scholarly journals Airway Transmural Pressures in an Airway Tree During Bronchoconstriction in Asthma

Author(s):  
Tilo Winkler

Airway transmural pressure in healthy homogeneous lungs with dilated airways is approximately equal to the difference between intraluminal and pleural pressure. However, bronchoconstriction causes airway narrowing, parenchymal distortion, dynamic hyperinflation, and the emergence of ventilation defects (VDefs) affecting transmural pressure. This study aimed to investigate the changes in transmural pressure caused by bronchoconstriction in a bronchial tree. Transmural pressures before and during bronchoconstriction were estimated using an integrative computational model of bronchoconstriction. Briefly, this model incorporates a 12-generation symmetric bronchial tree, and the Anafi and Wilson model for the individual airways of the tree. Bronchoconstriction lead to the emergence of VDefs and a relative increase in peak transmural pressures of up to 84% compared to baseline. The highest increase in peak transmural pressure occurred in a central airway outside of VDefs, and the lowest increase was 27% in an airway within VDefs illustrating the heterogeneity in peak transmural pressures within a bronchial tree. Mechanisms contributing to the increase in peak transmural pressures include increased regional ventilation and dynamic hyperinflation both leading to increased alveolar pressures compared to baseline. Pressure differences between intraluminal and alveolar pressure increased driven by the increased airway resistance and its contribution to total transmural pressure reached up to 24%. In conclusion, peak transmural pressure in lungs with VDefs during bronchoconstriction can be substantially increased compared to dilated airways in healthy homogeneous lungs and is highly heterogeneous. Further insights will depend on the experimental studies taking these conditions into account.

2019 ◽  
pp. 113-120 ◽  
Author(s):  
Vladimir A. Pyalchenkov ◽  
Dmitry V. Pyalchenkov ◽  
Vladimir V. Dolgushin ◽  
Gennadiy A. Kulyabin

The article deals with the results of experimental studies of the load of the cutting structure of rolling cutter bit depending on the errors of its manufacture. The results of field studies of bits indicate a significant decrease in the resistance of the supports of the rollers, the elements of the cutting structure and sinking on the bit with an increase in the height of the rollers. One of the reasons for reducing the resistance of supports and cutting structure in this case is the uneven distribution of the axial load in the sections. We have tested a batch of bits to establish quantitative regularities between the accuracy of bit production and the load of the cutting structure. The difference in height of chosen bits is varied from 0,34 to 1,28 mm. We have carried out the tests on a special stand, which allowed us to determine the value of the axial force acting on the individual crowns of each cutter bit. It is established that with an unfavorable combination of the mutual position of the rollers, even within the tolerance of the difference in height, the axial load acting on one roller can change almost twice. The results of studies allow investigating the appointment of indicators of accuracy of bit production more reasonable.


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Melby Karina Zuniga Huertas ◽  
Paula dos Santos Fernandes Cavalcanti ◽  
André Torres Urdan

Purpose The purpose of this paper is to analyze the effect of exposure to prosocial media content (PMC) on the subsequent intention to donate to a prosocial cause of a rejected group versus a prosocial cause of a neutral group. The hypothesis, supported in two experimental studies, is that for the individual exposed to a PMC, the difference in the donations for social causes of a rejected group and a neutral group is smaller than for the individual exposed to a non-PMC. Design/methodology/approach Two between-subjects experimental studies were performed. In both studies, the individual’s emotional responses were manipulated through PMC (conditions: prosocial versus non-prosocial). Then, respondents were asked to split a fixed amount of money between two social actions whose beneficiaries were members of a rejected group versus members of a neutral group. Findings It was found that the difference in donation between the two actions associated with different types of beneficiaries (i.e. rejected group vs neutral group) was smaller for the individuals exposed to PMC than for individuals exposed to non-PMC. Research limitations/implications In this research, the donating behavior was operationalized by a simulated donation and not by a real donation. Practical implications Results suggest that PMC on the internet could be effective in reducing rejection for stigmatized dissociation groups for which it is difficult to get help. Social implications The results suggest that exposure to PMC on the internet can increase donations for rejected groups. The confirmation of the PMC effect on reducing negative outcomes opens the possibility to diminish negativity toward stigmatized groups. Originality/value Theoretically, the explanations are based on the social comparison theory.


