92 research outputs found

    Driving superconducting qubits into chaos

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    Kerr parametric oscillators are potential building blocks for fault-tolerant quantum computers. They can stabilize Kerr-cat qubits, which offer advantages towards the encoding and manipulation of error-protected quantum information. Kerr-cat qubits have been recently realized with the SNAIL transmon superconducting circuit by combining nonlinearities and a squeezing drive. These superconducting qubits can lead to fast gate times due to their access to large anharmonicities. However, we show that when the nonlinearities are large and the drive strong, chaos sets in and melts the qubit away. We provide an equation for the border between regularity and chaos and determine the regime of validity of the Kerr-cat qubit, beyond which it disintegrates. This is done through the quantum analysis of the quasienergies and Floquet states of the driven system, and is complemented with classical tools that include Poincar\'e sections and Lyapunov exponents. By identifying the danger zone for parametric quantum computation, we uncover another application for driven superconducting circuits, that of devices to investigate quantum chaos.Comment: 12 pages, 5 figure

    Prognostic importance of DNA from human papillomavirus in patients with oral squamous cell carcinoma

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    Survival of patients with oral squamous cell carcinoma (OSCC) is generally low, with the likelihood of locoregional recurrence or disease progression (LR/DP). Knowledge of prognostic factors for survival is key to achieving an understanding and increased survival. The present study aimed to identify prognostic factors for patients with OSCC, especially the presence of DNA from human papillomavirus (HPV). Retrospective cohort study including 119 patients with OSCC treated at the National Cancer Institute in Mexico City (2009-2013). Clinical information was obtained from patient records including LR/DP. Formalin-fixed, paraffin-embedded tissues were obtained and used for detecting DNA from different types of HPV. Potential prognostic factors for Overall Survival (OS) were analyzed using the Cox proportional hazards model. After model adjustment, factors associated with longer OS were a pre-treatment platelet count above 400,000/mm3 (HR=0.09, p=0.026) and response to primary treatment (HR=0.26, p=0.001). HPV DNA was present in 23 (19.3%) of the patients and importantly, type 16 found in 19 of them. Although survival of HPV-positive patients was longer, difference was not significant. However, among patients with LR/DP, HPV positivity was significantly associated with increased survival (HR=0.23, p=0.034). Importantly, survival was significantly different for HPV-positive patients with LR/DP > 6 months (HR=0.20, p=0.002), had higher absolute lymphocyte count at start of treatment (HR=0.50, p=0.028) or had local rescue treatment (HR=0.24, p=0.019). Although HPV positivity was not associated with a longer OS of OSCC patients, a better prognosis was significantly associated with HPV positivity and recurring or progressing disease, particularly with HPV type 16

    Effect of immunocastration on behaviour and blood parameters (cortisol and testosterone) of Holstein bulls

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    To evaluate the effect that immunocastration has on behaviour, testosterone and cortisol levels of feedlot Holstein bulls, 720 intact animals aged between 7 and 8 months, weighing 232±1.19 kg were randomly assigned to two treatments: immunocastration using the Bopriva vaccine and a placebo (360 animals per treatment). The bulls were slaughtered at day 239 of treatment. Animals were vaccinated on days 1, 21, 101, and 181, and on those same days testosterone levels were measured; while cortisol, glucose and creatin kinase measurements were done on day 181 and during exanguination at slaughter. Sexual, aggressive and social behaviours were evaluated and it was found that intact bulls showed a higher average of head butts, mounting, threats, flehmen sign and sniffing (P<0.05), no differences were found for vocalisations, lowering of the head and grooming (P>0.05). Testosterone levels in intact bulls remained at 0.47ng/mL throughout the study, however, by day 181 differences (P<0.05) were observed in immunised bulls, with values of 0.22ng/mL. At slaughter, testosterone levels were 0.21 ± 0.06 ng/mL in immunocastrated bulls and 0.54 ± 0.06 ng/mL in the placebo group. The use of immunocastration with Bopriva has shown to be effective to reduce testosterone, sexual and aggressive behaviours on Holstein bulls

