Slower velocity perception with stronger optokinetic nystagmus: A paradoxical perception in virtual reality.

BACKGROUND: Optokinetic nystagmus (OKN) was studied in an immersive virtual reality (VR) environment with both typical optokinetic stimulation (OKs) wherein the head-tracking is active (similar to be sitting in front of a rotating drum) or a unique stimulus (VR-OKs) wherein the head-tracking is turned off, so head movements do not update the visual image (which moves with the head). OBJECTIVE: To study both the perception of the stimulus velocity and eye movements while subjects rotated their head from side to side and the visual scene was either a typical OKs or VR-OKs. METHODS: 9 healthy participants (aged 23 ± 2.4 y/o) had head and eye movements recorded under typical OKs and VR-OKS while smoothly rotating their head horizontally from side to side. Stimulation was delivered using a virtual reality setup on top of an eye movements recording system. RESULTS: Under VR-OKs participants perceived faster stimulus velocity when the head and stimulus had the same direction as compared to the head and stimulus in opposite directions. When the head turned in the same direction as the stimulus, there were fewer fast phase eye movements than when it rotated counter to stimulus motion direction. Conversely, with typical OKs, participants perceived faster stimulus velocity when the head and stimulus had opposite directions as compared to the head and stimulus having the same direction. CONCLUSIONS: The seemingly paradoxical results in which slower stimulus velocity is perceived in tandem with stronger nystagmus can be explained by the simultaneous activation of the Vestibulo-Ocular Reflex and OKN in accordance with the various visual and vestibular stimuli.

Percolation-intercropping strategies to prevent dissemination of phytopathogens on plantations.

Phytophthora is one of the most aggressive and worldwide extended phytopathogens that attack plants and trees. Its effects produce tremendous economical losses in agronomy and forestry since no effective fungicide exists. We propose to combine percolation theory with an intercropping sowing configuration as a non-chemical strategy to minimize the dissemination of the pathogen. In this work, we model a plantation as a square lattice where two types of plants are arranged in alternating columns or diagonals, and Phytophthora zoospores are allowed to propagate to the nearest and next-to-nearest neighboring plants. We determine the percolation threshold for each intercropping configuration as a function of the plant's susceptibilities and the number of inoculated cells at the beginning of the propagation process. The results are presented as phase diagrams where crop densities that prevent the formation of a spanning cluster of susceptible or diseased plants are indicated. The main result is the existence of susceptibility value combinations for which no spanning cluster is formed even if every cell in the plantation is sowed. This finding can be useful in choosing a configuration and density of plants that minimize damages caused by Phytophthora. We illustrate the application of the phase diagrams with the susceptibilities of three plants with a high commercial value.

Pielonefritis por Escherichia coli en el Hospital Naval de Guayaquil-Ecuador / Pielonefritis by Escherichia coli in the Naval Hospital of Guayaquil-Ecuador

La Pielonefritis por Escherichia coli con frecuencia es de diagnóstico confuso haciéndose necesario combinar pruebas de urología con las de imagenologías, pudiendo generar complicaciones renales hasta poder convertiste en un caso hepático grave por las lesiones que se les infrinja a los riñones, es por ello que esta investigación se planteo como objetivo caracterizar los casos de Pielonefritis por E. coli en el Hospital Naval de Guayaquil. Estudio descriptivo de corte transversal, con una muestra de 33 pacientes. Empleando como técnica de recolección de datos sus historias clínicas, pruebas de sedimento urinario, urocultivo en medio aerobico y pruebas de imagenología. Teniendo como resultado que el sexo femenino (60,61%; n=20/33), con un 60,61% (n=20/33) evidencian diabettus milletus, con grado de inducción primaria 24,24% (n=8/33), presentando dolor lumbar (100% n=33/33), con dolor al orinar y nauseas (90,91%; n=30/33), en los exámenes de urología las colonias/ml valores>105 fue de 57,58% (n=19/33) con E. coli (100%; n=33/33) y las pruebas de imagenología arrojaron que un 60,61% (n=20) evidencia gas en el colector solo sistema, confirmando el diagnóstico pielonefritis. En conclusión, por lo solapado que tiende a ser el diagnostico del Pielonefritis por E. coli deben combinarse las pruebas de urología y las de imágenes(AU)

