Inclusion of ionizing radiation in a mathematical model for photosynthesis.

Ionizing radiation of astrophysical origin might have played an important role in biological evolution during the long course of Earth's evolution. Several phenomena might have induced intense fluctuations in background ionizing radiation, such as highly energetic stellar explosions. There might also be anthropogenic causes for environmental radiation fluctuations, resulting from nuclear industry activities. The inclusion of these effects in a mathematical model for photosynthesis provides a useful tool to account for the damages of the above-mentioned phenomena in vegetal life. Mathematical models for photosynthesis typically only consider ultraviolet radiation and photosynthetically active radiation, as they have been a ubiquitous physical factor in the settlement of vegetal life. In this work a mathematical model for aquatic photosynthesis is modified, from first principles, to include the action of particulate ionizing radiation on the photosynthetic process. After assuming an ansatz allowing to separate damage/repair kinetics of ultraviolet and ionizing radiations, a treatable mathematical expression of the model is obtained. This generalized model is presented as a function of radiometric and photometric magnitudes, making it prone to calibration and useful to apply to aquatic ecosystems under radiational stress due to gamma-ray bursts, cosmic ray bursts, solar storms, or other sources of ionizing radiations.

On the photosynthetic potential in the very Early Archean oceans.

In this work we apply a mathematical model of photosynthesis to quantify the potential for photosynthetic life in the very Early Archean oceans. We assume the presence of oceanic blockers of ultraviolet radiation, specifically ferrous ions. For this scenario, our results suggest a potential for photosynthetic life greater than or similar to that in later eras/eons, such as the Late Archean and the current Phanerozoic eon.

Response of phytoplankton functional types to Hurricane Fabian (2003) in the Sargasso Sea.

Understanding how tropical cyclones affect phytoplankton communities is important for studies on ecological variability. Most studies assessing the post-storm phytoplankton response rely on satellite observations of chlorophyll a concentration, which inform on the ocean surface conditions and the whole phytoplankton community. In this work, we assess the potential of the Massachusetts Institute of Technology marine ecosystem model to account for the response of individual phytoplankton functional types (PFTs, coccolithophores, diatoms, diazotrophs, mixotrophic dinoflagellates, picoeukaryotes, Prochlorococcus and Synechococcus) in the euphotic zone to the passage of Hurricane Fabian (2003) across the tropical and subtropical Sargasso Sea. Fabian induced a significant mean concentration increase (t-test, p < 0.05) of all PFTs in the tropical waters (except for Prochlorococcus), which was driven by the mean nutrient concentration increase and by a limited zooplankton grazing pressure. More specifically, the post-storm nutrient enrichment increased the contribution of fast-growing PFTs (e.g. diatoms and coccolithophores) to the total phytoplankton concentration and decreased the contribution of slow-growing dominant groups (e.g. picoeukaryotes, Prochlorococcus and Synechococcus), which lead to a significant increase (t-test, p < 0.05) of the Shannon diversity index values. Overall, the model captured the causal relationship between nutrient and PFT concentration increases in the tropical waters, although it only reproduced the most pronounced PFT responses such as those in the deep euphotic zone. In contrast, the model did not capture the oceanic perturbations induced by Fabian as observed in satellite imagery in the subtropical waters, probably due to its limited performance in this complex oceanographic area.

[Functional characterization of patients with cerebral palsy living in the Magallanes region and the Chilean Antarctic]. / Caracterización funcional de pacientes con parálisis cerebral que viven en la región de Magallanes y la Antártica Chilena.

OBJECTIVE: To functionally characterize patients with Cerebral Palsy (CP) living in the Magallanes Re gion and the Chilean Antarctic. PATIENT AND METHOD: Descriptive-retrospective observational study of patients with cerebral palsy, registered in the Outpatient Rehabilitation Program of the Corporación de Rehabilitación Club de Leones Cruz del Sur de Punta Arenas between 1986 and 2018. Patients with CP were clinically categorized and then functionally characterized according to gross motor skills (GMFCS), manual ability (MACS), feeding ability (EDACS), and communication function (CFCS). RESULTS: 106 patients were included. Regarding the clinical classification, the most common type of CP was bilateral spastic paralysis, with the highest percentage of functional involvement in each of the evaluated areas, followed by unilateral spastic paralysis, while cases of dystonic CP and other non-classifiable types presented were less frequent. According to the clinical subclassification, spastic diplegia was more frequent, especially affecting manual and communication skills level I compared with hemiplegia, while cases of mixed and unclassifiable quadriplegia were less frequent with greater overall involvement of level I feeding skills. CONCLUSION: The observed results of CP in the Magalla nes Region and the Chilean Antarctic are similar to studies available in the literature. The complete evaluation and classification of patients with CP enable a better understanding of the pathology for future studies.