    The long helical jet of the Lighthouse nebula, IGR J11014-6103

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    Jets from rotation-powered pulsars have so far only been observed in systems moving subsonically trough their ambient medium and/or embedded in their progenitor supernova remnant (SNR). Supersonic runaway pulsars are also expected to produce jets, but they have not been confirmed so far. We investigated the nature of the jet-like structure associated to the INTEGRAL source IGR J11014-6103 (the "Lighthouse nebula"). The source is a neutron star escaping its parent SNR MSH 11-61A supersonically at a velocity exceeding 1000 km/s. We observed the Lighthouse nebula and its jet-like X-ray structure through dedicated high spatial resolution observations in X-rays (Chandra) and radio band (ATCA). Our results show that the feature is a true pulsar's jet. It extends highly collimated over >11pc, displays a clear precession-like modulation, and propagates nearly perpendicular to the system direction of motion, implying that the neutron star's spin axis in IGR J11014-6103 is almost perpendicular to the direction of the kick received during the supernova explosion. Our findings suggest that jets are common to rotation-powered pulsars, and demonstrate that supernovae can impart high kick velocities to misaligned spinning neutron stars, possibly through distinct, exotic, core-collapse mechanisms.Comment: 8 pages, 6 figures, 1 table. Discussion (sec.3) expanded and typos fixed; results unchanged. Published on A&

    Scarification treatments in chepil seeds (Crotalaria longirostrata Hook. & Arn.) used to improve their germination

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    Objective: The objective was to evaluate different treatments of scarification to improve the germination, in seeds of chepil (Crotalaria longirostrata Hook. & Arn.). Design / Methodology / Approach:  The research was established at the Faculty of Veterinary Medicine and Animal Husbandry No. 2 of the Autonomous University of Guerrero. The chepil seeds were weighed and counted; Using a DCA, 2 experiments were established with 4 treatments of 4 repetitions each. Imbibition and germination were evaluated. The data was analyzed using a SAS® 9.0 statistical package. Results: The use of water at different temperatures and times presented positive results in imbibition and increased germination percentages; because when using water at 100 °C until cooling, the germination was 80 % and the control it barely reached 12.3 %. Study limitations / implications: Chepil is a wild species that has seeds with physical dormancy, which requires further research to accelerate and increase germination rates. Findings / conclusions:  The imbibition and germination was affected by the applied treatments. The seeds are chepil present physical or superficial dormancy that can be eliminated with the use of heat treatments; however, evaluations are needed to accelerate and find a higher percentage of germination.Objective: The objective was to evaluate different scarification treatments to improvegermination in chepil seeds (Crotalaria longirostrata Hook. & Arn.).Design/Methodology/Approach: The study was established in the School of VeterinaryMedicine and Zootechnics N. 2 of the Universidad Autónoma de Guerrero. The chepilseeds were weighed and counted; 2 experiments were established through a CRD with4 treatments of 4 repetitions each. Imbibition and germination were evaluated. The datawere analyzed with the statistical software package SAS® 9.0.Results: The use of water at different temperatures and times presented positive resultsin imbibition and increased the germination percentages. The treatment with water at100°C until cooling reached a germination of 80%, and the control of 12.3%. Study Limitations/Implications: Chepil is a wild species that has seeds with physicaldormancy, which is something that requires more research in order to accelerate andincrease the germination percentages.Findings/Conclusions: The imbibition and germination was affected by the treatmentsapplied. Chepil seeds presented physical or superficial dormancy that may be eliminatedwith the use of heat treatments; however, evaluations still need to be performed toaccelerate and find a higher percentage of germination

    Comparación de la castración quirúrgica al nacimiento versus inmunocastration sobre las características de la canal y carne en machos Holstein

