Publications by authors named "Boubaker S"

This paper studies the forecasting power of uncertainty emanating from the commodities market, energy market, economic policy, and geopolitical threats to the CBOE Volatility Index (VIX). In this study, the relationship between the various uncertainty metrics throughout the period 2012-2022, using a multi-model transfer function technique optimized by particle swarm optimization (PSO) is estimated. Furthermore, we utilize PSO for parameter optimization within the multi-model framework, improving model performance and convergence speed.

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Article Synopsis
  • The Genome Tunisia Project is a two-phase initiative (2022-2035) aimed at sequencing the Tunisian Genome and advancing personalized medicine in Tunisia, a diverse North African country affected by human migration patterns from various continents.
  • A multidisciplinary team of Tunisian experts is focused on addressing key priorities, such as determining the reference genome sequence, enhancing education and awareness, and improving infrastructure for personalized medicine integration.
  • The project involves collaboration among various stakeholders, including healthcare providers and policymakers, and aims to boost research and innovation in genomics while improving healthcare practices in the region.
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The present investigation was undertaken to evaluate the toxic effects of CoCl-induced hepatotoxicity and fatty acid changes in juvenile Cyprinus carpio. Fish were divided into six experimental groups in duplicate. The first group served as controls.

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Dimethoate (DMT) is one of the most harmful and commonly used organophosphate pesticides in agricultural lands to control different groups of parasitic insects. However, this pesticide is considered a dangerous pollutant for aquatic organisms following its infiltration in coastal ecosystems through leaching. Yet, our investigation aimed to gain new insights into the toxicity mechanism of DMT in the muscles of the green crab Carcinus aestuarii, regarding oxidative stress, neurotransmission impairment, histological aspects, and changes in lipid composition, assessed for the first time on the green crab's muscle.

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Objective: The cafeteria diet (CD), designed as an experimental diet mimicking the obesogenic diet, may contribute to the pathogenesis of inflammatory bowel diseases (IBD). This study delves into the influence of spirulina (SP) on obesity associated with colitis in Wistar rats.

Methods: The amino acids composition of SP was analyzed using HPLC-FLD.

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  • - This study focuses on the challenges of cancer management in Africa, particularly in Tunisia, where limited resources and health system issues affect cancer care and the need for better identification of hereditary cancer syndromes.
  • - Researchers analyzed clinicopathological data from 521 patients and performed genetic testing, identifying 36 BRCA mutations associated with hereditary breast and ovarian cancer syndrome, along with other rare syndromes like Li-Fraumeni and Bloom syndrome.
  • - The findings emphasize the importance of enhancing genetic education and implementing genetic screening programs in Tunisia and other African countries to improve cancer management and reduce hereditary disease burdens.
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The world is currently experiencing the environmental challenge of global warming, necessitating careful planning of carbon dioxide (CO ) emissions to deal with this problem. This study examines the environmental challenge posed by CO emissions from both a long and short-term perspective. In the long term, despite efforts made by countries, our change-point detection analysis shows that there has been no structural change in CO emissions since 1950.

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Achieving the global decarbonization goal under global conflicts is becoming more uncertain. Within this context, this article seeks to examine the effects of global environmental management and efforts to achieve this goal. Specifically, it investigates the role of democracy, control of corruption, and civil society participation as mechanisms that moderate the impact of environmental policy and legislation, particularly clean energy policy and climate change legislation (laws and regulations), on carbon emissions in highly polluted countries.

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Dimethoate is a broad-spectrum organophosphate insecticide and acaricide. Through various pathways, such as runoff and drift, dimethoate can reach marine environment, and easily impact common organisms in coastal areas, close to agriculture lands, namely crustaceans. The purpose of this study was to investigate the potential effects of dimethoate exposure (50, 100, and 200 μg/l), for 1 day, on a wide range of markers of oxidative stress and neurotransmission impairment, as well as fatty acids composition and histopathological aspect in the gills of the green crab Carcinus aestuarii.

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: Obesity is currently a major health problem due to fatty acid accumulation and excess intake of energy, which leads to an increase in oxidative stress, particularly in the liver. The main goal of this study is to evaluate the protective effects of spirulina (SP) against cafeteria diet (CD)-induced obesity, oxidative stress, and lipotoxicity in rats. The rats were divided into four groups and received daily treatments for eight weeks as follows: control group fed a standard diet (SD 360 g/d); cafeteria diet group (CD 360 g/d); spirulina group (SP 500 mg/kg); and CD + SP group (500 mg/kg, .

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Since the last two decades, financial markets have exhibited several transformations owing to recurring crises episodes that has led to the development of alternative assets. Particularly, the commodity market has attracted attention from investors and hedgers. However, the operational research stream has also developed substantially based on the growth of the artificial intelligence field, which includes machine learning and deep learning.

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Toll-like receptor 9 (TLR9) is an intracellular innate immunity receptor that plays a vital role in chronic inflammation and in recognizing pathogenic and self-DNA in immune complexes. This activation of intracellular signaling leads to the transcription of either immune-related or malignancy genes through specific transcription factors. Thus, it has been hypothesized that TLR9 may cause glioma.