A Robot-Assisted Therapy to Increase Muscle Strength in Hemiplegic Gait Rehabilitation.

This study examines the feasibility of using a robot-assisted therapy methodology based on the Bobath concept to perform exercises applied in conventional therapy for gait rehabilitation in stroke patients. The aim of the therapy is to improve postural control and movement through exercises based on repetitive active-assisted joint mobilization, which is expected to produce strength changes in the lower limbs. As therapy progresses, robotic assistance is gradually reduced and the patient's burden increases with the goal of achieving a certain degree of independence. The relationship between force and range of motion led to the analysis of both parameters of interest. The study included 23 volunteers who performed 24 sessions, 2 sessions per week for 12 weeks, each lasting about 1 h. The results showed a significant increase in hip abduction and knee flexion strength on both sides, although there was a general trend of increased strength in all joints. However, the range of motion at the hip and ankle joints was reduced. The usefulness of this platform for transferring exercises from conventional to robot-assisted therapies was demonstrated, as well as the benefits that can be obtained in muscle strength training. However, it is suggested to complement the applied therapy with exercises for the maintenance and improvement of the range of motion.

[Recommendations For The Management Of Spontaneous Intracerebral Hemorrhage During Hospitalization]. / Recomendaciones en el Abordaje del Hematoma Intracerebral Espontáneo Durante la Internación.

Stroke is the leading cause of neurological disability in people over 40 years of age and the fourth leading cause of death in Argentina. In the last ten years, the indexed publications related to the treatment of ischemic stroke were more numerous than those of hemorrhagic stroke. The objective of this material is to provide local and updated recommendations for the management of patients with spontaneous intracerebral hemorrhage during hospitalization. For the writing of this manuscript, diferent specialists were convened to form working groups. Ten central topics expressed as epidemiology, initial care, imaging, blood pressure treatment, reversal of antithrombotics, indication for surgery, seizure prophylaxis, prognosis, prevention of complications and resumption of antithrombotics were raised. For each topic, the most frequent questions of daily practice were raised through PICO questions. After a systematic review of the literature, recommendations were generated, evaluated using the GRADE system and agreed between authors and patients.

El accidente cerebrovascular (ACV) constituye la principal causa de discapacidad de origen neurológico en los adultos mayores a 40 años y la cuarta causa de muerte en Argentina. En los últimos diez años las publicaciones indexadas relacionadas al tratamiento del ACV isquémico fueron más numerosas que las de ACV hemorrágico. El objetivo de este material es proporcionar recomendaciones locales y actualizadas del abordaje de pacientes con hematoma intraparenquimatoso espontáneo durante la internación. Para la redacción de este manuscrito se convocó a especialistas en esta enfermedad que conformaron grupos de trabajo. Se plantearon 10 tópicos centrales expresados como epidemiologia, atención inicial, imágenes, tratamiento de la presión arterial, reversión de antitrombóticos, indicación de cirugía, profilaxis anticonvulsivante, pronóstico, prevención de complicaciones y reinicio de antitrombóticos. De cada tópico se plantearon mediante preguntas PICO los interrogantes más frecuentes de la práctica diaria. Luego de una revisión sistemática de la literatura, se generaron recomendaciones evaluadas mediante sistema GRADE y consensuadas entre autores y pacientes.

Cerebral aneurysms in children: are we talking about a single pathological entity?

PURPOSE: The objective of this article is to highlight the fact that cerebral aneurysms in children are heterogeneous unlike in the adult population. MATERIAL AND METHODS: This is a retrospective review of 17 children with intracranial aneurysms who were managed at a single institution from 2004 to 2009. RESULTS: The median age was 12 years (range 10 months-17 years). Sixty-five percent of the aneurysms were saccular and 24% were fusiform. There was one infectious and one distal lenticulostriate aneurysm. Patients with saccular aneurysms were predominantly male and presented more commonly with intracranial hemorrhage (91%). The fusiform aneurysms were dissecting in nature or chronic with intramural thrombus and mass effect. The treatment was dependent upon the type and location of the aneurysm. CONCLUSION: Pedriatic aneurysms are a heterogeneous group of intracranial arterial diseases with different etiologies, diverse morphology, and dissimilar clinical manifestations.

Some possible dynamical constraints for life's origin.

Oscillating biochemical reactions are common in cell dynamics and could be closely related to the emergence of the life phenomenon itself. In this work, we study the dynamical features of some classical chemical or biochemical oscillators where the effect of cell volume changes is explicitly considered. Such analysis enables us to find some general conditions about the cell membrane to preserve such oscillatory patterns, of possible relevance to hypothetical primitive cells in which these structures first appeared.

[Consensus on acute ischemic stroke]. / Consenso sobre accidente cerebrovascular isquémico agudo.

