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The correlation length ξ, a key quantity in glassy dynamics, can now be precisely measured for spin glasses both in experiments and in simulations. However, known analysis methods lead to discrepancies either for large external fields or close to the glass temperature. We solve this problem by introducing a scaling law that takes into account both the magnetic field and the time-dependent spin-glass correlation length. The scaling law is successfully tested against experimental measurements in a CuMn single crystal and against large-scale simulations on the Janus II dedicated computer.
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Weather observations are essential for crop monitoring and forecasting but they are not always available and in some cases they have limited spatial representativeness. Thus, reanalyses represent an alternative source of information to be explored. In this study, we assess the feasibility of reanalysis-based crop monitoring and forecasting by using the system developed and maintained by the European Commission- Joint Research Centre, its gridded daily meteorological observations, the biased-corrected reanalysis AgMERRA and the ERA-Interim reanalysis. We focus on Europe and on two crops, wheat and maize, in the period 1980-2010 under potential and water-limited conditions. In terms of inter-annual yield correlation at the country scale, the reanalysis-driven systems show a very good performance for both wheat and maize (with correlation values higher than 0.6 in almost all EU28 countries) when compared to the observations-driven system. However, significant yield biases affect both crops. All simulations show similar correlations with respect to the FAO reported yield time series. These findings support the integration of reanalyses in current crop monitoring and forecasting systems and point to the emerging opportunities linked to the coming availability of higher-resolution reanalysis updated at near real time.
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Here we assess the quality and in-season development of European wheat (Triticum spp.) yield forecasts during low, medium, and high-yielding years. 440 forecasts were evaluated for 75 wheat forecast years from 1993-2013 for 25 European Union (EU) Member States. By July, years with median yields were accurately forecast with errors below ~2%. Yield forecasts in years with low yields were overestimated by ~10%, while yield forecasts in high-yielding years were underestimated by ~8%. Four-fifths of the lowest yields had a drought or hot driver, a third a wet driver, while a quarter had both. Forecast accuracy of high-yielding years improved gradually during the season, and drought-driven yield reductions were anticipated with lead times of ~2 months. Single, contrasting successive in-season, as well as spatially distant dry and wet extreme synoptic weather systems affected multiple-countries in 2003, '06, '07, '11 and 12', leading to wheat losses up to 8.1 Mt (>40% of total EU loss). In these years, June forecasts (~ 1-month lead-time) underestimated these impacts by 10.4 to 78.4%. To cope with increasingly unprecedented impacts, near-real-time information fusion needs to underpin operational crop yield forecasting to benefit from improved crop modelling, more detailed and frequent earth observations, and faster computation.
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Productos Agrícolas , Unión Europea , Predicción/métodos , Estaciones del Año , Triticum/crecimiento & desarrollo , Productos Agrícolas/economía , Productos Agrícolas/crecimiento & desarrollo , Sequías , Unión Europea/organización & administración , Calor Extremo , Humanos , Modelos Estadísticos , Valor Predictivo de las Pruebas , Lluvia , Tiempo (Meteorología)RESUMEN
Experiments on spin glasses can now make precise measurements of the exponent z(T) governing the growth of glassy domains, while our computational capabilities allow us to make quantitative predictions for experimental scales. However, experimental and numerical values for z(T) have differed. We use new simulations on the Janus II computer to resolve this discrepancy, finding a time-dependent z(T,t_{w}), which leads to the experimental value through mild extrapolations. Furthermore, theoretical insight is gained by studying a crossover between the T=T_{c} and T=0 fixed points.
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Chaotic size dependence makes it extremely difficult to take the thermodynamic limit in disordered systems. Instead, the metastate, which is a distribution over thermodynamic states, might have a smooth limit. So far, studies of the metastate have been mostly mathematical. We present a numerical construction of the metastate for the d=3 Ising spin glass. We work in equilibrium, below the critical temperature. Leveraging recent rigorous results, our numerical analysis gives evidence for a dispersed metastate, supported on many thermodynamic states.
