2,369 research outputs found
Facomatosis. Estado actual
Se describen las facomatosis más frecuentes y principales dividiéndolas en dos grandes grupos polares siguiendo la tradicional e inveterada clasificación confeccionada por Brouwer y Van der Hoeve, es decir: neuroectodérmicas porque afectan fundamentalmente al sistema nervioso y las de origen mesodérmico que atacan preferencialmente en primera línea, al aparato circulatorio. Tras realizar un sucinto esbozo histórico, rememorar la estrecha vinculación existente entre la Oftalmología y demás especialidades médicas, se describe con minuciosidad las enfermedades de Von Recklinghausen o neurofibromatosis múltiple y la esclerosis cerebral tuberosa o enfermedad de Bourneville como máximas representantes del primer grupo y las de Sturge-Weber- Krabbe también denominada angiomatosis trigémino cerebral o meníngeo-cutánea o encéfalo-trigeminal y la enfermedad de Von Hippel-Lindau conocida igualmente por angioglioblastomatosis retino-cerebelosa como más habituales dentro de las mesodérmicas se incide en los medios diagnóstico, complejos cuadros clínicos multiformes y diversos tratamientos. De momento hasta hoy, las mesodérmicas revisten mejor pronóstico desde el punto de vista ocular se termina tras sintetizar los últimos avances en materia de Bioquímica, Biología Molecular y Celular haciendo hincapié en la posible génesis autoinmunitaria de todas las Facomatosis y en la futura prometedora terapia de las mismas, recurriendo al empleo de Células Madres.The most common Phakomatoses are divided into two groups following the long standing classification made by Brower and Van der Hoeve. The first group is of neuroectodermal origin affecting mainly the nervous system and the second is of mesodermal origin attacking preferentially the circulatory apparatus. After a succinct historical outline and review of the close link demonstrated between Ophthalmology and others medical specialties, the author puts forth a detailed description of Von Recklinghausen´s disease (multiple neurofibromatosis) and Tuberous Sclerosis (Bourneville disease) as primary representatives of the first group. In the second group we have Sturge-Weber- Krabbe, also called cerebro-trigeminal angiomatosis or meningo-cutaneus or encephalo-trigeminal and Von Hippel-Lindau´s disease also known as retino-cerebellar angioglioblastomatosis. The several diagnostic tools and different treatments of these complex pathologies are explained. All the entities of mesodermal origin have better ocular prognoses. After describing the latest developments in Biochemistry, Molecular and Cellular Biology and pointing out the possible autoimmune genesis of Phakomatoses, there is optimism for future therapies employing stem cells
The first report of South American edrioasteroids and the paleoecology and ontogeny of rhenopyrgid echinoderms
A new species of rhenopyrgid edrioasteroid Rhenopyrgus piojoensis sp. nov. is described form the Silurian (Lower Lud− low) Los Espejos Formation in the Precordillera of Argentina. This species is the first reported edrioasteroid from South America. Rhenopyrgids are widely distributed in Ordovician through Devonian deposits of most continents. Numerous juvenile specimens show that the general bodyplan is organized early in ontogeny and that the pedenculate zone lengthens with age. Phylogenetic analysis shows that rhenopyrgids are more closely related to edrioasterid edrioasteroids such as edrioblastoids and cyathocystids than to pyrgocystid isorophids.Fil: Sumrall, Colin D.. University of Tennessee; Estados UnidosFil: Heredia, Susana Emma. Universidad Nacional de San Juan. Facultad de Ingeniería. Instituto de Investigaciones Mineras; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Rodríguez, Cecilia María. Universidad Nacional de San Juan. Facultad de Ingeniería. Instituto de Investigaciones Mineras; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Mestre García, Ana Isabel. Universidad Nacional de San Juan. Facultad de Ingeniería. Instituto de Investigaciones Mineras; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin
A probabilistic patient scheduling model for reducing the number of no-shows
