scholarly journals Increased ventilatory variability and complexity in patients with hyperventilation disorder

2016 ◽  
Vol 120 (10) ◽  
pp. 1165-1172 ◽  
Author(s):  
Plamen Bokov ◽  
Marie-Noëlle Fiamma ◽  
Brigitte Chevalier-Bidaud ◽  
Cécile Chenivesse ◽  
Christian Straus ◽  
...  
Keyword(s):  
Breathing Pattern ◽  
Respiratory Control ◽  
Cardiopulmonary Exercise Test ◽  
Negative Slope ◽  
Probability Density Distribution ◽  
Nonnormal Distribution ◽  
Dysfunctional Breathing ◽  
The Stability ◽  
Ventilation Coefficient ◽  
The Relationship

It has been hypothesized that hyperventilation disorders could be characterized by an abnormal ventilatory control leading to enhanced variability of resting ventilation. The variability of tidal volume (VT) often depicts a nonnormal distribution that can be described by the negative slope characterizing augmented breaths formed by the relationship between the probability density distribution of VT and VT on a log-log scale. The objectives of this study were to describe the variability of resting ventilation [coefficient of variation (CV) of VT and slope], the stability in respiratory control (loop, controller and plant gains characterizing ventilatory-chemoresponsiveness interactions) and the chaotic-like dynamics (embedding dimension, Kappa values characterizing complexity) of resting ventilation in patients with a well-defined dysfunctional breathing pattern characterized by air hunger and constantly decreased PaCO2 during a cardiopulmonary exercise test. Compared with 14 healthy subjects with similar anthropometrics, 23 patients with hyperventilation were characterized by increased variability of resting tidal ventilation (CV of VT median [interquartile]: 26% [19-35] vs. 36% [28–48], P = 0.020; slope: −6.63 [−7.65; −5.36] vs. −3.88 [−5.91; −2.66], P = 0.004) that was not related to increased chemical drive (loop gain: 0.051 [0.039–0.221] vs. 0.044 [0.012–0.087], P = 0.149) but that was related to an increased ventilatory complexity (Kappa values, P < 0.05). Plant gain was decreased in patients and correlated with complexity (with Kappa 5 − degree 5: Rho = −0.48, P = 0.006). In conclusion, well-defined patients suffering from hyperventilation disorder are characterized by increased variability of their resting ventilation due to increased ventilatory complexity with stable ventilatory-chemoresponsiveness interactions.

scholarly journals The effect of seizure spread to the amygdala on respiration and onset of ictal central apnea

2020 ◽  
Vol 132 (5) ◽  
pp. 1313-1323 ◽  
Author(s):  
William P. Nobis ◽  
Karina A. González Otárula ◽  
Jessica W. Templer ◽  
Elizabeth E. Gerard ◽  
Stephen VanHaerents ◽  
...  
Keyword(s):  
Respiratory Depression ◽  
Respiratory Control ◽  
Brain Regions ◽  
Pathophysiological Mechanism ◽  
Central Apnea ◽  
Unexpected Death ◽  
Respiratory Dysfunction ◽  
Highly Correlated ◽  
Dysfunctional Breathing ◽  
The Relationship

OBJECTIVESudden unexpected death in epilepsy (SUDEP) is the leading cause of death for patients with refractory epilepsy, and there is increasing evidence for a centrally mediated respiratory depression as a pathophysiological mechanism. The brain regions responsible for a seizure’s inducing respiratory depression are unclear—the respiratory nuclei in the brainstem are thought to be involved, but involvement of forebrain structures is not yet understood. The aim of this study was to analyze intracranial EEGs in combination with the results of respiratory monitoring to investigate the relationship between seizure spread to specific mesial temporal brain regions and the onset of respiratory dysfunction and apnea.METHODSThe authors reviewed all invasive electroencephalographic studies performed at Northwestern Memorial Hospital (Chicago) since 2010 to identify those cases in which 1) multiple mesial temporal electrodes (amygdala and hippocampal) were placed, 2) seizures were captured, and 3) patients’ respiration was monitored. They identified 8 investigations meeting these criteria in patients with temporal lobe epilepsy, and these investigations yielded data on a total of 22 seizures for analysis.RESULTSThe onset of ictal apnea associated with each seizure was highly correlated with seizure spread to the amygdala. Onset of apnea occurred 2.7 ± 0.4 (mean ± SEM) seconds after the spread of the seizure to the amygdala, which was significantly earlier than after spread to the hippocampus (10.2 ± 0.7 seconds; p < 0.01).CONCLUSIONSThe findings suggest that activation of amygdalar networks is correlated with central apnea during seizures. This study builds on the authors’ prior work that demonstrates a role for the amygdala in voluntary respiratory control and suggests a further role in dysfunctional breathing states seen during seizures, with implications for SUDEP pathophysiology.

scholarly journals Minute-Ventilation Variability During Cardiopulmonary Exercise Test Is Higher In Idiopathic Dyspnoea Subjects Compared To Subjects With Breathing Pattern Disorder.

