macrosomia fetal fue más frecuente en pacientes con cesárea repetida (p<0.001) y la desproporción céfalo-pélvica (ICP) fue la indicación más frecuente de repetición de cesárea. Conclusiones: Podemos concluir que la opción de parto vaginal tras una cesárea anterior es segura y a menudo exitoso en un grupo seleccionado de pacientes, de ahí la importancia de identificar ...

Tumores neuroendocrinos del pulmón / Neuroendocrine tumors of the lung

Los tumores carcinoides comprenden un espectro de tumores neuroendocrinos, con algunas características histológicas y clínicas en común, pero con diferencias significativas en su pronóstico. Se presentan cuatro casos atendidos en nuestro hospital, y se hace una revisión de la literatura de esta patología poco frecuente.

Caracterización del patrón capilaroscópico del pliegue ungueal en personas sin enfermedad evidente mediante técnicas de inteligencia artificial. Prueba piloto / Characterization of the capillaroscopy pattern of the ungueal fold in persons without an evident illness by means of artificial intelligence techniques. Pilot assay

INTRODUCCIÓN: la microscopia capilar del pliegue ungueal proximal (capilaroscopia) es un método no invasivo para valorar la microvasculatura de la piel que contribuye al diagnóstico de diversos desórdenes autoinmunes y trastornos vasomotores. Las variantes anatómicas y las anomalías de los capilares no están netamente definidas y se pueden considerar en buena parte como medidas subjetivas. OBJETIVO: caracterizar los patrones capilaroscópicos del pliegue ungueal proximal mediante técnicas de inteligencia artificial en adultos sin patología evidente. MATERIALES Y MÉTODOS: en este estudio descriptivo se utilizó una cámara digital acoplada a un estéreomicroscopio para capturar 763 imágenes del lecho capilar del pliegue ungueal proximal de 42 sujetos. Además, se aplicó un proceso computarizado para analizar y obtener datos cuantitativos en cuanto a longitud o largo del capilar, ancho del asa capilar, polaridad o ángulo en grados del capilar, avascularidad, índice de tortuosidad y densidad capilar, de manera descriptiva (media, desviación estándar, valores mínimo y máximo y percentiles 5, 25, 50, 75 y 95). RESULTADOS: la mayoría de las características morfológicas estudiadas presentó asimetría positiva con la mediana inferior al promedio. CONCLUSIÓN: esta prueba piloto constituye un primer intento de caracterizar en forma cuantitativa los patrones del lecho capilar ungueal proximal en sujetos sin patología evidente. El método utilizado establece las bases para su aplicación en una muestra mayor; una fase posterior permitiría contrastar los patrones encontrados con aquellos que presentan sujetos con enfermedades del tejido conectivo y así obtener parámetros capilaroscópicos más objetivos para el diagnóstico de estas enfermedades.