64 research outputs found
Monitoreo de contaminantes y detección de genes alkb en la Zona Común de Pesca Argentino-Uruguaya
In this study, the presence of diverse pollutants in sediments samples was determined in the Río de la Plata and the Argentine-Uruguayan Common Fishing Zone (AUCFZ 35° S-38° S). In addition, the occurrence of microbial genes alkB, used as functional markers, was analyzed in order to determine the hydrocarbon degradation potential along this marine environment. Heavy metals were detected in sampling sites UY1, RdP4 and AR2. Cr was found in a range from < 5.0 to 20.7 mg kg-1, and Pb from not detectable (ND) to 26.0 mg kg-1. Both Cd and Hg showed values under detection limits (< 0.2 mg kg-1 and < 0.01 mg kg-1, respectively). Cu varied between ND and 24.6 mg kg-1, and it was the only metal that overcame the values recommended by the ISQG (Interim Sediment Quality Guideline), in the guide levels for biota protection in sediments (CCME, Canadian Council of Ministers of the Environment). Hydrocarbons, atrazine, glyphosate + AMPA (aminomethyl phosphonic acid) and pesticides values were under the quantification limits, while PCBs (from < 20.0 to 77.7 µg kg-1) exceeded the action level A for the ‘Recommendations for the Management of Dredging Material in Spanish Ports’. Purified microbial genomic DNA was obtained in eight from the nine analyzed samples, and the catabolic gen alkB was amplified in sampling sites UY2, UY1, RdP4, AR2 and AR1. Further studies are needed to evaluate the microbial biodegradation potential in this area. These researches mean a valuable input in order to investigate the impact of the anthropogenic disturbances on marine ecosystems and to understand the mechanisms of natural attenuation.En este estudio se determinó la presencia de diversos contaminantes en muestras de sedimentos en el Río de la Plata y la Zona Común de Pesca Argentino-Uruguaya (ZCPAU, 35° S-38° S). Además, se analizó la ocurrencia de genes alkB microbianos, utilizados como biomarcadores funcionales para determinar el potencial de degradación de hidrocarburos a lo largo de este ambiente marino. Se detectaron metales pesados en las estaciones UY1, RdP4 y AR2. El Cr se encontró en un rango entre < 5,0 y 20,7 mg kg-1, y el Pb entre no detectable (ND) y 26,0 mg kg-1. Tanto el Cd como el Hg mostraron valores por debajo de los límites de detección (< 0,2 mg kg-1 y < 0,01 mg kg-1, respectivamente). El Cu varió entre ND y 24,6 mg kg-1, y fue el único metal que sobrepasó los valores recomendados por la ISQG (Interim Sediment Quality Guideline), en los niveles guía en sedimentos para la protección de la biota (CCME, Canadian Council of Ministers of the Environment). Los valores de hidrocarburos, atrazina, glifosato + AMPA (ácido aminometil fosfónico) y pesticidas estuvieron por debajo del límite de cuantificación, mientras que los PCBs (desde < 20,0 a 77,7 µg kg-1) excedieron el nivel de acción A de las “Recomendaciones para la Gestión del Material de Dragado en los Puertos Españoles”. Se obtuvo ADN genómico microbiano purificado en ocho de las nueve muestras analizadas y se logró la amplificación del gen catabólico alkB en las estaciones UY2, UY1, RdP4, AR2 y AR1. Es necesario realizar estudios adicionales para evaluar el potencial de biodegradación microbiana en esta área. Estas investigaciones representan un valioso aporte para evaluar el impacto de las alteraciones antropogénicas sobre los ecosistemas marinos y para comprender los mecanismos de la atenuación natural
The Effect of Endurance Training on Pulmonary V˙O2 Kinetics in Solid Organs Transplanted Recipients
BACKGROUND: We investigated the effects of single (SL-ET) and double leg (DL-ET) high-intensity interval training on O2 deficit (O2Def) and mean response time (MRT) during square-wave moderate-intensity exercise (DL-MOD), and on the amplitude of V˙O2p slow component (SCamp), during heavy intensity exercise (DL-HVY), on 33 patients (heart transplant = 13, kidney transplanted = 11 and liver transplanted = 9). METHODS: Patients performed DL incremental step exercise to exhaustion, two DL-MOD tests, and a DL-HVY trial before and after 24 sessions of SL-ET (n = 17) or DL-ET (n = 16). RESULTS: After SL-ET, O2Def, MRT and SCamp decreased by 16.4% ± 13.7 (p = 0.008), by 15.6% ± 13.7 (p = 0.004) and by 35% ± 31 (p = 0.002), respectively. After DL-ET, they dropped by 24.9% ± 16.2 (p < 0.0001), by 25.9% ± 13.6 (p < 0.0001) and by 38% ± 52 (p = 0.0003), respectively. The magnitude of improvement of O2Def, MRT, and SCamp was not significantly different between SL-ET and DL-ET after training. CONCLUSIONS: We conclude that SL-ET is as effective as DL-ET if we aim to improve V˙O2p kinetics in transplanted patients and suggest that the slower, V˙O2p kinetics is mainly caused by the impairment of peripherals exchanges likely due to the immunosuppressive medications and disuse
