Efectos sobre los procesos cognitivos del entrenamiento basado en doble tarea en personas con enfermedad de Parkinson: una revisión sistemática / Effects on cognitive processes of dual-task training in people with Parkinson’s disease: a systematic review

Introducción: La doble tarea es una intervención no farmacológica en personas con condiciones neurodegenerativas, utilizada en la enfermedad de Parkinson (EP), principalmente para favorecer el desempeño motor. El objetivo de esta revisión es reunir la evidencia actual sobre cómo el entrenamiento de doble tarea afecta a los procesos cognitivos en personas que presenten EP. Material y métodos. Se desarrolló una revisión sistemática, aplicando las directrices de PRISMA, incluyendo artículos obtenidos en las bases de datos de PubMed, Web of Science, Science Direct y Springer Link. La calidad metodológica se evaluó mediante PEDro y ROBINS-I. Resultados: Doce artículos cumplieron con los criterios de inclusión y exclusión: nueve de ellos corresponden a ensayos controlados aleatorizados y los tres restantes fueron estudios no aleatorizados. Se identificaron mejoras en la atención y las funciones ejecutivas, aunque la diversidad en enfoques y duración dificulta llegar a conclusiones definitivas. Conclusiones: Es crucial expandir la investigación, estandarizando los programas de intervención. Del mismo modo, es importante llevar a cabo estudios longitudinales y controlados aleatorizados en muestras representativas que permitan llegar a conclusiones aplicables a otros contextos.(AU)

Introduction: Dual-tasking is a non-pharmacological intervention in people with neurodegenerative conditions, and is used in Parkinson’s disease (PD), primarily to enhance motor performance. The aim of this review is to compile the current evidence on how dual-task training affects cognitive processes in people with PD. Material and methods: A systematic review was undertaken, applying PRISMA guidelines, which included articles obtained from the PubMed, Web of Science, Science Direct and Springer Link databases. Methodological quality was assessed using PEDro and ROBINS-I. Results: Twelve articles met the inclusion and exclusion criteria: nine of them were randomized controlled trials, and the remaining three were non-randomized studies. Improvements in attention and executive functions were identified, although the diversity of approaches and duration means that reaching definitive conclusions is difficult. Conclusions: Increased research and standardized intervention programmes are essential. Longitudinal and randomized controlled studies in representative samples which provide conclusions that are applicable to other contexts are also important.(AU)

[Effects on cognitive processes of dual-task training in people with Parkinson's disease: a systematic review]. / Efectos sobre los procesos cognitivos del entrenamiento basado en doble tarea en personas con enfermedad de Parkinson: una revisión sistemática.

INTRODUCTION: Dual-tasking is a non-pharmacological intervention in people with neurodegenerative conditions, and is used in Parkinson's disease (PD), primarily to enhance motor performance. The aim of this review is to compile the current evidence on how dual-task training affects cognitive processes in people with PD. MATERIAL AND METHODS: A systematic review was undertaken, applying PRISMA guidelines, which included articles obtained from the PubMed, Web of Science, Science Direct and Springer Link databases. Methodological quality was assessed using PEDro and ROBINS-I. RESULTS: Twelve articles met the inclusion and exclusion criteria: nine of them were randomized controlled trials, and the remaining three were non-randomized studies. Improvements in attention and executive functions were identified, although the diversity of approaches and duration means that reaching definitive conclusions is difficult. CONCLUSIONS: Increased research and standardized intervention programmes are essential. Longitudinal and randomized controlled studies in representative samples which provide conclusions that are applicable to other contexts are also important.

