13 research outputs found
Financial distress and stock price crash risk in Egyptian firms
Economic policy uncertainty intensified as a result of the global financial crisis. To overcome these obstacles, firms handle issues with financial distress and crash risk more proactively. This paper offers new insights into the relationship between financial distress and crash risk on the Egyptian stock market during the period of 2014–2021 and presents how managers strengthen the bad news hoarding mechanism to their advantage. Data were collected via financial statements and reports obtained from the Thomson Reuters database using 824 annual observations of 103 Egyptian firms via the generalized method of moments and ordinary least squares. Results show a strong positive impact of financial distress on crash risk using OLS and GMM. Results support the role of managerial opportunism to cover up bad news that undermines a firm’s economic fundamentals. The findings support an agency theory of how financial distress affects crash risk. The findings support conducting robust tests for alternative financial distress and crash risk measures
Fabrication and Application of Zeolite/Acanthophora Spicifera Nanoporous Composite for Adsorption of Congo Red Dye from Wastewater
Systematic investigations involving laboratory, analytical, and field trials were carried out to obtain the most efficient adsorbent for the removal of congo red (CR) dye from industrial effluent. Modification of the zeolite (Z) by the Acanthophora Spicifera algae (AS; marine algae) was evaluated in terms of adsorption capability of the zeolite to remove CR dye from aqueous solution. The zeolite/algae composite (ZAS) was fabricated using the wet impregnation technique. The AS, Z, and the synthesized ZAS composite were analyzed utilizing various characterization techniques. The newly synthesized ZAS composite has an adsorption capacity that is significantly higher than that of Z and AS, particularly at low CR concentrations. Batch experiments were carried out to explore the effects of different experimental factors, as well as the dye adsorption isotherms and kinetics. Owing to the presence of intermolecular interactions, the computational analysis showed that the adsorption of the CR molecule on zeolite surfaces is exothermic, energetically favorable, and spontaneous. Furthermore, growing the zeolite surface area has no discernible effect on the adsorption energies in all configurations. The ZAS composite may be used as a low-cost substitute adsorbent for the removal of anionic dyes from industrial wastewater at lower dye concentrations, according to the experimental results. Adsorption of CR dye onto Z, AS, and ZAS adsorbents was adequately explained by pseudo-second-order kinetics and the Langmuir isotherm. The sorption mechanism was also evaluated using Weber’s intra-particle diffusion module. Finally, field testing revealed that the newly synthesized adsorbent was 98.0% efficient at extracting dyes from industrial wastewater, proving the foundation of modern eco-friendly materials that aid in the reuse of industrial wastewater
Age-Specific Gene Expression Signatures for Breast Tumors and Cross-Species Conserved Potential Cancer Progression Markers in Young Women
<div><p>Breast cancer in young women is more aggressive with a poorer prognosis and overall survival compared to older women diagnosed with the disease. Despite recent research, the underlying biology and molecular alterations that drive the aggressive nature of breast tumors associated with breast cancer in young women have yet to be elucidated. In this study, we performed transcriptomic profile and network analyses of breast tumors arising in Middle Eastern women to identify age-specific gene signatures. Moreover, we studied molecular alterations associated with cancer progression in young women using cross-species comparative genomics approach coupled with copy number alterations (CNA) associated with breast cancers from independent studies. We identified 63 genes specific to tumors in young women that showed alterations distinct from two age cohorts of older women. The network analyses revealed potential critical regulatory roles for Myc, PI3K/Akt, NF-κB, and IL-1 in disease characteristics of breast tumors arising in young women. Cross-species comparative genomics analysis of progression from pre-invasive ductal carcinoma <i>in situ</i> (DCIS) to invasive ductal carcinoma (IDC) revealed 16 genes with concomitant genomic alterations, <i>CCNB2, UBE2C, TOP2A</i>, <i>CEP55</i>, TPX2, <i>BIRC5, KIAA0101</i>, <i>SHCBP1</i>, <i>UBE2T</i>, <i>PTTG1</i>, <i>NUSAP1</i>, <i>DEPDC1</i>, <i>HELLS</i>, <i>CCNB1</i>, KIF4A, and <i>RRM2,</i> that may be involved in tumorigenesis and in the processes of invasion and progression of disease. Array findings were validated using qRT-PCR, immunohistochemistry, and extensive <i>in silico</i> analyses of independently performed microarray datasets. To our knowledge, this study provides the first comprehensive genomic analysis of breast cancer in Middle Eastern women in age-specific cohorts and potential markers for cancer progression in young women. Our data demonstrate that cancer appearing in young women contain distinct biological characteristics and deregulated signaling pathways. Moreover, our integrative genomic and cross-species analysis may provide robust biomarkers for the detection of disease progression in young women, and lead to more effective treatment strategies.</p></div
Dimethyl fumarate interferes with MyD88-dependent toll-like receptor signalling pathway in isoproterenol-induced cardiac hypertrophy model
Identification of genes specific to young women with breast cancer.