Stroke is the third cause of death and the first cause of disability in Argentina. Ischemic events constitute 80% of cases. It requires the implementation of systematized protocols that allow reducing the time of care, morbidity and mortality. Specialists from nine medical societies related to the care of patients with cerebrovascular disease participated in the consensus. A separate agenda was agreed upon in chapters and for the writing of them, work groups were formed with members of different medical specialties. The level of recommendation was discussed and agreed upon for each topic based on the best clinical evidence available for each of them. An adaptation to the local scope of the recommendations was made when it was considered necessary.The American Heart Association system was used to draft the recommendations and their level of evidence. The correction and editing were done by five external reviewers, who did not participate in the writing and with extensive experience in vascular pathology. Once the preliminary document was finalized, a general meeting was held with all the members of the working groups and the reviewers to reach final recommendations. The consensus covers the management of ischemic stroke in the pre-hospital phase, initial evaluation in the emergency center, recanalization therapies (thrombolysis and/ or mechanical thrombectomy), decompressive craniectomy, neuroimaging and clinical care in the hospital.

El accidente cerebrovascular es la tercera causa de muerte y la primera de discapacidad en la Argentina. Los eventos isquémicos constituyen el 80% de los casos. Los accidentes vasculares cerebrales requieren la implementación de protocolos sistematizados que permitan reducir los tiempos en la atención, la morbilidad y mortalidad. En el consenso participaron especialistas de nueve sociedades médicas relacionadas con la atención de pacientes con enfermedad cerebrovascular. Se consensuó un temario separado en capítulos y para la redacción de los mismos se conformaron grupos de trabajo con miembros de diferentes especialidades médicas. Se discutió y acordó para cada tema el nivel de recomendación en base a la mejor evidencia clínica disponible para cada tópico. Se realizó una adaptación al ámbito local de las recomendaciones cuando se consideró necesario. El sistema de la American Heart Association se utilizó para redactar las recomendaciones y su grado de evidencia. La corrección y edición fue realizada por cinco revisores externos, que no participaron en la redacción y con amplia experiencia en enfermedad vascular. Finalizado el documento preliminar, se organizó una reunión general con todos los integrantes de los grupos de trabajo y los revisores para redactar las recomendaciones definitivas. El consenso abarca la atención del paciente con accidente cerebrovascular isquémico en la fase pre-hospitalaria, evaluación inicial en la central de emergencias, terapias de recanalización (trombolisis y/o trombectomía mecánica), craniectomía descompresiva, neuroimágenes y cuidados clínicos en la internación.

Recomendaciones en el abordaje del hematoma intracerebral espontáneo durante la internación / Recommendations for the management of spontaneous intracerebral hemorrhage during hospitalization

Resumen El accidente cerebrovascular (ACV) constituye la principal causa de discapacidad de origen neuro- lógico en los adultos mayores a 40 años y la cuarta causa de muerte en Argentina. En los últimos diez años las publicaciones indexadas relacionadas al tratamiento del ACV isquémico fueron más numerosas que las de ACV hemorrágico. El objetivo de este material es proporcionar recomendaciones locales y actualiza- das del abordaje de pacientes con hematoma intraparenquimatoso espontáneo durante la internación. Para la redacción de este manuscrito se convocó a especialistas en esta enfermedad que conformaron grupos de trabajo. Se plantearon 10 tópicos centrales expresados como epidemiologia, atención inicial, imágenes, tratamiento de la presión arterial, reversión de antitrombóticos, indicación de cirugía, profilaxis anticonvulsivante, pronóstico, prevención de complicaciones y reinicio de antitrombóticos. De cada tópico se plantearon mediante preguntas PICO los interrogantes más frecuentes de la práctica diaria. Luego de una revisión sistemática de la literatura, se generaron recomendaciones evaluadas mediante sistema GRADE y consensuadas entre autores y pacientes.

Abstract Stroke is the leading cause of neurological disability in people over 40 years of age and the fourth leading cause of death in Argentina. In the last ten years, the indexed publications related to the treatment of ischemic stroke were more numerous than those of hemorrhagic stroke. The objective of this material is to provide local and updated recommendations for the management of patients with spontaneous intracere- bral hemorrhage during hospitalization. For the writing of this manuscript, diferent specialists were convened to form working groups. Ten central topics expressed as epidemiology, initial care, imaging, blood pressure treatment, reversal of antithrombotics, indication for surgery, seizure prophylaxis, prognosis, prevention of complications and resumption of antithrombotics were raised. For each topic, the most frequent questions of daily practice were raised through PICO questions. After a systematic review of the literature, recommendations were generated, evaluated using the GRADE system and agreed between authors and patients.

