ADS modules

We study the class of ADS rings and modules introduced by Fuchs. We give some connections between this notion and classical notions such as injectivity and quasi-continuity. A simple ring R such that R is ADS as a right R-module must be either right self-injective or indecomposable as a right R-module. Under certain conditions we can construct a unique ADS hull up to isomorphism. We introduce the concept of completely ADS modules and characterize completely ADS semiperfect right modules as direct sum of semisimple and local modules.Comment: 7 page

Defragmenting the terms self-employed, entrepreneur and business owner

There is a growing belief from a range of sources that the only way forward economically is through the support and growth of entrepreneurial behaviour (Olaison, & Sørensen, 2014). Consequently, governments have been developing policies to facilitate entrepreneurship, universities have set up programmes to encourage entrepreneurship and organisations exist to support entrepreneurship (Rae and Woodier-Harris N, 2012; Anderson et al, 2014). Unfortunately, it is not clear exactly what entrepreneurial behaviour is and is not (Hunter, 2012). There are multiple theories on the nature of entrepreneurial behaviour (Shook, Priem, & McGee, 2003; Davidson, 2004; O’Gorman, 2015). This lack of clarity and disagreement causes confusion about the roles and actions of people who engage in entrepreneurial behaviour (Lyons, Lynn, & Bhaird, 2015). Part of the confusion lies in the way people who own operate businesses are defined. Traditionally people who work for themselves are seen as either self-employed, entrepreneurs or business owners. However, despite having different meanings, the terms are often used interchangeably (Parker, 2004; Hartog et al., 2010; Van Solinge, 2015), primarily for the purpose of convenience or simplicity. The interchangeable use of the terms in an environment, in which entrepreneurial behaviour is the favoured phenomenon, is likely to suppress important debates around the nature of entrepreneurial behaviour. This suppression is likely to divert the attention of policy makers and supporters away from important issues concerning the different roles, functions and needs of the self-employed, entrepreneurs or business owners. As a result, support that focuses on entrepreneurship could be at the expense of the other roles. Therefore, there is a need for academic research to seek clarity concerning the use of different terms used to describe people who work for themselves. The authors intend to present a discussion paper that aims to generate some clarity around what the terms self-employed, entrepreneur and business owner actually mean. The purpose of this study is to consolidate a number of notions, theories and concepts found in the literature concerning the definition, conceptualisation and characterisation of self-employed, entrepreneur and business owner. The intention is to identify both similarities or overlaps and distinct differences, in order construct a model that embraces self-employed, entrepreneur and business owner in a single structure

A nationwide study on the knowledge, awareness, and practices towards COVID-19 in Saudi Arabia

Purpose: To investigate public knowledge, awareness and practice regarding COVID-19 in Saudi Arabia.Methods: A cross-sectional descriptive study was conducted, with a 16-item self-administered questionnaire. Data was collected using social media as the platform a day after the lockdown commenced in Saudi Arabia and data collection lasted from March 25 to April 25, 2020. Chi-square test was performed to determine the association between the variables.Results: The results showed that 96 % (n = 1505) of adults were aware of the clinical symptoms of COVID-19 and 57.9 % (n = 908) correctly identified that a stuffy nose and sneezing were less common in persons infected with the virus. A majority (95.4 %, n = 1495) agreed that there was no established therapeutic treatment for COVID-19. Further, 91.7 % (n = 1437) agreed that the virus could spread via respiratory droplets and only 46.2 % (n = 724) acknowledged that wearing face mask helped prevent transmission. The results also showed that 83.2 % (n = 1299) of the participants thought that visiting crowded places increased the likelihood of transmission.Conclusion: The findings of this study reveal that adults in Saudi Arabia are cognizant of COVID-19 and maintained good attitudes and practices regarding it. Furthermore, health education programs aimed at improving awareness of the disease and appropriate control measures will be beneficial in curbing the virus pandemic. Keywords: Saudi Arabia, Coronavirus, Pandemic, COVID-19, Flu, Symptom