Pyelonephritis by Escherichia coli is often of confused diagnosis making it necessary to combine urology tests with imaging, may cause renal complications until you can become a serious liver case due to injuries to the kidneys, That is why this research was aimed at characterizing the cases of Pyelonephritis by E. coli in the Naval Hospital of Guayaquil. Descriptive cross-sectional study, with a sample of 33 patients. Using as a data collection technique their clinical histories, urine sediment tests, uroculture in an aerobic environment and imaging tests. As a result, the female sex (60,61%; n=20/33), with 60.61% (n=20/33) showed diabettus milletus, with degree of primary induction 24.24% (n=8/33), presenting lumbar pain (100% n=33/33), with pain when urinating and nausea (90.91%; n=30/33), in urology examinations the colonies/ml values>105 was 57.58% (n=19/33) with E. coli (100%; n=33/33) and imaging tests showed that 60,61% (n=20) gas in the collector only system, confirming the diagnosis pyelonephritis. In conclusion, because of the overlapping that tends to be the diagnosis of Pyelonephritis by E. coli, urology and imaging tests should be combined(AU)

Síndrome de hombre en barril secundario a trauma raquimedular. Reporte de caso / Man-in-the-barrel syndrome secondary to spinal cord trauma. Case report

Resumen Presentamos caso de un varón de 77 años con antecedentes de alcoholismo, limitación crónica al flujo aéreo, y trauma encéfalo craneano (TEC) antiguo, que ingresa por cuadro de insuficiencia respiratoria global con descompensación aparentemente infecciosa que evoluciona tórpidamente con asistencia de ventilación mecánica no invasiva (VMNI) persistente. Se objetiva diparesia de predominio braquial proximal lo que hace sospechar síndrome de hombre en barril (SHB). Se completa estudio con resonancia nuclear magnética (RNM) de columna cervical que muestra severa atrofia medular desde bulbo distal hasta C4. El paciente se mantiene con VMNI c/ BiPAP y apoyo kinésico, con lo que logra progresiva mejoría ventilatoria.

We present a patient 77-year-old male with a history of alcoholism, chronic airflow limitation, and old brain trauma injury, who is admitted due to a global respiratory insufficiency with apparently infectious decompensation that evolves rapidly dependent on non-invasive mechanical ventilation and with a, Man-in-the-barrel syndrome. A magnetic resonance of cervical spine showed severe spinal atrophy from the distal medulla oblongata to C4. The patient remains with kinesic motor support, thereby achieving progressive ventilatory improvement.

Miastenia gravis refractaria con buena respuesta a rituximab: caso clínico / Refractory myasthenia gravis with good response to rituximab: report of one case

Myasthenia gravis (MG) is a heterogeneous disease, and there is no unique therapeutic approach for all patients. In 2013 the Myasthenia Gravis American Foundation (MGFA) panel of experts defined refractory MG as the lack of change or deterioration after the use of corticosteroids and two immunosuppressive agents, in adequate doses and time. We report a 51-years-old female with MG of bulbar predominance, who presented four myasthenic crises in 17 months despite the use of corticosteroids, azathioprine and mycophenolate. The high costs associated with her hospitalizations, as well as severe caloric - protein malnutrition, the need for tracheostomy and gastrostomy support, led us to use rituximab. The patient evolved with an excellent response, free of crises after 30 months. She gained 12 kg of weight, without tracheostomy and gastrostomy, only using pyridostigmine support 4 times a day.

Neutron flux measurements on a mock-up of a storage cask for high-level nuclear waste using 2.5 MeV neutrons.

To store and dispose spent nuclear fuel, shielding casks are employed to reduce the emitted radiation. To evaluate the exposure of employees handling such casks, Monte Carlo radiation transport codes can be employed. Nevertheless, to assess the reliability of these codes and nuclear data, experimental checks are required. In this study, a neutron generator (NG) producing neutrons of 2.5 MeV was employed to simulate neutrons produced in spent nuclear fuel. Different configurations of shielding layers of steel and polyethylene were positioned between the target of the NG and a NE-213 detector. The results of the measurements of neutron and γ radiation and the corresponding simulations with the code MCNP6 are presented. Details of the experimental set-up as well as neutron and photon flux spectra are provided as reference points for such NG investigations with shielding structures.

Desarrollo y validación de una metodología de cuantificación de fluconazol por UHPLC para emplear en el ensayo de disolución de comprimidos / Development and validation of UHPLC method for fluconazole quantification in tablets dissolution test

