7,754 research outputs found
QD3SET-1: A Database with Quantum Dissipative Dynamics Data Sets
Simulations of the dynamics of dissipative quantum systems utilize many
methods such as physics-based quantum, semiclassical, and quantum-classical as
well as machine learning-based approximations, development and testing of which
requires diverse data sets. Here we present a new database QD3SET-1 containing
eight data sets of quantum dynamical data for two systems of broad interest,
spin-boson (SB) model and the Fenna--Matthews--Olson (FMO) complex, generated
with two different methods solving the dynamics, approximate local thermalizing
Lindblad master equation (LTLME) and highly accurate hierarchy equations of
motion (HEOM). One data set was generated with the SB model which is a
two-level quantum system coupled to a harmonic environment using HEOM for 1,000
model parameters. Seven data sets were collected for the FMO complex of
different sizes(7- and 8-site monomer and 24-site trimer with LTLME and 8-site
monomer with HEOM) for 500--879 model parameters. Our QD3SET-1 database
contains both population and coherence dynamics data and part of it has been
already used for machine learning-based quantum dynamics studies.Comment: 14 pages, 3 figure
Fractura-luxación posterior de hombro tratada mediante la técnica de McLaughlin
Se presenta un caso de luxación posterior de hombro, con fractura por impactación
de la cabeza humeral, ocasionada por crisis convulsivas. Estas lesiones no son fáciles de reconocer
en los primeros momentos, y en nuestro caso se precisó de un estudio radiográfico en distintas
proyecciones y una TAC. Se realizó tratamiento quirúrgico mediante la técnica original de
McLaughlin. A los 7 meses de la intervención el paciente ha recuperado casi totalmente la movilidad
en dicho hombro y está libre de dolor.A case of posterior dislocation of the shoulder with locked fracture of the humeral
head after a convulsive seizure is reported. At first stages, this type is very difficult to recognize.
In our case, a radiographic study in different views and a CT-scan were needed. Surgical
treatment were carried out according to McLauglin's original technique. Seven months after surgery
the patient had regained almost complete range of shoulder motion and was pain-free
Estudio del apoyo metatarsal en bipedestación mediante podoscopio electrónico de alta resolución.
Con el jin de estudiar el apoyo metatarsal en bipedestación se
han realizado 780 registros en la plataforma PDS 93, correspondientes
a 390 individuos, no seleccionados, sin patología de la
marcha, 234 varones y 156 mujeres, con edades comprendidas
entre 24 y 41 años (edad media de 29,9 años).
En cada registro se ha recogido la presión ejercida por cada metatarsiano,
relacionando la carga obtenida con el peso, conjiguración
mecánica del pie y huella plantar: Los resultados obtenidos se
han procesado estadísticamente por medio del programa SPSS.
El porcentaje de las cargas medias obtenidas para cada metatarsiano
han sido: 16,85, 21,25, 23,88, 20,24 y 17,78%, existiendo
dqerencias sign$cativas para el apoyo de los metatarsianos
centrales (p < 0,001).
Todos los metatarsianos soportan carga en bipedestación, de
acuerdo con las teorías actuales. Sin embargo, aunque la distribución
del peso para el primer metatarsiano se aproxima al doble
de los otros, la carga máxima en g/cm2 se realiza en los metatarsianos
centrales
Spin-to-orbital angular momentum conversion in focusing, scattering, and imaging systems
We present a general theory of spin-to-orbital angular momentum (AM) conversion of light in focusing, scattering, and imaging optical systems. Our theory employs universal geometric transformations of non-paraxial optical fields in such systems and allows for direct calculation and comparison of the AM conversion efficiency in different physical settings. Observations of the AM conversions using local intensity distributions and far-field polarimetric measurements are discussed
Resorcinolic Lipids from Yucatecan Propolis
Propolis is a material produced by bees from a combination of plant exudates and wax, used to fill out cracks in the beehive and to defend against intruders and pathogenic microorganisms; it is recognized for its many biological activities and its chemical composition depends on the botanical sources close to the beehive. The objective of this investigation was to isolate and identify metabolites with antioxidant activity present in a propolis sample collected in Yucatan, Mexico. Purification of the bioactive metabolites was carried out using argentation chromatography, while the combination of 1H nuclear magnetic resonance (NMR), laser desorption ionization (LDI), gas chromatography-mass spectrometry (GC-MS) and biosynthetic origin data allowed their identification as resorcinolic lipids. Finally, the resin of Mangifera indica was identified as the botanical source of these metabolite
Suplementación con Trichantera gigantea en toretes Brahaman pastoreando Panicum maximun, en trópico medio
El trabajo se realizó en la finca los Guayabos de la vereda capotes de la inspección de Cumaca en el municipio de Tibacuy, a 1250 m.s.n.m., temperatura promedio de 2l°C y precipitación anual de 1.092 mm de precipitación anual, en la región del Sumapaz..
