Digital Holographic Microscopy of Phase Separation in Multicomponent Lipid Membranes

Lateral in-homogeneities in lipid compositions cause microdomains formation and change in the physical properties of biological membranes. With the presence of cholesterol and mixed species of lipids, phospholipid membranes segregate into lateral domains of liquid-ordered and liquid-disordered phases. Coupling of two-dimensional intralayer phase separations and interlayer liquid-crystalline ordering in multicomponent membranes has been previously demonstrated. By the use of digital holographic microscopy (DHMicroscopy), we quantitatively analyzed the volumetric dynamical behavior of such membranes. The specimens are lipid mixtures composed of sphingomyelin, cholesterol, and unsaturated phospholipid, 1,2-dioleoyl-sn-glycero-3-phosphocholine. DHMicroscopy in a transmission mode is an effective tool for quantitative visualization of phase objects. By deriving the associated phase changes, three-dimensional information on the morphology variation of lipid stacks at arbitrary time scales is obtained. Moreover, the thickness distribution of the object at demanded axial planes can be obtained by numerical focusing. Our results show that the volume evolution of lipid domains follows approximately the same universal growth law of previously reported area evolution. However, the thickness of the domains does not alter significantly by time; therefore, the volume evolution is mostly attributed to the changes in area dynamics. These results might be useful in the field of membrane-based functional materials

Do Country Size and Trade Openness Affect OPEC's Volatility?

The volatility in the global macroeconomic performance has been a striking feature that absorbs recently more attention. Against many influential factors, the role of openness and country size became a prominent debatable issue in explaining economic volatility in the literature. In this paper, we aim at investigating the mechanisms through which output volatility is affected by trade openness and country size, also, introducing those factors that matter most for explaining growth volatility. By using a panel dataset of OPEC during the period of 1970-2012 and employing GLS technique, the main results are threefold. First, trade openness leads the OPEC members to experience more volatility in economic growth. Second, more fluctuation is accompanied with smaller country size. Third, during the period of inspection, government expenditure and democracy are correlated to less volatility in OPEC. Keywords: Volatility, Country size, Openness, OPE

Biometric Indices and Their Relation with Age, Sex and Ethnicity

Objective: The aim of the present study was to evaluate the association of biometric indices with age, gender and ethnicity.Patients and Methods:  Three hundred and seventy patients entered the study from Basir Eye Clinic refractive assessment clinic. Sociodemographic data was gathered. Ocular parameters for both eyes and corneal curvature were measured by immersion technique and manual keratometry, respectively.Results: Axial length was significantly higher among male patients (P = 0.01) and vitreous chamber depth was significantly higher in females (P = 0.02). Axial length and vitreous chamber depth parameters were significantly higher among Arab patients (P = 0.01) compared to Persian patients and there was no other significant differences between these two groups. A significant increase in lens thickness and mean K (P < 0.001, coefficient = 0.15 and 0.023 respectively) and a significant reduction with axial length, anterior chamber depth and vitreous chamber depth (P < 0.001, coefficient = - 0.31, - 0.10 and - 0.37 respectively) were observed in correlation with the age of participants.Conclusion: There was correlation between axial length, depth of the anterior chamber, vitreous chamber depth, lens thickness and mean k with age of the participants. Male subjects and specific ethnicities such as Arab patients tend to have higher axial length values.Keywords: Axial length, anterior chamber depth, vitreous chamber depth, sex, age, Iran

Strategic management of organizational resources using predicting the organization's bankruptcy level: New approach using Monte Carlo Simulation

Purpose: There are several methods to predict organization bankruptcy; each of them has different accuracy. Another considerable note in investigating organization bankruptcy is the data considered for the study. The goal of this study is to determine which model is the most accurate in predicting organization bankruptcy. Research methodology: In this study, the initial data were used to compare predicting Monte Carlo processes that simulate bankruptcy models to compare models and results more accurately. Simulated data coefficient modification of Mckee, CA-SCORE, Springate, Zmijewski, Shirata, and Altman methods were implemented in some healthy and bankrupt organizations. After that, the results of each modified model were considered to determine the predicting bankruptcy accuracy. Results: Using the final Mckee's method, predicting organization bankruptcy was done in an organization and the results show that the given organization is on a trend of bankruptcy in 2025. Limitations: This research was only described in knowledge-based organizations. Contribution: The Mckee genetic method is more accurate than other methods. Also, modifying coefficient and by using simulated data shows that CA-SCORE and Shirata methods are not able to predict the organization's bankruptcy by using simulated data

Investigating, identifying and evaluating organizational and infrastructural strategic factors affecting organizational management processes from the perspective of productivity management

Purpose: The purpose of this present study is to investigate the impact of institutional and infrastructural factors on knowledge management processes from the perspective of Nonaka and Takeuchi with a case study of design offices of a product organization. Research methodology: The research is applied and is a descriptive survey in terms of data collection. The statistical population of the design offices of a product organization consisted of 75 people and the statistical sample was estimated 63 people. The research tool was a researcher-made questionnaire with a reliability of 77%. Results: The findings show that seven institutional and infrastructure factors affecting knowledge management processes were identified. Also prioritization by TOPSIS showed that organizational structure, culture and values, above average, can be deployed in the design office, and knowledge management policies and guidance are average, but information technology is below average. Limitation: The results extend the understanding of the role of quality of work-life in organizational effectiveness. The research findings have implications for human resource managers. Contribution: The results of the study help the human resource managers of organizations to identify the elements that affect the quality of work-life and help them in planning to increase organizational effectiveness by increasing employee satisfaction and motivation. Keywords: Knowledge management, Institution, Infrastructure, Nonaka and Takeuch