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    El objetivo fue comparar el efecto de la castración quirúrgica al nacimiento vs immunocastración, sobre las características de la canal y carne en machos Holstein en engorda; se utilizaron 720 machos Holstein aproximadamente de 7 a 8 meses de edad con peso inicial de 240.82 kg. Se formaron 2 tratamientos con 4 corrales de 90 animales en cada uno: toros castrados quirúrgicamente que fueron castrados 24 h después del nacimiento y toros inmunocastrados vacunados con Bopriva aplicando cuatro dosis, al día 1, 21, 101 y 181 de engorda. Se tomaron pesos individuales en cada vacunación. Los animales se sacrificaron a los 242 días de engorda. A partir de la segunda vacunación se observaron diferencias (P0.05) entre tratamientos mientras que los valores de b*, C* y H* fueron más altos (P<0.05) en los animales inmunocastrados. Para fines de producción, el sacrificar los machos Holstein al nacimiento, se obtienen animales más pesados y con mejores características en la canal; sin embargo es importante evaluar el impacto del bienestar animal por la castración al nacimiento

    Corredores socioambientales para la regeneración del río Pitillal en Puerto Vallarta

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    Desde inicios del 2021 el PAP ha realizado estudios sociales y ambientales de diferentes áreas de la zona de estudio en la ribera sur del río PItillal, para generar propuestas tales como: 1. Restauración de la ribera como parque lineal para la regeneración del paisaje: parque lineal con caminos en la ribera sur, áreas verdes, espacios de descanso, y puente peatonal que conecte con la ribera norte. 2. Mejoramiento de espacios públicos y naturales: Crear un paradigma de apreciación y cuidado con los espacios naturales; incentivar a que las personas reconozcan las dinámicas del agua para apreciar sus bondades; fortalecer valores en la comunidad como unidad, compromiso, cuidado por el medio ambiente. 3. Adecuación del paisaje: densificar con plantas de distintos niveles para que crezcan de manera íntegra.bajo criterios de sucesión ecológica. 4. Autoproducción del paisaje: Desarrollar diseños y estructuras de bambú para el mejoramiento del espacio público bajo criterios de producción social del hábitat. El objetivo del trabajo fue mejorar la vivienda y el espacio público y así propiciar la regeneración espacial, ecológica y social de la zona del Río Pitillal. Beneficiar, en primera instancia, a los habitantes de la zona, y puedan apropiarse del espacio de manera responsable, y que abone a las dinámicas sociales y a la identidad de las colonias vecinas. Generar espacios públicos y viviendas de calidad y vincular la regeneración ecológica del río. Donde a través de la vertiente de vivienda se solidifique el proyecto en la escala micro, enlazando no solo el mejoramiento del espacio público, sino también el habitar dentro del hogar de las personas.ITESO, A.C

    Declaración de Cancún: declaración internacional de Cancún sobre el derecho a la nutrición en los hospitales

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    La declaración de Cancún por el derecho humano de los enfermos a recibir una terapia nutricional oportuna y óptima en cualquier lugar donde se encuentren ha sido emitida por los Presidentes de las Sociedades y Asociaciones de Nutrición Clínica y Terapia Nutricional de América Latina y el Caribe, en el marco del XI Congreso de FELANPE/XV Congreso de AMAEE, en la Ciudad de Cancún Quintana Roo, México, el día 20 de mayo de 2008

    Alzheimer-Like Cell Alterations after Vanadium Pentoxide Inhalation

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    Vanadium (V), a widely distributed transition metal, has been considered toxic, which depends on the valence of the compound. V pentoxide (V2O5) is considered the most harmful. Its long-term exposure produces neurotoxicity. Mice exposed to inhaled V2O5 displayed less tubulin+ in testicular cells and dendritic spines loss, cell death, and CA1 neuropil modifications, considered as the result of V interaction with the cytoskeleton, which made us suppose that V2O5 inhalation could initiate CA1 cell alterations comparable to what happen in the brains of Alzheimer disease (AD) patients. This study intends to demonstrate pyramidal CA1 cytoskeletal changes in rats which inhaled V2O5. Twenty rats were exposed to V2O5 0.02 M one hour, three times a week for several months. Our findings showed that V2O5-exposed rats had cell death that reached 56,57% after six months; we also observed collapsed strong argyrophilic nuclei and characteristic flame-shaped somas in all V2O5-exposed animals hippocampus CA1 compared to controls. We also found somatodendritic deformations. Neurite’s cytoskeleton exhibited visible thickening and nodosities and prominent dendritic spine loss. Our results demonstrate that V2O5 induces AD-like cell death with evident cytoskeletal and synaptic alterations
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