Physiological features of the pressure-volume function of brain elasticity in man

1980 ◽  
Vol 53 (2) ◽  
pp. 166-172 ◽  
Author(s):  
Frederick H. Sklar ◽  
Chester W. Beyer ◽  
W. Kemp Clark

✓ The intracranial pressure-volume relationship of brain elasticity was examined in 20 patients with suspected disorders of the cerebrospinal fluid (CSF) system. Elasticity measurements were made as the patients were studied with a servo-controlled lumbar infusion technique to measure CSF absorptive capacity. The data were evaluated to determine the relationship between intracranial pressure (ICP) and volume, and between ICP variability and the level of ICP. The results confirm the exponential nature of the pressure-volume elasticity function in patients who are not critically ill. Eight of the 20 patients were shown to have normal CSF absorptive capacities, and there was no difference between their elasticity measurements and those of patients with absorptive defects. In addition, ICP variability was shown to be linearly related to the actual level of ICP. The physiological features of the pressure-volume elasticity function are reviewed. Based on these considerations, the clinical value and significance of elasticity measurements is questioned.

1972 ◽  
Vol 37 (5) ◽  
pp. 514-527 ◽  
Author(s):  
Stanley J. Goodman ◽  
Donald P. Becker ◽  
John Seelig

✓ Intracranial pressures above and below the tentorium, arterial blood pressure, heart rate, and respiratory rate were recorded continuously before, during, and after expansion of a supratentorial mass in awake unsedated cats. In general, as the mass enlarged, the intracranial pressure rose; however, considerable variation was observed among animals with respect to specific mass size and associated intracranial pressures. There was considerable variation in the relationship of supratentorial pressure to infratentorial pressure. No animal survived that had sustained a mass-induced pressure exceeding 1100 mm H2O, and survival was shorter with greater pressures. Systemic hypertension occurred always and only when the infratentorial pressure exceeded 600 mm H2O, regardless of the magnitude of the associated supratentorial intracranial pressure. The methodological limitations of previous studies of mass-induced intracranial hypertension appear to have been substantially reduced by the technique described.


1980 ◽  
Vol 239 (2) ◽  
pp. H189-H198 ◽  
Author(s):  
H. S. Goldberg

Static and dynamic properties governing the fluid movement into the pulmonary interstitium were examined in isolated canine lobes. The system was driven by altering intravascular presure (Piv) when the lobe was isogravimetric (change in weight (W) = 0) and allowing the lobe to become isogravimetric again. By making use of an analogy to charging a capacitor across a resistor, calculation of the filtration coefficient for transvascular fluid movement (KF) and determination of the pressure-volume relationship of the pulmonary interstitial space (Pis-Vis), with a minimum of untested assumptions, was possible. KF was found to be the same for fluid moving out of or into the intravascular space, and when the relationship between Piv and alveolar pressure (PAlv) was constant, KF was independent of transpulmonary pressure (PL). When PAlv exceeded Piv, changes in Piv did not influence KF, suggesting no significant change in either surface area available for fluid transudation or vascular permeability. The Pis-Vis curve for increasing values of Vis and Pis is best described by an exponential relationhip and is independent of PL. However, the Pis-Vis curve with decreasing values of Vis and Pis is dependent on PL.


1980 ◽  
Vol 53 (2) ◽  
pp. 173-179 ◽  
Author(s):  
Frederick H. Sklar ◽  
Jan T. Diehl ◽  
Chester W. Beyer ◽  
W. Kemp Clark

✓ The pressure-volume relationship of brain elasticity was determined in 32 patients during servo-controlled variable-rate lumbar infusions to measure net cerebrospinal fluid (CSF) absorptive capacity. Several indices were used to estimate ventricular size from computerized tomography scans. The results show a linear relationship between ventricular size and the elasticity slope which relates the natural logarithm of pressure to volume. It follows that a hydrocephalic patient should show a greater intracranial pulse amplitude at a given pressure than does a patient with normal-sized ventricles. Although these elasticity changes may simply be the result of the ventriculomegaly, it seems possible that the pressure-volume elasticity relationship may be of etiological importance in disorders of the CSF system.