2002 ◽  
Vol 92 (3) ◽  
pp. 1261-1266 ◽  
Author(s):  
Karen O. McKay ◽  
Barry R. Wiggs ◽  
Peter D. Paré ◽  
Roger D. Kamm

Alterations in airway wall anatomic properties and the consequential effects on airway narrowing have been assessed by use of computational models. In these models, it is generally assumed that at zero transmural pressure the airway wall exists in a zero-stress state. Many studies have shown that this is often not the case, as evidenced by a nonzero opening angle. In this study, we measured the opening angle of airway rings at zero transmural pressure to test this assumption. The airway tree was dissected from human, pig, sheep, and rabbit lungs. Airways were excised from the tree, and the opening angle was measured. There were obvious species and regional differences in opening angle. Rabbit airways from both extraparenchymal and intraparenchymal sites exhibited marked opening angles (7–82°). Extraparenchymal airways from sheep had large opening angles (up to 50°), but ovine intraparenchymal airways had small opening angles. Measurable opening angles were rarely observed in human and porcine airways of any size. The assumption of a stable zero-stress state at zero transmural pressure is therefore valid for human and porcine, but not rabbit and sheep, airways.


2019 ◽  
Vol 118 (7) ◽  
pp. 101-110
Author(s):  
Ms.U.Sakthi Veeralakshmi ◽  
Dr.G. Venkatesan

This research aims at measuring the service quality in public and private banking sector and identifying its relationship to customer satisfaction and behavioral intention. The study was conducted among 500 bank customers by using revised SERVQUAL instrument with 26 items. Behavioral intention of the customers was measured by using the behavioral intention battery. The researcher has used a seven point likert scaling to measure the expected and perceived service quality (performance) and the behavioral intention of the customer. The instrument was selected as the most reliable device to measure the difference-score conceptualization. It is used to evaluate service gap between expectation and perception of service quality. Modifications are made on the SERVQUAL instrument to make it specific to the Banking sector. Questions were added to the instrument like Seating space for waiting (Tangibility), Parking space in the Bank (Tangibility), Variety of products / schemes available (Tangibility), Banks sincere steps to handling Grievances of the customers (Responsiveness). The findings of the study revealed that the customer’s perception (performance) is lower than expectation of the service quality rendered by banks. Responsiveness and Assurance SQ dimensions were the most important dimensions in service quality scored less SQ gap. The study concluded that the individual service quality dimensions have a positive impact on Overall Satisfaction.


Author(s):  
Irina Mordous

The development of modern civilization attests to its decisive role in the progressive development of institutions. They identified the difference between Western civilization and the rest of the world. Confirmation of the institutional advantages of the West was its early industrialization. The genesis and formation of institutionalism in its ideological and conceptualmethodological orientation occurs as a process alternative to neoclassic in the context of world heterodoxia, which quickly spread in social science. Highlighting institutional education as a separate area of sociocultural activity is determined by the factor of differentiation of institutional theory as a whole. A feature of institutional education is its orientation toward the individual and his/her transformation into a personality. The content of institutional education is revealed through the analysis of the institution, which includes a set of established customs, traditions, ways of thinking, behavioral stereotypes of individuals and social groups. The dynamics of socio-political, economic transformations in Ukraine requires a review of the foundations of national education and determination of the prospects for its development in the 21st century in the context of institutionalism.


Author(s):  
O. M. Reva ◽  
V. V. Kamyshin ◽  
S. P. Borsuk ◽  
V. A. Shulhin ◽  
A. V. Nevynitsyn

The negative and persistent impact of the human factor on the statistics of aviation accidents and serious incidents makes proactive studies of the attitude of “front line” aviation operators (air traffic controllers, flight crewmembers) to dangerous actions or professional conditions as a key component of the current paradigm of ICAO safety concept. This “attitude” is determined through the indicators of the influence of the human factor on decision-making, which also include the systems of preferences of air traffic controllers on the indicators and characteristics of professional activity, illustrating both the individual perception of potential risks and dangers, and the peculiarities of generalized group thinking that have developed in a particular society. Preference systems are an ordered (ranked) series of n = 21 errors: from the most dangerous to the least dangerous and characterize only the danger preference of one error over another. The degree of this preference is determined only by the difference in the ranks of the errors and does not answer the question of how much time one error is more dangerous in relation to another. The differential method for identifying the comparative danger of errors, as well as the multistep technology for identifying and filtering out marginal opinions were applied. From the initial sample of m = 37 professional air traffic controllers, two subgroups mB=20 and mG=7 people were identified with statisti-cally significant at a high level of significance within the group consistency of opinions a = 1%. Nonpara-metric optimization of the corresponding group preference systems resulted in Kemeny’s medians, in which the related (middle) ranks were missing. Based on these medians, weighted coefficients of error hazards were determined by the mathematical prioritization method. It is substantiated that with the ac-cepted accuracy of calculations, the results obtained at the second iteration of this method are more ac-ceptable. The values of the error hazard coefficients, together with their ranks established in the preference systems, allow a more complete quantitative and qualitative analysis of the attitude of both individual air traffic controllers and their professional groups to hazardous actions or conditions.