2021 ◽  
Author(s):  
Andrew Eaton
Keyword(s):  
Time Domain ◽  
Exercise Test ◽  
Breathing Pattern ◽  
Ventilatory Threshold ◽  
Minute Ventilation ◽  
Cardiopulmonary Exercise Test ◽  
Cardiopulmonary Exercise ◽  
Abnormal Breathing ◽  
Dysfunctional Breathing

Abstract Background: Patients with abnormal breathing responses often report presenting with debilitating symptoms that negatively impact both physical and mental quality of life.Objective: To compare time-domain variability of ventilatory components of Idiopathic dyspnoea and Breathing Pattern Disorder during a progressive maximal exercise test, evaluating their relationship to other variables usually obtained during a cardiopulmonary exercise test.Methods: Analysis of time-domain variability (RMSSD) of minute-ventilation (VE) during a maximal cardiopulmonary exercise test of 13 subjects with Idiopathic dyspnoea and 13 subjects with dysfunctional breathing pattern. Data was compared by a two-tailed Student T-test.Results: Idiopathic dyspnoea subjects exhibited a greater Minute-Ventilation Variability (31.5 ± 6.2 Vs 25.4 l/min ± 8.0, p >0.05). Inspiratory tidal volume time ratio (VTin/ti) (1.96 ± 0.7 Vs 2.58 ± 0.6, p >0.05) and Breathing Frequency (35 ± 9.3 Vs 43 breath/min ± 8.2 p >0.05) were also significantly lower in Idiopathic Dyspnoea compared to Breathing Pattern Disorder subjects.Conclusions: Time-domain variability of minute ventilation during exercise is greater in Idiopathic Dyspnoea compared to the Breathing Pattern Disorder subject’s possible highlighting a lower ventilatory threshold.

Irregularities and power law distributions in the breathing pattern in preterm and term infants

1998 ◽  
Vol 85 (3) ◽  
pp. 789-797 ◽  
Author(s):  
U. Frey ◽  
M. Silverman ◽  
A. L. Barabási ◽  
B. Suki
Keyword(s):  
Power Law ◽  
Critical Region ◽  
Breathing Pattern ◽  
Respiratory Control ◽  
Probability Density Distribution ◽  
Time Interval ◽  
Paired Data ◽  
Term Infants ◽  
Young Infants ◽  
Postconceptional Age

Unlike older children, young infants are prone to develop unstable respiratory patterns, suggesting important differences in their control of breathing. We examined the irregular breathing pattern in infants by measuring the time interval between breaths (“interbreath interval”; IBI) assessed from abdominal movement during 2 h of sleep in 25 preterm infants at a postconceptional age of 40.5 ± 5.2 (SD) wk and in 14 term healthy infants at a postnatal age of 8.2 ± 4 wk. In 10 infants we performed longitudinal measurements on two occasions. We developed a threshold algorithm for the detection of a breath so that an IBI included an apneic period and potentially some periods of insufficient tidal breathing excursions (hypopneas). The probability density distribution ( P ) of IBIs follows a power law, P (IBI)∼IBI−α, with the exponent α providing a statistical measurement of the relative risk of insufficient breathing. With maturation, α increased from 2.62 ± 0.4 at 41.2 ± 3.6 wk to 3.22 ± 0.4 at 47.3 ± 6.4 wk postconceptional age, indicating a decrease in long hypopneas (for paired data P = 0.002). The statistical properties of IBI were well reproduced in a model of the respiratory oscillator on the basis of two hypotheses: 1) tonic neural inputs to the respiratory oscillator are noisy; and 2) the noise explores a critical region where IBI diverges with decreasing tonic inputs. Accordingly, maturation of infant respiratory control can be explained by the tonic inputs moving away from this critical region. We conclude that breathing irregularities in infants can be characterized by α, which provides a link between clinically accessible data and the neurophysiology of the respiratory oscillator.

