Decoherence in a double-slit quantum eraser

We study and experimentally implement a double-slit quantum eraser in the presence of a controlled decoherence mechanism. A two-photon state, produced in a spontaneous parametric down conversion process, is prepared in a maximally entangled polarization state. A birefringent double-slit is illuminated by one of the down-converted photons, and it acts as a single-photon two-qubits controlled not gate that couples the polarization with the transversal momentum of these photons. The other photon, that acts as a which-path marker, is sent through a Mach-Zehnder-like interferometer. When the interferometer is partially unbalanced, it behaves as a controlled source of decoherence for polarization states of down-converted photons. We show the transition from wave-like to particle-like behavior of the signal photons crossing the double-slit as a function of the decoherence parameter, which depends on the length path difference at the interferometer.Comment: Accepted in Physical Review

Myristic acid potentiates palmitic acid-induced lipotoxicity and steatohepatitis associated with lipodystrophy by sustaning de novo ceramide synthesis.

Palmitic acid (PA) induces hepatocyte apoptosis and fuels de novo ceramide synthesis in the endoplasmic reticulum (ER). Myristic acid (MA), a free fatty acid highly abundant in copra/palmist oils, is a predictor of nonalcoholic steatohepatitis (NASH) and stimulates ceramide synthesis. Here we investigated the synergism between MA and PA in ceramide synthesis, ER stress, lipotoxicity and NASH. Unlike PA, MA is not lipotoxic but potentiated PA-mediated lipoapoptosis, ER stress, caspase-3 activation and cytochrome c release in primary mouse hepatocytes (PMH). Moreover, MA kinetically sustained PA-induced total ceramide content by stimulating dehydroceramide desaturase and switched the ceramide profile from decreased to increased ceramide 14:0/ceramide16:0, without changing medium and long-chain ceramide species. PMH were more sensitive to equimolar ceramide14:0/ceramide16:0 exposure, which mimics the outcome of PA plus MA treatment on ceramide homeostasis, than to either ceramide alone. Treatment with myriocin to inhibit ceramide synthesis and tauroursodeoxycholic acid to prevent ER stress ameliorated PA plus MA induced apoptosis, similar to the protection afforded by the antioxidant BHA, the pan-caspase inhibitor z-VAD-Fmk and JNK inhibition. Moreover, ruthenium red protected PMH against PA and MA-induced cell death. Recapitulating in vitro findings, mice fed a diet enriched in PA plus MA exhibited lipodystrophy, hepatosplenomegaly, increased liver ceramide content and cholesterol levels, ER stress, liver damage, inflammation and fibrosis compared to mice fed diets enriched in PA or MA alone. The deleterious effects of PA plus MA-enriched diet were largely prevented by in vivo myriocin treatment. These findings indicate a causal link between ceramide synthesis and ER stress in lipotoxicity, and imply that the consumption of diets enriched in MA and PA can cause NASH associated with lipodystrophy

Control of quantum interference in the quantum eraser

We have implemented an optical quantum eraser with the aim of studying this phenomenon in the context of state discrimination. An interfering single photon is entangled with another one serving as a which-path marker. As a consequence, the visibility of the interference as well as the which-path information are constrained by the overlap (measured by the inner product) between the which-path marker states, which in a more general situation are non-orthogonal. In order to perform which-path or quantum eraser measurements while analyzing non-orthogonal states, we resort to a probabilistic method for the unambiguous modification of the inner product between the two states of the which-path marker in a discrimination-like process.Comment: Submitted to New Journal of Physics, March 200

Relaciones entre la zonalidad petrológica y metalogénica de los macizos lerzolíticos de las cadenas alpinas del Mediterráneo Occidental (Cordillera Bético-Rifeña y Kabylias)