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We first reproduce on the Janus and Janus II computers a milestone experiment that measures the spin-glass coherence length through the lowering of free-energy barriers induced by the Zeeman effect. Secondly, we determine the scaling behavior that allows a quantitative analysis of a new experiment reported in the companion Letter [S. Guchhait and R. Orbach, Phys. Rev. Lett. 118, 157203 (2017)].PRLTAO0031-900710.1103/PhysRevLett.118.157203 The value of the coherence length estimated through the analysis of microscopic correlation functions turns out to be quantitatively consistent with its measurement through macroscopic response functions. Further, nonlinear susceptibilities, recently measured in glass-forming liquids, scale as powers of the same microscopic length.
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The objective of the present study was to estimate genetic parameters for skin thickness (ST) and postweaning weight gain (PWG550) in Nellore cattle. Records were obtained from 152,392 Nellore animals born between 2001 and 2011. ST was measured in the posterior region of the animal's scapula with a millimeter caliper. The animals were assigned to different contemporary groups, formed on the basis of farm, year, sex, feeding regimen at weaning, date of weaning, feeding regimen at 450 days of age, and date of weighing at 450 days of age. The genetic parameters were estimated by Bayesian analysis using the GIBBS1F90 program. The mean ST and PWG550 observed were 7.71 ± 2.04 mm and 115.95 ± 36.17 kg, respectively. The posterior mean estimates of heritability (h2) were 0.12 ± 0.02 and 0.29 ± 0.02 for ST and PWG550, respectively. The posterior mean estimates of the phenotypic, genetic, and environmental correlations between the traits were 0.16 ± 0.0, 0.17 ± 0.02, and 0.17 ± 0.09, respectively. The traits ST and PWG550 showed sufficient additive genetic variance to be used as selection criteria in breeding programs. The low genetic correlation obtained indicates that genes favoring the expression of one trait may not influence the other. Consequently, a selection favoring ST would be less efficient in increasing PWG550.
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Bovinos/genética , Modelos Genéticos , Carácter Cuantitativo Heredable , Piel/anatomía & histología , Aumento de Peso/genética , Animales , Teorema de Bayes , Cruzamiento , Bovinos/anatomía & histología , Bovinos/fisiología , Femenino , Interacción Gen-Ambiente , MasculinoRESUMEN
We study the off-equilibrium dynamics of the three-dimensional Ising spin glass in the presence of an external magnetic field. We have performed simulations both at fixed temperature and with an annealing protocol. Thanks to the Janus special-purpose computer, based on field-programmable gate array (FPGAs), we have been able to reach times equivalent to 0.01 s in experiments. We have studied the system relaxation both for high and for low temperatures, clearly identifying a dynamical transition point. This dynamical temperature is strictly positive and depends on the external applied magnetic field. We discuss different possibilities for the underlying physics, which include a thermodynamical spin-glass transition, a mode-coupling crossover, or an interpretation reminiscent of the random first-order picture of structural glasses.
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We numerically study the aging properties of the dynamical heterogeneities in the Ising spin glass. We find that a phase transition takes place during the aging process. Statics-dynamics correspondence implies that systems of finite size in equilibrium have static heterogeneities that obey finite-size scaling, thus signaling an analogous phase transition in the thermodynamical limit. We compute the critical exponents and the transition point in the equilibrium setting, and use them to show that aging in dynamic heterogeneities can be described by a finite-time scaling ansatz, with potential implications for experimental work.
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The objectives of pre-transplant assessment are: a) to ensure that transplantation is technically possible; b) to ensure that the recipient's chances of survival are not compromised by transplantation; c) to ensure that graft survival is not limited by premature death; d) to ensure that pre-existing conditions are not exacerbated by transplantation; e) to identify measures to be taken to minimize perioperative and postoperative complications; f) to inform patients of the likely risks and benefits of transplantation. During the long-term follow-up of living donor kidney transplant recipients, clinicians have to pay attention to the possible recurrence of the primary renal disease, to the identification and, if possible, prevention of noncompliance, and, finally, to immunological monitoring.
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Trasplante de Riñón , Donadores Vivos , Selección de Paciente , Estado de Salud , Humanos , Pruebas Inmunológicas , Enfermedades Renales/diagnóstico , Monitorización InmunológicaRESUMEN
Chronic allograft dysfunction (CAD) represents the main cause of delayed graft loss. Several mechanisms, immunological and not, are involved in the pathogenesis of CAD, some of which are modifiable. Suboptimal immunosuppression may induce subclinical acute rejections, identifiable by histology and influencing graft survival. Typical transplant recipients' comorbidities such as hypertension, diabetes and dyslipidemia accelerate CAD progression. Calcineurin inhibitors, which are known to be nephrotoxic, play a key role in the onset of CAD through several mechanisms. Therapeutic interventions to stop or at least slow down CAD progression involve all these modifiable factors by means of comorbidity correction, tailored immunosuppression and, in some cases, withdrawal of calcineurin inhibitors.