1999 ◽  
Vol 17 (11) ◽  
pp. 3603-3611 ◽  
Author(s):  
Dympna Waldron ◽  
Ciaran A. O'Boyle ◽  
Michael Kearney ◽  
Michael Moriarty ◽  
Desmond Carney

PURPOSE: Despite the increasing importance of assessing quality of life (QoL) in patients with advanced cancer, relatively little is known about individual patient's perceptions of the issues contributing to their QoL. The Schedule for the Evaluation of Individual Quality of Life (SEIQoL) and the shorter SEIQoL–Direct Weighting (SEIQoL-DW) assess individualized QoL using a semistructured interview technique. Here we report findings from the first administration of the SEIQoL and SEIQoL-DW to patients with advanced incurable cancer. PATIENTS AND METHODS: QoL was assessed on a single occasion using the SEIQoL and SEIQoL-DW in 80 patients with advanced incurable cancer. RESULTS: All patients were able to complete the SEIQoL-DW, and 78% completed the SEIQoL. Of a possible score of 100, the median QoL global score was as follows: SEIQoL, 61 (range, 24 to 94); SEIQoL-DW, 60.5 (range, 6 to 95). Psychometric data for SEIQoL indicated very high levels of internal consistency (median r = .90) and internal validity (median R2 = 0.88). Patients' judgments of their QoL were unique to the individual. Family concerns were almost universally rated as more important than health, the difference being significant when measured using the SEIQoL-DW (P = .002). CONCLUSION: Patients with advanced incurable cancer were very good judges of their QoL, and many patients rated their QoL as good. Judgments were highly individual, with very high levels of consistency and validity. The primacy given to health in many QoL questionnaires may be questioned in this population. The implications of these findings are discussed with regard to clinical assessment and advance directives.


Foods ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 394
Author(s):  
Cheng-Han Li ◽  
Chun-Hung Hsieh ◽  
Cheng-Chu Hung ◽  
Ching-Wei Cheng

After completing the production of preserved eggs, traditionally, the degree of gelling is judged by allowing workers to tap the preserved eggs with their fingers and sense the resulting oscillations. The amount of oscillation is used for the quality classification. This traditional method produces varying results owing to the differences in the sensitivity of the individual workers, who are not objective. In this study, dielectric detection technology was used to classify the preserved eggs nondestructively. The impedance in the frequency range of 2–300 kHz was resolved into resistance and reactance, and was plotted on a Nyquist diagram. Next, the diagram curve was fitted in order to obtain the equivalent circuit, and the difference in the compositions of the equivalent circuits corresponding to gelled and non-gelled preserved eggs was analyzed. A preserved egg can be considered an RLC series circuit, and its decay rate is consistent with the decay rate given by mechanical vibration theory. The Nyquist diagrams for the resistance and reactance of preserved eggs clearly showed that the resistance and reactance of gelled and non-gelled eggs were quite different, and the classification of the eggs was performed using Bayesian network (BN). The results showed that a BN classifier with two variables, i.e., resistance and reactance, can be used to classify preserved eggs as gelled or non-gelled, with an accuracy of 81.0% and a kappa value of 0.62. Thus, a BN classifier based on resistance and reactance demonstrates the ability to classify the quality of preserved egg gel. This research provides a nondestructive method for the inspection of the quality of preserved egg gel, and provides a theoretical basis for the development of an automated preserved egg inspection system that can be used as the scientific basis for the determination of the quality of preserved eggs.


1997 ◽  
Vol 50 (1) ◽  
pp. 1-38 ◽  
Author(s):  
Iain Provan

It is well known that the seeds from which the modern discipline of OT theology grew are already found in 17th and 18th century discussion of the relationship between Bible and Church, which tended to drive a wedge between the two, regarding canon in historical rather than theological terms; stressing the difference between what is transient and particular in the Bible and what is universal and of abiding significance; and placing the task of deciding which is which upon the shoulders of the individual reader rather than upon the church. Free investigation of the Bible, unfettered by church tradition and theology, was to be the way ahead. OT theology finds its roots more particularly in the 18th century discussion of the nature of and the relationship between Biblical Theology and Dogmatic Theology, and in particular in Gabler's classic theoreticalstatementof their nature and relationship. The first book which may strictly be called an OT theology appeared in 1796: an historical discussion of the ideas to be found in the OT, with an emphasis on their probable origin and the stages through which Hebrew religious thought had passed, compared and contrasted with the beliefs of other ancient peoples, and evaluated from the point of view of rationalistic religion. Here we find the unreserved acceptance of Gabler's principle that OT theology must in the first instance be a descriptive and historical discipline, freed from dogmatic constraints and resistant to the premature merging of OT and NT — a principle which in the succeeding century was accepted by writers across the whole theological spectrum, including those of orthodox and conservative inclination.


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