Gamet-lherzolite facies, Ariegite and Seiland subfacies of the spinel-lherzolite facies and plagioclase-lherzolite facies have been identified in the Serranía de Ronda, Beni Bousera and Collo lherzolitic massifs. These petrological facies occur in a zonal arrangement: gamet lherzolite are in contact with the overlaying metapelitic sequence and spinel then plagioclase lherzolite occur inwards, representing the innermost zones in the former mantle body. The various occurrences of mineralizations can be classified in two main groups: one of them is essentialIy made up of chromite and Ni arsenides with pyroxene and/or cordierite as gangue minerals; the other consists Qf Fe-Ni-Cu sulfides and graphite, with pyroxene, plagioclase and phlogopite as gangue minerals. In both groups, the ores with the more refractory composition were the first to crystallize in the hotter core of the diapir while those other with a more differentiated composition were formed later within the external zones. The close correlation between petrological and metallogenical roning supports a magmatic origin of the mineralizations related to the petrologic evolution of the mantle bodies. The mineralizing liquids• originated from magmas generated by partial melting of the peridotites. The former migrated outwards, from the internal part of the bodies, during which marked interaction with the enclosing rocks and complex fractionation processes took place under moderate to low pressure conditions.En los macizos lerzolíticos de la Serranía de Ronda, de Beni Bousera y de Collo se han identificado facies de lerzolitas con granate, facies de lerzolitas con espinela (subfacies Ariegita y Seiland) y facies de lerzolitas con plagioclasa. Estas facies petrológicas se distribuyen de forma que las lerzolitas con granate se sitúan en contacto con la unidad metapelítica suprayacente, mientras que las lerzolitas con espinela y con plagioclasa lo hacen en posiciones progresivamente más alejadas, representando zonas cada vez más internas en el primitivo cuerpo ultramáfico. Los diferentes indicios de mineralización pueden dividirse en dos grupos: uno compuesto esencialmente por cromita y arseniuros de níquel con ganga de piroxenos y/o cordierita, y el otro constituido por sulfuros de Fe-Ni-Cu con grafito y con piroxenos, plagioclasa y flogopita como minerales de la ganga. En ambos grupos las mineralizaciones de composición más refractaria son las primeras en cristalizar y lo hacen en las etapas más tempranas en las zonas más internas del diapiro, mientras que las de composición más diferenciada lo hacen más tarde en posiciones más periféricas. La fuerte interrelación entre la zonación petrológica y metalogénica apoya una génesis para las mineralizaciones íntimamente asociada a la evolución petrológica de los diapiros del manto. Los líquidos mineralizantes derivan de magmas generados mediante la fusión parcial de las peridotitas y habrían migrado hacia la periferia sufriendo un complejo proceso de fraccionación e interacción con las rocas encajantes, en condiciones de presión moderadas a bajas

Is there an association between sleep disorders and diabetic foot? A scoping review

Diabetic foot is associated with a low quality of life since physical disabilities, mood disturbances and psychological disorders are frequent. One of the most important biological processes to ensure quality of life is sleep. Sleep disorders can impair glycemic control in patients with diabetes mellitus or even cause long-term type 2 diabetes mellitus. The aim of this study is to carry out a scoping review about the association between sleep cycle disorders and diabetic foot. PubMed, Scopus, CINAHL, PEDro, Cochrane Library, SCIELO and EMBASE databases were chosen for the search and the following terms were used: “diabetic foot”,“sleep*”,“rest-activity”,“mood” and“behavior”. All the studies should include outcome variables about sleep and diabetic foot. Finally, 12 articles were selected, all of whichwere observational. The most frequent variables were those regarding diabetic foot ulcer aspects and diabetic neuropathy on one side, and obstructive sleep apnea, sleep duration and sleep quality on the other side. The results suggest that there is a possible association between obstructive sleep apnea and the presence or history of diabetic foot ulcers. No direct associations between sleep quality or sleep duration and diabetic foot or diabetic foot ulcer variables have been found

Rapid bottom-water circulation changes during the last glacial cycle in the coastal low-latitude NE Atlantic

Previous paleoceanographic studies along the NW African margin focused on the dynamics of surface and intermediate waters, whereas little attention has been devoted to deep-water masses. Currently, these deep waters consist mainly of North Atlantic Deep Waters as part of the Atlantic Meridional Overturning Circulation (AMOC). However, this configuration was altered during periods of AMOC collapse. We present a highresolution reconstruction of bottom-water ventilation and current evolution off Mauritania from the last glacial maximum into the early Holocene. Applying redox proxies (Mo, U and Mn) measured on sediments from off Mauritania, we describe changes in deep-water oxygenation and we infer the evolution of deep-water conditions during millennial-scale climate/oceanographic events in the area. The second half of Heinrich Event 1 and the Younger Dryas were recognized as periods of reduced ventilation, coinciding with events of AMOC reduction. We propose that these weakening circulation events induced deficient deep-water oxygenation in the Mauritanian upwelling region, which together with increased productivity promoted reducing conditions and enhanced organic-matter preservation. This is the first time the effect of AMOC collapse in the area is described at high resolution, broadening the knowledge on basin-wide oceanographic changes associated with rapid climate variability during the last deglaciation