No-shows in medical centres cause under-utilisation of resources and increase waiting times in specialty health care services. Although this problem has been addressed in literature, behavioural issues associated with the patient's socio-demographic characteristics and diagnosis have not been widely studied. In this article, we propose a model that includes such behavioural issues in order to reduce impact of no-shows in medical services. The objective is maximising the health centre's expected revenue by using show-up probabilities estimated for each combination of patient and appointment slot. Additionally, the model considers the requirements imposed by both the health centre's management and the health authorities. An extension of the model allows overbooking in some appointment slots. Experimental results show that the proposed model can reduce the waiting list length by 13%, and to attain an increase of about 5% in revenue, when comparing to a model that assigns patients to the first available slot
Simulation of swift boron clusters traversing amorphous carbon foils
We use a simulation code to study the interaction of swift boron clusters (Bn+, n=2–6, 14) with amorphous carbon foils. We analyze different aspects of this interaction, such as the evolution of the cluster structure inside the target, the energy and angle distributions at the detector or the stopping power ratio. Our simulation code follows in detail the motion of the cluster fragments through the target and in the vacuum until reaching a detector, taking into account the following interactions: (i) wake force, (ii) Coulomb repulsion among cluster fragments, (iii) stopping force, and (iv) elastic scattering with the target nuclei. Electron capture and loss by each fragment is also included in the code, affecting the above-mentioned interactions. The clusters size grows inside the foil due mainly to the Coulomb explosion but this increase is less pronounced in the plane transversal to the beam direction because of the alignment effect of the wake forces. We obtain an enhancement of the stopping power ratio that increases with the projectile energy and with the number of molecular constituents. Our results agree very well with the available experimental data for the thicker foils (≳10 μg∕cm2) and are compatible (within the experimental error bars) for the thinner foils.This work has been financially supported by the Spanish Ministerio de Educación y Ciencia (Contract Nos. BFM2003-04457-C02-01 and BFM2003-04457-C02-02). S.H.A. thanks the Fundación CajaMurcia for financial support and C.D.D. thanks the Spanish Ministerio de Educación y Ciencia for support under the Ramón y Cajal Program
Coulomb-explosion imaging of CH2+: target-polarization effects and bond-angle distribution
The effect of target polarization fields on the bond-angle distribution following the foil-induced Coulomb explosion of CH2+ has been measured. Incorporating a detailed model description of the polarization effects and other target effects into a Monte Carlo simulation of the experiment, a good description of the various observables is obtained. In particular, the bond-angle distribution is found to agree with existing ab initio calculations.This work has been supported in part by the German-Israel Foundation for Scientific Research (GIF) under Contract No. I-707-55.7/2001, the Spanish Ministerio de Ciencia y Tecnología (Project Nos. BFM2003-04457-C02-01/02 and HA2001-0052), the DAAD in the framework of the Acciones Integrados Program 2002/03, and the European Community within the Research Training Network “Electron Transfer Reactions.” One of the authors (S.H.A.) thanks the Fundación Cajamurcia for a Postdoctoral Grant
Reactivation of Paleozoic structures during Cenozoic deformation in the Cordón del Plata and Southern Precordillera ranges (Mendoza, Argentina)