TITLE: Efectos sobre los procesos cognitivos del entrenamiento basado en doble tarea en personas con enfermedad de Parkinson: una revisión sistemática.Introducción. La doble tarea es una intervención no farmacológica en personas con condiciones neurodegenerativas, utilizada en la enfermedad de Parkinson (EP), principalmente para favorecer el desempeño motor. El objetivo de esta revisión es reunir la evidencia actual sobre cómo el entrenamiento de doble tarea afecta a los procesos cognitivos en personas que presenten EP. Material y métodos. Se desarrolló una revisión sistemática, aplicando las directrices de PRISMA, incluyendo artículos obtenidos en las bases de datos de PubMed, Web of Science, Science Direct y Springer Link. La calidad metodológica se evaluó mediante PEDro y ROBINS-I. Resultados. Doce artículos cumplieron con los criterios de inclusión y exclusión: nueve de ellos corresponden a ensayos controlados aleatorizados y los tres restantes fueron estudios no aleatorizados. Se identificaron mejoras en la atención y las funciones ejecutivas, aunque la diversidad en enfoques y duración dificulta llegar a conclusiones definitivas. Conclusiones. Es crucial expandir la investigación, estandarizando los programas de intervención. Del mismo modo, es importante llevar a cabo estudios longitudinales y controlados aleatorizados en muestras representativas que permitan llegar a conclusiones aplicables a otros contextos.

Verifiable Blind Quantum Computing with Trapped Ions and Single Photons.

We report the first hybrid matter-photon implementation of verifiable blind quantum computing. We use a trapped-ion quantum server and a client-side photonic detection system networked via a fiber-optic quantum link. The availability of memory qubits and deterministic entangling gates enables interactive protocols without postselection-key requirements for any scalable blind server, which previous realizations could not provide. We quantify the privacy at ≲0.03 leaked classical bits per qubit. This experiment demonstrates a path to fully verified quantum computing in the cloud.

Breaking the Entangling Gate Speed Limit for Trapped-Ion Qubits Using a Phase-Stable Standing Wave.

All laser-driven entangling operations for trapped-ion qubits have hitherto been performed without control of the optical phase of the light field, which precludes independent tuning of the carrier and motional coupling. By placing ^{88}Sr^{+} ions in a λ=674 nm standing wave, whose relative position is controlled to ≈λ/100, we suppress the carrier coupling by a factor of 18, while coherently enhancing the spin-motion coupling. We experimentally demonstrate that the off-resonant carrier coupling imposes a speed limit for conventional traveling-wave Mølmer-Sørensen gates; we use the standing wave to surpass this limit and achieve a gate duration of 15 µs, restricted by the available laser power.

Robust Quantum Memory in a Trapped-Ion Quantum Network Node.

We integrate a long-lived memory qubit into a mixed-species trapped-ion quantum network node. Ion-photon entanglement first generated with a network qubit in ^{88}Sr^{+} is transferred to ^{43}Ca^{+} with 0.977(7) fidelity, and mapped to a robust memory qubit. We then entangle the network qubit with a second photon, without affecting the memory qubit. We perform quantum state tomography to show that the fidelity of ion-photon entanglement decays ∼70 times slower on the memory qubit. Dynamical decoupling further extends the storage duration; we measure an ion-photon entanglement fidelity of 0.81(4) after 10 s.

Pancreatic steatosis: A frequent finding in a Chilean population.

INTRODUCTION AND AIMS: Pancreatic steatosis is an incidental radiologic finding in asymptomatic patients, and its clinical importance is unclear. PRIMARY AIM: to study the prevalence of pancreatic steatosis (PS) in consecutive patients registered at our hospital, that underwent computed axial tomography (CAT) scanning of the abdomen and pelvis, excluding known pancreatic diseases. Secondary aim: to review the association of PS with the demographic and clinical data of the patients, as well as with hepatic steatosis (HS). MATERIALS AND METHODS: An observational study was conducted on adult patients that had CAT scans of the abdomen and pelvis. DEFINITIONS: a) tissue density was measured in Hounsfield units (HU) in five 1 cm2 areas of the pancreas, three areas of the spleen, and in segments VI and VII of the liver; b) fatty pancreas: a difference < -10 HU between the mean pancreas and mean spleen densities; and c) fatty liver: density < 40 HU. We registered the epidemiologic and laboratory data of the patients. The association of those factors with the presence of PS was analyzed using SPSS version 24.0 software, and statistical significance was set at a p < 0.05. RESULTS: Of the 203 patients, PS was found in 61 (30%). The patients with PS were significantly older and had a higher body mass index. We found no significant association with the rest of the parameters studied, nor with HS (55 patients). None of the patients had symptoms attributable to a disease of the exocrine pancreas. CONCLUSIONS: Fatty infiltration of the pancreas is a frequent finding in CAT scans, and its clinical importance is unclear. Aging of the population and the increase in obesity underline the need for future studies on PS.

