A possible method to solve the sign problem is developed by modifying the original theory. Considering several modifications of the partition function, the observable in the original theory is ...reconstructed from the identity connecting the observables in the original and modified theories. We demonstrate that our method gives the correct results, even if the original theory has the severe sign problem, by using a simple one-dimensional integral.
We develop a way of improving complex Langevin dynamics motivated by the Lefschetz-thimble decomposition of integrals. In our method, arbitrary observables of an original model with multiple ...Lefschetz thimbles are computed by a modified model with a single thimble. We apply our modification method to a one-dimensional integral in which the naive implementation of the complex Langevin dynamics fails to reproduce the exact results due to the severe sign problem. We show that the toy model can be modified so that the new model consists of a single Lefschetz thimble. We find that correct results can be obtained by the improved complex Langevin dynamics.
Our decisions often balance what we observe and what we desire. A prime candidate for implementing this complex balancing act is the basal ganglia pathway, but its roles have not yet been examined ...experimentally in detail. Here, we show that a major input station of the basal ganglia, the caudate nucleus, plays a causal role in integrating uncertain visual evidence and reward context to guide adaptive decision-making. In monkeys making saccadic decisions based on motion cues and asymmetric reward-choice associations, single caudate neurons encoded both sources of information. Electrical microstimulation at caudate sites during motion viewing affected the monkeys' decisions. These microstimulation effects included coordinated changes in multiple computational components of the decision process that mimicked the monkeys' similarly coordinated voluntary strategies for balancing visual and reward information. These results imply that the caudate nucleus plays causal roles in coordinating decision processes that balance external evidence and internal preferences.
Background:Although anticoagulation is the key treatment to prevent stroke in patients with atrial fibrillation (AF), including elderly patients, anticoagulation is sometimes withheld for elderly ...people because of concerns about frailty. However, it remains unknown whether frailty increases bleeding events.Methods and Results:A total of 120 consecutive non-valvular AF patients admitted with symptoms of AF or congestive heart failure were included in this study. Frailty was assessed using the Cardiovascular Health Study (CHS) frailty index. We performed a retrospective analysis of the risk factors associated with major bleeding events. After a median follow-up of 518 days, major bleeding events occurred in 17 (14.2%) patients. Patients with major bleeding events had a higher CHS frailty index (P=0.015). The cutoff value for high-risk CHS frailty index was 2 (area under the ROC curve: 0.68 95% confidence interval (CI): 0.57–0.78). The event-free rates at 2 years were 97.6% (95% CI: 83.9–99.7) in patients with a CHS frailty index <2 and 59.6% (95% CI: 27.9–81.0) for those with a CHS frailty index ≥2 (P<0.001).Conclusions:Frailty is associated with increased bleeding events related to anticoagulant therapy in patients previously hospitalized with AF. Greater care should be taken with patients with a CHS frailty index ≥2.
The use of left ventricular mechanical dyssynchrony (LVMD), which has been reported to be responsible for unfavorable outcomes, might improve conventional risk-stratification by clinical indices ...including QRS duration (QRSd) and systolic dysfunction in patients with heart failure (HF).
Following measurements of 12-lead QRSd and left ventricular ejection fraction (LVEF), three-dimensional (3-D) LVMD was evaluated as a standard deviation (phase SD) of regional mechanical systolic phase angles by gated myocardial perfusion imaging in 829 HF patients. Patients were followed up for a mean period of 37 months with a primary endpoint of lethal cardiac events (CEs). In an overall multivariate Cox proportional hazards model, phase SDs were identified as significant prognostic determinants independently. The patients were divided into 4 groups by combining with the cut-off values of LVEF (35% and 50%) and QRSd (130 ms and 150 ms). The groups with lower LVEF and prolonged QRSd more frequently had CEs than did the other groups. Patient groups with LVEF < 35% and with 35% ≦ LVEF < 50% were differentiated into low-risk and high-risk categories by using an optimal phase SD cut-off value of both QRSd thresholds.
3-D LVMD can risk-stratify HF patients with mid-range as well as severe abnormalities of QRSd and systolic dysfunction.
The division of labor between the dorsal and ventral visual pathways has been well studied, but not often with direct comparison at the single-neuron resolution with matched stimuli. Here we directly ...compared how single neurons in MT and V4, mid-tier areas of the two pathways, process binocular disparity, a powerful cue for 3D perception and actions. We found that MT neurons transmitted disparity signals more quickly and robustly, whereas V4 or its upstream neurons transformed the signals into sophisticated representations more prominently. Therefore, signaling speed and robustness were traded for transformation between the dorsal and ventral pathways. The key factor in this tradeoff was disparity-tuning shape: V4 neurons had more even-symmetric tuning than MT neurons. Moreover, the tuning symmetry predicted the degree of signal transformation across neurons similarly within each area, implying a general role of tuning symmetry in the stereoscopic processing by the two pathways.