Renoprotective effect of red grape (Vitis vinifera L.) juice and dark raisins against hypercholesterolaemia-induced tubular renal affection in albino rats

Background: Red grape juice (RGJ) and dark raisins (DR) are rich in polyphenols and antioxidants. This study aimed to assess the efficacy of RGJ and DR in protec- ting the renal tubules against hypercholesteraemic-induced pathological changes.  Materials and methods: Forty albino rats divided into four groups (n = 10) were utilised in this study. They included the control, high cholesterol diet (HCD)-fed, HCD+RGJ-fed, and HCD+DR-fed groups. Body weight gain, food and water in- take, blood and insulin levels, lipid profile and kidney functions were assessed at the start of the experiment and after 12 weeks. The right kidney was dissected out and processed for both light and electron microscopic examination. Desmin and cytokeratin antibodies were utilised as histologic markers to assess the integrity of the proximal (PTs) and distal tubules (DTs) of the kidney.  Results: Administration of HCD resulted in hypercholesterolaemia in rats as evi- denced by the lipid profile. The PTs of hypercholesteraemic rats appeared dilated with hyaline casts and mitochondria in most of the tubular cells were affected. Immunohistochemical assessment revealed affection of both PTs and DTs. Both RGJ and DR, when administered along with the HCD for 12 weeks, improved the lipid profile, kidney functions as well as the histologic and cellular changes-induced by hypercholesterolaemia in the rats. The effect of raisins was superior to RGJ which might be due to its high contents of fibres and proteins.  Conclusions: This study highlighted the importance of supplementation of red grape and raisins in protection against the harmful effects induced by deposition of fat on the renal tubules’ structure and function.

Developmental nmda receptor dysregulation in the infantile neuronal ceroid lipofuscinosis mouse model

Protein palmitoylation and depalmitoylation alter protein function. This post-translational modification is critical for synaptic transmission and plasticity. Mutation of the depalmitoylating enzyme palmitoyl-protein thioesterase 1 (PPT1) causes infantile neuronal ceroid lipofuscinosis (CLN1), a pediatric neurodegenerative disease. However, the role of protein depalmitoylation in synaptic maturation is unknown. Therefore, we studied synapse development in Ppt1-/- mouse visual cortex. We demonstrate that the developmental N-methyl-D-aspartate receptor (NMDAR) subunit switch from GluN2B to GluN2A is stagnated in Ppt1-/- mice. Correspondingly, Ppt1-/- neurons exhibit immature evoked NMDAR currents and dendritic spine morphology in vivo. Further, dissociated Ppt1-/- cultured neurons show extrasynaptic, diffuse calcium influxes and enhanced vulnerability to NMDA-induced excitotoxicity, reflecting the predominance of GluN2B-containing receptors. Remarkably, Ppt1-/- neurons demonstrate hyperpalmitoylation of GluN2B as well as Fyn kinase, which regulates surface retention of GluN2B. Thus, PPT1 plays a critical role in postsynapse maturation by facilitating the GluN2 subunit switch and proteostasis of palmitoylated proteins

Synthesis and antibacterial effects of cobalt–cellulose magnetic nanocomposites

© The Royal Society of Chemistry. Green synthesis is employed to prepare cobalt/cellulose nanocomposites with cubic (α-cobalt) cobalt as a main component with antibacterial and magnetic properties. An in situ reduction of aqueous solutions of cobalt ions on a model cellulose substrate surface using hydrogen gas affords spherical, cellulose-stabilised cobalt nanoclusters with magnetic properties and an average diameter of 7 nm that are distributed evenly over the surface of the cellulose fibres. These cobalt/cellulose nanocomposites exhibit good antibacterial action against opportunistic pathogens both Gram-positive (S. aureus) and Gram-negative (E. coli, A. baumannii and P. aeruginosa), with zones of inhibition up to 15 mm, thereby encouraging the deployment of these advanced materials for the treatment of wastewater or within medical dressings. This method of preparation is compared with the analogous in situ reduction of cobalt ions on a cellulose surface using sodium borohydride as reducing agent