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Background: Thyroid cancer (TC) is a common endocrine malignancy that frequently harbours the oncogenic V600E BRAF mutation. This mutation has received considerable attention in recent years for its potential utility in the risk stratification and management of TC. This study aims to investigate BRAF mutational status in thyroid cancer of Libyan patients and their association with clinicopathological factors.

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COVID-19 has posed unprecedented challenges to global finances because of its unparalleled global scope, with both concomitant shocks as well as the likely altering of risk assessments and forecasts for the foreseeable future. As the effects of COVID-19 on financial markets and institutions have been widely addressed by various literature, we systematically synthesize this literature. Through a comprehensive search process, we extract and review 818 articles.

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Using gender as a theoretical framework, we analyse the dynamics of debt and equity financing during the COVID-19 pandemic for a cross-country sample of 8,921 private firms. We provide evidence of a slight gender bias in debt financing, with creditors favouring female entrepreneurs when dealing with cash flow problems during the COVID-19 pandemic. We find no evidence of gender bias in equity financing.

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This paper investigates the potential hedging and safe-haven properties of several alternative investment assets, including gold, Bitcoin, oil, and the oil price volatility index (OVX), against the risks of the Saudi stock market and its constituent sectors in different phases of the COVID-19 pandemic. Using daily data, we employ the bivariate dynamic conditional correlation-generalized autoregressive conditional heteroskedasticity (DCC-GARCH) technique to model volatilities and conditional correlations. Our findings show that all investigated alternative investment assets had a time-varying hedging role in the Saudi stock market, which became expensive during the early stages of the COVID-19 pandemic.

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The paper examines whether the structure of the risk factor disclosure in an IPO prospectus helps explain the cross-section of first-day returns in a sample of Chinese initial public offerings. This paper analyzes the semantics and content of risk disclosure based on an unsupervised machine learning algorithm. From both long-term and short-term perspectives, this paper explores how the information effect and risk effect of risk disclosure play their respective roles.

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Article Synopsis
  • The first COVID-19 case in Saudi Arabia was reported on March 2, 2020, and by June 22, 2022, cases surged to 788,294, highlighting the urgent need for effective pandemic response strategies.
  • This study aims to analyze historical COVID-19 data from Saudi Arabia and develop accurate forecasting models using ARIMA and Prophet techniques to predict new infections, recoveries, and deaths.
  • The research found that both models performed well, with ARIMA being slightly better at forecasting while Prophet was easier to use, providing valuable insights for future pandemic preparedness and showcasing the effectiveness of Saudi Arabia's response measures.
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Statistical properties that vary with time represent a challenge for time series forecasting. This paper proposes a change point-adaptive-RNN (CP-ADARNN) framework to predict crude oil prices with high-dimensional monthly variables. We first detect the structural breaks in predictors using the change point technique, and subsequently train a prediction model based on ADARNN.

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  • * A total of 236 E. coli isolates were tested, revealing that 4.2% were positive for the O157:H7 strain, and many isolates exhibited various virulence factors associated with this pathogen.
  • * The findings indicate that E. coli O157:H7 is present in healthy cattle, suggesting a potential risk for food-borne diseases in humans, highlighting the importance of monitoring this pathogen in the food supply.
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Breast cancer has different epidemio-clinical characteristics in Middle East and North-African populations compared to those reported in the Western countries. The aim of this study is to analyze the epidemiological and clinico-pathological features of breast cancer in Tunisia and to determine prognostic factors with special interest to family history, Ki-67 proliferation index and comorbidity. We retrospectively reviewed epidemiological and clinico-pathological data from patients' medical records, treated in the Medical Oncology Department at Abderrahmane Mami Hospital, in the period 2011-2015.

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Xeroderma pigmentosum (XP) is a DNA repair disease that predisposes to early skin cancers as cutaneous melanoma. Melanoma microenvironment contains inflammatory mediators, which would be interesting biomarkers for the prognosis or for the identification of novel therapeutic targets. We used a PCR array to evaluate the transcriptional pattern of 84 inflammatory genes in melanoma tumors obtained from XP patients (XP-Mel) and in sporadic melanoma (SP-Mel) compared to healthy skin.

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The evolution of the COVID-19 pandemic is highly unpredictable; however, its impacts are limited to neither a single sector nor a single country. This study evaluates the performance and efficiency of 49 Islamic banks across 10 countries during 2019-2020 to assess how those banks can preserve their performance and remain resilient in the aftermath of the COVID-19 pandemic. Using the conventional inverse data envelopment analysis (InvDEA) approach, we show that because of reductions in their outputs, 31 out of the 49 banks studied would need to reduce their inputs so that their efficiency can remain unchanged.

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This study provides new evidence on how risk spillovers occur from the United States to developing economies in Africa during the COVID-19 pandemic. The results show that downside risk exposures of African markets, financial firms and banks particularly increased during Phase I (30 January to 30 April 2020). The nature and magnitude of downside risk exposures of African financial markets were similar to those of the United States.

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We use the Conditional Value-at-Risk (CoVaR) model to develop the systemic contagion index (SCI) for cryptocurrencies and examine their spillover effects. The SCI exhibits the highest value during the COVID-19 period, indicating evidence of pandemic-driven contagion channels. Similarly, cryptocurrency systemic networks show that the COVID-19 period induced increased interconnections, highlighting a higher number of systemic contagion channels.

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