Investment Opportunity in Companies and Audit Report Lags: Evidence from Iran

The main objective of this study was to investigate the relationship between investment opportunities of companies and the delay in presenting the audit report. To measure the investment opportunities, company ranking method was used based on three ratio of market value to book value of assets, the ratio of market value to book value of equity and the ratio of gross property, machinery and equipment. To test the research hypotheses, data on 77 companies including 847 firm-year observation was collected from 2003 to 2013 and panel data method was used for estimating multivariate regression model. Results of the statistical tests conducted on the hypotheses showed that companies with more investment opportunities in comparison with other companies had shorter delay in the audit report

The interactions between Reactive Black 5 and human serum albumin: combined spectroscopic and molecular dynamics simulation approaches

Azo dyes are made in significant amounts annually and released into the environment after being employed in the industry. There are some reports about the toxic effects of these dyes on several organisms. Thus, the textile dye Reactive Black 5 (RB5) has been examined for its cytotoxic effects on the human serum albumin (HSA) structure. Molecular interaction between RB5 and HSA indicated the combination of docking methods, molecular dynamic simulation, and multi-spectroscopic approaches. HSA's intrinsic fluorescence was well quenched with enhancing RB5 level, confirming complex formation. Molecular dynamics (MD) simulation was done to study the cytotoxic effects of RB5 and HSA conformation. Molecular modeling revealed that the RB5-HSA complex was stabilized by hydrogen bonds and van der Waals interactions. The results of molecular docking revealed that the binding energy of RB5 to HSA was - 27.94 kJ/mol. The change in secondary structure causes the annihilation of hydrogen bonding networks and the reduction of biological activity. This research can indicate a suitable molecular modeling interaction of RB5 and HAS and broaden our knowledge for azo dye toxicity under natural conditions

Interaction of reactive Red195 with human serum albumin: Determination of the binding mechanism and binding site by spectroscopic and molecular modeling methods

Reactive Red195 (RR195) was the first synthetic color patented for textile dying in 1856. Azo dyes have arisen considerable environmental concerns in recent decades due to the large volume of water they require throughout the coloring process and the polluted of industrial sewage. Azo dye due to their chemical composition, including aromatic rings, azoic linkages, and amino groups, are not bio-degradable and exceedingly resistant in the aquatic environment, posing an acute threat to human health. In this investigation, to estimate the toxicity of the RR195 at the protein level, the influences of RR195 on human serum albumin (HSA) were described by molecular modeling, steady-state fluorescence, ultraviolet-visible spectroscopy (UV�Vis), circular dichroism spectroscopy (CD), and Thermal stability (Tm). The alteration in entropy (�S) and enthalpy (�H) showed that hydrophobic forces were the dominant intermolecular forces in the binding of the RR195 to HSA. The binding constant of HSA�RR195 is high, presenting that RR195, which has a high affinity to HSA. The changes of protein secondary structure in the presence of the RR195 approved by CD spectroscopy method. A small reduction in the RG value of the HSA-RR195 system demonstrated a conformational difference in the compaction of HSA

A survey on data aggregation techniques in IoT sensor networks

© 2019, Springer Science+Business Media, LLC, part of Springer Nature. There is a growing interest in using wireless sensor technologies in various Internet of things scenarios. Considering the huge growth of smart objects and their applications, the need to collect and analyze their product data are becoming one of the main challenges. Sensor nodes are powered by batteries, efficient operations in term of energy are critical. Toward that end, it is desirable for a sensor node to eliminate redundancies in the received data from the neighboring nodes before transferring the final data to the central station. Data aggregation is one of the influential techniques in elimination of data redundancy and improvement of energy efficiency; also it increases the lifespan of Wireless Sensor Networks. In addition, the efficient data aggregation protocol can reduce network traffic. When a specific objective takes place in a specific area, it might be detected by more than one sensor. Considering the main challenges and aspects of data aggregation in wireless sensor networks, a review on different types of data aggregation techniques and protocols are presented in this paper. The ultimate objective of this study is to make the basic foundations to develop new advanced designs based on data integration techniques and clustering that have been proposed so far. Major techniques of data integration in wireless sensor networks covering ground, underground and underwater sensor networks are presented in this paper and the applications, advantages and disadvantages of using each technique are described

A novel insight into the cytotoxic effects of Tephrosin with calf thymus DNA: Experimental and in silico approaches

Tephrosin (TP) is a retinoid isoflavonoid that possesses various pharmacological and biological properties such as antitumor activity, anti-inflammatory, antimicrobial, anthelmintic, and anti-insect effects. In this work, the DNA binding characteristics of Tephrosin (TP) and its cytotoxic effect on cancer cell lines were investigated by the different techniques. The binding interaction between TP with calf thymus DNA (ctDNA) has been described using multispectroscopic methods and computational calculations. The results of UV�Visible absorption showed the occurrence of groove binding between TP and ctDNA, which was also supported by the results from a negligible change in CD signal and melting temperature (Tm), as well as the quenching effect of TP on DNA. Furthermore, various thermodynamic parameters revealed that the binding process was spontaneous and the main driving-forces were hydrophobic forces. Besides with this research, computational experiments showed that TP as a DNA binding agent, inserted into the minor groove of B-DNA fragment with a C-G rich region, and forming a stable complex. MTT analysis of TP against MCF-7 cell lines represented a high cytotoxic effect