An Experimental Investigation on Thermal Conductivity and Viscosity of Graphene doped CNTs /TiO2 Nanofluid

2020 ◽  
Vol 17 (3) ◽  
Author(s):  
A.M. Zetty Akhtar ◽  
M.M. Rahman ◽  
K. Kadirgama ◽  
M.A. Maleque
Keyword(s):  
Thermal Conductivity ◽  
Zeta Potential ◽  
Base Fluid ◽  
Minimum Quantity Lubrication ◽  
Cutting Fluid ◽  
Cutting Zone ◽  
Observation Method ◽  
The Stability ◽  
The Relationship ◽  
Zeta Potential Analysis

This paper presents the findings of the stability, thermal conductivity and viscosity of CNTs (doped with 10 wt% graphene)- TiO2 hybrid nanofluids under various concentrations. While the usage of cutting fluid in machining operation is necessary for removing the heat generated at the cutting zone, the excessive use of it could lead to environmental and health issue to the operators. Therefore, the minimum quantity lubrication (MQL) to replace the conventional flooding was introduced. The MQL method minimises the usage of cutting fluid as a step to achieve a cleaner environment and sustainable machining. However, the low thermal conductivity of the base fluid in the MQL system caused the insufficient removal of heat generated in the cutting zone. Addition of nanoparticles to the base fluid was then introduced to enhance the performance of cutting fluids. The ethylene glycol used as the base fluid, titanium dioxide (TiO2) and carbon nanotubes (CNTs) nanoparticle mixed to produce nanofluids with concentrations of 0.02 to 0.1 wt.% with an interval of 0.02 wt%. The mixing ratio of TiO2: CNTs was 90:10 and ratio of SDBS (surfactant): CNTs was 10:1. The stability of nanofluid checked using observation method and zeta potential analysis. The thermal conductivity and viscosity of suspension were measured at a temperature range between 30˚C to 70˚C (with increment of 10˚C) to determine the relationship between concentration and temperature on nanofluid’s thermal physical properties. Based on the results obtained, zeta potential value for nanofluid range from -50 to -70 mV indicates a good stability of the suspension. Thermal conductivity of nanofluid increases as an increase of temperature and enhancement ratio is within the range of 1.51 to 4.53 compared to the base fluid. Meanwhile, the viscosity of nanofluid shows decrements with an increase of the temperature remarks significant advantage in pumping power. The developed nanofluid in this study found to be stable with enhanced thermal conductivity and decrease in viscosity, which at once make it possible to be use as nanolubricant in machining operation.

A FORECAST OF PRODUCTIVE LONGEVITY OF HOLSTEIN COWS BY INDIRECT SIGNS

2020 ◽  
Author(s):  
З.С. САНОВА
Keyword(s):  
Correlation Coefficient ◽  
Aging Process ◽  
Direct Relationship ◽  
Stability Index ◽  
Age At First Calving ◽  
Group I ◽  
Predicted Values ◽  
The Stability ◽  
Relationship Of ◽  
The Relationship

В статье представлены материалы о взаимосвязи продолжительности продуктивного использования коров с характеристикой устойчивости к деградации, с возрастом отела и удоем. В исследованной, разнородной по происхождению, группе животных для прогноза продуктивного периода коров, обусловленного устойчивостью к деградации и возрастом первого отела, пригодно уравнение регрессии, аргументами в котором являются индекс устойчивости, возраст первого отела в первой и второй степенях. Коэффициент корреляции межу предсказанными значениями продуктивного периода и его фактическими величинами в I группе составляет 0,502, во II - 0,604. При этом крайние варианты прогнозируются со статистическими ошибками 5 мес при оценке индекса устойчивости по 2 лактациям и 4,1 мес по 3, а средние варианты, соответственно, 1,6 и 1,51 мес. Индекс устойчивости к процессу старения является важной характеристикой биологических особенностей коров, определяющий их продуктивное долголетие. Его оценка по первым 2 и 3 лактациям имеет прямолинейную связь с продуктивным периодом (r=0,4109 и r=0,5270), соответственно. Зависимость продуктивного периода от возраста первого отела криволинейная — с увеличением возраста первого отела сокращается срок продуктивного использования, при возрасте первого отела более 1400 дней срок продуктивного использования колеблется от 1,33 до 1,41 лактации. Коэффициент корреляции между этими характеристиками коров составляет - 0,2164 в I и - 0,2620 во II группах. The article presents materials about the relationship of the duration of productive use of cows with the characteristic of resistance to degradation, with the age of calving and milk yield. In the studied group of animals, which is heterogeneous in origin, the regression equation is suitable for predicting the productive period of cows due to resistance to degradation and the age of the first calving, the arguments of which are the stability index, the age of the first calving in the first and second degrees. The correlation coefficient between the predicted values of the productive period and its actual values in group I is 0.502, in group II - 0.604. At the same time, the extreme variants are predicted with statistical errors of 5 months when evaluating the stability index for 2 lactations and 4.1 months for 3, and the average variants, respectively, are 1.6 and 1.51 months. The index of resistance to the aging process is an important characteristic of the biological characteristics of cows, which determines their productive longevity. Its estimate for the first 2 and 3 lactations has a direct relationship with the productive period (r=0.4109 and r=0.5270), respectively. The dependence of the productive period age at first calving curvilinear with increasing age at first calving reduces the time to productive use, while age at first calving of more than 1400 days, the period of productive use ranges from 1.33 to 1.41 lactation. The correlation coefficient between these characteristics of cows is-0.2164 in I and-0.2620 in II groups.