2019 ◽  
Vol 14 (4) ◽  
pp. 251-263
Author(s):  
Daniel J. Carabellese ◽  
Michael J. Proeve ◽  
Rachel M. Roberts

Purpose The purpose of this paper is to explore the relationship of two distinct variants of dispositional shame (internal and external shame) with collaborative, purpose-driven aspects of the patient–provider relationship (working alliance) and patient satisfaction. The aim of this research was to conduct a preliminary investigation into the relevance of dispositional shame in a general healthcare population. Design/methodology/approach In total, 127 community members (mean age 25.9 years) who reported that they had regularly seen a GP over the past year were recruited at an Australian university. Participants were asked to reflect on their relationship with their GP, and completed instruments assessing various domains of shame, as well as working alliance and patient satisfaction. Findings Non-parametric correlations were examined to determine the direction and strength of relationships, as well as conducting mediation analyses where applicable. Small, negative correlations were evident between external shame and working alliance. Both external and internal shame measures were also negatively correlated with patient satisfaction. Finally, the relationship of external shame to patient satisfaction was partially mediated by working alliance. Practical implications Both the reported quality of patient–provider working alliance, and level of patient satisfaction are related to levels of dispositional shame in patients, and working alliance may act as a mediator for this relationship. Originality/value The findings from this preliminary study suggest that internal and external shame are important factors to consider in the provision of medical care to maximise the quality of patient experience and working alliance.


2016 ◽  
Vol 11 (3) ◽  
pp. 802-810 ◽  
Author(s):  
Nitin Yashwant Patil ◽  
Ravi M. Warkhedkar

Purpose In the past decade, much has been written about knowledge management (KM) in the manufacturing; however, less attention has been paid to the Indian automobile ancillary industries located in Chinchwad, Pune. It is suitable to find out the relationship of the factors of the study. It helps in identifying the hierarchy of factors to be taken, and interlinking of production department with KM improves the productivity of the industries. Categorization of these principles based on their driving power (principles which hold other principles) and dependence (principles which are dependent on other principles) has also been examined for KM implementation to study the driving power and dependence power of these principles. This paper aims to determine the roadmap of KM implementation and categorize KM principles based on their driving power for manufacturing industries with the use of the interpretive structural modeling (ISM)-based model. The results indicate that the principles possessing higher driving power, such as KM, inventory control, quality control, productivity and scheduling and their interlinking. The major contribution of this research lies in the development of contextual relationship among various identified factors of KM and determination of their driving and dependence power through a single systemic framework. Design/methodology/approach In this paper, author find out the suitability ISM for Indian Automobile industries to find the relation among the variables. Findings ISM model has been developed for the hierarchy of the identified KM. As ISM model results a hypothetical hierarchy which needs a proper quantitative analysis to evaluate their percentage effectiveness in the hierarchy. Research limitations/implications It is applied to automobile industries with limited number of variables that will show the dependence variable and driving variables and their interrelations. It can be applied other fields to fine the relationship of variables. Practical implications The ISM may be used in supply chain management and total quality management to find interlinking between the variables. Originality/value The limited data collected from Pimpri Chinchwad industrial area of Pune from Maharashtra state (India).


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Muhammad Asim Rafique ◽  
Yumei Hou ◽  
Muhammad Adnan Zahid Chudhery ◽  
Nida Gull ◽  
Syed Jameel Ahmed

PurposeInnovations are imperative for organizational growth and sustainability. This study focuses on the employees' innovative behavior, a source of organizational innovations, which has received substantial attention from the researchers. Based on the psychological empowerment theory, the study exposes the effect of the various dimensions of public service motivation (PSM) on employees' innovative behavior (IB) in public sector institutions especially in the context of developing countries such as Pakistan. Moreover, the study also investigates the mediating role of psychological empowerment (PSE) between the dimensions of PSM and IB.Design/methodology/approachThis study used the cross-sectional research design. By using random sampling, the adapted survey questionnaires were used to collect data from 346 faculty members of public sector universities located in provincial capitals of Pakistan. A partial least square–structural equation modeling (PLS-SEM) tool was used to assess the proposed hypotheses through SMART-PLS software.FindingsResults revealed that attraction to policymaking (APM), compassion (COM), self-sacrifice (SS) have a significant impact on employees' PSE and their innovative behavior, while the relationship of commitment to the public interest (CPI) with PSE and IB was found insignificant. Moreover, PSE partially mediated the relationship between PSM dimensions and employees' IB.Originality/valueThere was a scarcity of research on IB especially in public sector institutions such as academia. This study theoretically contributed to the literature by providing a refined picture in assessing the proposed relationship of the constructs. This is also one of the original studies that examine the relationship between the dimensions of PSM and IB.


