399 research outputs found

    Maude: specification and programming in rewriting logic

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    Maude is a high-level language and a high-performance system supporting executable specification and declarative programming in rewriting logic. Since rewriting logic contains equational logic, Maude also supports equational specification and programming in its sublanguage of functional modules and theories. The underlying equational logic chosen for Maude is membership equational logic, that has sorts, subsorts, operator overloading, and partiality definable by membership and equality conditions. Rewriting logic is reflective, in the sense of being able to express its own metalevel at the object level. Reflection is systematically exploited in Maude endowing the language with powerful metaprogramming capabilities, including both user-definable module operations and declarative strategies to guide the deduction process. This paper explains and illustrates with examples the main concepts of Maude's language design, including its underlying logic, functional, system and object-oriented modules, as well as parameterized modules, theories, and views. We also explain how Maude supports reflection, metaprogramming and internal strategies. The paper outlines the principles underlying the Maude system implementation, including its semicompilation techniques. We conclude with some remarks about applications, work on a formal environment for Maude, and a mobile language extension of Maude

    Microsurgical clipping vs Woven EndoBridge (WEB) device for the management of unruptured wide-neck bifurcation aneurysms

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    The Woven EndoBridge device (WEB) was introduced in 2010 to treat wide-neck bifurcation aneurysms (WNBAs). Three landmark studies have been conducted to assess its safety and efficacy: WEBCAST, WEBCAST 2, and French Observatory Study. However, these studies have not compared its safety and efficacy to other treatment modalities. In this study, we compare WEB versus microsurgical clipping in the management of unruptured WNBA. We conducted a retrospective study of unruptured WNBA meeting the morphological criteria to be amenable for WEB treatment operated on at our institution. Surgical morbidity, mortality, and occlusion rates were assessed. We compared our results to those reported in the cumulative population of the three WEB landmark studies at 1 year. A total of 84 patients with 89 WNBA were included. The most common aneurysm location was the middle cerebral artery bifurcation (n = 67/89, 75%). No operative mortality was observed. Morbidity comprised small-vessel vasospasm (n = 1/89, 1%) resulting in hemiparesis vs. 3% morbidity for WEB (p = .324). All but one (n = 1/89, 1%) WNBA were completely occluded vs WEB occlusion rate of 53% at 1 year, statistically significantly worse (p < .001). In our analysis, we were not able to show superiority of WEB in terms of procedural morbidity in comparison to microsurgical clipping, defined as worsening in mRS. Microsurgical clipping achieves statistically significantly higher rates of complete aneurysm occlusion, thus posing the question of whether the WEB should be presented as a viable, comparable alternative to patients amenable to surgical treatment

    Riesgos Intensivos y Extensivos en América Central entre 1990 y 2015

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    América Central es una región expuesta a diversos fenómenos naturales, tanto geológicos como hidrometeorológicos, eventos que combinados con las características históricas, culturales y socioeconómicas hacen que sus países presenten condiciones idóneas de riesgo y por ende se ven afectados por los desastres. Para este trabajo se hace un análisis del origen de los riesgos extensivos e intensivos América Central entre 1990 y 2015, donde se identifican las causas del porqué algunos países se vean más afectados que otros, ya sea por los pequeños o grandes desastres. La metodología está basada en la información obtenida de las bases de datos de desastres EM-DAT y DesInventar, de las cuales se obtuvo que Costa Rica fue el país que registró más eventos desastrosos, mientras que entre El Salvador, Guatemala y Honduras se distribuyeron la mayor cantidad de muertos, afectados y viviendas tanto afectadas como destruidas por riesgos extensivos como intensivos. El uso de bases de datos de desastres es una útil herramienta para la gestión del riesgo y el ordenamiento territorial de países en desarrollo

    A climatology of low level wind regimes over Central America using a weather type classification approach

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    Based on the potential of the weather types classification method to study synoptic features, this study proposes the application of such methodology for the identification of the main large scale patterns related with weather in Central America. Using ERA Interim low-level winds in a domain that encompasses the intra-Americas sea, the eastern tropical Pacific, southern North America, Central America and northern South America, the K-means clustering algorithm was applied to find recurrent regimes of low-level winds. Eleven regimes were identified and good coherency between the results and known features of regional circulation was found. It was determined that the main large scale patterns can be either locally forced or a response to tropical-extratropical interactions. Moreover, the local forcing dominates the summer regimes whereas mid latitude interactions lead to winter regimes. The study of the relationship between the large scale patterns and regional precipitation shows that winter regimes are related with the Caribbean-Pacific precipitation seesaw. Summer regimes, on the other hand, enhance the Caribbean-Pacific precipitation with contrasting distribution as a function of the dominant regimes. A strong influence of ENSO on the frequency and duration of the regimes was found. It was determined that the specific effect of ENSO on the regimes depends on whether the circulation is locally forced or lead by the interaction between the tropics and the mid-latitudes. The study of the cold surges using the information of the identified regimes revealed that three regimes are linkable with the occurrence of cold surges that affect Central America and its precipitation. As the winter regimes are largely dependent of mid-latitude interaction with the tropics, the effect that ENSO has on the Jet Stream is reflected in the winter regimes. An automated analysis of large scale conditions based on reanalysis and/or model data seems useful for both dynamical studies and as a tool to support forecasting. The application of the approach implemented in this study may be promising to improve current understanding on how large scale conditions affect regional weather.Universidad de Costa Rica/[805-B3-600]/UCR/Costa RicaUCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Básicas::Centro de Investigaciones Geofísicas (CIGEFI