An elementary quantum network of entangled optical atomic clocks.

Optical atomic clocks are our most precise tools to measure time and frequency1-3. Precision frequency comparisons between clocks in separate locations enable one to probe the space-time variation of fundamental constants4,5 and the properties of dark matter6,7, to perform geodesy8-10 and to evaluate systematic clock shifts. Measurements on independent systems are limited by the standard quantum limit; measurements on entangled systems can surpass the standard quantum limit to reach the ultimate precision allowed by quantum theory-the Heisenberg limit. Although local entangling operations have demonstrated this enhancement at microscopic distances11-16, comparisons between remote atomic clocks require the rapid generation of high-fidelity entanglement between systems that have no intrinsic interactions. Here we report the use of a photonic link17,18 to entangle two 88Sr+ ions separated by a macroscopic distance19 (approximately 2 m) to demonstrate an elementary quantum network of entangled optical clocks. For frequency comparisons between the ions, we find that entanglement reduces the measurement uncertainty by nearly [Formula: see text], the value predicted for the Heisenberg limit. Today's optical clocks are typically limited by dephasing of the probe laser20; in this regime, we find that entanglement yields a factor of 2 reduction in the measurement uncertainty compared with conventional correlation spectroscopy techniques20-22. We demonstrate this enhancement for the measurement of a frequency shift applied to one of the clocks. This two-node network could be extended to additional nodes23, to other species of trapped particles or-through local operations-to larger entangled systems.

Experimental quantum key distribution certified by Bell's theorem.

Cryptographic key exchange protocols traditionally rely on computational conjectures such as the hardness of prime factorization1 to provide security against eavesdropping attacks. Remarkably, quantum key distribution protocols such as the Bennett-Brassard scheme2 provide information-theoretic security against such attacks, a much stronger form of security unreachable by classical means. However, quantum protocols realized so far are subject to a new class of attacks exploiting a mismatch between the quantum states or measurements implemented and their theoretical modelling, as demonstrated in numerous experiments3-6. Here we present the experimental realization of a complete quantum key distribution protocol immune to these vulnerabilities, following Ekert's pioneering proposal7 to use entanglement to bound an adversary's information from Bell's theorem8. By combining theoretical developments with an improved optical fibre link generating entanglement between two trapped-ion qubits, we obtain 95,628 key bits with device-independent security9-12 from 1.5 million Bell pairs created during eight hours of run time. We take steps to ensure that information on the measurement results is inaccessible to an eavesdropper. These measurements are performed without space-like separation. Our result shows that provably secure cryptography under general assumptions is possible with real-world devices, and paves the way for further quantum information applications based on the device-independence principle.

Measuring Ion Oscillations at the Quantum Level with Fluorescence Light.

We demonstrate an optical method for detecting the mechanical oscillations of an atom with single-phonon sensitivity. The measurement signal results from the interference between the light scattered by a trapped atomic ion and that of its mirror image. We detect the oscillations of the atom in the Doppler cooling limit and reconstruct average trajectories in phase space. We demonstrate single-phonon sensitivity near the ground state of motion after electronically induced transparency cooling. These results could be applied for motion detection of other light scatterers of fundamental interest, such as trapped nanoparticles.

The Panopticon device: An integrated Paul-trap-hemispherical mirror system for quantum optics.

We present the design and construction of a new experimental apparatus for the trapping of single Ba+ ions in the center of curvature of an optical-quality hemispherical mirror. We describe the layout, fabrication, and integration of the full setup, consisting of a high-optical access monolithic "3D-printed" Paul trap, the hemispherical mirror, a diffraction-limited in-vacuum lens (NA = 0.7) for collection of atomic fluorescence, and a state-of-the art ultra-high vacuum vessel. This new apparatus enables the study of quantum electrodynamics effects such as strong inhibition and enhancement of spontaneous emission and achieves a collection efficiency of the emitted light in a single optical mode of 31%.

Wavelength-scale errors in optical localization due to spin-orbit coupling of light.

