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Variability + Entropy

Kirsty Y Wan, Raymond E Goldstein
Active living organisms exhibit behavioral variability, partitioning between fast and slow dynamics. Such variability may be key to generating rapid responses in a heterogeneous, unpredictable environment wherein cellular activity effects continual exchanges of energy fluxes. We demonstrate a novel, noninvasive strategy for revealing nonequilibrium control of swimming-specifically, in an octoflagellate microalga. These organisms exhibit surprising features of flagellar excitability and mechanosensitivity, which characterize a novel, time-irreversible "run-stop-shock" motility comprising forward runs, knee-jerk shocks with dramatic beat reversal, and long stops during which cells are quiescent yet continue to exhibit submicron flagellar vibrations...
August 3, 2018: Physical Review Letters
Daniela Bassi, Ramona Cabiddu, Renata G Mendes, Natália Tossini, Vivian M Arakelian, Flávia C R Caruso, José C Bonjorno Júnior, Ross Arena, Audrey Borghi-Silva
BACKGROUND: Type 2 diabetes Mellitus (T2DM) is associated with cardiac autonomic dysfunction, which is an independent predictor of mortality in chronic diseases. However, whether the coexistence of systemic arterial hypertension (HTN) with DMT2 alters cardiac autonomic modulation remains unknown. OBJECTIVE: To evaluate the influence of HTN on cardiac autonomic modulation and cardiorespiratory fitness in subjects with DMT2. METHODS: 60 patients of both genders were evaluated and allocated to two groups: DMT2 patients (n = 32; 51 ± 7...
July 2018: Arquivos Brasileiros de Cardiologia
Alicja Płuciennik, Michał Stolarczyk, Maria Bzówka, Agata Raczyńska, Tomasz Magdziarz, Artur Góra
BACKGROUND: Here, we present an R package for entropy/variability analysis that facilitates prompt and convenient data extraction, manipulation and visualization of protein features from multiple sequence alignments. BALCONY can work with residues dispersed across a protein sequence and map them on the corresponding alignment of homologous protein sequences. Additionally, it provides several entropy and variability scores that indicate the conservation of each residue. RESULTS: Our package allows the user to visualize evolutionary variability by locating the positions most likely to vary and to assess mutation candidates in protein engineering...
August 14, 2018: BMC Bioinformatics
David C Buitenweg, Ilja L Bongers, Dike van de Mheen, Hans A M van Oers, Chijs van Nieuwenhuizen
PURPOSE: Quality of life (QoL) is a broad outcome that is often used to assess the impact of treatment and care interventions in mental health services. QoL, however, is known to be influenced by individual values and preferences. To investigate this heterogeneity on the individual level, this study aimed to distinguish classes with distinct QoL profiles in a broad group of people with severe mental health problems and to identify the QoL domains that are most strongly related to the classes...
August 13, 2018: Quality of Life Research
Sikander Ali
In the present study, fungal biotransformation of synthetic levodopa to stable dopamine in an l-ascorbate-mediated thermophilic-aerobic biochemical reaction was investigated. A mutant strain of Aspergillus oryzae EMS-6 was used for the preparation of mycelial biomass. The mutant was previously developed through EMS-induced mutagenesis and repressed against l-cysteine HCl. Growth parameters such as rate of cultivation (48 h), initial pH (6) and incubation temperature (30 °C) supported 18.84 g/l biomass with 23 g/l glucose consumption...
August 2018: 3 Biotech
Darlene Lu, Yorghos Tripodis, Louis Gerstenfeld, Serkalem Demissie
Motivation: Clustering algorithms like K-Means and standard Gaussian mixture models (GMM) fail to account for the structure of variability of replicated data or repeated measures over time. Additionally, a priori cluster number assumptions add an additional complexity to the process. Current methods to optimize cluster labels and number can be inaccurate or computationally intensive for temporal gene expression data with this additional variability. Results: An extension to a model-based clustering algorithm is proposed using mixtures of mixed effects polynomial regression models and the EM algorithm with an entropy penalized log-likelihood function (EPEM)...
August 8, 2018: Bioinformatics
Frederick Schneider, Jan Martin, Gerhard Schneider, Christian M Schulz
BACKGROUND: Excessive workload may impair patient safety. However, little is known about emergency care providers' workload during the treatment of life-threatening cases including cardiopulmonary resuscitation (CPR). Therefore, we tested the hypothesis that subjective and physiological indicators of workload are associated with the patient's initial NACA score and that workload is particularly high during CPR. METHODS: NASA task load index (NASA-tlx) and alarm codes were obtained for 216 sorties of pre-hospital emergency medical care...
