291 research outputs found
Quantum-based solution of time-dependent complex Riccati equations
Using the Wei-Norman theory we obtain a time-dependent complex Riccati
equation (TDCRE) as the solution of the time evolution operator (TEO) of
quantum systems described by time-dependent (TD) Hamiltonians that are linear
combinations of the generators of the ,
and Lie algebras. Using a recently developed solution for
the time evolution of these quantum systems we solve the TDCRE recursively as
generalized continued fractions, which are optimal for numerical
implementations, and establish the necessary and sufficient conditions for the
unitarity of the TEO in the factorized representation. The inherited symmetries
of quantum systems can be recognized by a simple inspection of the TDCRE,
allowing effective quantum Hamiltonians to be associated with it, as we show
for the Bloch-Riccati equation whose Hamiltonian corresponds to that of a
generic TD system of the Lie algebra . As an application, but
also as a consistency test, we compare our solution with the analytic one for
the Bloch-Riccati equation considering the Rabi frequency driven by a complex
hyperbolic secant pulse generating spin inversion, showing an excellent
agreement.Comment: 10 Pages, 1 Figur
The neural correlates of the awe experience: Reduced defaultmode network activity during feelings of awe
Delusions in frontotemporal lobar degeneration
We assessed the significance and nature of delusions in frontotemporal lobar degeneration (FTLD), an important cause of young-onset dementia with prominent neuropsychiatric features that remain incompletely characterised. The case notes of all patients meeting diagnostic criteria for FTLD attending a tertiary level cognitive disorders clinic over a three year period were retrospectively reviewed and eight patients with a history of delusions were identified. All patients underwent detailed clinical and neuropsychological evaluation and brain MRI. The diagnosis was confirmed pathologically in two cases. The estimated prevalence of delusions was 14 %. Delusions were an early, prominent and persistent feature. They were phenomenologically diverse; however paranoid and somatic delusions were prominent. Behavioural variant FTLD was the most frequently associated clinical subtype and cerebral atrophy was bilateral or predominantly right-sided in most cases. We conclude that delusions may be a clinical issue in FTLD, and this should be explored further in future work
Disorders of Consciousness due to Traumatic Brain Injury: Functional Status Ten Years Post-Injury
Few studies have assessed the long-term functional outcomes of patients with a disorder of consciousness due to traumatic brain injury (TBI). This study examined functional status during the first 10 years after TBI among a cohort with disorders of consciousness (i.e., coma, vegetative state, minimally conscious state). The study sample included 110 individuals with TBI who were unable to follow commands prior to inpatient rehabilitation and for whom follow-up data were available at 1, 2, 5, and 10 years post-injury. The sample was subdivided into those who demonstrated command-following early (before 28 days post-injury) versus late (≥ 28 days post-injury or never). Functional Independence Measure (FIM) at 1, 2, 5, and 10 years following TBI was used to measure functional outcomes. Measureable functional recovery occurred throughout the 10-year period, with more than two thirds of the sample achieving independence in mobility and self-care, and about one quarter achieving independent cognitive function by 10 years. Following commands prior to 28 days was associated with greater functional independence at all outcome time-points. Multi-trajectory modeling of recovery of three FIM subscales (self-care, mobility, cognition) revealed four distinct prognostic groups with different temporal patterns of change on these subscales. More than half the sample achieved near-maximal recovery by 1 year post-injury, while the later command-following subgroups recovered over longer periods of time. Significant late functional decline was not observed in this cohort. Among a cohort of patients unable to follow commands at the time of inpatient rehabilitation, a substantial proportion achieved functional independence in self-care, mobility, and cognition. The proportion of participants achieving functional independence increased between 5 and 10 years post-injury. These findings suggest that individuals with disorders of consciousness may benefit from ongoing functional monitoring and updated care plans for at least the first decade after TBI
