A comprehensive analysis of calendar anomalies in mature and emerging markets: essays on the major calendar anomalies in the US and Saudi markets

The research begins with a comprehensive study on 4 major calendar anomalies at industry level in the US market for 90 years which include a break point period in 1952. Daily returns are examined for the weekday, turn-of-the-month, January and Halloween effects and the results confirm that the effects of these anomalies exist and persist uniformly across almost all industries in both periods before and after the break point. Hence, calendar effects are driven by economic events affecting all industries rather than by industry-specific factors. The thesis starts with the US market given the maturity of the market and the extended data available which will provide an overall understanding of the topic of calendar anomalies. To delve deeper into the topic of calendar anomalies the research attempt to investigate the famous weekday effect in an emerging market, Saudi Arabia. This will give a deeper understanding of the topic since investors attributed to this market have many behavioural aspects that could affect the anomaly like cultural and religious beliefs. The research studies the existence of the anomaly in 15 industries in the Saudi stock market by applying a break point in June 2013 where there was a change in the weekend days. The findings confirm the existence of the anomaly pre-June 2013 only, providing evidence that the break point event of changing the weekend days directly affected the anomaly. From this standpoint, the research continue to explore the pre-holiday effect in Saudi Arabia to further investigate the effect of culture and religion on calendar anomalies. The study examines the anomaly in both market and industry level to confirm whether the effect is limited to certain sectors or is a wide-market phenomenon affecting all industries similarly. The data covers daily returns for both the general market and 15 industries over a period of almost 11 years, from 2009 to 2020. The findings confirm the existence of the pre-holiday effect at the general market and industry level for religious holidays, however, there is no evidence found on the existence of the anomaly on non-religious holidays

The Role of Family Physicians in Mental Health Care: Screening, Diagnosis, and Treatment Options

amily physicians play a pivotal role in the early detection, diagnosis, and management of mental health disorders within the community. This review article delves into the multifaceted responsibilities of family physicians in the realm of mental health care. Emphasizing the importance of primary care settings as the first point of contact for many patients, the article underscores the need for effective screening tools and methodologies tailored for these environments. The diagnostic precision of family physicians, often challenged by the broad spectrum of mental health symptoms, is explored alongside the potential implications of misdiagnoses. Furthermore, the article evaluates various treatment options, from pharmacological interventions to psychotherapy, and their applicability in primary care settings. The integration of technological advancements, such as electronic health records and telemedicine, is also discussed in the context of enhancing patient care. The review concludes by highlighting the importance of educating primary care physicians to not only pay close attention to the mental health of their patients, but also to be able to accurately screen and diagnose mental health issues using various diagnostic tools. Moreover, it is critical to develop more useful tools that can be used in the context of primary care settings

Between Shari'ah and International Standards: Protecting the Rights of the Child under Saudi Arabia's Human Rights Law

Between international standards and Islamic law, are children’s rights in Saudi Arabia protected? My research revolves around this question. It looks at the rights and best interests of the child in Saudi Arabia. What rights does international law grant children and similarly, what rights does Islamic law – Shari’ah grant them? Are international child laws currently being implemented as fully as it is possible under Islamic Law - Shari'ah law, as some claim? Or, as others allege, are Islam and Shari'ah law being used as excuses to deprive children of their rights and ‘best interests’ as intended by the United Nations Convention on the Rights of the Child (UNCRC)? Indeed, many practitioners in the region argue that it is not Shari'ah that imposes most of the alleged limitations on the exercise of children’s rights (as conceived in the UNCRC) in Muslim states, but that it is the governments themselves that do so. According to this view, the states are not implementing Islamic law as it should be implemented, but rather are using the notion of Islamic law (or allowing it to be used) as an instrument to deflect criticism from international human rights advocates. So, the question that imposes itself here is; whether convergence between international Children’s Rights and Islamic Children’s Rights can be reached in Saudi Arabia or not. More specifically, are the human rights of children and their best interests in Saudi Arabia, a country governed by Islamic Law, protected

Propane dry reforming over cerium promoted catalyst: enhancement of synthesis gas production under reduced carbon deposition