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Aqsa Ameer ◽  
Farah Naz ◽  
Bushra Gul Taj ◽  
Iqra Ameer

Purpose The purpose of this study is to determine the effect of conscientiousness and extraversion personality traits on project success. The relationship is mediated by affective professional commitment, whilst the relationship between personality traits and project success is moderated by organizational project management maturity. Design/methodology/approach The deductive approach is used to achieve the objectives of this study. Data were collected through a purposive sampling technique from 250 respondents with the help of questionnaires from information technology sectors. The structural equation modelling (SEM) in partial least squares-SEM and SPSS is used to analyse the data and to examine the hypothesis. Findings The outcomes demonstrate the partial mediating impact of affective professional commitment between the relationship of conscientiousness and extraversion personalities with project success. Additionally, it proves the moderating effects of project management maturity between the relationship of conscientiousness and extraversion personalities with project success. Practical implications This study reflects that employee personality appears to be a reliable indicator of how an employee is faithful to his profession. This faithfulness or duty decides the employee’s execution in terms of offering a successful project. Thus, achieving employee commitment needs to be done by completing the project successfully by the organizations in the presence of project management maturity systems. Originality/value It is the first study of its kind to provide experimental proof of the impact of a manager’s personality traits on project success in the presence of affective professional commitment (mediator) and organizational project management maturity (moderator).


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Jodie Louise Stewart ◽  
Karl Kilian Konrad Wiener

Purpose This paper aims to examine the quality of the relationship between a supervisor and their subordinate, conceptualised as leader member exchange (LMX), and the mediating influence of subordinate’s job embeddedness on job satisfaction. The LMX model considered the four-gender dominant leadership style facets, female – affect and loyalty (communal), and male – contribution and professional respect (agentic). Social role theory was applied to explain societies influence on leadership style. The moderating influence of supervisor gender on the relationship of LMX facets and subordinate embeddedness is investigated. Design/methodology/approach This cross-sectional survey study of 213 self-selected employed participants investigated the mediation of job embeddedness LMX and job embeddedness and the moderation impact of supervisor gender on this mediation. Findings Job embeddedness mediated the relationship between all four facets of LMX and job satisfaction. Supervisor gender did not moderate the relationships of the four LMX facets and job embeddedness. These findings highlight the potential impact of a homogeniuos sample in relation to industry type and culture as this may impact on the findings. That is, participants in this study were predominantly females working in female dominant industries. Originality/value This study builds on the work of Collins et al. (2014) who examined the moderating impact of subordinate gender on the mediating relationship of job embeddedness on the relationship between LMX facets and job satisfaction. Previously, the gender role of supervisors on this relationship was not explored.


2018 ◽  
Vol 25 (9) ◽  
pp. 4125-4138 ◽  
Author(s):  
Sami R.M. Musallam

PurposeThe purpose of this paper is to investigate the direct and indirect effect of the existence of risk management on the relationship between audit committee and corporate social responsibility (CSR) disclosure in Palestine.Design/methodology/approachThe study utilizes a panel data of 31 Palestinian listed companies from 2010 to 2016. It also utilizes structural equation modeling (SEM) model.FindingsThe results of SEM model find a significant positive relationship of the existence of risk management, audit committee meeting and audit committee size with CSR disclosure. However, audit committee financial expertise has a significant negative relationship with CSR disclosure. The results also find a significant relationship of audit committee meeting and audit committee financial expertise with CSR disclosure through the existence of risk management.Practical implicationsThis study is important to policymakers, accounting professionals and shareholders on the extent to which audit committee related to such committee efficiency in monitoring CSR disclosure.Social implicationsThis study adds to the existing literature by investigating the direct and indirect effect of the existence of risk management on the relationship between audit committee and CSR disclosure in Palestine as one of the youngest market in region that assists to test the validity of agency theory in a young and small emerging market context.Originality/valueIt is the first study to investigate the direct and indirect effect of the existence of risk management on the relationship between audit committee and CSR disclosure in Palestine.


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