Association between the donor to recipient ICG-PDR variation rate and the functional recovery of the graft after orthotopic liver transplantation: A case series
Background: Despite current advances in liver transplant surgery, post-operative early allograft dysfunction still complicates the patient prognosis and graft survival. The transition from the donor has not been yet fully understood, and no study quantifies if and how the liver function changes through its transfer to the recipient. The indocyanine green dye plasma disappearance rate (ICG-PDR) is a simple validated tool of liver function assessment. The variation rate between the donor and recipient ICG-PDR still needs to be investigated. Materials and methods: Single-center retrospective study. ICG-PDR determinations were performed before graft retrieval (T1) and 24 hours after transplant (T2). The ICG-PDR relative variation rate between T1 and T2 was calculated to assess the graft function and suffering/recovering. Matched data were compared with the MEAF model of graft dysfunction. Objective: To investigate whether the variation rate between the donor ICG-PDR value and the recipient ICG-PDR measurement on first postoperative day (POD1) can be associated with the MEAF score. Results: 36 ICG-PDR measurements between 18 donors and 18 graft recipients were performed. The mean donor ICG-PDR was 22.64 (SD 6.35), and the mean receiver's ICG-PDR on 1st POD was 17.68 (SD 6.60), with a mean MEAF value of 4.51 (SD 1.23). Pearson's test stressed a good, linear inverse correlation between the ICG-PDR relative variation and the MEAF values, correlation coefficient -0.580 (p = 0.012). Conclusion: The direct correlation between the donor to recipient ICG-PDR variation rate and MEAF was found. Measurements at T1 and T2 showed an up- or downtrend of the graft performance that reflect the MEAF values
Probabilistic 3D surface reconstruction from sparse MRI information
Surface reconstruction from magnetic resonance (MR) imaging data is
indispensable in medical image analysis and clinical research. A reliable and
effective reconstruction tool should: be fast in prediction of accurate well
localised and high resolution models, evaluate prediction uncertainty, work
with as little input data as possible. Current deep learning state of the art
(SOTA) 3D reconstruction methods, however, often only produce shapes of limited
variability positioned in a canonical position or lack uncertainty evaluation.
In this paper, we present a novel probabilistic deep learning approach for
concurrent 3D surface reconstruction from sparse 2D MR image data and aleatoric
uncertainty prediction. Our method is capable of reconstructing large surface
meshes from three quasi-orthogonal MR imaging slices from limited training sets
whilst modelling the location of each mesh vertex through a Gaussian
distribution. Prior shape information is encoded using a built-in linear
principal component analysis (PCA) model. Extensive experiments on cardiac MR
data show that our probabilistic approach successfully assesses prediction
uncertainty while at the same time qualitatively and quantitatively outperforms
SOTA methods in shape prediction. Compared to SOTA, we are capable of properly
localising and orientating the prediction via the use of a spatially aware
neural network.Comment: MICCAI 202
Signatures for Majorana neutrinos in collider
We study the possibilities to detect Majorana neutrinos in
colliders for different center of mass energies.
We study the final state
which are, due to leptonic number violation, a clear signature for intermediate
Majorana neutrino contribution. Such a signal (final lepton have the opposite
charge of the initial lepton) is not possible if the heavy neutrinos are Dirac
particles. In our calculation we use the helicity formalism to obtain analytic
expressions for the amplitude and we have considered that the intermediate
neutrinos can be either on shell or off shell. Finally we present our results
for the total cross-section and for the angular distribution of the final
lepton. We also include a discussion on the expected events number as a
function of the input parameters.Comment: Latex file with 12 pages and 6 figures. Submited to Phys. Rev.
Signatures of Right-Handed Majorana neutrinos and gauge bosons in Collisions
The process is studied in the framework of
the Left-Right symmetric model. It is shown that this reaction and for the arbitrary final lepton are likely to be discovered for
CLIC collider option.
For relatively light doubly charged Higgs boson its mass does not have much
influence on the discovery potential, while for heavier values the probability
of the reaction increases.Comment: 18 pages, 7 figures, LaTe
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