Three essays on the impact of political and economic shocks during childhood on health outcomes : evidence from developing countries

Indiana University-Purdue University Indianapolis (IUPUI)The dissertation consists of three essays which attempt to capture causal relationships between shocks during childhood and before birth, and later health outcomes. Exogenous shocks such as the experiences of war and political upheaval are treated as natural experiments which minimize problems of endogeneity and selection that are present in most association studies. The first essay examines how exposure to civil war during childhood affects females’ outcomes including age at first marriage, fertility, and second generation infant mortality using the Biafra war which took place in Nigeria between years 1967 and 1970. The study uses difference-in-difference analysis to show that females that witnessed war during early adolescence got married younger than their peers not exposed to the war, and were more likely to have higher fertility and second-generation infant mortality. The second essay uses the same shock, the Biafra war, to test if males’ and females’ exposure to community-level violence results in higher risk of experiencing domestic violence in their marital relationships in the long-run. The study conducts difference-in-difference analysis on females and males separately to show that the males’ exposure to the war at ages 13 and older is the main mechanism behind females being victims of domestic violence in the long-run. The third essay examines the impact of acute prenatal stress on birth weight using the 2011 Egyptian revolution fatalities as an indicator for exposure to violence and stressful events. Results show that higher prenatal stress resulting from political conflict during the first and second trimesters of pregnancy has a significant negative impact on birth weight. This finding is robust to restricting the sample to siblings’ data and using mother fixed effects, suggesting that neither observable nor unobservable characteristics of mothers are driving the results

Constructing a new mixed probability distribution with fuzzy reliability estimation

This paper deals with constructing mixed probability distribution from mixing exponential (β) and Rayleigh along with β. Accordingly, the mixing proportions are ( α/(α+1) ) and ( 1/(α+1) ).At that point, the mixed PDF and CDF were investigated in this study. The mixed reliability has determined based on estimating its two parameters (α,β) by three different methods, which are maximum likelihood, moments and percentiles method. The fuzzy reliability estimators are compared and the results of comparison are explained based on simulation procedure with detailed tables

The Association of COVID-19 Pandemic Stress With Health-Related Quality of Life in the Kingdom of Saudi Arabia: A Cross-Sectional Analytical Study

Background: There is a global disaster since WHO declared Covid-19 as a pandemic. With the increase in cases & mortality rate, various health issues viz., stress, mental disorders and altered health-related quality of life have been noted as a result of pandemic and lockdowns. This study aimed to assess the association of COVID-19 pandemic stress with health-related quality of life in the Kingdom of Saudi Arabia.Methodology: It was a cross-sectional analytical study. Subjects included 878 citizens and residents of Saudi Arabia aged 18 years and above. Convenience, non-probability sampling technique was used. A web-based, self-administered, electronic questionnaire in Arabic language having three sections; Sociodemographic & clinical profile, Standard PSS-10, and Standard SF-12 was used as the study tool and distributed through various social media means. The study period was of 2 months. Data were analyzed using SPS version 25. Descriptive statistics, Pearson's correlation coefficient, independent sample t-test and the one-way analysis of variance (ANOVA) were employed for suitable statistical analysis.Results: Almost two-thirds of the subjects were between the age of 18 to < 40 and majority (74.1%) being females. Majority (83.0%) reported as having no chronic diseases, and 69.5% had no contact history with COVID-19 cases. The mean of MCS & PCS was (32.34 ± 25.30) & (41.65 ± 11.82), respectively. Majority (67.6%) had a moderate level of COVID-19 stress. A significant negative relationship between total stress scores and HRQOL domains was observed.Conclusion: Majority subjects had a moderate level of stress related to COVID-19 lockdown. Stress during COVID-19 has a significant negative association with both physical and mental HRQOL in which MCS was significantly lower than PCS. It is recommended to evaluate the effectiveness of stress management program and follow a holistic approach

The Mechanism Underlying Transient Weakness in Myotonia Congenita

In addition to the hallmark muscle stiffness, patients with recessive myotonia congenita (Becker disease) experience debilitating bouts of transient weakness that remain poorly understood despite years of study. We performed intracellular recordings from muscle of both genetic and pharmacologic mouse models of Becker disease to identify the mechanism underlying transient weakness. Our recordings reveal transient depolarizations (plateau potentials) of the membrane potential to -25 to -35 mV in the genetic and pharmacologic models of Becker disease. Both Na + and Ca 2+ currents contribute to plateau potentials. Na + persistent inward current (NaPIC) through Na V 1.4 channels is the key trigger of plateau potentials and current through Ca V 1.1 Ca 2+ channels contributes to the duration of the plateau. Inhibiting NaPIC with ranolazine prevents the development of plateau potentials and eliminates transient weakness in vivo. These data suggest that targeting NaPIC may be an effective treatment to prevent transient weakness in myotonia congenita

Improving the decision-making process in the higher learning institutions via electronic records management system adoption