The tectonic style of the eastern morphostructural units of the Central Andes between 32°20´ and 33°20´S is strongly influenced by pre- Andean structures, especially those developed during the late Carboniferous-Early Permian San Rafael orogeny of the Gondwanan orogenic cycle. Moreover, in the study area pre-Carboniferous rocks were deformed in Late Devonian-early Carboniferous times by the Chanic orogeny. In this paper we argue that the Cordón del Plata and the Southern Precordillera ranges, first order features of the eastern ranges of the Andes, have been shaped in large part by the Permian event. Our data suggest that the double verging character of the Andean Precordillera fold- thrust belt is mainly the result of the reactivation of Gondwanan structures which conform a fold-thrust belt with distinct characteristics north and south of 33°S. The northern sector of this belt corresponds to a bivergent system, while the southern sector had a widespread east vergence. The vergence of the Chanic structures is more difficult to determine, but we infer a westward vergence in the Frontal Cordillera and western sector of Precordillera, and an eastern vergence in the eastern sector of the Precordillera. The sharp disappearance of the Precordillera morphostructural unit south of 33°S is inferred here to be related to the distribution of inherited Permian structures.El estilo tectónico del sector oriental de las unidades morfoestructurales de los Andes Centrales entre los 32°20´y 33°20´S se encuentra fuertemente influenciado por estructuras pre-andinas, especialmente aquellas desarrolladas durante el Carbonífero superior-Pérmico Inferior y asociadas al orógeno San Rafael del ciclo orogénico Gondwánico. Además, en el área de estudio, las rocas pre-carboníferas se deformaron durante el Devónico Superior y Carbonífero inferior, en relación con la orogenia Chánica. En este trabajo discutimos los rasgos de primer orden del sector oriental de los Andes, que comprende al Cordón del Plata y a la Precordillera Austral, fueron en gran parte modelados a partir del evento pérmico. Nuestros datos sugieren que la doble vergencia de una faja plegada y corrida en la Precordillera Andina es el resultado principalmente de la reactivación de estructuras gondwánicas que conformaron una faja plegada y corrida con características distintivas al norte y sur de los 33°S. El sector norte de la faja corresponde a un sistema bivergente, mientras que el sector sur posee una vergencia predominantemente oriental. La vergencia de las estructuras chánicas es más difícil de predecir, pero se sugiere aquí una vergencia hacia el oeste para las estructuras de la Cordillera Frontal y el sector occidental de la Precordillera y otra hacia el este para las estructuras del sector oriental de la Precordillera. Se infiere que la marcada desaparición de la Precordillera como unidad morfoestructural andina al sur de los 33° está relacionada a la distribución de estructuras chánicas y gondwánicas
Intermediate snowpack melt-out dates guarantee the highest seasonal grasslands greening in the Pyrenees
In mountain areas, the phenology and productivity of grassland are closely related to snow dynamics. However, the influence that snow melt timing has on grassland growing still needs further attention for a full understanding, particularly at high spatial resolution. Aiming to reduce this knowledge gap, this work exploits 1 m resolution snow depth and Normalized Difference Vegetation Index observations acquired with an Unmanned Aerial Vehicle at a sub-alpine site in the Pyrenees. During two snow seasons (2019–2020 and 2020–2021), 14 NDVI and 17 snow depth distributions were acquired over 48 ha. Despite the snow dynamics being different in the two seasons, the response of grasslands greening to snow melt-out exhibited a very similar pattern in both. The NDVI temporal evolution in areas with distinct melt-out dates reveals that sectors where the melt-out date occurs in late April or early May (optimum melt-out) reach the maximum vegetation productivity. Zones with an earlier or a later melt-out rarely reach peak NDVI values. The results obtained in this study area, suggest that knowledge about snow depth distribution is not needed to understand NDVI grassland dynamics. The analysis did not reveal a clear link between the spatial variability in snow duration and the diversity and richness of grassland communities within the study area
New lithostratigraphy for the Cantabrian Mountains: A common tectono-stratigraphic evolution for the onset of the Alpine cycle in the W Pyrenean realm, N Spain