Quasi-static properties of one-dimensional permalloy nanostructures: A comparative analysis as a function of geometrical parameters
En el presente estudio se describen las propiedades magnéticas de nanohilos y nanotubos de Permalloy a través de simulaciones micromagnéticas. Estas propiedades son evaluadas en función de los diámetros externos de tales nanoestructuras unidimensionales cuando el campo magnético aplicado es paralelo y perpendicular al eje fácil de las mismas. Además se varió el diámetro de las nanoestructuras con el objeto de discutir las similitudes y diferencias en las propiedades magnéticas como función de su longitud.The present study describes the magnetic properties of nanotubes and nanowires of Permalloy through micromagnetic simulations. These properties are evaluated as a function of the external diameters of such one-dimensional nanostruc-tures when the magnetic field applied is parallel and perpendicular to the easy axis of the nanostructures. In addition, the diameter of the nanostructures was also varied in order to discuss the similarities and differences in the magnetic properties as a function of their length.Fil: Levis, S.. Universidad Nacional de Córdoba; ArgentinaFil: Villegas, A.. Universidad Nacional de Córdoba; ArgentinaFil: Escrig, J.. Universidad de Santiago de Chile; Chile. Centro Para El Desarrollo de la Nanociencia y Nanotecnología; ChileFil: Bajales Luna, Noelia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Física Enrique Gaviola. Universidad Nacional de Córdoba. Instituto de Física Enrique Gaviola; ArgentinaFil: D. M. Arciniegas, Jaimes. Universidad Nacional de Córdoba; Argentin
Definition and Verification of Security Configurations of Cyber-Physical Systems
The proliferation of Cyber-Physical Systems (CPSs) is rais ing serious security challenges. These are complex systems, integrating
physical elements into automated networked systems, often containing a
variety of devices, such as sensors and actuators, and requiring complex
management and data storage. This makes the construction of secure
CPSs a challenge, requiring not only an adequate specification of secu rity requirements and needs related to the business domain but also
an adaptation and concretion of these requirements to define a security
configuration of the CPS where all its components are related. Derived
from the complexity of the CPS, their configurations can be incorrect
according to the requirements, and must be verified. In this paper, we
propose a grammar for specifying business domain security requirements
based on the CPS components. This will allow the definition of security
requirements that, through a defined security feature model, will result
in a configuration of services and security properties of the CPS, whose
correctness can be verified. For this last stage, we have created a cata logue of feature models supported by a tool that allows the automatic
verification of security configurations. To illustrate the results, the pro posal has been applied to automated verification of requirements in a
hydroponic system scenario.Ministerio de Ciencia y Tecnología RTI2018-094283-B-C33 (ECLIPSE)Junta de Andalucía METAMORFOSIS (US-1381375)Junta de Castilla.La Mancha SBPLY-17-180501-000202 (GENESIS
Papel del agua en la gelatinización delalmidón de maíz: estudio por calorimetríadiferencial de barrido
The thermal behavior of corn starch (Sigma Aldrich) was studied by differential scanning calorimetry (DSC). The endothermic peak in the DSC thermogram is associated to the starch gelatinization transition process. Initial phase of process and range in which it occurs is governed mainly by starch concentration in the solution, and the botanical source. This study demonstrates that the parameters associated to the observation method, in the DSC analysis, are influential in the determination of the maize starch gelatinization. In this way, the transition peak temperature, gelatinization enthalpy, and range of temperature are parameters that have to be considered when the moisture of sample and heating rate are changed with a homogenous grain size. For the DSC analysis, samples were prepared whit moisture values of 60, 65, 70, 75 and 80% (w/w), and heated at r = 2, 5, and 10◦C/min. Similarly, for fixed values of moisture (80%), the values of the heating rate were 2, 5, 7, 10 y 15◦C/min. Results indicate that the amount of water has influence over the enthalpy transition; however the peak temperature Tp remains invariable. The variation also depends of rate which transformation is made. Analysis allowed corroborating, that starch transition depends on extrinsic factors during the process. This knowledege about starch gelatinization is very useful for optimizing industrial process derivate of it.PACS: 64.60.