A spatial analysis of COVID-19 reported cases in the Gauteng province, South Africa: Identifying wards to be targeted early in future infectious diseases outbreak

The COVID-19 pandemic caused major disruptions and contributed to the loss of livelihoods and income. The pandemic also provided public health and health systems policy shifts towards better promotion and protection in responding to such disasters and emergencies. Due to differing effects of socio-economic infectious disease vulnerabilities and pre-pandemic levels of preparedness for health emergencies, health system strengthening requires targeted and ununiform implementation. We employ spatial statistical methods on the COVID-19 confirmed cases in identifying wards that could be targeted for strengthening health security in the Gauteng Province, South Africa. In this way, the identified high-risk wards would be more effective and prepared to respond to future pandemics and emergencies.Comment: 21 pages, 10 figures and 9 table

The effect of audit committee characteristics and auditor changes on financial restatement in Iran

El presente estudio tiene como objetivo comprender y familiarizarse más con el impacto y las funciones del comité de auditoría y sus características, incluida la experiencia y la independencia de los miembros, las experiencias relacionadas y el cambio de auditor sobre la calidad de la información financiera en las empresas que cotizan en la Bolsa de Valores de Teherán (TSE). Los datos requeridos se recopilan de 105 empresas que cotizan en el TSE durante 2012-2016 y se utiliza el modelo de regresión logística para la prueba de hipótesis. Los hallazgos del estudio indican un impacto positivo y significativo de las características del comité de auditoría, excepto la independencia de la auditoría que representa una asociación negativa, y los cambios de auditor en la reexpresión financiera. La innovación del presente estudio en relación con otros estudios realizados radica en la evaluación simultánea de las características del comité de auditoría y el cambio de auditor sobre la calidad de la información financiera. Dichos resultados podrían ser apropiados para que los profesionales de acciones y valores cumplan con el organigrama del comité de auditoría, requieran el uso de principios de gobierno corporativo y proporcionen voluntariamente un informe de gobierno corporativo.The present study aims to realize and become more familiar with the impact and the functions of audit committee and its characteristics, including the expertise and independence of members, related experiences, and change of auditor on the quality of financial reporting in companies listed on the Tehran Stock Exchange (TSE). The required data are gathered from 105 listed companies on the TSE during 2012-2016 and logistic regression model is used for the hypothesis testing. The findings of the study indicate a positive and significant impact of audit committee characteristics, except audit independency which represents a negative association, and changes of auditor on financial restatement. The innovation of the present study relative to other conducted studies lies in the simultaneous evaluation of audit committee characteristics and change of auditor on the quality of financial reporting. Such results could be appropriate for Stocks and Securities practitioners to comply with the chart of the audit committee, to necessitate the use of corporate governance principles, and to voluntarily provide a corporate governance reportUniversidad Pablo de Olavid

Synthesis of Polyamide 6 by Anionic Polymerization of ε-Caprolactam in an Internal Mixer: Effect of Polymerization Reaction Time

The main objective of the present work was to synthesis polyamide 6 through anionic polymerization of ε-caprolactam in an internal mixer. The reaction time and the rheological properties of samples during the polymerization were studied. The samples were characterized by Thermo Gravimetry Analysis (TGA), Differential Scanning Calorimeter (DSC) and FT-IR spectrometer. The melt flow behavior and viscoelastic properties of the samples were studied by using a Rheometric Mechanical Spectrometer (RMS). The polymerization reaction was found to be very fast such that it completed within 6 minutes as could be detected by following the mixing torque which reached to a steady state after passing a maximum. These results suggest that there is a reaction time above which the viscoelastic behavior of the samples almost remained unchanged, while the viscosity and elasticity of the samples continue to decrease with polymerization reaction time as a result of thermochemical degradation

Comparison of Antibacterial Effects of Photodynamic Therapy and An Irrigation Activation System on Root Canals Infected With Enterococcus faecalis: An In Vitro Study