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Rechazo de Injerto/prevención & control , Supervivencia de Injerto/efectos de los fármacos , Terapia de Inmunosupresión/métodos , Inmunosupresores/efectos adversos , Enfermedades Renales/inducido químicamente , Trasplante de Riñón , Inhibidores de la Calcineurina , Funcionamiento Retardado del Injerto , Complicaciones de la Diabetes , Dislipidemias/complicaciones , Rechazo de Injerto/inmunología , Humanos , Hipertensión Renal/complicaciones , Terapia de Inmunosupresión/efectos adversos , Inmunosupresores/administración & dosificación , Enfermedades Renales/diagnóstico , Enfermedades Renales/prevención & control , Fallo Renal Crónico/prevención & control , Factores de Riesgo , Índice de Severidad de la Enfermedad , Resultado del TratamientoRESUMEN
We study numerically the nonequilibrium dynamics of the Ising spin glass, for a time spanning 11 orders of magnitude, thus approaching the experimentally relevant scale (i.e., seconds). We introduce novel analysis techniques to compute the coherence length in a model-independent way. We present strong evidence for a replicon correlator and for overlap equivalence. The emerging picture is compatible with noncoarsening behavior.
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Vidrio/química , Modelos Químicos , CinéticaRESUMEN
Living kidney transplantation has become increasingly widespread to reduce organ shortage. Very few studies have prospectively investigated the donor's long-term risks. Living donation is a complex medical decision in which different actors are involved. This therapeutic option needs educational programs for potential donors, recipients, and transplant professionals to make them aware of the possible risks and benefits. It is important to fully exploit living-donor kidney transplantation.
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Trasplante de Riñón , Donadores Vivos , Grupo de Atención al Paciente , Humanos , Factores de RiesgoRESUMEN
The increased efficiency of immunosuppressive drugs obtained in the last few years has significantly reduced the incidence of acute rejection, prolonging transplant survival rates. The inevitable trade-off was however an increased rate of post-transplant infections and malignancies. Furthermore, this problem might get more and more serious in the next future due to the increasing incidence of cancer in immunosuppressed transplant recipients; the introduction of new immunosuppressive strategies is expected to extend significantly allograft survival. The inclusion of older recipients in transplant programs will also likely increase this problem. Thus, cancer may represent a serious cause of morbidity and mortality in patients otherwise successfully treated by organ transplantation. Nevertheless, effective approaches to deal with malignancies in immunosuppressed patients are still far from the clinical arena. Therefore, once cancer occurs in a transplant recipient, clinicians only have two options: to reduce or withdraw the immunosuppression eventually causing acute or chronic allograft rejection, or to continue the standard immunosuppressive therapy while beginning specific therapy for the malignancy. Several clinical studies suggest that the use of immunosuppressive drugs may result in increased cancer incidence, in transplant as well as autoimmune disease patients. This clinical observation is supported by experimental data showing that these drugs enhance cancer cell growth characteristics and inhibit DNA repair mechanisms, clearly suggesting that the increased incidence of neoplastic disease in patients treated with several immunosuppressive drugs is at least partially independent of their immunosuppressive action. In this scenario it is of particular interest the fact that some immunosuppressive drugs have both an anti-rejection and anti-neoplastic activity. In this review we focus our attention on this potential dual role of immunosuppressive therapy in the development of neoplasia in transplanted patients.