2018: PloS One
Federica Mura, Grzegorz Gradziuk, Chase P Broedersz
Measuring and quantifying nonequilibrium dynamics in active biological systems is a major challenge because of their intrinsic stochastic nature and the limited number of variables accessible in any real experiment. We investigate what nonequilibrium information can be extracted from noninvasive measurements using a stochastic model of soft elastic networks with a heterogeneous distribution of activities, representing enzymatic force generation. In particular, we use this model to study how the nonequilibrium activity, detected by tracking two probes in the network, scales as a function of the distance between the probes...
July 20, 2018: Physical Review Letters
Huiyan Yu, Changkui Sun, Wendong Liu, Zhifeng Li, Zhongming Tan, Xiaochen Wang, Jianli Hu, Shanqiu Shi, Changjun Bao
BACKGROUND: With the increasing incidence of scrub typhus in recent years, it is of great value to analyse the spatial and temporal distribution of scrub typhus by applying micro-geographical studies at a reasonably fine scale, and to guide the control and management. METHODS: We explored the use of maximum entropy modelling method to confirm the spatial and temporal distribution of scrub typhus according to the occurrence locations of human cases in Jiangsu Province...
August 6, 2018: BMC Infectious Diseases
Harpuneet Kaur, B K Sawhney, S K Jawandha
Maturity is the key factor which determines the storage life and ripening quality of fruits. In order to provide marketing flexibility and to guarantee the acceptable eating quality to the buyer it is very critical to determine the right maturity stage. Maturity indices are also important for trade regulation, marketing strategy and for the efficient use of labor and resources. The proposed system is based on implementation of image processing techniques on the JPEG images of different maturity stages of the plum variety 'Satluj Purple' grown under sub-tropical conditions...
August 2018: Journal of Food Science and Technology
Chih-Hao Chen, Sung-Chun Tang, Ding-Yuan Lee, Jiann-Shing Shieh, Dar-Ming Lai, An-Yu Wu, Jiann-Shing Jeng
Acute stroke commonly affects cardiac autonomic responses resulting in reduced heart rate variability (HRV). Multiscale entropy (MSE) is a novel non-linear method to quantify the complexity of HRV. This study investigated the influence of intracerebral hemorrhage (ICH) locations and intraventricular hemorrhage (IVH) on the complexity of HRV. We recruited 93 supratentorial ICH patients (male 59%, mean age 61 years), and the locations of ICH included basal ganglia (n = 40), thalamus (n = 35), and lobar (n = 18) group...
July 31, 2018: Scientific Reports
Daniele De Martino, Anna Mc Andersson, Tobias Bergmiller, Călin C Guet, Gašper Tkačik
Which properties of metabolic networks can be derived solely from stoichiometry? Predictive results have been obtained by flux balance analysis (FBA), by postulating that cells set metabolic fluxes to maximize growth rate. Here we consider a generalization of FBA to single-cell level using maximum entropy modeling, which we extend and test experimentally. Specifically, we define for Escherichia coli metabolism a flux distribution that yields the experimental growth rate: the model, containing FBA as a limit, provides a better match to measured fluxes and it makes a wide range of predictions: on flux variability, regulation, and correlations; on the relative importance of stoichiometry vs...
July 30, 2018: Nature Communications
Everton Falcão de Oliveira, Eunice Aparecida Bianchi Galati, Alessandra Gutierrez de Oliveira, Elizabeth Ferreira Rangel, Bruno Moreira de Carvalho
In some transmission foci of Leishmania infantum in Brazil, Lutzomyia cruzi could be considered the main vector of this pathogen. In addition, L. cruzi is a permissive vector of L. amazonensis. Its geographical distribution seems to be restricted and limited to Cerrado and Pantanal biomes, which includes some areas in Brazil and Bolivia. Considering that predicting the distribution of the species involved in transmission cycles is an effective approach for assessing human disease risk, this study aims to predict the spatial distribution of L...