    Maude: specification and programming in rewriting logic

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    AbstractMaude is a high-level language and a high-performance system supporting executable specification and declarative programming in rewriting logic. Since rewriting logic contains equational logic, Maude also supports equational specification and programming in its sublanguage of functional modules and theories. The underlying equational logic chosen for Maude is membership equational logic, that has sorts, subsorts, operator overloading, and partiality definable by membership and equality conditions. Rewriting logic is reflective, in the sense of being able to express its own metalevel at the object level. Reflection is systematically exploited in Maude endowing the language with powerful metaprogramming capabilities, including both user-definable module operations and declarative strategies to guide the deduction process. This paper explains and illustrates with examples the main concepts of Maude's language design, including its underlying logic, functional, system and object-oriented modules, as well as parameterized modules, theories, and views. We also explain how Maude supports reflection, metaprogramming and internal strategies. The paper outlines the principles underlying the Maude system implementation, including its semicompilation techniques. We conclude with some remarks about applications, work on a formal environment for Maude, and a mobile language extension of Maude

    Effect of fatigue strength exercise on anterior thigh skin temperature rewarming after cold stress test

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    Although dynamic thermography skin temperature assessment has been used in medical field, scientific evidence in sports is scarce. The aim of the study was to assess changes in anterior thigh skin temperature in response to a cold stress test after a strength exercise fatiguing protocol. Ten physically active adults performed a familiarization session and two strength exercise sessions, one with dominant and the other with non-dominant lower limb. Participants performed bouts of 10 concentric and eccentric contractions of leg extensions in an isokinetic device until reaching around 30% of force loss. Infrared thermographic images were taken at baseline conditions and after the fatigue level from both thighs after being cooled using a cryotherapy system. ROIs included vastus medialis, rectus femoris, adductor and vastus lateralis. Skin temperature rewarming was assessed during 180s after the cooling process obtaining the coefficients of the following equation: ΔSkin temperature = β0 + β1 * ln(T), being β0 and β1 the constant and slope coefficients, respectively, T the time elapsed following the cold stress in seconds, and ΔSkin temperature the difference between the skin temperature at T respect and the pre-cooling moment. Lower β0 and higher β1 were found for vastus lateralis and rectus femoris in the intervention lower limb compared with baseline conditions (p  0.6). Adductor only showed differences in β0 (p = 0.01 and ES = 0.92). The regressions models obtained showed that β0 and β1 had a direct relationship with age and muscle mass, but an inverse relationship with the number of series performed until 30% of fatigue (R2 = 0.8). In conclusion, fatigue strength exercise results in a lower skin temperature and a faster thermal increase after a cold stress test

    Effect of fatigue strength exercise on anterior thigh skin temperature rewarming after cold stress test

    Get PDF
    Although dynamic thermography skin temperature assessment has been used in medical field, scientific evidence in sports is scarce. The aim of the study was to assess changes in anterior thigh skin temperature in response to a cold stress test after a strength exercise fatiguing protocol. Ten physically active adults performed a familiarization session and two strength exercise sessions, one with dominant and the other with non-dominant lower limb. Participants performed bouts of 10 concentric and eccentric contractions of leg extensions in an isokinetic device until reaching around 30% of force loss. Infrared thermographic images were taken at baseline conditions and after the fatigue level from both thighs after being cooled using a cryotherapy system. ROIs included vastus medialis, rectus femoris, adductor and vastus lateralis. Skin temperature rewarming was assessed during 180s after the cooling process obtaining the coefficients of the following equation: ΔSkin temperature = β0 + β1 * ln(T), being β0 and β1 the constant and slope coefficients, respectively, T the time elapsed following the cold stress in seconds, and ΔSkin temperature the difference between the skin temperature at T respect and the pre-cooling moment. Lower β0 and higher β1 were found for vastus lateralis and rectus femoris in the intervention lower limb compared with baseline conditions (p 0.6). Adductor only showed differences in β0 (p = 0.01 and ES = 0.92). The regressions models obtained showed that β0 and β1 had a direct relationship with age and muscle mass, but an inverse relationship with the number of series performed until 30% of fatigue (R² = 0.8). In conclusion, fatigue strength exercise results in a lower skin temperature and a faster thermal increase after a cold stress test.S
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