The Pyrenean-Cantabrian Orogen arose through the collision of the Iberian and Eurasian plates, mostly in Cenozoic times. This orogen comprises two main mountain ranges, the Pyrenees to the east, and the Cantabrian Mountains to the west. To date, the early Alpine tectono-sedimentary phases preserved in the Cantabrian Mountains, of Permian and Triassic age, have been considered independently from the same phases in neighbouring basins of SW Europe, and even from the eastern part of the same orogeny (the Pyrenean orogeny). In consequence, the beginning of the Alpine cycle in the Cantabrian Mountains has been interpreted within a specific geodynamic context, far from the general evolutionary phases of the western Peri-Tethys basins. Through detailed field work, including geological mapping, sedimentology, lithostratigraphy and petrology of volcanic rocks, and new palaeontological data, here we define several new lithostratigraphical formations and five new tectono-sedimentary cycles (TS I-V) for the initial phases of evolution of the Mesozoic Basque-Cantabrian Basin, interrupted by periods of tectonic stability. To complete this information, we include data from an onshore borehole (Villabona Mine) and two offshore boreholes constrained by 2D reflection seismic profiles acquired in the North Iberian continental platform. The main tectono-sedimentary cycles, related to the deposition of five major identified lithostratigraphic units, can be described as follows: TS I (late Gzelian-early Asselian), relating to the late Variscan deformation and preserved in a single outcrop in all the Cantabrian Mountains (San Tirso Formation). This formation is constituted by medium-distal alluvial fan deposits in which humid intervals predominate, forming some thin coal beds. TS II (Asselian-Sakmarian), a post-Variscan extensional phase with associated calc-alkaline magmatism, represented by profuse volcanic and volcanosedimentary intercalations in the early Permian sedimentary basins (Acebal Formation) and small plutons in surrounding areas. TS III (Kungurian), or reactivation of the post-Variscan extension leading to alluvial and lacustrine carbonate sedimentation in arid climate conditions, which do not change during the rest of the Permian and Triassic periods (Sotres Formation). A generalized karstification in the basin represents the end of Permian deposition, followed by an interruption in sedimentation longer than 30 Myr. The Permian tectono-sedimentary cycles (TS II and TS III) are contemporary with Variscan belt collapse and the basins are controlled by extensional reactivation of NE-SW and E-W Variscan structures, and NW-SE late Variscan structures. TS IV (late Anisian–middle Carnian), renewed sedimentation in more extensive basins, precursors of the great Mesozoic Basque-Cantabrian Basin. This cycle is represented by fluvial deposits (Cicera Formation, or Buntsandstein facies), which are interrupted by the first Mesozoic marine ingression (Rueda Formation, or Muschelkalk facies). TS V (Norian-Rhaetian), or shallow marine carbonate deposits (Transición Formation) related to increasingly compartmentalized sub-basins, controlled by normal faults. This final TS is broadly connected with different basins of the western Peri-Tethys domain. The identification of units TS I-V in the Cantabrian Mountains along with the volcanic character of TS II, all indicate the development of a common post-Variscan to early Alpine tectono-sedimentary evolution for the whole Pyrenean-Cantabrian realm
INYECCIONES INTRACUTÁNEAS DE AGUA ESTÉRIL EN EL ROMBO DE MICHAELIS PREVIA ANESTESIA LOCAL: UNA TERAPIA COMPLEMENTARIA PARA EL ALIVIO DE DOLOR DURANTE EL PARTO
IntroductionSterile water injections in the Rhombus of Michaelis are used as a simple technique to alleviate back pain during childbirth. However, the technique itself is painful and requires two professionals to carry it out. ObjectiveTo assess the level of pain associated with the technique of sterile water injection after the injection of lidocaine, compared to the technique of sterile water injection without lidocaine. The aim was also to assess whether both techniques (with and without lidocaine) reduce back pain during childbirth. Material and Methods A semi-experimental study was carried out. The level of pain was assessed using the VAS scale before the technique, during the technique, and 30 minutes after the technique in two groups of expectant mothers (with and without lidocaine). The expectant mothers were divided randomly into two groups. The SPSS programme was used for the data analysis. Results The results showed that the technique with lidocaine could be undertaken by one professional and was significantly less painful than the technique without the anesthetic. In both cases, the level of pain stated prior to the sterile water injection was reduced 30 minutes after the injection. The reduction in pain was clinically relevant. Conclusions Sterile water injection in the Rhombus of Michaelis is an effective technique for reducing back pain during childbirth. The injection of lidocaine prior to the technique enables its use without the main disadvantage: pain on injection of sterile water.IntroducciónLas inyecciones de agua estéril en el Rombo de Michaelis se usan como técnica simple para aliviar el dolor lumbar durante el parto. Pero la técnica es dolorosa y requiere de dos profesionales para su realización.ObjetivoEvaluar el nivel de dolor de la técnica de la inyección de agua estéril previa inyección de lidocaína respecto de la técnica de inyección de agua estéril sin lidocaína. Así mismo, se pretendía evaluar si ambas técnicas (sin lidocaína y con lidocaína) disminuían el dolor lumbar durante el parto.Material y MétodosSe llevó a cabo un estudio cuasi-experimental. Se evaluó el nivel de dolor mediante la escala EVA antes de la técnica, durante la técnica y a los 30 minutos de la técnica en dos grupos de gestantes (sin lidocaína y con lidocaína). Las gestantes fueron asignadas a ambos grupos de forma aleatoria. Para el análisis de los datos, se utilizó el programa estadístico SPSS.Resultados Los resultados mostraron que la técnica con lidocaína es significativamente menos dolorosa que sin lidocaína y la puede realizar un solo profesional. Así mismo, el nivel de dolor referido antes de la técnica disminuyó en ambos casos a los 30 minutos de forma clínicamente relevante.ConclusionesLas inyecciones de agua estéril en el Rombo de Michaelis constituyen una técnica efectiva para la reducción del dolor lumbar durante el parto. Además, la inyección de lidocaína previa a la técnica permite su uso evitando su principal inconveniente, el dolor al inyectar el agua estéril
Orogenias paleozoicas en los Andes de Argentina y Chile y en la Península Antártica
Congreso Geológico Argentino (20º. 2017. San Miguel de Tucumán, Argentina). Simposio de Téctonica pre-andinaDurante el Neoproterozoico y Paleozoico, los Andes de Argentina y Chile, y desde fines del Paleozoico también la Península Antártica, formaron parte del margen SO de Gondwana. Durante este tiempo se acrecionaron a dicho margen varios fragmentos continentales de tamaño y aloctonía variable; denominados de N a S: Antofalla, Chi-Cu, Patagonia Occidental y Antártida Occidental. Estos fragmentos formaban parte de placas litosféricas, en ocasiones divididas en subplacas. La colisión de dichos fragmentos continentales con Gondwana y una última subducción bajo dicho margen, dieron lugar a 6 orogenias de extensión temporal y espacial limitada.Instituto Geológico y Minero de España, EspañaDepartamento de Geología, Universidad de Oviedo, EspañaUniversidad de Río Negro, ArgentinaServicio Geológico y Minero Argentino, ArgentinaInstituto De Bio y Geociencias Del NOA, Consejo Nacional de Investigaciones Científicas y Técnicas, ArgentinaInstituto De Bio y Geociencias Del NOA, Universidad Nacional de Salta, ArgentinaDepartamento de Geodinámica, Universidad del País Vasco, EspañaFacultad de Geología, Universidad de Barcelona, EspañaDepartamento de Geología, Universidad de Chile, ChileUniversidad Andrés Bello, ChileUnidad de Tectónica, Consejo Nacional de Investigaciones Científicas y Técnicas, ArgentinaFacultad de Geología, Universidad de Buenos Aires, ArgentinaÁrea de Geología, Universidad Rey Juan Carlos, EspañaUniversidad de Salta, ArgentinaInstituto de Investigación en Paleobiología y Geología, Universidad de Río Negro, ArgentinaInstituto de Investigación en Paleobiología y Geología, Consejo Nacional de Investigaciones Científicas y Técnicas, ArgentinaCentro de Investigaciones Geológicas, Universidad de La Plata, ArgentinaUniversidad de San Juan, ArgentinaPeer reviewe
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