Manifold Learning Approach for Chaos in the Dripping Faucet

Dripping water from a faucet is a typical example exhibiting rich nonlinear phenomena. For such a system, the time stamps at which water drops separate from the faucet can be directly observed in real experiments, and the time series of intervals \tau_n between drop separations becomes a subject of analysis. Even if the mass m_n of a drop at the onset of the n-th separation, which cannot be observed directly, exhibits perfectly deterministic dynamics, it sometimes fails to obtain important information from time series of \tau_n. This is because the return plot \tau_n-1 vs. \tau_n may become a multi-valued function, i.e., not a deterministic dynamical system. In this paper, we propose a method to construct a nonlinear coordinate which provides a "surrogate" of the internal state m_n from the time series of \tau_n. Here, a key of the proposed approach is to use ISOMAP, which is a well-known method of manifold learning. We first apply it to the time series of $\tau_n$ generated from the numerical simulation of a phenomenological mass-spring model for the dripping faucet system. It is shown that a clear one-dimensional map is obtained by the proposed approach, whose characteristic quantities such as the Lyapunov exponent, the topological entropy, and the time correlation function coincide with the original dripping faucet system. Furthermore, we also analyze data obtained from real dripping faucet experiments which also provides promising results.Comment: 9 pages, 10 figure

Salted Radish Root Biology during Food Processing

White radish root (daikon) is an important vegetable in Japanese food culture and has spawned the development of various cooking and processing methods. takuan-zuke is the major processed food derived from daikon. Takuan-zuke is prepared by the dehydration of the root using a salt-press or a weighted stone, or by sun-drying, followed by salt-aging using salt or salted rice bran. The color of takuan-zuke changes to yellow during salt-aging. We determined the effects of dehydration and salt-aging on the metabolism of daikon using takuan-zuke. In the yellowing reaction, the generation of daikon isothiocyanate was significant, requiring a temperature of ≥10°C and pH ≥5. The color change of the sun-dried takuan-zuke was the most significant. Moreover, we investigated the nutritional characteristics of takuan-zuke. In the sun-dried daikon, metabolism progressed for 3 weeks during drying, with increase in the concentrations of γ-aminobutyric acid (GABA) and proline as well as drying stress metabolites. In the salt-pressed daikon, GABA concentrations temporarily increased due to osmotic stress but then decreased on metabolic inhibition by salt permeation. In addition, no change in the concentration of proline was observed under salt-press conditions. The results showed a marked difference between the stress response of the living and processed root

Premorbid Clinical Frailty Score and 30‐day mortality among older adults in the emergency department

Objectives: The association between frailty and short-term prognosis has not been established in critically ill older adults presenting to the emergency department. We sought to examine the association between premorbid frailty and 30-day mortality in this patient population. Methods: This is a retrospective observational study on older adults aged over 75 who were triaged as Level 1 resuscitation with subsequent admissions to intermediate units or intensive care units (ICUs) in a single critical care center, from January to December 2019. We excluded patients with out-of-hospital cardiac arrest or those transferred from other hospitals. Frailty was evaluated by the Clinical Frailty Scale (CFS) from the patients' chart reviews. The primary outcome was 30-day mortality, and we examined the association between frailty scored on the CFS and 30-day mortality using a multivariable logistic regression model with CFS 1-4 as a reference. Results: A total of 544 patients, median age: 82 years (interquartile rang 78 to 87), were included in the study. Of these, 29% were in shock and 33% were in respiratory failure. The overall 30-day mortality was 15.1%. The adjusted risk difference (95% confidence interval [CI]) in mortality for CFS 5, CFS 6, and CFS 7-9 was 6.3% (-3.4 to 15.9), 11.2% (0.4 to 22.0), and 17.7% (5.3 to 30.1), respectively; and the adjusted risk ratio (95% CI) was 1.45 (0.87 to 2.41), 1.85 (1.13 to 3.03), and 2.44 (1.50 to 3.96), respectively. Conclusion: The risk of 30-day mortality increased as frailty advanced in critically ill older adults. Given this high risk of short-term outcomes, ED clinicians should consider goals of care conversations carefully to avoid unwanted medical care for these patients