Substantiation the machine with a basket for the application of mineral fertilizers and other bulk materials with the upper arrangement of the feeding device

2019 ◽  
pp. 37-43
Author(s):  
Fesenko, H.
Keyword(s):  
Fat Body ◽  
Mineral Fertilizer ◽  
The Body ◽  
Mineral Fertilizers ◽  
Analytical Mechanics ◽  
Bulk Materials ◽  
The Stability ◽  
Working Bodies ◽  
The Relationship ◽  
Stable Flow

Purpose. Increasing the uniformity of distribution of mineral fertilizers and other bulk materials due to the stability of their feed from the body to the spreading working bodies using the top feeder. Methods. The following methods are used to achieve this aim: the method of comparing the differences between individual groups of fertilizers, the method of analyzing the properties of a new technical system, the method of functional inventiveness, and the methods of theoretical and analytical mechanics. Results. The traction body of the conveyor of the upper feed of the body fat body machine for mineral fertilizers and other bulk materials was substantiated and the relationship between the height of its scrapers and the distance between them was established, as well as the nature of the mineral fertilizer pressure on the curvilinear wall of the body. In addition, the design of the advanced body fertilizer spreader is justified, which ensures a stable flow of fertilizers from the body due to the improvement of the top feeder. Conclusions. Because of the conducted researches, the advantages of machines equipped with top feeder are found. They create the conditions for the forced feeding mineral fertilizers and other loose materials from the container to the distribution bodies, which is a prerequisite for their evenness on the surface. With this, the imperfection of known machines with the top feeder constrains their introduction into agricultural production. On this account, a more thoroughly constructed solution of the body feeder of the top feed is substantiated, in which the conveyor provides a stable supply of fertilizers from the body with reduced energy consumption during operation. Keywords: analysis, feed, upper device, conveyor, stability, fertilizers, flow ability, body.

FINANCIAL CRISES AND THE PUBLICATION OF THE FINANCIAL STATEMENTS OF BANKS IN SPAIN, 1844–1868

2004 ◽  
Vol 31 (2) ◽  
pp. 1-26 ◽  
Author(s):  
Mercedes Bernal Lloréns
Keyword(s):  
19Th Century ◽  
Financial Reporting ◽  
Economic Performance ◽  
Financial Crises ◽  
Limited Liability ◽  
Financial Statements ◽  
Early Response ◽  
Banking Regulations ◽  
The Stability ◽  
The Relationship

Financial crises have had a decisive influence on banking regulations in Spain. During the mid-19th century the publication of the financial statements of banks was considered key to the stability of the financial system. All new joint stock banking companies were to publish their statements in the Madrid Gazette in return for the privilege of limited liability. Similar obligations were placed on issuing banks. The copious publication of financial statements coincided with a period of financial prosperity. However, the crises that followed from 1864 to 1868 led to a reduction in the official publication of statements. This paper is concerned with an early response to crises in financial reporting. The study focuses on the relationship between the publication of accounting statements by banks and the GDP in Spain during the mid-19th century. The results suggest that the frequency of publication of financial statements may be an indicator of economic performance.

scholarly journals Cats in the forest: predicting habitat adaptations from humerus morphometry in extant and fossil Felidae (Carnivora)