<p>(<b>A</b>)The unsupervised principal component analysis (PCA) separated samples according to their age group hence supporting the conclusion that there is a distinct gene expression changes associated with the tumor in different age groups. The red spheres refer to young patients (≤45; Young), green for 45–55 years (Pre), and blue for ≥55 years (Post). (<b>B</b>) Venn diagram characterizing differential gene expression between and specific to different age groups. The red circle (left) shows the 804 probes that are differentially expressed between Young and Post; 77 probes (corresponding to 63 genes) were found to be specific to tumor in young women only (circled in <i>light pink)</i>. <b>(C</b>) Unsupervised two-dimensional hierarchical clustering of all tumor samples based on their gene expression similarity using young-age-specific 77 probes was performed using Pearson’s correlation with average linkage clustering. The hierarchical clustering revealed clear pattern of genes deregulation defining two main transcriptome clusters, one was mainly composed primarily younger cases, and one was composed of primarily elderly women. Samples are denoted in columns and genes are denoted in rows (gene symbols listed on the right). The expression level of each gene across the samples is scaled to [−4, 4] interval. These mapped expression levels are depicted using a color scale as shown at the bottom of the figure, as such highly expressed genes are indicated in red, intermediate in black, and weakly expressed in green.</p
List of 16 cross-species conserved DCIS to IDC potential progression gene signature.
<p><sup>1</sup>Genes with asterisk are also located in the chromosomal CNA region and ** Mutation found in patients in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0063204#pone.0063204-1" target="_blank">[30]</a>.</p><p><sup>a</sup>DCIS indicates fold change between the mean values of expression observed in DCIS (ductal carcinoma <i>in situ</i>) and age-matched normal controls.</p><p><sup>b</sup>IDC indicates fold change between the mean values of expression observed in IDC (invasive ductal carcinoma) and age-matched normal controls.</p><p><sup>c</sup>Hazard ration (HR) with 95% confidence intervals and <sup>d</sup>logrank P-value for Recurrence free survival (RFS) using data from Gyorfffy et al <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0063204#pone.0063204-Gyorffy1" target="_blank">[51]</a>.</p><p><sup>†</sup> and <sup>‡</sup> logrank P-value for distant metastasis free survival using data from GSE7390 <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0063204#pone.0063204-Desmedt1" target="_blank">[52]</a> and GSE12093 <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0063204#pone.0063204-Zhang1" target="_blank">[53]</a>, respectively. NS. Not significant; na:Not available.</p
Progression from ductal carcinoma in situ (DCIS) to invasive ductal carcinoma (IDC) in young women.
<p>(<b>A</b>) The Venn diagram illustrates that there are 1015 genes differentially expressed (up- or down-regulated) in DCIS compared to normal, whereas 4873 genes differentially expressed in IDC compared to normal controls. 143 genes differentially regulated between IDC and DCIS (green circle). (<b>B</b>) The functional analysis of 16 potential progression genes identified through cross-species comparative genomics analysis. Y-axis indicates the significance (-log P value) of the functional association that is dependent on the number of genes in a class as well as biologic relevance. The threshold line represents a P value of 0.05. (<b>C</b>) Gene interaction networks and pathways analyses of 16-gene progression signature. Green/red indicates decreased/increased mRNA expression in IDC compared to normal controls. The color intensity is correlated with fold change. Straight lines are for direct gene to gene interactions, dashed lines are for indirect ones. (<b>D</b>) Invasive breast tumor cases (from TCGA, Nature 2012 <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0063204#pone.0063204-1" target="_blank">[30]</a>) displayed altered amplification/homozygous deletion/up-or down-regulation (RNA) or mutation in our 16-progression gene signature. Cases are denoted in columns, and genes in rows (gene symbols are listed on the left).</p
Protein expression of selected genes by immunohistochemical staining in breast cancer patients’ samples using antibodies directed against (B) TGFA, (C) IL1RN, and (D) PI3K.
<p>Representative images of positively stained tumors are shown (magnification, ×200).</p
Age-specific patients’ characteristics.
<p>Age-specific patients’ characteristics.</p
Functional and network analyses of genes specific to young women.
<p>(<b>A</b>) The gene ontology and functional analysis of young-age-tumor specific genes (up/down-regulated) were performed using the Ingenuity knowledge base. X-axis indicates the significance (-log P value) of the functional/pathway association that is dependent on the number of genes in a class as well as biologic relevance. The threshold line represents a P value of 0.05. (<b>B–C</b>) Gene interaction network analyses of genes specific to young women and very young women, respectively. Top scoring gene interaction networks with high relevancy scores (with highest relevance score) are shown. Green/red indicates decreased/increased mRNA expression in younger patients compared to older counterparts. The color intensity is correlated with fold change. Straight lines are for direct gene to gene interactions, dashed lines are for indirect ones (<b>D</b>) QRTPCR validation. Grey bars represent microarray hybridizations, and, and dark bars represent values from qRT-PCR. Ratio of expression for each gene in older group (>45) to very young group (≤35) is shown as fold change. A significant correlation existed between the microarray and realtime RT-PCR results.</p