July 2018: PLoS Neglected Tropical Diseases
Ai Ping Zhang, Yi Wang, Qin Li Xiong, Xiao Gang Wu, Xiao Ming Sun, Yan Meng Huang, Lin Zhang, Kai Wen Pan
Based on the current distribution information and 19 environmental variables data, we used the maximum entropy model to simulate the suitable distribution of Picea likiangensis var. likiangensis, P. purpurea and P. wilsonii in the last interglacial, Last Glacial Maximum, Mid- Holocene and present. The results from such modelling were validated by pollen data. We analyzed the relationship between species distribution dynamics and climate change, and then speculated the cryptic refugia of those species. Both the areas under the receiver operating characteristic curves and the verification results from pollen data indicated high accuracy of the model results...
July 2018: Ying Yong Sheng Tai Xue Bao, the Journal of Applied Ecology
E L Estallo, F Sangermano, M Grech, F Ludueña-Almeida, M Frías-Cespedes, M Ainete, W Almirón, T Livdahl
Aedes aegypti (Diptera: Culicidae) is an urban mosquito involved in the transmission of numerous viruses, including dengue, chikungunya and Zika. In Argentina, Ae. aegypti is the main vector of dengue virus and has been involved in several outbreaks in regions ranging from northern to central Argentina since 2009. In order to evaluate areas of potential vector-borne disease transmission in the city of Córdoba, Argentina, the present study aimed to identify the environmental, socioeconomic and demographic factors driving the distribution of Ae...
July 20, 2018: Medical and Veterinary Entomology
Elaine Aparecida de Oliveira, Anne Kastelianne França da Silva, Diego Giuliano Destro Christofaro, Laís Manata Vanzella, Rayana Loch Gomes, Franciele Marques Vanderlei, Luiz Carlos Marques Vanderlei
BACKGROUND: Type 1 diabetes mellitus can cause autonomic changes, which can be assessed by heart rate variability. Among the heart rate variability assessment methods, the symbolic analysis and Shannon entropy, based on the Chaotic dynamics, have gained prominence. OBJECTIVE: To compare heart rate variability indexes, obtained through symbolic analysis and Shannon entropy, in young adults with type 1 diabetes mellitus and healthy young individuals, associated with the analysis of linear indexes; and to verify if there are associations between the indexes obtained by the symbolic analysis and by Shannon entropy and linear indexes in diabetic individuals...
July 16, 2018: Arquivos Brasileiros de Cardiologia
Xu Duan, Joohyun Rhee, Ranjana K Mehta, Divya Srinivasan
Obesity rates in the geriatric population have emerged as a serious health concern in recent decades. Yet, obesity-related differences in neuromuscular performance and motor control during fatiguing tasks, and how they are modified by gender, specifically among older adults, are still largely unexplored. The first aim of this study was to understand obesity and gender-related differences in endurance time among older adults. Motor variability has been linked with inter-individual differences in the rate of fatigue development, and as potentially revealing underlying mechanisms of neuromuscular control...
2018: Frontiers in Physiology
Anupam K Gupta, Dane Webster, Rolf Müller
Echolocating bats use ultrasonic pulses to collect information about their environments. Some of this information is encoded at the baffle structures-noseleaves (emission) and pinnae (reception)-that act as interfaces between the bats' biosonar systems and the external world. The baffle beam patterns encode the direction-dependent sensory information as a function of frequency and hence represent a view of the environment. To generate diverse views of the environment, the bats can vary beam patterns by changes to (1) the wavelengths of the pulses or (2) the baffle geometries...
June 2018: Physical Review. E
Congjie Ou, Sumiyoshi Abe
Several years ago, it had been discussed that nonlogarithmic entropies, such as the Tsallis q-entropy cannot be applied to systems with continuous variables. Now, in their recent paper [Phys. Rev. E 97, 012104 (2018)10.1103/PhysRevE.97.012104], Oikonomou and Bagci have modified the form of the q-entropy for discrete variables in such a way that its continuum limit exists. Here, it is shown that this modification violates the expandability property of entropy, and their work is actually supporting evidence for the absence of the q-entropy for systems with continuous variables...
June 2018: Physical Review. E
Evan Lowry, Mohammad Piri
It is well accepted that nanopore size is a controlling parameter in determining the phase behavior of confined adsorbate molecules. Despite this knowledge, the quantitative effect of surface chemistry on the confined phase behavior is a factor that remains obfuscated. Obtaining a complete understanding of the variables controlling confined phase behavior is a critical step in developing more complete equations of state for predictive modeling. To this end, a combined experimental and molecular modeling study was conducted to investigate the effects of surface chemistry and wetting on the confined phase behavior of propane and n-butane in modified and unmodified silica MCM-41...
July 30, 2018: Langmuir: the ACS Journal of Surfaces and Colloids
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