Binocular disparity is detected in the primary visual cortex by a process similar to calculation of local cross-correlation between left and right retinal images. As a consequence, correlation-based ...neural signals convey information about false disparities as well as the true disparity. The false responses in the initial disparity detectors are eliminated at later stages in order to encode only disparities of the features correctly matched between the two eyes. For a simple stimulus configuration, a feed-forward nonlinear process can transform the correlation signal into the match signal. For human observers, depth judgement is determined by a weighted sum of the correlation and match signals rather than depending solely on the latter. The relative weight changes with spatial and temporal parameters of the stimuli, allowing adaptive recruitment of the two computations under different visual circumstances. A full transformation from correlation-based to match-based representation occurs at the neuronal population level in cortical area V4 and manifests in single-neuron responses of inferior temporal and posterior parietal cortices. Neurons in area V5/MT represent disparity in a manner intermediate between the correlation and match signals. We propose that the correlation and match signals in these areas contribute to depth perception in a weighted, parallel manner.
This article is part of the themed issue ‘Vision in our three-dimensional world’.
Although it is known that assessment and management of the nutritional status of patients are important for treatment of patients with heart failure (HF), there are currently no established ...indicators. Therefore, we investigated the effects of nutritional parameters as well as conventional parameters on the prognosis of HF patients. A total of 1954 consecutive HF patients with left ventricular ejection fraction (LVEF) less than 50% were enrolled in this study. Transthoracic echocardiography was performed and conventional parameters for HF patients and parameters to assess nutritional status were measured in all patients. Patients were followed up with a primary endpoint of lethal cardiac events (CEs) for 30.2 months. During the follow-up period, cardiac events were documented in 619 HF patients. The CEs group had a lower level of cholinesterase (201.5U/L vs 265.2U/L, P <0.0001), lower estimated GFR (35.2 ml/min/1.73m2 vs 50.3ml/min/1.73m2, P< 0.0001), and lower Geriatric Nutritional Risk Index (GNRI) (91.9 vs 100.0, P< 0.0001) than those in the non-CEs group. Serum cholinesterase, estimated GFR, and GNRI were identified as significant prognostic determinants in multivariate analysis. ROC analyses revealed cut-off values of serum cholinesterase, estimated GFR, and GNRI of 229U/L, 34.2 ml/min/1.73m2, and 95.6, respectively, for identifying high-risk HF patients. HF patients with serum cholinesterase< 229U/L, estimated GFR<34.3 ml/min/1.73m2, and GNRI< 95.6 had a significantly greater rate of CEs than that in the other patients (P<0.0001). Low serum cholinesterase and low GNRI can predict cardiac mortality risk in systolic HF patients with renal dysfunction.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
An acrylic block copolymer system is a promising candidate for the functional adhesives bearing good weatherability as well as high transparency. Coated layers of the acrylic block copolymers were ...prepared by the solution coating method using a polymethylmethacrylate-block-poly(n-butylacrylate)-block-polymethylmethacrylate triblock copolymer (MAM) and a polymethylmethacrylate-block-poly(n-butylacrylate) diblock copolymer (MA). The thickness of the prepared specimens was 50 μm, which is typical of the pressure-sensitive adhesives. Atomic force microscope (AFM) observations and two-dimensional small-angle X-ray scattering (2d-SAXS) measurements were performed to analyze the nano structures and to discuss the effects of the drying temperature on the nano structures. Note that better physical properties were obtained in the specimen prepared at the lower drying temperature. The AFM observations revealed cylindrical morphology for the annealed MAM neat specimen. On the other hand, the 2d-SAXS measurements revealed spherical morphology for all of the specimens including MAM neat and MA/MAM blends. The effects of the drying temperature on the ordering regularity of spheres, d spacing, and radius of sphere has been examined quantitatively. It was found that the ordering regularity of spheres was more improved for the higher drying temperature. As for the behaviors of d and R, the experimental results exhibited very complicated behaviors as a function of the drying temperature. Namely, d and R increased as a function of the drying temperature, which is completely opposite to the general behaviors of the block copolymer microdomain structure as d or R ∝ T−1/3 for the upper critical solution temperature system where the interaction between two kinds of the constituent block chains is decreased with an increase in temperature. The effect of structure freezing during the solvent evaporation was taken into account and such complicated behaviors of experimental results (d and R) could be almost perfectly explained. It is concluded by this study that the poor regularity of the sphere ordering provides softer property with larger elongation at break for the coated film, which is more suitable as the pressure-sensitive adhesives.
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•The coated layers of the acrylic block copolymers were prepared by the solution coating method.•A lower drying temperature in the solution coating provides better mechanical properties for the pressure-sensitive adhesive, while it gives poorer ordering regularity of spherical microdomains, as revealed by small-angle X-ray scattering.•The poor regularity of the sphere ordering provides softer property with larger elongation at break for the coated film, which is suitable for the pressure-sensitive adhesive.•The effect of structure freezing during the solvent evaporation was taken into account and complicated behaviors of experimental results (d spacing and radius of sphere) could be almost perfectly explained.
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