A commutative version of the group ring

We construct a commutative version of the group ring and show that it allows one to translate questions about the normal generation of groups into questions about the generation of ideals in commutative rings. We demonstrate this with an alternative proof of a result about the normal generation of the free product of two cyclic groups.Comment: 31 pages, preprint. Reason for revision: additions to content; in particular rewritten Section 5 and new Section 6 adde

PENGEMBANGAN KURIKULUM DAYAH COT KALA PADA ERA KERAJAAN PERLAK, ACEH

Abstract: This study examines the development of the Dayah Cot Kala curriculum during the Perlak Kingdom. The curriculum of Islamic educational institutions has changed from time to time. This is influenced by various factors, ranging from the demands of the times, state policies, and the socio-culture of the surrounding community. Using a historical approach, this literature study proposes the findings that Dayah Cot Kala in the era of the Perlak Kingdom was the first Islamic educational institution in Indonesia and even in Southeast Asia. This dayah already has an ideal curriculum that is ahead of its time, and does not recognize the dichotomy between religious education and general education as happened to the dayah institution during its decline, both during the colonial period and the post-colonial period. This study aims to determine the factors that influence curriculum development at that time.Keywords: curriculum, Islamic education, dayah, Aceh, the Kingdom of PerlakAbstrak: Studi ini mengkaji pengembangan kurikulum Dayah Cot Kala pada masa Kerajaan Perlak. Kurikulum lembaga pendidikan Islam mengalami perubahan dari masa ke masa. Hal ini dipengaruhi oleh berbagai faktor, mulai dari tuntutan zaman, kebijakan negara, dan sosial budaya masyarakat di sekitarnya. Dengan menggunakan pendekatan historis, studi kepustakaan ini mengajukan temuan bahwa Dayah Cot Kala di era Kerajaan Perlak merupakan lembaga pendidikan Islam pertama kali di Indonesia bahkan di Asia Tenggara. Dayah ini telah mempunyai kurikulum yang ideal dan mendahului masanya, juga tidak mengenal dikotomi antara pendidikan agama dengan pendidikan umum sebagaimana yang terjadi pada lembaga dayah di masa kemundurannya, baik pada masa penjajahan dan masa pasca penjajahan. Penelitian ini bertujuan untuk mengetahui faktor-faktor yang mempengaruhi pengembangan kurikulum pada masa itu.Kata Kunci: kurikulum, pendidikan Islam, dayah, Aceh, Kerajaan Perla

Koszul-Morita duality

We construct a generalization of Koszul duality in the sense of Keller--Lef\`evre for not necessarily augmented algebras. This duality is closely related to classical Morita duality and specializes to it in certain cases.Comment: 12 page

Cocommutative coalgebras: homotopy theory and Koszul duality

We extend a construction of Hinich to obtain a closed model category structure on all differential graded cocommutative coalgebras over an algebraically closed field of characteristic zero. We further show that the Koszul duality between commutative and Lie algebras extends to a Quillen equivalence between cocommutative coalgebras and formal coproducts of curved Lie algebras.Comment: 38 page

Diagnostic accuracy of multidetector computed tomography scan in mediastinal masses assuming histopathological findings as gold standard

Purpose: Aim of the study was to: 1) present MDCT characteristics of different mediastinal mass lesions, 2) estimate proportion of benign and malignant mediastinal mass lesions based on MDCT findings, and 3) find out the diagnostic accuracy with sensitivity, specificity, positive predictive value, and negative predictive value of MDCT in mediastinal mass lesions assuming histopathology as gold standard. Material and methods: This study was an analysis of 60 patients who underwent MDCT scan for characterisation of mediastinal mass lesion, and subsequently imaging findings were verified with pathological diagnosis. Results: Out of 60 patients 65% were malignant and 35% were benign. Metastatic carcinoma was the leading diagnosis. Sensitivity of MDCT in this study came out to be 94%, specificity is 90%, with a positive predictive value of 94% and negative predictive value of 90% with diagnostic accuracy of 93%. Conclusions: Mediastinal mass lesion can be accurately diagnosed with MDCT which is a non-invasive and easily available modality requiring clinical data for accurate diagnosis and management. Co-relation of MDCT findings with other imaging findings is complex and requires adequate clinical data for optimum diagnostic confidence

Quality of care in University Hospitals in Saudi Arabia: systematic review

Objectives: To identify the key issues, problems, barriers and challenges particularly in relation to the quality of care in university hospitals in the Kingdom of Saudi Arabia (KSA), and to provide recommendations for improvement. Methods: A systematic search was carried out using five electronic databases, for articles published between January 2004 and January 2015. We included studies conducted in university hospitals in KSA that focused on the quality of healthcare. Three independent reviewers verified that the studies met the inclusion criteria, assessed the quality of the studies and extracted their relevant characteristics. All studies were assessed using the Institute of Medicine indicators of quality of care. Results: Of the 1430 references identified in the initial search, eight studies were identified that met the inclusion criteria. The included studies clearly highlight a need to improve the quality of healthcare delivery, specifically in areas of patient safety, clinical effectiveness and patient-centredness, at university hospitals in KSA. Problems with quality of care could be due to failures of leadership, a requirement for better management and a need to establish a culture of safety alongside leadership reform in university hospitals. Lack of instructions given to patients and language communication were key factors impeding optimum delivery of patient-centred care. Decisionmakers in KSA university hospitals should consider programmes and assessment tools to reveal problems and issues related to language as a barrier to quality of care. Conclusions: This review exemplifies the need for further improvement in the quality of healthcare in university hospitals in KSA. Many of the problems identified in this review could be addressed by establishing an independent body in KSA, which could monitor healthcare services and push for improvements in efficiency and quality of care