Psycological Impact Of COVID-19 Pandemic On Dental Student: A Cross-Sectional Pilot Study

Background and purpose: The covid-19 disease is widely spreading worldwide and has adversely impacted mental health in society, especially among the medical staff. In addition to the stresses related to the outbreak of covid-19, the suspension of in-person classes, undertaking electronic online learning, and concerns about achieving clinical skills cause increasing anxiety and stress in dental students, which might be related to increased mental health problems. Thus, the present study examined dental students’ levels of stress, anxiety, and depression in Shahrekord during the covid-19 pandemic. Methods: In this cross-sectional study, 110 dental students completed the questionnaires of demographic data and depression, anxiety, and stress scale (DASS-21) in 2021. The data were analyzed with SPSS. Results: In the DASS-21 questionnaire, the rate of depression was 57%, anxiety 76%, and stress 33%. The total score of the DASS-21 questionnaire was significantly different between the two genders (P<0.05), and the mean score of females was significantly higher than males. Conclusion: The prevalence of depression and anxiety in dental students, especially females, was high during the covid-19 pandemic

The relationship between hardiness and burnout among the teachers of the universities and higher educational institutes - case study

Burnout is the physical, mental and emotional collapse combined with the negative attitudes toward the job and lack of attention to the clients. The most significant signs of burnout include absence from work, successive delays and various psychosomatic complaints and conflict in the workplace. Hardiness is a personal characteristic adjusting the way to cope with the stressful situations. This study examines the relationship between burnout and hardiness of the teachers of a higher education institute. In doing so, there are three factors including emotional exhaustion, depersonalization and lack of personal accomplishment which measure the burnout. Additionally, hardiness has three components of commitment, control and challenge. This survey aims at determining the relationship between the elements through correlation coefficient. The population is composed of all teachers of a higher education institute. The participants were 120 teachers. Given the unknown variance of the population, the variance ratio was equal to p (p-1) to specify the sample. The value of p was equal to q. The error (d) was equal to 0.05 and the sample size composed of 53 persons. After sampling and analyzing the results by the correlation coefficient, it was found that any of the burnout components werecorrelated with the three elements of hardiness

Kinetics and Mechanism of Reactions of Disubstituted Octahedral Metal Carbonyls with Phosphorus Donor Ligands and Germanium Tetraiodide

The kinetics and mechanism of the reactions of (tmpa)W-(CO)^ and (tmen)W(CO)^ (tmpa = N,N,N',N'-tetramethy1-1,3-diaminopropane and tmen = N,N,N1,N1-tetramethylethylenediamine) with four phosphorus donor ligands (triisopropyl phosphite, triphenyl phosphite, triphenylphosphine and "constrained phosphite", 4-methyl-2,6,7-trioxa-l-phosphabicylo[2.2.2]octane) in xylene have been investigated in detail. These reactions were found to take place by the ring-opening of the bidentate ligand in a reversible step which leads to the formation of a five-coordinate intermediate of the type [(h^-tmpa)W(CO)or [(h^-tmen)W(CO). The intermediate then reacts with one molecule of phosphorus ligand, L, to form a six-coordinate intermediate, which can either expel the bidentate ligand and react with another molecule of L leading to the formation of a new disubstituted tungsten tetracarbonyl or go through a ring-reclosure step to form a seven-coordinate activated com-2 2plex or intermediate of the type [(h -tmpa)W(CO)^(L)] or [(h - tmen)W(CO)^(L)] which then regenerates the substrate through the expulstion of the L molecule. This mechanism is consistent with the observed rate behavior in these systems. For the reaction of (tmpa)W(CO)^ with the "constrained phosphite", an intermediate of the type [(h1-tmpa)W(CO)4P(OCH2)3CCH3] was isolated and identified

The relationship between hardiness and burnout among the teachers of the universities and higher educational institutes - case study

Burnout is the physical, mental and emotional collapse combined with the negative attitudes toward the job and lack of attention to the clients. The most significant signs of burnout include absence from work, successive delays and various psychosomatic complaints and conflict in the workplace. Hardiness is a personal characteristic adjusting the way to cope with the stressful situations. This study examines the relationship between burnout and hardiness of the teachers of a higher education institute. In doing so, there are three factors including emotional exhaustion, depersonalization and lack of personal accomplishment which measure the burnout. Additionally, hardiness has three components of commitment, control and challenge. This survey aims at determining the relationship between the elements through correlation coefficient. The population is composed of all teachers of a higher education institute. The participants were 120 teachers. Given the unknown variance of the population, the variance ratio was equal to p (p-1) to specify the sample. The value of p was equal to q. The error (d) was equal to 0.05 and the sample size composed of 53 persons. After sampling and analyzing the results by the correlation coefficient, it was found that any of the burnout components werecorrelated with the three elements of hardiness