Consenso sobre accidente cerebrovascular isquémico agudo / Consensus on acute ischemic stroke

El accidente cerebrovascular es la tercera causa de muerte y la primera de discapacidad en la Argentina. Los eventos isquémicos constituyen el 80% de los casos. Los accidentes vasculares cerebrales requieren la implementación de protocolos sistematizados que permitan reducir los tiempos en la atención, la morbilidad y mortalidad. En el consenso participaron especialistas de nueve sociedades médicas relacionadas con la atención de pacientes con enfermedad cerebrovascular. Se consensuó un temario separado en capítulos y para la redacción de los mismos se conformaron grupos de trabajo con miembros de diferentes especialidades médicas. Se discutió y acordó para cada tema el nivel de recomendación en base a la mejor evidencia clínica disponible para cada tópico. Se realizó una adaptación al ámbito local de las recomendaciones cuando se consideró necesario. El sistema de la American Heart Association se utilizó para redactar las recomendaciones y su grado de evidencia. La corrección y edición fue realizada por cinco revisores externos, que no participaron en la redacción y con amplia experiencia en enfermedad vascular. Finalizado el documento preliminar, se organizó una reunión general con todos los integrantes de los grupos de trabajo y los revisores para redactar las recomendaciones definitivas. El consenso abarca la atención del paciente con accidente cerebrovascular isquémico en la fase pre-hospitalaria, evaluación inicial en la central de emergencias, terapias de recanalización (trombolisis y/o trombectomía mecánica), craniectomía descompresiva, neuroimágenes y cuidados clínicos en la internación.

Stroke is the third cause of death and the first cause of disability in Argentina. Ischemic events constitute 80% of cases. It requires the implementation of systematized protocols that allow reducing the time of care, morbidity and mortality. Specialists from nine medical societies related to the care of patients with cerebrovascular disease participated in the consensus. A separate agenda was agreed upon in chapters and for the writing of them, work groups were formed with members of different medical specialties. The level of recommendation was discussed and agreed upon for each topic based on the best clinical evidence available for each of them. An adaptation to the local scope of the recommendations was made when it was considered necessary.The American Heart Association system was used to draft the recommendations and their level of evidence. The correction and editing were done by five external reviewers, who did not participate in the writing and with extensive experience in vascular pathology. Once the preliminary document was finalized, a general meeting was held with all the members of the working groups and the reviewers to reach final recommendations. The consensus covers the management of ischemic stroke in the pre-hospital phase, initial evaluation in the emergency center, recanalization therapies (thrombolysis and/ or mechanical thrombectomy), decompressive craniectomy, neuroimaging and clinical care in the hospital.

Aneurismas cerebrales en la infancia: un solo nombre para diferentes enfermedades / Cerebral aneurysms in infancy: a name for different diseases

Objetivo. Resaltar la heterogeneidad de los aneurismas cerebrales en la población pediátrica. Material y método. 19 pacientes con 20 aneurismas intracraneanos fueron tratados en nuestro Hospital en los ultimos 6 años.Resultados. La edad media fue de 12 años (rango 10 meses a 17 años). 65 %de los aneurismas fueron saculares, 25% fusiformes, hubo un aneurisma infeccioso y otro lenticuloestriado distal. Los pacientes con aneurismas saculares fueron predominantemente varones y se manifestaron más comúnmente con hemorragia intracraneana (92%). Los aneurismas fusiformes se originaron posteriormente a una disección o fueron crónicos con trombo mural y ejerciendo efecto de masa. La terapéutica fue diferente según el tipo aneurismático. Conclusión. Los aneurismas pediátricos son un grupo heterogéneo de enfermedades arteriales intracraneanas con manifestaciones clínicas, morfología y terapéutica diferentes.

Aneurismas cerebrales en la infancia: un solo nombre para diferentes enfermedades / Cerebral aneurysms in infancy: a name for different diseases

Objetivo. Resaltar la heterogeneidad de los aneurismas cerebrales en la población pediátrica. Material y método. 19 pacientes con 20 aneurismas intracraneanos fueron tratados en nuestro Hospital en los ultimos 6 años.Resultados. La edad media fue de 12 años (rango 10 meses a 17 años). 65 %de los aneurismas fueron saculares, 25% fusiformes, hubo un aneurisma infeccioso y otro lenticuloestriado distal. Los pacientes con aneurismas saculares fueron predominantemente varones y se manifestaron más comúnmente con hemorragia intracraneana (92%). Los aneurismas fusiformes se originaron posteriormente a una disección o fueron crónicos con trombo mural y ejerciendo efecto de masa. La terapéutica fue diferente según el tipo aneurismático. Conclusión. Los aneurismas pediátricos son un grupo heterogéneo de enfermedades arteriales intracraneanas con manifestaciones clínicas, morfología y terapéutica diferentes.(AU)