This is an accepted manuscript of an article published by KSII in KSII Transactions on Internet and Information Systems on 31/01/2021, available online: http://itiis.org/digital-library/24232 The accepted version of the publication may differ from the final published version.Electronic Records Management System (ERMS) is a computer program or set of applications that is utilized for keeping up to date records along with their storage. ERMS has been extensively utilized for enhancing the performance of academic institutions. The system assists in the planning and decision-making processes, which in turn enhances the competencies. However, although ERMS is significant in supporting the process of decision-making, the majority of organizations have failed to take an initiative to implement it, taking into account that are some implementing it without an appropriate framework, and thus resulted in the practice which does not meet the accepted standard. Therefore, this study identifies the factors influencing the adoption of ERMS among employees of HLI in Yemen and the role of such adoption in the decision-making process, using the Unified Theory of Acceptance and Use of Technology (UTAUT) along with Technology, Organization and Environment (TOE) as the underpinning theories. The study conducts a cross-sectional survey with a questionnaire as the technique for data collection, distributed to 364 participants in various Yemeni public Higher Learning Institutions (HLI). Using AMOS as a statistical method, the findings revealed there are significant and positive relationships between technology factors (effort expectancy, performance expectancy, IT infrastructure and security), organizational factors (top management support, financial support, training, and policy),environmental factors (competitiveness pressure, facilitating conditions and trust) and behavioral intention to adopt ERMS, which in return has a significant relationship with the process of decision-making in HLI. The study also presents a variety of theoretical and empirical contributions that enrich the body of knowledge in the field of technology adoption and the electronic record’s domain

Persistent Inward Currents Play a Role in Muscle Dysfunction Seen in Myotonia Congenita

Myotonia congenita is a rare skeletal muscle channelopathy caused by a reduced chloride channel (ClC-1) current, which results in debilitating muscle hyperexcitability, prolonged contractions, and transient episodes of weakness. The excitatory events that trigger myotonic action potentials in the absence of stabilizing ClC-1 current are not fully understood. My in vitro intracellular recordings from a mouse homozygous knockout of ClC-1 revealed a slow after-depolarization (AfD) that triggers myotonic action potentials. The AfD is well-explained by a tetrododoxin-sensitive and voltage-dependent Na+ persistent inward current (NaPIC). Notably, this NaPIC undergoes slow inactivation over seconds, thus providing the first mechanistic explanation for the end of myotonic runs. Highlighting the significance of this mechanism, we show that ranolazine and elevated serum divalent cations eliminate myotonia by inhibiting AfD and NaPIC. The electrophysiological events responsible for the transient weakness are not well understood either. My in vitro intracellular recordings revealed a novel behavior, in which the muscle is functionally inexcitable for seconds to minutes. This hanging behavior, as I refer to it, is likely to be responsible for periods of weakness described by patients and is explained by another persistent inward current. Partial pharmacological block of this other PIC decreases the hanging behavior in myotonic muscle. This work significantly changes our understanding of the mechanisms underlying myotonia and transient weakness seen in myotonia congenita and reveals a novel and highly effective therapeutic target

Persistent Inward Currents Play a Role in Muscle Dysfunction Seen inMyotonia Congenita

Myotonia congenita is a rare skeletal muscle channelopathy caused by a reduced chloride channel (ClC-1) current, which results in debilitating muscle hyperexcitability, prolonged contractions, and transient episodes of weakness. The excitatory events that trigger myotonic action potentials in the absence of stabilizing ClC-1 current are not fully understood. My in vitro intracellular recordings from a mouse homozygous knockout of ClC-1 revealed a slow after-depolarization (AfD) that triggers myotonic action potentials. The AfD is well-explained by a tetrododoxin-sensitive and voltage-dependent Na+ persistent inward current (NaPIC). Notably, this NaPIC undergoes slow inactivation over seconds, thus providing the first mechanistic explanation for the end of myotonic runs. Highlighting the significance of this mechanism, we show that ranolazine and elevated serum divalent cations eliminate myotonia by inhibiting AfD and NaPIC. The electrophysiological events responsible for the transient weakness are not well understood either. My in vitro intracellular recordings revealed a novel behavior, in which the muscle is functionally inexcitable for seconds to minutes. This hanging behavior, as I refer to it, is likely to be responsible for periods of weakness described by patients and is explained by another persistent inward current. Partial pharmacological block of this other PIC decreases the hanging behavior in myotonic muscle. This work significantly changes our understanding of the mechanisms underlying myotonia and transient weakness seen in myotonia congenita and reveals a novel and highly effective therapeutic target

Microeconomics of Brand Loyalty: Learning, Switching, and Uncertainty

In a world of competition, loyalty to a particular brand has a significant role in the behaviour of economic agents and the outcome of markets. The objective of this thesis is to examine the microeconomics of brand loyalty from three dimensions: consumer learning by using markets with switching costs, and uncertainty in product quality. The various methodologies used are based on extensions, modeling, and integrative analysis of some works in the literature, most notably those of Klemperer, Pepall, Thisse, Gabszewicz, Schwartz and Wilde, and Tirole. Brand loyalty arising from the above mentioned perspectives is tackled via three models. The first model is a two-period model examining the optimal pricing strategies to be adopted by an incumbent firm in a market characterized by sequential entry of firms and endogenous learning costs of consumers. The second model is a three-stage model examining the optimal pricing strategies to be adopted by a new entrant and an incumbent firm within a duopoly market with existence of switching costs. Sequential entry is assumed and sequential reactionary pricing strategies are derived. The third model is an integrative model dealing with consumer uncertainty in the quality of offered brands coupled with degree of price competitiveness of firms. Consumers are classified by their shopping behaviour whereas firms are differentiated by being honest, dishonest or opportunistic. Our findings indicate that the nature of brand loyalty alters market behaviour according to relative learning costs, fixed disutility of switching to an inexperienced brand, and joint probability of uncertain outcomes. In particular, consumer learning yields first-mover advantage, whereas the existence of switching costs softens price competition based on reactionary strategies, and uncertainty in product quality induces historical reputation of firms as an important determinant of consumer loyalty