Introduction: Enterococcus faecalis is a resistant bacterium which is the most abundant species in infected root canals. Photodynamic therapy (PDT) is a method for killing the bacteria with active Oxygen radicals generated in a photosensitizer when exposed to centralized light. Furthermore, as a new method of canal disinfection, a variety of irrigation activation systems have been introduced, one of which is GentleFile (GF) with rotary movements and spiral effects for antibacterial action. This study aimed to compare the effectiveness of the two mentioned methods when used with and without Sodium Hypochlorite in eliminating E. faecalis from infected root canals.Methods: Fifty-eight uniradicular teeth were randomly divided into 4 experimental groups of 14. Two specimens were selected for later scanning electron microscopy in order to screen the procedure steps. In each experimental group, 10 samples were selected to be treated with GF or PDT; 3 of them were selected as positive controls and the other one sample was chosen as a negative control. Experimental groups were as follows: (1) Irrigation activation system, (2) Irrigation activation system + sodium hypochlorite, (3) PDT, and (4) PDT+ sodium hypochlorite. The specimens were then cultured for a bacterial colony count.Results: The decrease in the bacterial count after the treatment with the irrigation activation system was 99.8% (P = 0.011) and when the system was used with sodium hypochlorite, it was 100% (P = 0.001). The antibacterial effect of PDT was 90.08% (P = 0.011) and it was 99.7% when PDT was combined with sodium hypochlorite (P = 0.011).Conclusion: All four methods can be administered as complementary methods in root canal disinfection. According to the results of disinfection in the experimental groups of current study it is concluded that integration of new technologies such as activation irrigation system or PDT in Combination with NaOCl ameliorates disinfection of root canal and can provide several advantages in the endodontic outcome.

Familial colorectal cancertype X in central Iran: A new clinicopathologic description

Background: Familial colorectal cancer type X (FCCX) is a subtype of mismatchrepair (MMR)-proficient colorectal cancerin whichthe patients are clinicallyat risk for Lynch syndrome (LS), a common hereditary cancer predisposing syndrome.In this study, we describeda new clinicopathological feature of the condition in central Iran. Subjects and Methods: We designed a descriptive, retrospective study to screenat-riskcolorectal cancer (CRC) patients,usingAmsterdam II criteria and Molecular analysis in Isfahan (central Iran) throughout 2000-2013 period. Results: 219 early-onset (≤ 50 years) CRC patients of 1659 were selected for the evaluation. Amsterdam II criteria were positive in 45 families; of whom 31 were finally analyzed by molecular testing. MMR deficiency was detected in 7/31 probands (22.6%) as affected to LS, so 24 families (77.4%) were identified as FCCX. The mean age of the probands at diagnosis among FCCX families was 45.3 years (range 24-69) versus 38.0 years (range 31-50) in LS families.The frequency of CRC among FCCX and LS families was calculated 27.9% and 67.5%, respectively. Also, the most frequent extracolonic cancer among both FCCX and LS families was stomach by 25.5% and 30.8%, respectively. Tumor site was proximal to the splenic flexure in 20.8% and 57.1% of index CRC patients in FCCX and LS families, respectively. Conclusion: Given the relative high frequency of FCCXand its different phenotype among Iranian populations, we need to set up more advanced molecular studies for exploration of unknown molecular pathways leading to tumorigenesis in this class of CRC patients

On weak law of large numbers for sums of negatively superadditive dependent random variables

In this paper, we extend Kolmogorov–Feller weak law of large numbers for maximal weighted sums of negatively superadditive dependent (NSD) random variables. In addition, we make a simulation study for the asymptotic behavior in the sense of convergence in probability for weighted sums of NSD random variables

On weak law of large numbers for sums of negatively superadditive dependent random variables

In this paper, we extend Kolmogorov–Feller weak law of large numbers for maximal weighted sums of negatively superadditive dependent (NSD) random variables. In addition, we make a simulation study for the asymptotic behavior in the sense of convergence in probability for weighted sums of NSD random variables

The relationship between corporate governance characteristics and agency costs

The present study aims to evaluate the contributing factors to agency costs in Iran. In this regard, 112 companies were studied over 2010 - 2016. Since the model is dynamic and the dependent variable suffers from a lag, the generalized method of moments is employed to free the independent variables and the disruptive component. The findings indicate a significant lag in the dependent variable of all three models. An audit committee’s presence significantly affects the decline of agency costs in all three models. Moreover, results suggest that family companies and the state shareholders of all three models have no significant impact on the agency costs. The existence of financial leverage matching with all three models causes the decline of agency costs. In terms of assets, Larger companies based on the three models have more agency costs as well