Joint modelling of longitudinal biomarker and gap time between recurrent events: copula-based dependence

In this paper, we will extend the joint model of longitudinal biomarker and recurrent event via copula function for accounting the dependence between the two processes. The general idea of joining separate processes by allowing model-specific random effect may come from different families distribution. It is a main advantage of the proposed method that a copula construction does not constrain the choice of marginal distributions of random effects. A maximum likelihood estimation with importance sampling technique as a simple and easy understanding method is employed to model inference. To evaluate and verify the validation of the proposed joint model, a bootstrapping method as a model-based resampling is developed. Our proposed joint model is also applied to pemphigus disease data for assessing the effect of biomarker trajectory on risk of recurrence.     

Managing the tensions between service and advocacy: The case of the AJEEC Social Change Service Organization,Naqab, Israel

The tension between providing services to marginalized groups and organizing them for advocacy to challenge power structures is a fundamental dilemma for Social Change Service Organizations (SCSO). This dilemma exists in many civil society organizations, especially those that work with indigenous communities, such as the Bedouin in Israel, where providing immediate services and advocating for policy change are crucial. Literature shows the tensions that arise from combining service provision and advocacy. However, there are very few studies showing how these organizations manage and overcome these tensions sustainably. The present study is an exploratory case study using the AJEEC (Arab‐Jewish Center for Empowerment, Equality, and Cooperation) in the Naqab as an instrumental single case. It provides an in‐depth understanding of the tensions AJEEC is facing and reveals AJEEC’s unique approach and strategies for managing these tensions effectively and sustainably within the social, political, and cultural contexts. It presents implications for research, policy, and practice.     

India’s Social Development in a Decade of Reforms: 1990–91/1999–2000

The economic reforms initiated in India in 1991 have brought about visible upliftment of economic conditions of the country. This paper examines if the economic process is associated with an enhancement of India’s social development in equal measure in the reform decade of nineties. Ray (1989) considered thirteen social indicators of India and constructed the country’s social development index (SDI) as a certain weighted average of the selected indicators, for the years between 1950–51 and 1975–76. The present work broadly follows Ray (1989) in tracking the social development in the decade of economic reforms from 1990–91 to 1999–2000. The movement of SDI in nineties has been compared with the movements of India’s per capita income and plan expenditure on the social sector. The results show that though there has been growth in the social sector, it is not by far quite encouraging and perhaps more needs to be done in the social sector. The views expressed in the article are those of the author and not of the institution he serves.     

Marginalized to double marginalized: My mutational intersectionality between the East and the West

Intersectionality allows better understanding of the differences between individuals' experiences. In this article, I use intersectionality to explore how my lived experience of marginalization is different from one context to another. I reflect on how the nature of intersectionality and the intensity of oppression are altered by context. Grounded in a brief reflection of my fragmented experience in two different contexts, I explore how my identities and their intersection “mutate” from the Egyptian context to the UK context. Then, I reflect on how the intensity of oppression changed with this alteration in my intersectionality. In contextualizing my intersectional experience, first I problematize viewing intersectionality as a fixed acontextual ontology. Second, as a student immigrant and racialized minority in the United Kingdom, I seek to extend intersectionality and move beyond the traditional categories of race, class, gender, religion, and sexuality to include precarity as a pivotal social category that amplifies the intensity of oppression and marginalization, especially when intersected with race and gender. Finally, in sharing my reflection as a Middle Eastern woman, I contribute my unique experiences into the conversation, and a voice that has been muted, invisibled, marginalized, and excluded from the literature.     

Ridge Autoregression Estimation: LS Method

In an AR (p)-model, least-squares estimation of the parameters is considered when it is suspected that the parameters may belong to a linear subspace and the estimated covariance matrix is ill-conditioned. Accordingly, we define five estimators and study their properties in an asymptotic setup to discover dominance properties based on asymptotic distributional bias (ADB), MSE (ADMSE) matrices, and under quadratic risks (ADQR).     

A nonparametric test of symmetry based on the overlapping coefficient

In this paper, we introduce a new nonparametric test of symmetry based on the empirical overlap coefficient using kernel density estimation. Our investigation reveals that the new test is more powerful than the runs test of symmetry proposed by McWilliams [31]. Intensive simulation is conducted to examine the power of the proposed test. Data from a level I Trauma center are used to illustrate the procedures developed in this paper.     

‘Spite effects’ in tax evasion experiments

This paper sets out to consider individuals’ motivations to evade taxation. Experimental results indicate that individuals do not simply maximize pecuniary welfare. Their behaviour is consistent with the presence of a ‘spite effect’ when their perceptions are that enforcement variables are ‘excessive’.     

A double exponentially weigiited moving average control procedure with variable sampling intervals

Shewhart, cumulative sum (CUSUM), and exponentially weighted moving average (EWMA) control procedures with variable sampling intervals (VSI) have been investigated in recent years for detecting shifts in the process mean. Such procedures have been shown to be more efficient when compared with the corresponding fixed sampling interval (FSI) charts with respect to the average time to signal (ATS) when the average run length (ARL) values of both types of procedures are held equal. Frequent switching between the different sampling intervals can be a complicating factor in the application of control charts with variable sampling intervals. In this article, we propose using a double exponentially weighted moving average control procedure with variable sampling intervals (VSI-DEWMA) for detecting shifts in the process mean. It is shown that the proposed VSI-DEWMA control procedure is more efficient when compared with the corresponding fixed sampling interval FSI-DEWMA chart with respect to the average time to signal (ATS) when the average run length (ARL) values of both types of procedures are held equal. It is also shown that the VSI-DEWMA procedure reduces the average number of switches between the sampling intervals and has similar ATS properties as compared to the VSI-EMTMA control procedure     

Estimation of Sib–Sib Correlation via a Kotz-Type Density Function

We estimate sib–sib correlation by maximizing the log-likelihood of a Kotz-type distribution. Using extensive simulations we conclude that estimating sib–sib correlation using the proposed method has many advantages. Results are illustrated on a real life data set due to Galton. Testing of hypothesis about this correlation is also discussed using the three likelihood based tests and a test based on Srivastava's estimator. It is concluded that score test derived using Kotz-type density performs the best.