Among others, the light hydrocarbon (C1-C4 alkanes) dry reforming process has attracted considerable attention with increasing global oil price, for developing sustainable environmentally-compatible synthesis gas (H2/CO mixtures) production and utilisation technologies. However, the foremost advantage of immediate suitability for gas-to-liquids (GTL) fuels’ conversion has been prevented by severe carbon deposition, the main challenge that rapidly deactivates the catalyst and the attendant economic implications. As a result, the principal goal of this study was to improve the dry reforming process through two main strategies, namely: carbon-resilient catalyst design, and reactor operation. In particular, a bimetallic catalyst which is based on Ni, the key ingredient in industrial reforming catalysts, was promoted by cerium as a rare earth metal that is well known for its high capacity for oxygen storage as well as its flexibility in redox state.Catalysts were prepared by co-impregnation using cobalt, nickel and cerium nitrate on γ-alumina support. Bimetallic catalyst of 5wt%Co-10wt%Ni was promoted with 0-2.5wt% cerium in 0.5wt% increments. Catalyst physicochemical properties were measured via various techniques including N2-physisorption, H2-chemisorption, temperature programmed desorption of NH3, CO2, C3H8, CH4 and CO, UV–vis diffuse reflectance spectroscopy. Morphological examination such as XRD, TEM and SEM and thermogravimetric analysis for calcination, reduction and oxidation were also undertaken. CO2-TPD results demonstrated the basicity of the promoted catalyst was nearly doubled. XRD analysis confirmed the presence of CeO2 and TEM images verified the metal dispersion data obtained from H2-chemisorption.Catalyst evaluation, reaction kinetics studies and O2-co-feeding investigation were performed in a fixed-bed reactor of 15 mm ID at 798–923 K under atmospheric pressure. The increase in catalyst basicity was reflected in catalyst activity as syngas production was successfully increased with Ce content before attaining a plateau at 1.5wt% while total carbon in spent catalysts was reduced to almost zero beyond this critical Ce loading. Conversely, reforming kinetic and deactivation coefficients that estimated from transient data over longevity runs of 72 h, validated the improvement in the promoted catalyst. Nevertheless, reactor operational studies indicated the ability to enhance syngas production under O2-co-feeding and fluidisation approaches

Catalytic fixed bed membrane reactor operation for hydrocarbon conversion processes

Dry/CO2 reforming is one the hydrocarbon processes that recently has beeninteresting due to it is ability of producing a lower synthesis gas ratio (H2/CO).This synthesis gas is a highly significant product since it costs more than 50%of the total capital cost of gas to liquid (GTL) process. However, since thisreaction is thermodynamically limited, higher temperature or lower pressure isrequired to achieve higher conversion. Typically, reaction temperaturesbetween 1073 and 1173 K are used for catalytic dry reforming reactions.Consequently, these extreme temperatures lead to a severe carbondeposition causing a catalyst deactivation which is the major difficulty relatedto CO2 reforming reaction. This has pushed the efforts to be focused mainlyon the development of new catalysts. In fact, dry reforming of propane is anequilibrium-limited reaction which can be shifted to the product side byremoving one of the products out of the system which can be achieved usinga selective membrane reactor.This research is dedicated to investigate and study the catalytic performanceof dry reforming of propane over cobalt-nickel catalyst under the temperaturerange of 773-973 K. This bimetallic catalyst supported on δ-Al2O3 has beenutilized in this research since it exhibits better activity, selectivity, anddeactivation resistance than monometallic catalysts. Based on this, theprimary aims of this thesis are to examine this catalyst and to study the impactof using membrane reactor. In addition, the reaction mechanism and kineticare investigated using a fixed-bed reactor.Experimental observations have exposed that the catalyst is offering goodresults under this reaction. The catalysts analysis has confirmed the presenceof metal oxides in the catalyst. However, only at a lower carbon dioxide topropane ratio, i.e. lower than 3.5, a carbon signal has been reported. Theactivation energy study indicates that the process is unlimited by diffusion.The reaction order for propane and carbon dioxide has been found to be zeroand 1.17 respectively. This in turn has indicated that C3H8 activation reactionis taking place rapidly and carbon dioxide is suggested to be involved in therate determining step. In membrane reactor operation, the production rates forH2 and CO have been reported to increase as the sweep gas flow rateincreases. The co-current mode offers higher production rate and morestability than counter-current mode over the range of feed ratio. On the otherhand, fixed bed reactor shows stable performance and produces more COand H2 for both modes