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Inmunosupresores/uso terapéutico , Trasplante de Riñón , Neoplasias/inducido químicamente , Neoplasias/prevención & control , Complicaciones Posoperatorias/inducido químicamente , Complicaciones Posoperatorias/prevención & control , Humanos , Inmunosupresores/efectos adversosRESUMEN
The objective of the present study was to determine whether the intima-media thickness (IMT) is independently related with obesity, and central fat accumulation in healthy subjects. Common carotid artery IMT, parameters of body fat accumulation and distribution (body mass index, waist circumference, waist-to-hip ratio), blood pressure levels, and circulating fasting insulin, glucose, and lipid (cholesterol, HDL-cholesterol, triglycerides, LDL-cholesterol) levels were determined in a population of non-diabetic normal weight and obese subjects. Smoking habits (packs-years) were also taken into account. 239 healthy subjects (143 women and 96 men), with age ranging between 18 and 45 years, were enrolled into the study. They were divided indo two groups according to the body mass index (BMI), obese (132 subjects, 77 woman and 55 men, with BMI greater than 27.0) and controls (107 subjects: 66 women and 41 men, with BMI lower than 27.0). Common carotid artery intima-media thickness was measured by B-mode ultrasound imaging. Fasting plasma metabolic parameters (glucose and lipids) and insulin levels were determined by enzymatic and radioimmunological assays, respectively. Insulin sensitivity was estimated by insulin tolerance test (ITT) and the rate constant for plasma glucose disappearance (KITT) during the 3- to 15-min period following the regular insulin injection was taken as a measure of in vivo insulin action. Obese patients showed higher IMT than controls, and IMT was significantly associated with BMI in the whole population (r = 0.316, p < 0.001). Age (r = 0.327, p < 0.001), KITT (r = -0.201, p < 0.01), fasting blood glucose (r = 0.187, p < 0.01), LDL-chol (r = 0.201, p < 0.01), smoking (r = 0.147, p < 0.05), MBP levels (r = 0.154, p < 0.05), cholesterol (r = 0.152, p < 0.05) and HDL-chol (r = -0.159, p < 0.05) were also significantly associated with IMT. Age (r = 0.330, p < 0.05), BMI (r = 0.299, p < 0.01), waist (r = 0.312, p < 0.001), WHR (r = 0.266, p < 0.001) and KITT (r = -0.259, p < 0.01) were the parameters most strongly correlated with IMT in women, and age (r = 0.324, p < 0.001), BMI (r = 0.338, p < 0.001) waist (r = 0.325, p < 0.001) and LDL-chol (r = 0.283, p < 0.01) where the parameters most strongly correlated with IMT in men. When a stepwise multiple regression analysis was performed for the whole population, only age (p < 0.001) and BMI (p < 0.001) maintained a significant positive relationship with IMT. When a stepwise multiple regression analysis was performed separately for men and women, BMI or waist circumference or WHR were alternatively entered into the model; interestingly, only age, BMI and waist were still significantly correlated with IMT, whereas WHR did not maintain a significant correlation with IMT. In conclusion, BMI and waist circumference, but not WHR, are strongly and independently associated with the IMT of common carotid artery. These results suggests that central fat accumulation may accelerate the development of earlier clinically silent stages of atherosclerosis, thus possibly explaining the higher prevalence of cardiovascular diseases in patients with abdominal obesity.
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Traumatismos de las Arterias Carótidas/etiología , Traumatismos de las Arterias Carótidas/patología , Arteria Carótida Común/patología , Obesidad/complicaciones , Adolescente , Adulto , Femenino , Humanos , Masculino , Microcirculación/patología , Persona de Mediana Edad , Obesidad/patología , Factores de Riesgo , Túnica Íntima/patologíaRESUMEN
Pseudouridine is a modified nucleoside derived from RNA catabolism; the concentration of this nucleoside is elevated in body fluids of both tumour-bearing and human immunodeficiency virus (HIV) infected patients. We used an HPLC procedure to evaluate the serum pseudouridine concentration in patients with chronic hepatitis C in an attempt to determine whether the nucleoside serum concentration was related to the response to alpha-interferon treatment. We found that: a) pseudouridine serum concentration was increased significantly in 76% (29/39) of patients with chronic hepatitis C at the time of diagnosis and before any therapeutic treatment; b) pseudouridine excretion was higher in patients affected by chronic hepatitis C with cirrhosis; c) there was a positive correlation between response to therapy and pseudouridine serum concentration in patients undergoing treatment with alpha-interferon; d) during one year of alpha-interferon treatment, the pseudouridine serum concentration remained within the normal range in responder patients. These results indicate that serum pseudouridine might be useful as a valuable biochemical marker with which to monitor chronic hepatitis C patients treated with alpha-interferon.