-i, 61.25.hk, 61.25.hp, 83.10.TvEl comportamiento térmico del almidón de maíz (Sigma Aldrich) se estudió através de calorimetría diferencial de barrido (DSC). El pico endotérmico observadoen el perfil DSC se asocia al proceso de transición de gelatinizacióndel almidón. La fase inicial del proceso y el rango en el que éste ocurre, está gobernada principalmente por la concentración del almidón en solución. Enesta investigación se demuestra que los parámetros relacionados con el métodode observación, en un análisis de DSC influyen al momento de determinar lagelatinización del almidón de maíz. De esta forma, la temperatura del picode transición, la entalpía de gelatinización y el intervalo de temperatura degelatinización son los parámetros en estudio cuando se varía la humedad dela muestra y velocidad de calentamiento con un tamaño de grano homogéneo.Para los análisis, se tomaron valores de humedad de 60, 65, 70, 75 y 80%(p/p), para una velocidad de calentamiento de 2, 5 y 10◦C/min. De igualmodo, para un valor fijo de humedad (80%), se utilizó una velocidad de calentamientode 2, 5, 7, 10 y 15◦C/min. Los resultados indican que la cantidad deagua influye significativamente sobre la entalpía de gelatinización del proceso,pero la temperatura del pico Tp de la endoterma se mantiene constante. Elvalor de la entalpía disminuye a medida que la cantidad de agua aumenta.Las variaciones también son dependientes de la rapidez con que se efectúa latransformación. Los análisis permitieron corroborar, que esta transición en elalmidón es dependiente de factores extrínsecos durante el proceso. Este conocimientosobre la gelatinización del almidón es útil para optimizar procesosindustriales derivados de éste.PACS: 64.60.-i, 61.25.hk, 61.25.hp, 83.10.T
The lowest hanging fruit: Beneficial gene knockouts in past, present, and future crop evolution
It is now well-documented that gene knockout (loss-of-function) alleles have played a prominent role in crop evolution during domestication, diversification, and improvement. This includes dramatic examples from the very origins of agriculture to the monumental yield increases of the Green Revolution. Recent advances in the generation of whole genome sequence data and functional investigations into the molecular genetic basis of crop traits continue to reveal the existence of considerable beneficial loss of function in crop species. These discoveries now inspire contemporary efforts to use targeted gene knockouts powered by modern gene editing tools to accelerate crop breeding. Here we trace the history and future of loss of function as a powerful mechanism of crop evolution and review the reasons gene knockouts might have been particularly important in past crop evolution and why they continue to be a “lowest hanging fruit” for directing crop evolution through molecular breeding in pursuit of more productive, resilient, and nutritious crops
Papel del agua en la gelatinización delalmidón de maíz: estudio por calorimetríadiferencial de barrido
The thermal behavior of corn starch (Sigma Aldrich) was studied through differential scanning calorimetry (DSC). The endothermic peak observed in the DSC profile is associated with the transition process of starch gelatinization. The initial phase of the process and the range in which it occurs is governed mainly by the concentration of the starch in solution. In this investigation it is demonstrated that the parameters related to the method of observation, in a DSC analysis influence when determining the gelatinization of corn starch. In this way, the temperature of the transition peak, the gelatinization enthalpy and the gelatinization temperature range are the parameters under study when the sample humidity and heating rate are varied with a homogeneous grain size. For the analyzes, values were taken of humidity of 60, 65, 70, 75 and 80% (w / w), for a heating rate of 2, 5 and 10 ° C / min. Similarly, for a fixed humidity value (80%), a heating rate of 2, 5, 7, 10 and 15 ° C / min was used. The results indicate that the amount of water significantly influences the enthalpy of gelatinization of the process, but the temperature of the Tp peak of the endotherm remains constant. The value of the enthalpy decreases as the amount of water increases.The variations are also dependent on how quickly the transformation takes place. The analyzes allowed corroborating that this