Promoting Responsible Business Practices: A Case of Chambers of Commerce

Employer organizations and business associations are the advocates of private organizations’ interests. They also provide a platform for private enterprises to tap into synergetic and collaborative opportunities. Chambers of commerce, in particular, as well-organized establishments in the business environment are in a unique position to guide and assist organizations to thrive and stay competitive. To this end, recently, chambers of commerce have embarked on fostering responsible business practices among their members. The raison d’être behind this movement and the types of action taken have been largely neglected by the academic research. This study examines a number of leading chambers of commerce and business associations from both developed and developing countries in an attempt to shed light on the current responsible business practices in these organizations

Insights into the binding interaction of Reactive Yellow 145 with human serum albumin from a biophysics point of view

The interaction between Reactive Yellow 145 (RY145) and human serum albumin (HSA) under physiological conditions was studied by the methods of multiple spectroscopic, molecular docking, and molecular dynamic (MD) simulation. Fluorescence data revealed that the fluorescence quenching of HSA by RY145 resulted from the formation of the RY145–HSA complex. According to the modified Stern–Volmer equation, the effective quenching constants (KA) between RY145 and HSA at two different temperatures were obtained to be 114.15 × 104, and 52.55 × 104 L/mol, respectively. ΔH and ΔS were determined to be negative, showing that van der Waals force and hydrogen bonds were the governing intermolecular force in stabilizing the complex. The outcomes of UV– visible spectra, fluorescence spectroscopy, and CD spectra exhibited apparent modifications in the microenvironment and conformation of HSA, particularly for the secondary structure. The MD simulation and molecular docking supported experimental findings

Deciphering the DNA-binding affinity, cytotoxicity and apoptosis induce as the anticancer mechanism of Bavachinin: An experimental and computational investigation

One of the most important mechanism by which bioflavonoids can exert their effects in cancer treatment, is through their interaction with bio-macromolecules such as DNA. Recent literature emphasizes the role of Bavachinin (BVC) as an emerging anticancer agent. However, there are no reports on its ability to interact with DNA. The present study investigated the DNA binding properties of BVC by many spectroscopic and computational approaches. The evidences are provided from UV–visible and CD spectral analyses illustrated that BVC interacted with ctDNA through minor groove binding mode. Based on the thermodynamic analyses, it can be inferred that the binding process was spontaneous, and the hydrophobic interaction played a major role in BVC-ctDNA binding. In silico molecular docking and dynamic simulation finally strengthened our experimental results that BVC was located in the minor groove (AT- rich) region of B-DNA structure and resulted in the slight alteration in the secondary structure of DNA during the interaction process. Additionally, BVC indicated significant cytotoxicity against MCF-7 breast cancer cells. Furthermore, quantitative analyses demonstrate that BVC treatment significantly increased the expression of pro-apoptotic genes; p53, caspase-3, -8, and -9 in MCF-7 cells. In order to further investigate the molecular targets of BVC, molecular docking studies indicated a relatively good binding affinity of BVC with pro-apoptotic proteins. In effect, BVC can be considered as a small organic compound with DNA binding property, appropriate cytotoxic activity, and potential of apoptotic inducing that can be adopted for medical science and pharmacy

Bi-allelic Mutations in ALDH5A1 is associated with succinic semialdehyde dehydrogenase deficiency and severe intellectual disability

Homozygous mutations of ALDH5A1 have been reportedly associated with Succinic semialdehyde dehydrogenase deficiency (SSADHD) that affects gamma-aminobutyric acid (GABA) catabolism and evinces a wide range of clinical phenotype from mild intellectual disability to severe neurodegenerative disorders. We report clinical and molecular data of a Lor family with 2 affected members presenting with severe intellectual disability, developmental delay, and generalized tonic-clonic seizures. A comprehensive genetic study that included whole-exome sequencing identified a homozygous missense substitution (NM001080:c.G1321A:p.G441R) in ALDH5A1 (Aldehyde Dehydrogenase 5 Family Member A1) gene, consistent with clinical phenotype in the patients and co-segregating with the disease in the family. The non-synonymous mutation, p.G441R, affects a highly conserved amino acid residue, which is expected to cause a severe destabilization of the enzyme. Protein modeling demonstrated an impairment of the succinic semialdehyde (SSA) binding tunnel accessibility, and the anticipation of the protein folding stability and dynamics was a decrease in the free energy by 4.02 kcal/mol. Consistent with these in silico findings, excessive gamma -hydroxybutyrate (GHB) could be detected in patients' urine as the byproduct of the GABA pathway. SSADHD, Succinic semialdehyde dehydrogenase deficiency; GABA, gamma-aminobutyric acid; ALDH5A1, Aldehyde Dehydrogenase 5 Family Member A1; GHB, gamma -hydroxybutyrate; SSA, succinic semi aldehyde; WISC, Wechsler Intelligence Scale for Children; CNS, central nervous system ; EEG, electroencephalography; EEEF, empirical effective energy functions; ASD, autism spectrum disorder; ADHD, attention deficit hyperactivity disorder; IQ, intelligence quotient; EMG, electromyography; NCV, nerve conduction velocity; CP, cerebral palsy