Paleobiology ◽  
10.1666/12001 ◽  
2013 ◽  
Vol 39 (3) ◽  
pp. 323-344 ◽  
Author(s):  
Carlo Meloro ◽  
Sarah Elton ◽  
Julien Louys ◽  
Laura C. Bishop ◽  
Peter Ditchfield
Keyword(s):  
Morphological Variability ◽  
Olduvai Gorge ◽  
Environmental Predictors ◽  
Linear Measurements ◽  
Multivariate Statistical ◽  
Linear Discriminant ◽  
Related Group ◽  
Discriminant Analyses ◽  
The Stability ◽  
The Relationship

Mammalian carnivores are rarely incorporated in paleoenvironmental reconstructions, largely because of their rarity within the fossil record. However, multivariate statistical modeling can be successfully used to quantify specific anatomical features as environmental predictors. Here we explore morphological variability of the humerus in a closely related group of predators (Felidae) to investigate the relationship between morphometric descriptors and habitat categories. We analyze linear measurements of the humerus in three different morphometric combinations (log-transformed, size-free, and ratio), and explore four distinct ways of categorizing habitat adaptations. Open, Mixed, and Closed categories are defined according to criteria based on traditional descriptions of species, distributions, and biome occupancy. Extensive exploratory work is presented using linear discriminant analyses and several fossils are included to provide paleoecological reconstructions.We found no significant differences in the predictive power of distinct morphometric descriptors or habitat criteria, although sample splitting into small and large cat guilds greatly improves the stability of the models. Significant insights emerge for three long-canine cats:Smilodon populator,Paramachairodus orientalis, andDinofelissp. from Olduvai Gorge (East Africa).S. populatorandP. orientalisare both predicted to have been closed-habitat adapted taxa. The false “sabertooth”Dinofelissp. from Olduvai Gorge is predicted to be adapted to mixed habitat. The application of felid humerus ecomorphology to the carnivoran record of Olduvai Gorge shows that the older stratigraphic levels (Bed I, 1.99–1.79 Ma) included a broader range of environments than Beds II or V, where there is an abundance of cats adapted to open environments.

AN INTERACTIONAL APPROACH TO ATTRIBUTIONAL DIMENSIONS IN DYSPHORIA

1990 ◽  
Vol 18 (2) ◽  
pp. 267-277 ◽  
Author(s):  
Janet E. Eschen ◽  
David S. Glenwick
Keyword(s):  
Attributional Style ◽  
The Self ◽  
Regression Analyses ◽  
Self Blame ◽  
Attributional Style Questionnaire ◽  
Standard Manner ◽  
Stability Dimension ◽  
The Stability ◽  
The Relationship

To investigate the possible contributions to dysphoria of interactions among attributional dimensions, 105 freshmen and sophomores were administered the Attributional Style Questionnaire and the Beck Depression Inventory. Analyses examined the relationship to dysphoria of (a) the traditional composite score; (b) multiple regression analyses including interactions among the various dimensions; and (c) indices of behavioral self-blame, characterological self-blame, and external blame. The results provided modest support for the specific hypothesized interactional model and, to a large extent, appeared to support the validity of the standard manner in which dysphoric attributional style is viewed. Refinements of the traditional model are suggested, involving the self-blame construct, the possible role of the stability dimension, and the relationship between controllability and positive event attributions.

Some Relationship between Safety Factor of Earthquake Slope and Related Parameters

2011 ◽  
Vol 422 ◽  
pp. 688-692
Author(s):  
Xiao Hei He ◽  
Geng You Han ◽  
Rui Hua Xiao
Keyword(s):  
Numerical Simulation ◽  
Rock Mechanics ◽  
Safety Factor ◽  
Limit Equilibrium ◽  
Static Method ◽  
Acceleration Coefficient ◽  
The Wenchuan Earthquake ◽  
Stability Of Slope ◽  
The Stability ◽  
The Relationship

Abstract:Since the Wenchuan earthquake happened, the slope stability had been paid much more attention. The safety factor is an important parameter that can be used to evaluate the stability of slope. The pseudo-static method that based on limit equilibrium and the method of numerical simulation can calculate the safety factor accurately, but the velocity that gets the result is slow. If we can establish the relationship between safety factor and some other parameters, then we can calculate the safety factor by using the relationship more quickly. This paper establishes much relationship, such as the relationship between the rock mechanics parameters and the average danymic safety factor, the relationship between the rock mechanics parameters and the ratio of average danymic safety factor to static safety factor, the relationship between the rock mechanics parameters and the average earthquake acceleration coefficient, the relationship between the average earthquake acceleration coefficient and the ratio of average danymic safety factor to static safety factor, and the relationship between the earthquake acceleration coefficient and the ratio of danymic safety factor to static safety factor on the condition of different rock mass.

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