El fluconazol es un agente antimicótico, ampliamente utilizado en la prevención y tratamiento de infecciones fúngicas. Actualmente, las técnicas empleadas para la valoración de este activo se realizan por Cromatografía Líquida de Alta Performance (HPLC, por sus siglas en inglés), la cual insume mayor tiempo y gasto de solventes que las nuevas tecnologías por Cromatografía Líquida de Ultra Alta Performance (UHPLC, por sus siglas en inglés). Por esta razón, desde nuestro laboratorio se llevo a cabo el desarrollo y la validación de una nueva metodología por UHPLC con el objeto de valorar fluconazol en un ensayo de disolución de comprimidos. La misma emplea como sistema de detección un detector ultravioleta-visible (λ=260nm), fase móvil compuesta por una mezcla de acetonitrilo:agua (25:75) y columna de fase reversa (C18) a una temperatura de 40°C. Los correspondientes ensayos de validación mostraron que la metodología desarrollada es selectiva, lineal, exacta y precisa para concentraciones entre 14 y 278 µg/ mL, se probó que es robusta frente a pequeñas modificaciones del sistema, permitió ahorrar un 91% de acetonitrilo y fue aproximadamente 4 veces más rápida que la codificada en USP para comprimidos de fluconazol.

Fluconazole is an antifungal agent widely used in prevention and treatment of fungal infections. Currently, quantification methodologies are performed by High Performance Liquid Chromatography (HPLC), which normally takes more time and solvent consumption than the new technologies by Ultra High Performance Liquid Chromatography (UHPLC). For this reason, we carried out the development and validation of a new UHPLC methodology in order to evaluate fluconazole in a tablet dissolution test. It uses ultraviolet-visible detector (λ = 260nm), a mobile phase composed of a mixture of acetonitrile:water (25:75) and a reverse phase column (C18) at a temperature of 40°C. The corresponding validation tests showed that the methodology is selective, linear, accurate and precise for concentrations between 14 and 278 µg / mL, robust against small system modifications, it allowed to save 91% of acetonitrile and it was approximately 4 times faster than USP fluconazole tablets dissolution test.

Análisis y modelado de la cultura de seguridad de un hospital mexicano mediante cadenas de Markov / Analysis and modelling of safety culture in a Mexican hospital by Markov chains

Introducción. El objetivo de este estudio fue analizar y modelar la cultura de seguridad con cadenas de Markov, así como predecir o priorizar respecto al tiempo el comportamiento evolutivo de la cultura de seguridad del personal de salud de un hospital mexicano. Método. Se utilizó la teoría de cadenas de Markov. Los datos empleados para el análisis fueron obtenidos de un estudio previo basado en el Cuestionario de Actitudes Seguras (CAS-MX-II), considerando las siguientes 6 dimensiones: clima de seguridad, trabajo en equipo, satisfacción laboral, reconocimiento del nivel de estrés, percepción de la dirección y ambiente de trabajo. Resultados. Entre los hallazgos destacan las predicciones o priorizaciones del tiempo aproximado de posibles arraigos en el comportamiento evolutivo de la cultura de seguridad respecto a clima de seguridad (12 años; 24,1%); trabajo en equipo (8 años; 34,61%); satisfacción laboral (11 años; 52,4%); reconocimiento del nivel de estrés (8 años; 19,35%) y percepción de la dirección (22 años; 27,87%). En la dimensión ambiente de trabajo no fue posible determinar información del comportamiento del personal, es decir, no se obtuvo información de arraigo cultural. Conclusiones. En general, se detectan debilidades en la cultura de seguridad del hospital, lo que constituye una oportunidad para proponer cambios en las políticas mandatorias que permitan su fortalecimiento (AU)

Introduction. The objective of this study was to analyse and model the safety culture with Markov chains, as well as predicting and/or prioritizing over time the evolutionary behaviour of the safety culture of the health's staff in one Mexican hospital. Method. The Markov chain theory has been employed in the analysis, and the input data has been obtained from a previous study based on the Safety Attitude Questionnaire (CAS-MX-II), by considering the following 6 dimensions: safety climate, teamwork, job satisfaction, recognition of stress, perception of management, and work environment. Results. The results highlighted the predictions and/or prioritisation of the approximate time for the possible integration into the evolutionary behaviour of the safety culture as regards the “slightly agree” (Likert scale) for: safety climate (in 12 years; 24.13%); teamwork (8 years; 34.61%); job satisfaction (11 years; 52.41%); recognition of the level of stress (8 years; 19.35%); and perception of the direction (22 years; 27.87%). The work environment dimension was unable to determine the behaviour of staff information, i.e. no information cultural roots were obtained. Conclusion. In general, it has been shown that there are weaknesses in the safety culture of the hospital, which is an opportunity to suggest changes to the mandatory policies in order to strengthen it (AU)

UVER and UV index at high altitude in Northwestern Argentina.