COVID-19-Related Acute Respiratory Distress Syndrome in a Pregnant Woman Supported on ECMO: The Juxtaposition of Bleeding in a Hypercoagulable State

A 40-year-old pregnant woman at 28 weeks of gestation was diagnosed with severe acute respiratory failure syndrome (ARDS) due to coronavirus disease 2019 (COVID-19). She had severe hypoxemia despite the use of mechanical ventilation and muscle relaxant infusion. Veno-venous extracorporeal membrane oxygenation (VV-ECMO) was used, and she had a cesarian section while on ECMO support. She developed disseminated intravascular coagulation (DIC) with overt bleeding. This was managed by a multidisciplinary team (MDT) and a change of the ECMO circuit resulted in a dramatic improvement of her coagulation profile. Both the mother and the baby were discharged and went home in good condition

The rapid response team in outpatient settings identifies patients who need immediate intensive care unit admission: A call for policy maker

Background: Caregivers in the ambulatory care setting with differing clinical background could encounter a patient at high risk of deterioration. In the absence of a dedicated acute care team, the response to an unanticipated medical emergencies in these settings is likely to have a poor outcome. Objective: To describe our experience in implementing an intensivist-led rapid response team (RRT) in the outpatient settings that identified patients who needed immediate Intensive Care Unit (ICU) admission. The effect on in hospital arrests, mortality, and ICU outcome is not the scope of this study. Materials and Methods: This retrospective descriptive study was performed from January 1, 2009 to December 31, 2011 in a tertiary hospital. Data from hospital records were used (none from patients′ records). Consent was not needed. Measurements: Direct ICU admissions from the outpatient areas. Results: There were 90 patients cared for by RRT in the outpatient′s settings, 76 adult, and 14 pediatric patients. A total of12 adult patients were transferred directly to ICU. Among the patient who were transferred to the emergency department, additional four patients required to be transferred to ICU (total 16 patients [17.7%], 15 adult, and one pediatric patient). Follow-up at 24 h in the ICU showed death of one adult oncology patient (6.25%), and discharge of two patients (12.5%). Nine patients (81%) were still sick to require longer ICU stay. Conclusion: Intensivist-led RRT in outpatient settings identifies patients who are critically ill and in need of immediate ICU admission. Thus, an intensivist-led RRT policy in the outpatient settings needs to be implemented hospital wide

Detection and Classification of COVID-19 by Radiological Imaging Modalities Using Deep Learning Techniques: A Literature Review

Coronavirus disease (COVID-19) is a viral pneumonia that originated in China and has rapidly spread around the world. Early diagnosis is important to provide effective and timely treatment. Thus, many studies have attempted to solve the COVID-19 classification problems of workload classification, disease detection, and differentiation from other types of pneumonia and healthy lungs using different radiological imaging modalities. To date, several researchers have investigated the problem of using deep learning methods to detect COVID-19, but there are still unsolved challenges in this field, which this review aims to identify. The existing research on the COVID-19 classification problem suffers from limitations due to the use of the binary or flat multiclass classification, and building classifiers based on only a few classes. Moreover, most prior studies have focused on a single feature modality and evaluated their systems using a small public dataset. These studies also show a reliance on diagnostic processes based on CT as the main imaging modality, ignoring chest X-rays, as explained below. Accordingly, the aim of this review is to examine existing methods and frameworks in the literature that have been used to detect and classify COVID-19, as well as to identify research gaps and highlight the limitations from a critical perspective. The paper concludes with a list of recommendations, which are expected to assist future researchers in improving the diagnostic process for COVID-19 in particular. This should help to develop effective radiological diagnostic data for clinical applications and to open future directions in this area in general