transition in elalmidon is dependent on extrinsic factors during the process. This knowledge about starch gelatinization is useful for optimizing industrial processes derived from it.El comportamiento térmico del almidón de maíz (Sigma Aldrich) se estudió através de calorimetría diferencial de barrido (DSC). El pico endotérmico observadoen el perfil DSC se asocia al proceso de transición de gelatinizacióndel almidón. La fase inicial del proceso y el rango en el que éste ocurre, está gobernada principalmente por la concentración del almidón en solución. Enesta investigación se demuestra que los parámetros relacionados con el métodode observación, en un análisis de DSC influyen al momento de determinar lagelatinización del almidón de maíz. De esta forma, la temperatura del picode transición, la entalpía de gelatinización y el intervalo de temperatura degelatinización son los parámetros en estudio cuando se varía la humedad dela muestra y velocidad de calentamiento con un tamaño de grano homogéneo.Para los análisis, se tomaron valores de humedad de 60, 65, 70, 75 y 80%(p/p), para una velocidad de calentamiento de 2, 5 y 10◦C/min. De igualmodo, para un valor fijo de humedad (80%), se utilizó una velocidad de calentamientode 2, 5, 7, 10 y 15◦C/min. Los resultados indican que la cantidad deagua influye significativamente sobre la entalpía de gelatinización del proceso,pero la temperatura del pico Tp de la endoterma se mantiene constante. Elvalor de la entalpía disminuye a medida que la cantidad de agua aumenta.Las variaciones también son dependientes de la rapidez con que se efectúa latransformación. Los análisis permitieron corroborar, que esta transición en elalmidón es dependiente de factores extrínsecos durante el proceso. Este conocimientosobre la gelatinización del almidón es útil para optimizar procesosindustriales derivados de éste
Methodology for selecting atmospheric monitoring sitesin urban areas affected by emissions from mobile sources
El monitoreo atmosférico es una de las etapas fundamentales en la identificación de estrategias para minimizar, prevenir y controlar los impactos de la dispersión de contaminantes en el aire, sobre la salud pública y el ambiente. Por tanto, el objetivo principal de este articulo consiste en proponer una metodología para la selección de sitios de monitoreo atmosférico en zonas urbanas afectadas por las emisiones de fuentes móviles. Primeramente se identificaron los sitios que presentaban mayor flujo vehicular y se priorizaron teniendo presente los siguientes criterios de selección: seguridad, influencia de otras fuentes, facilidad del montaje de los equipos, accesibilidad al sitio, identificación de barreras y obstáculos, registro histórico de datos y grado de concentración usando el software CALINE 3.La modelación agrupo datos característicos de las vías, meteorológicos y de flujo vehicular de un año típico de la zona en estudio. A cada uno de estos parámetros le es asignada una valoración cuantitativa, la cual define los sitios donde se realizará el monitoreo. Como resultados se desarrolló una guía para seleccionar los lugares en donde se puedan desarrollar campañas de monitoreo atmosférico asociadas a fuentes móviles. La metodología fue aplicada en la ciudad de Cartagena de Indias haciendo uso del modelo de calidad del aire CALINE3.Atmospheric monitoring is one of the fundamental steps in identifying strategies to minimize, prevent and control the impact of the dispersion of pollutants in the air, on public health and the environment. Therefore, the main objective of this article is to propose a methodology for selecting air monitoring sites in urban areas affected by emissions from mobile sources. First, the places with the highest vehicular flow were identified and prioritized according to the following selection criteria: safety, influence of other sources, ease of assembly of equipment, accessibility to the site, identification of barriers and obstacles, historical record of data and degree concentration of the pollutant: in this case carbon monoxide, using CALINE 3 software. The modeling grouped characteristic data related with roads, meteorology and vehicular flow of a typical year of the zone under study. A quantitative assessment is assigned to each of these parameters, which defines the sites where the monitoring will be performed. As a result, it was developed a guide to select those places where atmospheric monitoring campaigns related with mobile sources can be held. This methodology was applied in the city of Cartagena de Indias by using air quality model for assessment, CALINE
- …