Measurements of ultraviolet erythemal radiation (UVER) made during two years at three sites located at altitudes over 1000ma.s.l. in Northwestern Argentina (Salta, San Carlos, and El Rosal) have been used to estimate and analyze the UV Index (UVI) and the cumulative doses at these locations. For the UVER irradiance, data of January (maximum values) and June (minimum values) have been analyzed as representative of the year for all locations. The UVI reaches extreme (>11) values in >20% of the analyzed days in Salta (1190ma.s.l.), while these are reached in San Carlos (1611ma.s.l.) and El Rosal (3355ma.s.l.) in >40% of the analyzed days. Finally, the cumulative doses over an average year have also been studied for each location. The doses received during austral summer and autumn are of the same order, and represent one third of the annual dose, while the doses received during austral winter and spring represent one sixth of the annual dose approximately.

Neuromielitis óptica y lupus eritematoso sistémico en un hombre: caso clínico / Neuromyelitis optica presenting concomitantly with systemic lupus erythematosus: report of one case

Neuromyelitis optica (NMO) is a severe demyelinating disease of the central nervous system, which preferentially attacks the optic nerve and spinal cord. It is associated with antibodies against aquaporin 4. Morbidity and mortality are higher than in multiple sclerosis and its treatment focuses on immunosuppressive drugs. Immunomodulators are contraindicated. We report a previously healthy 35-year-old man, presenting with NMO concomitantly with systemic lupus erythematosus. His evolution was torpid with three outbreaks in the 10 months after the diagnosis, requiring a first-line therapy with methylprednisolone and cyclophosphamide and then a second-line therapy with rituximab.

[Analysis and modelling of safety culture in a Mexican hospital by Markov chains]. / Análisis y modelado de la cultura de seguridad de un hospital mexicano mediante cadenas de Markov.

INTRODUCTION: The objective of this study was to analyse and model the safety culture with Markov chains, as well as predicting and/or prioritizing over time the evolutionary behaviour of the safety culture of the health's staff in one Mexican hospital. METHOD: The Markov chain theory has been employed in the analysis, and the input data has been obtained from a previous study based on the Safety Attitude Questionnaire (CAS-MX-II), by considering the following 6 dimensions: safety climate, teamwork, job satisfaction, recognition of stress, perception of management, and work environment. RESULTS: The results highlighted the predictions and/or prioritisation of the approximate time for the possible integration into the evolutionary behaviour of the safety culture as regards the "slightly agree" (Likert scale) for: safety climate (in 12 years; 24.13%); teamwork (8 years; 34.61%); job satisfaction (11 years; 52.41%); recognition of the level of stress (8 years; 19.35%); and perception of the direction (22 years; 27.87%). The work environment dimension was unable to determine the behaviour of staff information, i.e. no information cultural roots were obtained. CONCLUSION: In general, it has been shown that there are weaknesses in the safety culture of the hospital, which is an opportunity to suggest changes to the mandatory policies in order to strengthen it.

[Neuromyelitis optica presenting concomitantly with systemic lupus erythematosus: Report of one case]. / Neuromielitis óptica y lupus eritematoso sistémico en un hombre: Caso clínico.

Neuromyelitis optica (NMO) is a severe demyelinating disease of the central nervous system, which preferentially attacks the optic nerve and spinal cord. It is associated with antibodies against aquaporin 4. Morbidity and mortality are higher than in multiple sclerosis and its treatment focuses on immunosuppressive drugs. Immunomodulators are contraindicated. We report a previously healthy 35-year-old man, presenting with NMO concomitantly with systemic lupus erythematosus. His evolution was torpid with three outbreaks in the 10 months after the diagnosis, requiring a first-line therapy with methylprednisolone and cyclophosphamide and then a second-line therapy with rituximab.

Trastornos del espectro alcohólico fetal: biomarcadores del consumo de etanol durante la gestación / Fetal alcohol spectrum disorders: biomarkers of ethanol consumption during pregnancy / Perturbações do espectro do alcoolismo fetal: biomarcadores de consumo de etanol durante a gravidez

El consumo de alcohol durante la gestación está asociado con un amplio espectro de efectos adversos conocidos como trastornos del espectro alcohólico fetal (TEAF). Así es como a través del dosaje de los esteres etílicos de ácidos grasos (FAEEs) en meconio, como biomarcadores de exposición prenatal al consumo de etanol, nos brinda una herramienta importantísima en el screening de los recién nacidos, facilitando la confi rmación del diagnóstico y la intervención clínica adecuada en los individuos afectados por esta problemática con una mejora en las expectativas y calidad de vida. El síndrome alcohólico fetal (SAF) representa el clásico síndrome y la manifestación más grave inducido por el alcohol de forma repetida durante el embarazo. Dado el carácter heterogéneo de las alteraciones clínicas presentes en los recién nacidos expuestos a etanol, la mayoría de los cuales no son específi cos, conlleva a un diagnóstico del TEAF extremadamente difícil.