Validez y fiabilidad de un instrumento para la valoración de la entrevista clínica en médicos residentes de medicina de familia: el cuestionario GATHA-RES

ObjetivoComprobar la validez de contenido, la consistencia interna y la fiabilidad intraobservador de un cuestionario para la evaluación de la comunicación médico-paciente de los residentes de medicina de familia.DiseñoEstudio observacional, de validación de un instrumento de medida.EmplazamientoNivel de atención primaria. Unidades docentes de medicina de familia y comunitaria.Población de estudioPara el análisis de validez, 25 médicos residentes de medicina familiar y comunitaria. Para el análisis de fiabilidad, 48 médicos de la misma especialidad.Mediciones e intervencionesPara la construcción del cuestionario, se partió de una versión (GATHA-BASE), compuesta por 42 ítems seleccionados por un panel compuesto por 60 médicos de familia. Para la validez de contenido, se utilizaron 68 encuentros clínicos con pacientes simulados, que fueron videograbados y evaluados. La validez de contenido del cuestionario se estudió mediante un análisis factorial, y para medir su consistencia interna se calcularon los coeficientes alfa de Cronbach. La fiabilidad intraobservador de la versión GATHA-RES fue evaluada mediante los índices kappa y los coeficientes de correlación intraclase.ResultadosObtuvimos una versión del GATHA-RES con 27 ítems. El análisis factorial reveló la existencia de 9 factores: «empatía», «anamnesis», «bidireccionalidad», «negociación», «información», «miscelánea 1», «miscelánea 2» y «centrado en el paciente», que mostraron una buena correlación con los contenidos teóricos y formales del cuestionario original (inicialmente agrupados en 3 secciones: actitudes, tareas comunicacionales y habilidades). Todos los coeficientes de correlación intraclase presentaron cifras ≥ 0,90.ConclusionesEl cuestionario GATHA-RES es un instrumento válido y fiable que puede ser usado para la evaluación de las habilidades comunicacionales de los médicos de familia en formación.ObjectiveTo check the validity of content, the internal consistency and the intra-observer reliability of a questionnaire to evaluate the doctor-patient communication of family medicine residents.DesignObservation study, to validate a measurement instrument.SettingPrimary care. Family and community medicine teaching units.Study populationFor the validity analysis: 25 family and community medicine residents. For the reliability analysis: 48 doctors in the same speciality.Measurements and interventionsThe questionnaire was constructed on the basis of a version (GATHABASE) composed of 42 items selected by a panel of 60 general practitioners. For content validity, 68 clinical encounters with simulated patients, video-recorded and evaluated, were used. The questionnaire's validity content was studied through a factorial analysis. To measure its internal consistency, Cronbach's alpha coefficients were calculated. Intra-observer reliability of the GATHA-RES version was evaluated through the kappa indexes and the intra-class correlation coefficients.ResultsWe obtained a version of the GATHA-RES with 27 items. The factorial analysis revealed that there were 9 factors («empathy», «anamnesis», «two-way communication», «negotiation», «information», «miscellaneous 1», «miscellaneous 2» and «patient-focused») which showed close correlation with the theoretical and formal contents of the original questionnaire (originally grouped in three sections: attitudes, communication tasks and skills). All the intraclass correlation coefficients had figures ≥ 0.90.ConclusionsThe GATHA-RES questionnaire is a valid and reliable instrument that can be used for evaluating the communication skills of general practitioners in training

Generating G2G_2--cosmologies with perfect fluid in dilaton gravity

We present a method for generating exact diagonal $G_2$-cosmological solutions in dilaton gravity coupled to a radiation perfect fluid and with a cosmological potential of a special type. The method is based on the symmetry group of the system of $G_2$-field equations. Several new classes of explicit exact inhomogeneous perfect fluid scalar-tensor cosmologies are presented.Comment: 10 pages, LaTe