Far-field optical imaging techniques allow the determination of the position of point-like emitters and scatterers [1-3]. Although the optical wavelength sets a fundamental limit to the image resolution of unknown objects, the position of an individual emitter can in principle be estimated from the image with arbitrary precision. This is used for example in the determination of stars position [4] or in optical super-resolution microscopy [5]. Furthermore, precise position determination is an experimental prerequisite for the manipulation and measurement of individual quantum systems, such as atoms, ions, and solid-state-based quantum emitters [6-8]. Here we demonstrate that spin-orbit coupling of light in the emission of elliptically polarized emitters can lead to systematic, wavelength-scale errors in the estimation of the emitters position. Imaging a single trapped atom as well as a single sub-wavelength-diameter gold nanoparticle, we demonstrate a shift between the emitters measured and actual positions which is comparable to the optical wavelength. For certain settings, the expected shift can become arbitrarily large. Beyond optical imaging techniques, our findings could be relevant for the localization of objects using any type of wave that carries orbital angular momentum relative to the emitters position with a component orthogonal to the direction of observation.

Interference of Single Photons Emitted by Entangled Atoms in Free Space.

The generation and manipulation of entanglement between isolated particles has precipitated rapid progress in quantum information processing. Entanglement is also known to play an essential role in the optical properties of atomic ensembles, but fundamental effects in the controlled emission and absorption from small, well-defined numbers of entangled emitters in free space have remained unobserved. Here we present the control of the emission rate of a single photon from a pair of distant, entangled atoms into a free-space optical mode. Changing the length of the optical path connecting the atoms modulates the single-photon emission rate in the selected mode with a visibility V=0.27±0.03 determined by the degree of entanglement shared between the atoms, corresponding directly to the concurrence C_{ρ}=0.31±0.10 of the prepared state. This scheme, together with population measurements, provides a fully optical determination of the amount of entanglement. Furthermore, large sensitivity of the interference phase evolution points to applications of the presented scheme in high-precision gradient sensing.

Pérfil biomédico de la trabajadora sexual: Lebu, julio de 1992 a octubre de 1994 / Biomedical profile of the sexual worker: Lebu, jule of 1992 to october of 1994

Mucho se ha hablado de la importancia del control de la prostitución dada la proliferación abrumadora de casos del virus de inmunodeficiencia humana y otras ETS, pero poco se ha estudiado del pérfil biomédico y social de este grupo de tan alto riesgo epidemiológico. Este trabajo ha pretendido definir el pérfil biomédico de este grupo de mujeres de Lebu, determinado parámetros de edad, estado civil, paridad, MAC, antecedentes de ETS y hábitos tabáquicos y alcohólicos. Los resultados obtenidos nos revelan que las mujeres que trabajan con el sexo son madres solteras, en su mayoría con una paridad promedio de 2 hijos. El antecedente de ETS está presente en la mayoría de ellas, sólo un tercio se protege usando preservativo y tienen una alta ingesta de alcohol y consumo de tabaco. Esto lleva a orientar políticas de salud mental que permitan obordar aspectos como los anteriormente estudiados que logren mejorar la calidad de vida de este grupo de mujeres

The influence of perfusate temperature on the responses of a superficial vein in the carotid baroreceptor reflex in dogs.

In chloralose-anaesthetised dogs, both vagus nerves were cut and both carotid sinuses vascularly isolated and perfused with blood. The left hind limb was vascularly isolated and the femoral artery and the central end of a superficial metatarsal vein were perfused at constant flows with blood from an oxygenator. Femoral venous pressure was held constant. Arterial and venous responses were determined by measuring changes in arterial perfusion pressure and in the pressure gradient between the superficial metatarsal and femoral veins. Large step increases in carotid sinus pressure resulted in an average decrease in venous gradient of 5.6% when the temperature of the venous perfusate was 38 degrees C and a significantly (P less than 0.01) greater response (8.8%) when the perfusate was at 31 degrees C. When the venous perfusate was cooled from 38 to 31 degrees C, venous gradient increased by averages of 89% when carotid pressure was low, 64% when carotid pressure was high and 32% after lumbar sympathectomy. These responses are significantly different from each other (P less than 0.05). It is concluded that the reflex responses of the superficial vein to maximal stimulation of the baroreceptors were small but they were significantly protentiated by cooling the perfusate. The venous constriction in response to cooling was reduced by raising the carotid pressure and further reduced by surgical sympathectomy.