Leucaena leucocephala in ruminant nutrition
It is a common situation in extensive ruminant production systems in tropical countries to have low production indicators due to nutrient deficiencies in the diet. An economic alternative to increase animal production is the incorporation of legumes (fodder and fruits) in the diet. This review, presents an analysis of the positive and negative effects of Leucaena leucocephala consumption by ruminants, with particular emphasis on the secondary compound mimosine. Leucaena due to its high nutrient content, rumen by-pass protein supply and its possible effect on the reduction of greenhouse gas (attributed to tannins) has become one of the legumes most commonly used in ruminant feeding practices. However, in countries where leucaena has been introduced, its use is still limited to levels below 30% inclusion in the diet, due to the secondary compound mimosine and its isomers (3,4 and 2,3 DHP), which can induce toxicity, even when animals are inoculated with rumen fluid containing the bacteria Synergistes jonesii reported as responsible for degrading these compounds in the rumen. In the Yucatan Peninsula, Mexico, ruminants consuming leucaena can tolerate more than 50% inclusion in the diet, without having a negative impact on production, attributed intake to mimosine and its isomers. We conclude that in animals not adapted, the intake would be limited to low inclusion levels (less than 30% inclusion in the diet), mainly because of mimosine and its derivatives. The decrease in intake or diet digestibility seem to better explain the reduction in methane production, however, in vivo studies are required to clearly establish the mechanism of action. It has been reported the presence of different bacteria to S. jonessi that would have the ability to degrade mimosine and its derivatives, however, the activity of these bacteria and its effectiveness must be confirmed in vivo
Necrotic loxoscelism in lower limb and reconstruction with skin autograft
Loxesceles are small spiders, from 9 to 25 mm, with a dark brown spot on the dorsal part in the shape of an inverted violin. They are common in northwestern Mexico and can live at temperatures of 8 to 40°C. These spiders are considered of medical importance because their venom is dermonecrotic, with proteolytic and necrotic action, which is generated in two apocrine glands. The cutaneous clinical picture is the most frequent, with edema, erythema and ischemia that tends to evolve to ulceration and deep necrosis. The key to treatment is early debridement to avoid complications. We presented the case of a 57-year-old female patient who developed an inflammatory condition secondary to a fiddler spider bite involving the left lower extremity. Her evolution to necrosis and late diagnosis required surgical debridement and use of negative pressure therapy (VAC), followed by harvesting and placement of partial thickness skin autograft, obtaining a successful aesthetic and functional result
Lightning Impulse Current Tests on Conductive Fabrics
Submitted to "Journal of Industrial Textiles"The large amount of electric current associated to lightning discharges is hazardous for living beings, equipment, structures and buildings. To protect those targets against lightning are used Lightning Protection Systems (LPS). However, there are some temporary outdoor activities and backcountry places where an adequate LPS cannot be set up mainly due to the large dimensions of its components and its heavy weight. On the search of light weight lightning protection materials that can be used as part of special LPS, we research some types of electroconductive fabrics by applying high lightning impulse currents in laboratory. The fabric samples checked were pieces of 10 cm x 10 cm: two rip-stop type, a plain-weave, a non-woven and a carbon-impregnated polymeric, all of them obtained commercially. Under laboratory conditions, these samples were subject to subsequent lightning impulse currents registering the voltage and current signals. Optical and scanning electron microscope inspections were performed after tests. Despite some changes visualized as marks left on the fabric surface, the results show that investigated conductive textiles can endure ground currents produced by atmospheric lightning since they withstand the several applied laboratory lightning impulse currents. The outcomes suggest that the weave pattern of the conductive fabric influences the lightning current tolerance, enabling some conductive fabrics to be used in heavy-current applications and as part of personal LPS for outdoor, backcountry and mobile shelters, particularly when lightweight and portability are mandatory
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