Alcohol consumption during pregnancy is associated with a wide range of adverse effects known as fetal alcohol spectrum disorders (FASDs). Through the measurement of Fatty Acid Ethyl Esters (FAEEs) in meconium, as biomarkers of prenatal alcohol exposure, we have a very important tool in the screening of newborns, facilitating the confi rmation of diagnosis and adequate clinical intervention in individuals affected by this problem with improvements in life quality and expectancy. Fetal Alcohol Syndrome (FAS) represents the classic syndrome and the most serious condition is caused by repetitive alcohol consumption during pregnancy. Due to the heterogeneous characteristics of clinical alterations of newborns exposed to ethanol, most of which are not specifi c, diagnosis of FASDs is extremely diffi cult.

O consumo de álcool durante a gravidez é associado a um amplo espectro de efeitos adversos conhecidos, tais como transtornos do espectro do alcoolismo fetal (TEAF). É assim como através da dosagem dos ésteres etílicos de ácidos graxos (FAEEs) em mecô- nio, como biomarcadores de exposição pré-natal ao consumo de etanol, fornece uma ferramenta importantíssima na triagem de recém-nascidos, aprimorando a confi rmação do diagnóstico e a intervenção clínica adequada em indivíduos afectados por este problema com uma melhoria das expectativas e qualidade de vida. Síndrome alcoólica fetal (FAS) representa a síndrome clássica e a mais grave manifestação induzida frequentemente pelo álcool durante a gravidez. Dada a heterogeneidade das alterações clínicas em recémnascidos expostos ao etanol, a maioria das quais são não-específi cas, esta situação gera um diagnóstico de TEAF extremamente difícil.

Domestic mites on the hair/scalp, pillows, and mattresses of mite-sensitized children in a subtropical area

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Trombosis de seno venoso secundaria a traumatismo encéfalo craneano: caso clínico / Cerebral vein thrombosis secondary to closed head injury: Report of one case

Intracranial sinus thrombosis (1ST) after closed head injury is an uncommon but potentially serious complication. It has no correlation with the severity of the injury. The symptoms and clinical course are highly variable. The most frequent but least specific symptom is severe headache. Cerebral lesions and neurologic signs develop in half of patients with IST. We report a 29 year-old male who had an IST after a severe closed head injury. The patient initially developed headache and had later 2 secondarily generalized seizures. The magnetic resonance imaging showed a superior sagittal sinus thrombosis. Anticoagulation with unfractionated heparin and intravenous phenytoin was started. At the moment of this report he is asymptomatic and continues with oral anticoagulants and phenytoin.

Síndrome anti-GQ1b: Descripción de cuatro pacientes y revisión de la literatura / Anti-GQ1b syndrome: Report of four cases

Anti-GQ1b syndrome includes Miller Fisher Syndrome (MFS), Guillain Barré Syndrome (GBS), Bickerstaff`s brain stem encephalitis (BBE) and Acute Ophtamoplegia (AO). We report four patients aged 16 to 76 years, with anti-GQ1b syndrome. All presented with MFS, one of them evolved to GBS pharyngeal-cervical-brachial variant and other to GBS with BBE. All had a previous history of diarrhea or upper respiratory tract infection. All had positive anti-GQ1b serum antibodies. Both brain magnetic resonance imaging and cerebrospinal fluid analysis were normal. Electrophysiology studies were compatible with a demyelinating disease. Two patients needed airway protection with an orotracheal tube and developed dysautonomia. All four patients were treated with immunomodulation. On the sixth month follow-up, patients had only minimal alterations in the neurological examination.

[Anti-GQ1b syndrome: report of four cases]. / Síndrome anti-GQ1b: Descripción de cuatro pacientes y revisión de la literatura.

Anti-GQ1b syndrome includes Miller Fisher Syndrome (MFS), Guillain Barré Syndrome (GBS), Bicker staff`s brain stem encephalitis (BBE) and Acute Ophtamoplegia (AO). We report four patients aged 16 to 76 years, with anti-GQ1b syndrome. All presented with MFS, one of them evolved to GBS pharyngeal-cervical-brachial variant and other to GBS with BBE. All had a previous history of diarrhea or upper respiratory tract infection. All had positive anti-GQ1b serum antibodies. Both brain magnetic resonance imaging and cerebrospinal fluid analysis were normal. Electrophysiology studies were compatible with a demyelinating disease. Two patients needed airway protection with an orotracheal tube and developed dysautonomia. All four patients were treated with immunomodulation. On the sixth month follow-up, patients had only minimal alterations in the neurological examination.